JP2002130856A - Refrigerating cycle device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerating cycle device capable of expanding the capacity control range of an internal heat exchanger and functioning the internal heat exchanger even upon the reversible cycle of a refrigerating cycle, in the refrigerating cycle device employing a refrigerant capable of becoming a supercritical condition in a radiator such as carbon dioxide or the like. SOLUTION: A second expanding mechanism unit is provided at the high pressure refrigerant inlet port of the internal heat exchanger for the refrigerating cycle device to control the amount of expansion before and after the internal heat exchanger and change a high pressure refrigerant temperature whereby an internal heat exchanging capacity is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle apparatus using a refrigerant that can be brought into a supercritical state by a radiator such as carbon dioxide.

[0002]

2. Description of the Related Art Hitherto, a refrigeration cycle apparatus of this type is known from Japanese Patent Application Laid-Open No. H11-193967.

FIG. 1 shows the refrigeration cycle apparatus.
This will be described with reference to FIG.

As shown in FIG. 12, a compressor 101, a radiator 102, an expansion mechanism 103, a heat absorber 104, an internal heat exchanger 105, an internal heat exchanger bypass 106, a bypass flow control valve 107, the compressor 101 A refrigeration cycle apparatus is configured by including a discharged refrigerant temperature sensor 108, a discharged refrigerant pressure sensor 110, and a controller 109 of the bypass flow rate adjusting valve 107.

[0005] With the above structure, a refrigerant that can be brought into a supercritical state by a radiator such as carbon dioxide is sealed therein, and the compressor 10
The high-pressure high-temperature refrigerant gas compressed in 1 passes through the radiator 102 to become a high-pressure high-temperature refrigerant gas near normal temperature, and becomes a low-temperature high-pressure refrigerant gas in the internal heat exchanger 105. And
Decompressed by the expansion mechanism 103 to become a low-temperature two-phase refrigerant,
The heat is absorbed by the heat absorber 104 to form a low-pressure refrigerant gas, which is heated by the internal heat exchanger 105 and
Then, the refrigerating cycle using the well-known internal heat exchanger 105 is performed.

At this time, the discharged refrigerant temperature sensor 10
8 and the controller 109 controls the bypass flow rate regulating valve 107 so that the detection value of the discharged refrigerant pressure sensor 110 becomes a set value.
By adjusting the capacity of the control unit 5, the control for improving the efficiency can be performed.

[0007]

First, in such a conventional cooling and heating water heater, there is a problem that the capacity control range of the internal heat exchanger is so narrow that it cannot be kept below a certain level.

[0008] Second, there is a problem that the internal heat exchanger does not function when the refrigeration cycle is switched by a four-way valve or the like.

The present invention has been made to solve such a conventional problem, and can extend the control range of the capacity of the internal heat exchanger. It is an object of the present invention to provide a refrigeration cycle device in which a vessel can function.

[0010]

In order to achieve the above object, the refrigeration cycle apparatus of the present invention divides the expansion mechanism into a first expansion mechanism and a second expansion mechanism and controls the high pressure of the internal heat exchanger. These are provided at the refrigerant side entrance and exit, respectively.

According to the present invention, it is possible to obtain a refrigeration cycle apparatus in which the capacity control range of the internal heat exchanger can be expanded and the internal heat exchanger can function even in a reversible cycle of the refrigeration cycle. .

Another means is to connect the internal heat exchanger so that the flow of the refrigerant becomes countercurrent when the use side heat exchanger acts as a radiator.

According to the present invention, there is provided a refrigeration cycle apparatus in which the capacity control range of the internal heat exchanger can be expanded and the internal heat exchanger can function even in a reversible cycle of the refrigeration cycle. Can be

Another means is to connect the internal heat exchanger so that the flow of the refrigerant becomes countercurrent when the use side heat exchanger acts as a heat absorber.

According to the present invention, there is provided a refrigeration cycle apparatus in which the capacity control range of the internal heat exchanger can be expanded and the internal heat exchanger can function even in a reversible cycle of the refrigeration cycle. Can be

Another means is to provide a flow path switching four-way valve at the high pressure refrigerant inlet / outlet of the internal heat exchanger so as not to change the flow direction of the refrigerant in the internal heat exchanger when the refrigerating cycle is reversed.

According to the present invention, a refrigeration cycle apparatus can be provided in which the capacity control range of the internal heat exchanger can be expanded and the internal heat exchanger can function even when the refrigerating cycle is a reversible cycle. Can be

Another means is to provide a four-way switching valve for preventing the refrigerant flow direction of the internal heat exchanger from being changed in response to the reversal of the refrigeration cycle at the high pressure refrigerant inlet / outlet of the internal heat exchanger. The first expansion mechanism is provided between the high-pressure refrigerant outlet of the exchanger and the four-way switching valve.

According to the present invention, there is provided a refrigeration cycle apparatus in which the internal heat exchanger can function even when the refrigerating cycle is a reversible cycle.

Another means is that a second expansion mechanism is provided between the high-pressure refrigerant inlet of the internal heat exchanger and the four-way switching valve.

According to the present invention, there is provided a refrigeration cycle apparatus in which the capacity control range of the internal heat exchanger can be expanded and the internal heat exchanger can function even when the refrigerating cycle is a reversible cycle. Can be

Another means is that the pressure reduction amount when the second expansion mechanism is fully opened is smaller than the pressure reduction amount when the expansion mechanism is fully opened.

According to the present invention, there is provided a refrigeration cycle apparatus in which the capacity control range of the internal heat exchanger can be expanded and the internal heat exchanger can function even when the refrigerating cycle is a reversible cycle. Can be

Another means is provided with means for detecting the temperature of the medium that exchanges heat with the refrigerant in the use-side heat exchanger, and the first expansion mechanism and the second expansion mechanism are controlled so as to reach a temperature set by the detected value. It controls the expansion mechanism.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Another means is provided with temperature detecting means for detecting the low pressure refrigerant inlet / outlet temperature of the internal heat exchanger, and controls the first expansion mechanism and the second expansion mechanism based on the detected values. is there.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with temperature detecting means for detecting a high-pressure refrigerant inlet temperature and a low-pressure refrigerant inlet temperature of the internal heat exchanger, and based on these detected values, the first expansion mechanism and the second expansion mechanism.
This is for controlling the expansion mechanism.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with a temperature detecting means for detecting a refrigerant temperature at an endothermic exchange portion and a suction of the compressor, and controls the first expansion mechanism and the second expansion mechanism based on the detected values. It is.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with detecting means for detecting the temperature and pressure of the compressor suction section, and controls the first expansion mechanism section and the second expansion mechanism section based on the detected values.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with a detecting means for detecting the number of revolutions of the compressor, and controls the first expansion mechanism and the second expansion mechanism based on the detected value.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with a detecting means for detecting a refrigerant circulating amount of the refrigeration cycle, and the first value is detected based on the detected value.
And the second expansion mechanism.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Another means is that the internal heat exchanger has a plurality of refrigerant circuits, and each circuit is provided with an on-off valve.

According to the present invention, a refrigeration cycle apparatus capable of expanding the capacity control range of the internal heat exchanger can be obtained.

Another means is to provide a pipe connecting the use side heat exchanger and the expansion mechanism and a pipe connecting the outdoor heat exchanger and the expansion mechanism to the refrigerant flow direction of the expansion mechanism with respect to the reversal of the refrigeration cycle. Provide a flow path switching four-way valve that does not change, provided an internal heat exchanger that exchanges heat between the high-pressure refrigerant before the pressure is reduced by the expansion mechanism and the low-pressure refrigerant before the suction of the compressor,
The internal heat exchanger has a plurality of refrigerant circuits, and each circuit is provided with an on-off valve.

According to the present invention, a refrigeration cycle apparatus can be provided in which the capacity control range of the internal heat exchanger can be expanded and the internal heat exchanger can function even when the refrigerating cycle is a reversible cycle. Can be

Further, another means is to provide a temperature detecting means for the medium which exchanges heat with the refrigerant in the use side heat exchanger, and to control the on-off valve so as to reach a temperature set by the detected value.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus in which the internal heat exchanger can function even in the reversible cycle of the refrigeration cycle. A control method for effectively operating the internal heat exchanger is obtained.

Another means is to provide a temperature detecting means for detecting the low pressure refrigerant inlet / outlet temperature of the internal heat exchanger, and to control the on-off valve based on the detected values.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Another means is to provide temperature detecting means for detecting the high-pressure refrigerant inlet temperature and the low-pressure refrigerant inlet temperature of the internal heat exchanger, and to control the on-off valve based on the detected values.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with temperature detecting means for detecting the temperature of the refrigerant at the endothermic exchange portion and the suction of the compressor, and controls the on-off valve based on the detected values.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with a detecting means for detecting the temperature and pressure of the compressor suction section, and controls the on-off valve based on the detected values.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigerating cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with a detecting means for detecting the number of revolutions of the compressor, and controls the on-off valve based on the detected value.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

Further, another means is provided with a detecting means for detecting the amount of circulating refrigerant in the refrigeration cycle, and controls the on-off valve based on the detected value.

According to the present invention, the capacity control range of the internal heat exchanger can be expanded, and the refrigeration cycle apparatus can function even when the refrigerating cycle is a reversible cycle. A control method for effectively operating the internal heat exchanger is obtained.

[0056]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides an internal heat exchanger for exchanging heat between a high-pressure refrigerant before being depressurized by a first expansion mechanism and a low-pressure refrigerant before suction of a compressor. And a second expansion mechanism provided at the high-pressure refrigerant inlet of
When the expansion mechanism is controlled in the closing direction, the temperature of the high-pressure refrigerant entering the internal heat exchanger decreases, and the refrigerant temperature difference can be reduced until it reaches the same temperature as the low-pressure refrigerant. Conversely, if the second expansion mechanism is controlled in the opening direction, the temperature of the high-pressure refrigerant entering the internal heat exchanger rises and the temperature difference between the high-pressure refrigerant and the low-pressure refrigerant can be increased.

Further, when the use side heat exchanger acts as a radiator, the internal heat exchanger is connected so that the flow of the refrigerant becomes countercurrent. When the heat is used as the radiator, the internal heat exchanger is connected. This has the effect that the heat exchange of the exchanger can be performed efficiently.

Further, when the use side heat exchanger acts as a heat absorber, the internal heat exchanger is connected so that the flow of the refrigerant becomes countercurrent. When the heat is used as the heat absorber, the internal heat exchanger is connected. This has the effect that the heat exchange of the exchanger can be performed efficiently.

Further, a four-way switching valve is provided at the inlet and outlet of the high-pressure refrigerant of the internal heat exchanger so as not to change the flow direction of the refrigerant in the internal heat exchanger against reversal of the refrigeration cycle. In either case, the heat exchange of the internal heat exchanger can be efficiently performed.

The piping connecting the use side heat exchanger and the expansion mechanism and the piping connecting the outdoor heat exchanger and the expansion mechanism should not change the refrigerant flow direction of the expansion mechanism when the refrigeration cycle is reversed. A flow path switching four-way valve is provided, and an internal heat exchanger for exchanging heat between the high-pressure refrigerant before being depressurized by the expansion mechanism and the low-pressure refrigerant before suctioning the compressor is provided,
By switching the flow path switching four-way valve in synchronization with the switching of the cooling / heating refrigeration cycle, the internal heat exchanger can function by inserting the high-pressure refrigerant before depressurization into the internal heat exchanger in both the cooling and heating refrigeration cycles. It has the action of:

Further, a pipe connecting the use side heat exchanger and the first expansion mechanism and a pipe connecting the outdoor heat exchanger and the first expansion mechanism are provided with a first expansion mechanism for reversal of the refrigeration cycle. Heat exchange between the high-pressure refrigerant before the pressure is reduced by the first expansion mechanism and the low-pressure refrigerant before the suction of the compressor by providing a flow switching four-way valve that does not change the refrigerant flow direction of the compressor And a second expansion mechanism provided at the high-pressure refrigerant inlet of the internal heat exchanger. By switching the flow path switching four-way valve in synchronization with the cooling / heating refrigeration cycle switching, either the cooling / heating refrigeration cycle is provided. However, since the flow directions of the two expansion mechanisms are not changed, the operation load of the expansion mechanisms can be reduced.

Further, a pipe connecting the use side heat exchanger and the first expansion mechanism and a pipe connecting the outdoor heat exchanger and the first expansion mechanism are provided with a first expansion mechanism for reversal of the refrigeration cycle. Heat exchange between the high-pressure refrigerant before the pressure is reduced by the first expansion mechanism and the low-pressure refrigerant before the suction of the compressor by providing a flow switching four-way valve that does not change the refrigerant flow direction of the compressor A second expansion mechanism is provided at the high-pressure refrigerant inlet of the internal heat exchanger, and the amount of pressure reduction when the second expansion mechanism is fully opened is smaller than that of the first expansion mechanism. By switching the four-way switching valve in synchronization with the switching of the refrigeration cycle, the flow direction of the two expansion mechanisms does not change in both the cooling and heating refrigeration cycles, so the second expansion mechanism is dedicated to internal heat exchanger capacity control. And the first expansion mechanism is dedicated to cycle control. It is possible. At this time, by reducing the amount of decompression when the second expansion mechanism is fully opened as much as possible, there is an effect that the capacity of the internal heat exchanger can be improved.

Further, a temperature detecting means for the medium which exchanges heat with the refrigerant in the use side heat exchanger is provided, and the first expansion mechanism and the second expansion mechanism are controlled so as to reach the temperature set by the detected value. When the second expansion mechanism is controlled in the closing direction and the first expansion mechanism is opened accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger decreases, and the refrigerant with the low-pressure refrigerant is controlled. The temperature difference becomes smaller and the internal heat exchanger capacity decreases. For this reason, in the heat absorber, the heating area increases and the heat absorbing ability decreases. In the radiator, the degree of superheat at the suction of the compressor is reduced, so that the discharge temperature is reduced, and the capacity of the radiator is reduced by lowering the refrigerant temperature. Conversely, when the second expansion mechanism is controlled to open, and the first expansion mechanism is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger rises and the refrigerant temperature difference with the low-pressure refrigerant increases. Internal heat exchanger capacity is increased. For this reason, in the heat absorber, the heating area decreases, and the heat absorbing ability increases. The radiator has an effect that the discharge temperature rises because the degree of superheat at the suction of the compressor rises, and the capacity increases by raising the refrigerant temperature of the radiator.

Further, a temperature detecting means for detecting the temperature of the low pressure refrigerant inlet / outlet of the internal heat exchanger is provided, and the first expansion mechanism and the second expansion mechanism are controlled by the detected values. When the first expansion mechanism is controlled in the direction in which the expansion mechanism is closed, the temperature of the high-pressure refrigerant entering the internal heat exchanger decreases, the refrigerant temperature difference with the low-pressure refrigerant decreases, and the internal heat exchange decreases. The ability is reduced. For this reason, the low-pressure refrigerant outlet temperature decreases. Conversely, when the second expansion mechanism is controlled to open, and the first expansion mechanism is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger rises and the refrigerant temperature difference with the low-pressure refrigerant increases. Internal heat exchanger capacity is increased. For this reason, the low-pressure refrigerant outlet temperature increases. This has the effect of controlling the first expansion mechanism and the second expansion mechanism to have a low-pressure refrigerant outlet temperature corresponding to the low-pressure refrigerant inlet temperature of the internal heat exchanger.

Further, a temperature detecting means for detecting the high-pressure refrigerant inlet temperature and the low-pressure refrigerant inlet temperature of the internal heat exchanger is provided, and the first expansion mechanism and the second expansion mechanism are controlled based on the detected values. When the second expansion mechanism is controlled in the closing direction and the first expansion mechanism is opened accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger decreases, and the refrigerant temperature difference with the low-pressure refrigerant decreases. Smaller and the internal heat exchanger capacity is reduced. Conversely, when the second expansion mechanism is controlled to open, and the first expansion mechanism is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger rises and the refrigerant temperature difference with the low-pressure refrigerant increases. Internal heat exchanger capacity is increased. The refrigerant temperature difference in the internal heat exchanger is detected based on the high-pressure refrigerant inlet temperature and the low-pressure refrigerant inlet temperature of the internal heat exchanger, and the first expansion mechanism and the second expansion mechanism are controlled so as to be set values. It has the action of:

Further, a temperature detecting means for detecting a refrigerant temperature of the heat absorber and the suction of the compressor is provided, and the first expansion mechanism and the second expansion mechanism are controlled by the detected values. When the first expansion mechanism is controlled in the direction in which the expansion mechanism is closed, the temperature of the high-pressure refrigerant entering the internal heat exchanger decreases, the refrigerant temperature difference with the low-pressure refrigerant decreases, and the internal heat exchange decreases. The ability is reduced. For this reason, the compressor suction temperature decreases. Conversely, when the second expansion mechanism is controlled to open, and the first expansion mechanism is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger rises and the refrigerant temperature difference with the low-pressure refrigerant increases. Internal heat exchanger capacity is increased.
As a result, the compressor suction temperature increases. This has the effect of controlling the first expansion mechanism and the second expansion mechanism so that the difference in refrigerant temperature between the heat absorber and the suction of the compressor becomes a set value.

Further, a detecting means for detecting the temperature and pressure of the compressor suction section is provided, and the first expansion mechanism section and the second expansion mechanism section are controlled by these detection values.
Of the inflation mechanism in the closing direction, and the first
When the expansion mechanism is opened, the temperature of the high-pressure refrigerant entering the internal heat exchanger decreases, the refrigerant temperature difference from the low-pressure refrigerant decreases, and the internal heat exchanger capacity decreases. For this reason, the compressor suction temperature decreases. Conversely, when the second expansion mechanism is controlled to open, and the first expansion mechanism is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger rises and the refrigerant temperature difference with the low-pressure refrigerant increases. Internal heat exchanger capacity is increased. As a result, the compressor suction temperature increases. Thereby, the first pressure is set so that the compressor suction temperature becomes a set value corresponding to the compressor suction pressure.
This has the effect of controlling the expansion mechanism and the second expansion mechanism.

Further, a detecting means for detecting the number of revolutions of the compressor is provided, and the first expansion mechanism and the second expansion mechanism are controlled by the detected value, and the second expansion mechanism is closed. When the direction is controlled in the direction and the first expansion mechanism is opened accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger decreases, the refrigerant temperature difference from the low-pressure refrigerant decreases, and the internal heat exchanger capacity decreases. For this reason, the degree of superheat at the suction of the compressor is reduced, so that the discharge temperature is reduced. Conversely, when the second expansion mechanism is controlled to open, and the first expansion mechanism is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger rises and the refrigerant temperature difference with the low-pressure refrigerant increases. Internal heat exchanger capacity is increased. In a cycle having such an action, the amount of circulating refrigerant changes in accordance with a change in the number of revolutions of the compressor. The smaller the amount of circulating refrigerant, the better the heat exchange efficiency, and therefore, it is necessary to suppress the internal heat exchange capacity. For this reason, it has the effect of adjusting the control amounts of the first expansion mechanism and the second expansion mechanism in accordance with the rotation speed of the compressor.

Further, a detecting means for detecting the amount of refrigerant circulating in the refrigeration cycle is provided, and the first expansion mechanism and the second expansion mechanism are controlled based on the detected value. When the control is performed in the closing direction and the first expansion mechanism is opened accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger decreases, the refrigerant temperature difference with the low-pressure refrigerant decreases, and the internal heat exchanger capacity decreases. . For this reason, the degree of superheat at the suction of the compressor is reduced, so that the discharge temperature is reduced. Conversely, when the second expansion mechanism is controlled to open, and the first expansion mechanism is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger rises and the refrigerant temperature difference with the low-pressure refrigerant increases. Internal heat exchanger capacity is increased. In a cycle having such an operation, the smaller the amount of circulating refrigerant is, the better the heat exchange efficiency is. Therefore, it is necessary to suppress the internal heat exchange capacity. For this reason, the first expansion mechanism and the second expansion mechanism have an effect of adjusting the control amount in accordance with the refrigerant circulation amount.

Further, the internal heat exchanger has a plurality of refrigerant circuits, each of which is provided with an on-off valve, and the internal heat exchanger capacity is changed stepwise by the number of operating high-pressure-side on-off valves. Further, by opening only the high pressure side on / off valve corresponding to the circuit in which the low pressure side on / off valve is closed and closing the other high pressure side on / off valves, the internal heat exchange capacity can be minimized.

The piping connecting the use side heat exchanger and the expansion mechanism and the piping connecting the outdoor heat exchanger and the expansion mechanism should not change the flow direction of the refrigerant in the expansion mechanism when the refrigeration cycle is reversed. Provide an internal heat exchanger that exchanges heat between the high-pressure refrigerant before the pressure is reduced by the expansion mechanism and the low-pressure refrigerant before the suction of the compressor, and the refrigerant circuit of the internal heat exchanger is provided. A plurality of valves are provided with on-off valves in each circuit, and the internal heat exchanger capacity is changed stepwise by the number of operating on-off valves on the high pressure side. The internal heat exchange capacity can be minimized by opening only the high pressure side on / off valve corresponding to the circuit in which the low pressure side on / off valve is closed, and closing the other high pressure side on / off valves. Furthermore, by switching the four-way switching valve in synchronization with the switching of the cooling / heating refrigeration cycle, the internal heat exchanger functions by allowing the high-pressure refrigerant before pressure reduction to enter the internal heat exchanger in both the cooling and heating refrigeration cycles. It has the effect of being able to.

Further, a means for detecting the temperature of the medium which exchanges heat with the refrigerant in the use side heat exchanger is provided, and the on-off valve is controlled so as to reach a temperature set by the detected value. If the number of open units is reduced, the internal heat exchanger capacity will decrease, so the heat absorber will increase the heating area and decrease the heat absorption capacity. Decrease. And
When controlling the direction to increase the number of open high pressure side on-off valves,
Since the internal heat exchanger capacity is increased, the heat absorber has the effect of decreasing the heating area and increasing the heat absorption capacity, and the radiator has the effect that the discharge temperature rises due to the rise in the compressor suction temperature and the heat dissipation capacity increases.

Further, a temperature detecting means for detecting the low pressure refrigerant inlet / outlet temperature of the internal heat exchanger is provided, and the on / off valve is controlled by these detected values. As a result, the internal heat exchanger capacity is reduced, so that the compressor suction temperature is reduced. Conversely, if control is performed in a direction to increase the number of open high-pressure side on-off valves, the internal heat exchanger capacity increases, so that the compressor suction temperature increases. This has the effect of controlling the temperature of the low-pressure refrigerant outlet to correspond to the low-pressure refrigerant inlet temperature of the internal heat exchanger.

Further, a temperature detecting means for detecting the high-pressure refrigerant inlet temperature and the low-pressure refrigerant inlet temperature of the internal heat exchanger is provided, and the on-off valves are controlled by these detected values. If the control is performed in the decreasing direction, the capacity of the internal heat exchanger is reduced, so that the compressor suction temperature is reduced. Conversely, if control is performed in a direction to increase the number of open high-pressure side on-off valves, the internal heat exchanger capacity increases, so that the compressor suction temperature increases. This has the effect of determining the operation of the on-off valve from the high-pressure refrigerant inlet temperature and the low-pressure refrigerant inlet temperature of the internal heat exchanger, and controlling the compressor suction temperature.

Further, a temperature detecting means for detecting the temperature of the refrigerant at the heat sink and the suction of the compressor is provided, and the on-off valve is controlled based on the detected values. As a result, the internal heat exchanger capacity is reduced, so that the compressor suction temperature is reduced. Conversely, if control is performed in a direction to increase the number of open high-pressure side on-off valves, the internal heat exchanger capacity increases, so that the compressor suction temperature increases. This has the effect of controlling the compressor suction temperature according to the heat absorber temperature.

Further, a temperature detecting means for detecting the temperature and the pressure of the compressor suction section is provided, and the on-off valve is controlled based on these detected values. As the internal heat exchanger capacity decreases, the compressor suction temperature decreases. Conversely, if control is performed in a direction to increase the number of open high-pressure side on-off valves, the internal heat exchanger capacity increases, so that the compressor suction temperature increases. This has the effect of controlling the compressor suction temperature according to the compressor suction pressure.

Further, a temperature detecting means for detecting the number of revolutions of the compressor is provided, and the on-off valve is controlled based on the detected value. Since the capacity of the compressor decreases, the compressor suction temperature decreases and the discharge temperature decreases. Conversely, if control is performed to increase the number of open high-pressure side on-off valves, the internal heat exchanger capacity increases, so the compressor suction temperature increases,
The discharge temperature rises. In a cycle having such an action, the amount of circulating refrigerant changes in accordance with a change in the number of revolutions of the compressor. The smaller the amount of circulating refrigerant, the better the heat exchange efficiency, and therefore, it is necessary to suppress the internal heat exchange capacity. For this reason, it has the effect of controlling each on-off valve according to the compressor speed.

Further, a temperature detecting means for detecting the amount of circulating refrigerant in the refrigeration cycle is provided, and the on-off valves are controlled based on these detected values. Since the exchanger capacity decreases, the compressor suction temperature decreases, and the discharge temperature decreases. Conversely, if control is performed to increase the number of open high-pressure side on-off valves, the internal heat exchanger capacity increases, so that the compressor suction temperature increases and the discharge temperature increases. In a cycle having such an operation, the smaller the amount of circulating refrigerant is, the better the heat exchange efficiency is. Therefore, it is necessary to suppress the internal heat exchange capacity. Therefore, there is an effect that each open / close valve is controlled according to the amount of circulating refrigerant.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0080]

(Embodiment 1) FIG. 1 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. The compressor 101, the outdoor heat exchanger 1, the expansion valve A2, the use side heat exchanger 3, the internal heat exchanger 105, the cooling / heating switching four-way valve 4, and the expansion with the internal heat exchanger 105 interposed therebetween. An expansion valve B5 provided on the opposite side of the valve A2, a heat exchange medium temperature sensor 6 for exchanging heat in the use side heat exchanger 3, and an input of a detection value of the heat exchange medium temperature sensor 6; And a controller 7 for controlling the opening degree of the expansion valve B5 to constitute a refrigeration cycle apparatus.

According to the above configuration, when the refrigerant which can be brought into a supercritical state with a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the compressor 1
The high-pressure high-temperature refrigerant gas compressed in 01 passes through the outdoor heat exchanger 1 at the cooling / heating switching four-way valve 4 to become a high-pressure high-temperature refrigerant gas near normal temperature, and the expansion valve B5 controls the pressure reduction amount to control the temperature. After being adjusted, the internal heat exchanger 105 becomes a low-temperature high-pressure refrigerant gas. The pressure is reduced by the expansion valve A2 to become a low-temperature low-pressure two-phase refrigerant.
Then, the heat is absorbed by the cooling-heat switching four-way valve 4 to be heated through the internal heat exchanger 105 and returned to the compressor 101.

On the contrary, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. And the temperature is adjusted by controlling the amount of pressure reduction by the expansion valve A2, and becomes a low-temperature high-pressure refrigerant gas by the internal heat exchanger 105. Then, the pressure is reduced by the expansion valve B5 to become a low-temperature and low-pressure two-phase refrigerant, the heat is absorbed by the outdoor heat exchanger 1 to become a low-pressure refrigerant gas, and the cooling / heating switching four-way valve 4 heats through the internal heat exchanger 105. Then, the process returns to the compressor 101. At this time, in the internal heat exchanger 105, the flow of the high-pressure refrigerant and the flow of the low-pressure refrigerant become countercurrent, so that heat exchange with good heat exchange efficiency can be performed.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat absorber, thereby enabling efficient operation. .

The expansion valves A2 and B5 are controlled so that the expansion valve on the upstream side of the refrigerant flow is used for controlling the capacity of the internal heat exchanger 105, and the expansion valve on the downstream side is controlled by the refrigeration cycle. When controlling the expansion valve for controlling the capacity in the closing direction, and opening the expansion valve for controlling the refrigeration cycle accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 decreases. The temperature difference between the refrigerant and the low-pressure refrigerant is reduced, and the capacity of the internal heat exchanger is reduced. For this reason, in the heat absorber, the heating area increases and the heat absorbing ability decreases. In the radiator, the degree of superheat at the suction of the compressor is reduced, so that the discharge temperature is reduced, and the capacity of the radiator is reduced by lowering the refrigerant temperature. At this time, if the capacity control expansion valve is closed until the temperature difference between the high-pressure refrigerant and the low-pressure refrigerant disappears, the heat exchange amount of the internal heat exchanger 105 can be made zero, and the capacity control range is improved.

Conversely, when the expansion valve for controlling the capacity is controlled to open, and the expansion valve for controlling the refrigeration cycle is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 rises, and The refrigerant temperature difference increases and the internal heat exchanger capacity increases. For this reason, in the heat absorber, the heating area decreases, and the heat absorbing ability increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

The opening degree of the expansion valve A2 and the expansion valve B5 is controlled by the controller 7 by utilizing such a refrigeration cycle operation so that the detection value of the heat exchange medium temperature sensor 6 becomes a set value. Thus, the capacity of the use side heat exchanger 3 can be adjusted.

(Embodiment 2) FIG. 2 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted. An expansion valve B5 provided on the opposite side of the expansion valve A2 across the internal heat exchanger 105, an internal heat exchanger low-pressure side inlet temperature sensor 8, an internal heat exchanger low-pressure side outlet temperature sensor 9, and these sensors The detected value is input to the expansion valve A2 and the expansion valve B5.
The refrigeration cycle apparatus is configured by including the controller 7 for controlling the opening degree of the refrigeration cycle.

According to the above configuration, when a refrigerant that can be brought into a supercritical state by a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the high pressure high temperature refrigerant gas compressed by the compressor 101 is used. Is passed through the outdoor heat exchanger 1 at the cooling / heating switching four-way valve 4 to become a warm high-pressure refrigerant gas near normal temperature. The temperature is adjusted by controlling the amount of decompression by the expansion valve B5, and the internal heat exchanger 105 It becomes a low-temperature high-pressure refrigerant gas. Then, the pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, the heat is absorbed by the use-side heat exchanger 3 to become a low-pressure refrigerant gas, and the cooling and heating switching four-way valve 4 passes through the internal heat exchanger 105. It is heated and returns to the compressor 101. At this time, in the internal heat exchanger 105, the flow of the high-pressure refrigerant and the flow of the low-pressure refrigerant become countercurrent, so that heat exchange with good heat exchange efficiency can be performed.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. And the temperature is adjusted by controlling the amount of pressure reduction by the expansion valve A2, and becomes a low-temperature high-pressure refrigerant gas by the internal heat exchanger 105. Then, the pressure is reduced by the expansion valve B5 to become a low-temperature and low-pressure two-phase refrigerant, the heat is absorbed by the outdoor heat exchanger 1 to become a low-pressure refrigerant gas, and the cooling / heating switching four-way valve 4 heats through the internal heat exchanger 105. Then, the process returns to the compressor 101.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat absorber, thereby enabling efficient operation. .

The expansion valves A2 and B5 are controlled to control the expansion valve on the upstream side of the refrigerant flow for controlling the capacity of the internal heat exchanger 105, and the downstream expansion valve is controlled by the refrigerating cycle. When controlling the expansion valve for controlling the capacity in the closing direction, and opening the expansion valve for controlling the refrigeration cycle accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 decreases. The temperature difference between the refrigerant and the low-pressure refrigerant is reduced, and the capacity of the internal heat exchanger is reduced. For this reason, in the heat absorber, the heating area increases and the heat absorbing ability decreases. In the radiator, the degree of superheat at the suction of the compressor is reduced, so that the discharge temperature is reduced, and the capacity of the radiator is reduced by lowering the refrigerant temperature. At this time, if the capacity control expansion valve is closed until the temperature difference between the high-pressure refrigerant and the low-pressure refrigerant disappears, the heat exchange amount of the internal heat exchanger 105 can be made zero, and the capacity control range is improved.

Conversely, when the capacity control expansion valve is controlled to open and the refrigeration cycle control expansion valve is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 rises, and The refrigerant temperature difference increases and the internal heat exchanger capacity increases. For this reason, in the heat absorber, the heating area decreases, and the heat absorbing ability increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

Using such a refrigeration cycle operation, the low-pressure refrigerant outlet temperature is set according to the detection value of the internal heat exchanger low-pressure side inlet temperature sensor 8, and the internal heat exchanger low-pressure side outlet temperature sensor 9 is set. The refrigeration cycle can be adjusted to an efficient state by controlling the degree of opening of the expansion valve A2 and the expansion valve B5 by the controller 7 so that the detected value is equal to the set value.

(Embodiment 3) FIG. 3 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted. A flow switching four-way valve 10 via the internal heat exchanger 105, the expansion valve A2 and the expansion valve B5, an internal heat exchanger low pressure side inlet temperature sensor 8, an internal heat exchanger high pressure side inlet temperature sensor 11,
A refrigeration cycle device is configured by including a rotation speed detection device 12 of the compressor 101 and a controller 7 that controls the degree of opening of the expansion valve A2 and the expansion valve B5 using the detection values of these sensors as inputs.

With the above configuration, when a refrigerant that can be brought into a supercritical state with a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the compressor 1
01 is a cooling / heating switching four-way valve
The gas passes through the outdoor heat exchanger 1 to become a warm high-pressure refrigerant gas close to room temperature. The temperature is adjusted by controlling the amount of decompression by the expansion valve B5, and the internal heat exchange is performed via the flow path switching four-way valve 10. It becomes a low-temperature high-pressure refrigerant gas in the vessel 105. The pressure is reduced by the expansion valve A2 through the flow path switching four-way valve 10 to become a low-temperature and low-pressure two-phase refrigerant, and the heat is absorbed by the use side heat exchanger 3 to become a low-pressure refrigerant gas.
Then, the heat is passed through the internal heat exchanger 105 and returns to the compressor 101.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. Through the flow path switching four-way valve 10 to adjust the temperature by controlling the pressure reduction amount by the expansion valve A2. It becomes refrigerant gas. Then, the pressure is reduced by the expansion valve B5 through the flow path switching four-way valve 10 to become a low-temperature and low-pressure two-phase refrigerant, and the heat is absorbed by the outdoor heat exchanger 1 to become a low-pressure refrigerant gas. Is heated through the internal heat exchanger 105 and
Return to 01.

As described above, the internal heat exchanger can function even in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat absorber, and the flow path switching four-way valve is provided. By passing through 10, in the internal heat exchanger 105, the flows of the high-pressure refrigerant and the low-pressure refrigerant are opposed to each other, so that heat exchange with good heat exchange efficiency can be performed.

The expansion valves A2 and B5 are controlled so that the expansion valve on the upstream side of the refrigerant flow is used for controlling the capacity of the internal heat exchanger 105, and the expansion valve on the downstream side is controlled by the refrigeration cycle. When controlling the expansion valve for controlling the capacity in the closing direction, and opening the expansion valve for controlling the refrigeration cycle accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 decreases. The temperature difference between the refrigerant and the low-pressure refrigerant is reduced, and the capacity of the internal heat exchanger is reduced. For this reason, in the heat absorber, the heating area increases and the heat absorbing ability decreases. In the radiator, the degree of superheat at the suction of the compressor is reduced, so that the discharge temperature is reduced, and the capacity of the radiator is reduced by lowering the refrigerant temperature. At this time, if the capacity control expansion valve is closed until the temperature difference between the high-pressure refrigerant and the low-pressure refrigerant disappears, the heat exchange amount of the internal heat exchanger 105 can be made zero, and the capacity control range is improved.

Conversely, when the capacity control expansion valve is controlled to open and the refrigeration cycle control expansion valve is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 rises, and the temperature of the low-pressure refrigerant increases. The refrigerant temperature difference increases and the internal heat exchanger capacity increases. For this reason, in the heat absorber, the heating area decreases, and the heat absorbing ability increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

At this time, if the number of rotations of the compressor is small, the amount of circulating refrigerant decreases accordingly, and the flow rate of refrigerant decreases, so that the heat exchange time increases and the heat exchange efficiency of the internal heat exchanger 105 increases. It is necessary to suppress the ability to improve.

Utilizing such a refrigeration cycle operation, the high-pressure refrigerant inlet temperature is set according to the detection value of the internal heat exchanger low-pressure side inlet temperature sensor 8, and the high-pressure refrigerant inlet temperature is further set according to the rotation speed of the compressor. The controller 7 corrects the set value of the temperature and adjusts the opening degree of the expansion valve A2 and the expansion valve B5 so that the detection value of the internal heat exchanger high pressure side inlet temperature sensor 11 becomes the set value. , The refrigeration cycle can be adjusted to an efficient state.

In this embodiment, the number of revolutions of the compressor is detected by using the number-of-rotations detector, but the output of an inverter or the like or a set value may be used.

(Embodiment 4) FIG. 4 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the third embodiment are denoted by the same reference numerals, and detailed description is omitted. The utilization side heat exchanger refrigerant temperature sensor 13, the outdoor heat exchanger refrigerant temperature sensor 14, the compressor suction temperature sensor 15, and the expansion valves A2 and B5
The refrigeration cycle apparatus is configured by including the controller 7 for controlling the opening degree of the refrigeration cycle.

With the above configuration, when a refrigerant that can be brought into a supercritical state with a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the compressor 101
The high-pressure high-temperature refrigerant gas compressed at the cooling / heating switching four-way valve 4 passes through the outdoor heat exchanger 1 to become a high-pressure high-temperature refrigerant gas near normal temperature, and the expansion valve B5 controls the pressure reduction amount to adjust the temperature, Internal heat exchanger 1 via flow switching four-way valve 10
At 05, it becomes a low-temperature high-pressure refrigerant gas. Then, the pressure is reduced by the expansion valve A2 through the flow path switching four-way valve 10 to become a low-temperature and low-pressure two-phase refrigerant, and the heat is absorbed by the use-side heat exchanger 3 to become a low-pressure refrigerant gas. Then, it is heated through the internal heat exchanger 105 and returns to the compressor 101.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. Through the flow path switching four-way valve 10 to adjust the temperature by controlling the pressure reduction amount by the expansion valve A2. It becomes refrigerant gas. Then, the pressure is reduced by the expansion valve B5 through the flow path switching four-way valve 10 to become a low-temperature and low-pressure two-phase refrigerant, and the heat is absorbed by the outdoor heat exchanger 1 to become a low-pressure refrigerant gas. Is heated through the internal heat exchanger 105 and
Return to 01.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use-side heat exchanger 3 is operated as a radiator or a heat absorber, and the flow path switching four-way valve is provided. By passing through 10, in the internal heat exchanger 105, the flows of the high-pressure refrigerant and the low-pressure refrigerant are opposed to each other, so that heat exchange with good heat exchange efficiency can be performed.

The expansion valves A2 and B5 are controlled such that the upstream expansion valve of the refrigerant flow is used for controlling the capacity of the internal heat exchanger 105, and the downstream expansion valve is controlled to the refrigerating cycle. When controlling the expansion valve for controlling the capacity in the closing direction, and opening the expansion valve for controlling the refrigeration cycle accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 decreases. The temperature difference between the refrigerant and the low-pressure refrigerant is reduced, and the capacity of the internal heat exchanger is reduced. For this reason, in the heat absorber, the heating area increases and the heat absorbing ability decreases. In the radiator, the degree of superheat at the suction of the compressor is reduced, so that the discharge temperature is reduced, and the capacity of the radiator is reduced by lowering the refrigerant temperature. At this time, if the capacity control expansion valve is closed until the temperature difference between the high-pressure refrigerant and the low-pressure refrigerant disappears, the heat exchange amount of the internal heat exchanger 105 can be made zero, and the capacity control range is improved.

Conversely, when the capacity control expansion valve is controlled to open and the refrigeration cycle control expansion valve is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 rises, and The refrigerant temperature difference increases and the internal heat exchanger capacity increases. For this reason, in the heat absorber, the heating area decreases, and the heat absorbing ability increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

By utilizing such a refrigeration cycle operation, the compressor suction temperature is determined in accordance with a detection value acting as a heat absorber of the use side heat exchanger refrigerant temperature sensor 13 or the outdoor heat exchanger refrigerant temperature sensor 14. The controller 7 controls the degree of opening of the expansion valve A2 and the expansion valve B5 so that the detection value of the compressor suction temperature sensor 15 is equal to the set value. Can be adjusted to a good condition.

(Embodiment 5) FIG. 5 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted. By providing a flow path switching four-way valve 10 between the outdoor heat exchanger 1 and the use-side heat exchanger 3 for preventing the refrigerant flow direction of the expansion valve A2 and the internal heat exchanger 105 from changing in response to reversal of the refrigeration cycle. Construct a refrigeration cycle device.

With the above-described configuration, when a refrigerant that can be brought into a supercritical state by a radiator such as carbon dioxide is sealed and the use-side heat exchanger 3 is operated as a heat absorber, the compressor 101
The high-pressure high-temperature refrigerant gas compressed at the cooling / heating switching four-way valve 4 passes through the outdoor heat exchanger 1 to become a high-pressure high-temperature refrigerant gas near normal temperature, and passes through the flow path switching four-way valve 10 to the internal heat exchanger 105. And becomes a low-temperature, high-pressure refrigerant gas. And
The pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, and the heat is absorbed by the use-side heat exchanger 3 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas.
Then, the heat is passed through the internal heat exchanger 105 and returns to the compressor 101.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. Through the flow path switching four-way valve 10 and becomes a low-temperature high-pressure refrigerant gas in the internal heat exchanger 105. Then, the pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, and heat is absorbed by the outdoor heat exchanger 1 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas. The heat is passed through the internal heat exchanger 105 and the compressor 101
Return to.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat sink.

Further, since the inflow direction to the expansion valve A2 does not reverse due to the switching of the refrigeration cycle, there is no operation load for the reverse flow, and the expansion valve can be downsized. Further, the use of power in the expansion portion is facilitated because the direction of flow of the refrigerant does not change.

(Embodiment 6) FIG. 6 is a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted. A flow switching four-way valve 10 between the outdoor heat exchanger 1 and the use side heat exchanger 3 for preventing the refrigerant flow direction of the expansion valve A2, the internal heat exchanger 105, and the expansion valve B5 from being changed due to reversal of the refrigeration cycle.
A compressor suction temperature sensor 15, a compressor suction pressure sensor 16, a refrigerant circulation meter 17, and a controller that controls the opening of the expansion valve A2 and the expansion valve B5 based on the detection values of these sensors. The refrigeration cycle device is constituted by including the refrigeration cycle 7.

According to the above configuration, when a refrigerant that can be brought into a supercritical state with a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the compressor 101
The high-pressure and high-temperature refrigerant gas compressed in the above-described manner passes through the outdoor heat exchanger 1 at the cooling / heating switching four-way valve 4 to become a warm high-pressure refrigerant gas near normal temperature, and is depressurized at the expansion valve B5 via the flow path switching four-way valve 10. The temperature is adjusted by controlling the amount, and the internal heat exchanger 105 turns into a low-temperature high-pressure refrigerant gas. Then, the pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, and the heat is absorbed by the use-side heat exchanger 3 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas. Then, the heat is passed through the internal heat exchanger 105 and returns to the compressor 101.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. Through the flow path switching four-way valve 10 to control the amount of pressure reduction by the expansion valve A2 to adjust the temperature. The internal heat exchanger 105 controls the low-temperature high-pressure refrigerant gas. It becomes refrigerant gas. Then, the pressure is reduced by the expansion valve B5 to become a low-temperature and low-pressure two-phase refrigerant, and the heat is absorbed by the outdoor heat exchanger 1 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas. Is heated through the internal heat exchanger 105 and
Return to 01.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat absorber, and the flow path switching four-way valve is provided. By passing through 10, in the internal heat exchanger 105, the flows of the high-pressure refrigerant and the low-pressure refrigerant are opposed to each other, so that heat exchange with good heat exchange efficiency can be performed.

Further, since the inflow directions to the expansion valve A2 and the expansion valve B5 do not reverse due to the switching of the refrigerating cycle, there is no operation load for the reverse flow, and the expansion valve can be downsized. Further, the use of power in the expansion portion is facilitated because the direction of flow of the refrigerant does not change.

The expansion valve A2 is used for controlling the refrigeration cycle, and the expansion valve B5 is used for controlling the capacity of the internal heat exchanger 105 and the application is fixed. By reducing the amount of pressure reduction at the time of full opening as much as possible, for example, by increasing the nozzle diameter of the expansion valve B5, it is possible to suppress a decrease in the inlet temperature of the internal heat exchanger 105 on the high pressure side and improve the heat exchange efficiency. be able to.

When the expansion valve B5 is controlled to close and the expansion valve A2 is opened accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 decreases, and the difference in refrigerant temperature between the low-pressure refrigerant and the low-pressure refrigerant decreases. Smaller and the internal heat exchanger capacity is reduced. For this reason, in the heat absorber, the heating area increases and the heat absorbing ability decreases. In the radiator, the degree of superheat at the suction of the compressor is reduced, so that the discharge temperature is reduced, and the capacity of the radiator is reduced by lowering the refrigerant temperature. At this time, if the expansion valve B5 is closed until the temperature difference between the high-pressure refrigerant and the low-pressure refrigerant disappears, the heat exchange amount of the internal heat exchanger 105 can be made zero, and the capacity control range is improved.

Conversely, when the expansion valve B5 is controlled to open and the expansion valve A2 is closed accordingly, the temperature of the high-pressure refrigerant entering the internal heat exchanger 105 rises and the refrigerant temperature difference from the low-pressure refrigerant increases. The internal heat exchanger capacity increases. For this reason, in the heat absorber, the heating area decreases, and the heat absorbing ability increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

At this time, if the amount of circulating refrigerant is small, the heat exchange time is increased because the flow velocity of the refrigerant is reduced, and the heat exchange efficiency of the internal heat exchanger 105 is improved, so that the capacity must be suppressed.

Using such a refrigeration cycle operation, the compressor suction temperature is set according to the detection value of the compressor suction pressure sensor 16, and the set value of the compressor suction temperature is further set according to the refrigerant circulation amount. By correcting the opening degree of the expansion valve A2 and the expansion valve B5 by the controller 7 so that the detection value of the compressor suction temperature sensor 15 is equal to the set value, the efficiency of the refrigeration cycle is improved. Can be adjusted to a good condition.

(Embodiment 7) FIG. 7 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. Compressor 101 and radiator 1
02, the expansion mechanism 103, the heat sink 104, the internal heat exchanger 18 having a plurality of circuits, and the internal heat exchanger 18
And a high-pressure solenoid valve A20 and a high-pressure solenoid valve B21 provided in a high-pressure side circuit other than the high-pressure side circuit for exchanging heat with the circuit in which the low-pressure solenoid valve 19 is provided. The solenoid valve C22, the compressor suction temperature sensor 15, the heat absorber refrigerant temperature sensor 23, and the low pressure solenoid valve 19, the high pressure solenoid valve A20, the high pressure solenoid valve B21, and the high pressure solenoid valve C22 A refrigeration cycle apparatus is configured by including a controller 24 for controlling the opening and closing of the refrigeration cycle.

According to the above configuration, a refrigerant which can be brought into a supercritical state by a radiator such as carbon dioxide is sealed, and the compressor 10
The high-pressure high-temperature refrigerant gas compressed in step 1 passes through the radiator 102 to become a high-temperature high-pressure refrigerant gas near normal temperature, and becomes a low-temperature high-pressure refrigerant gas in the internal heat exchanger 18. Then, the pressure is reduced by the expansion mechanism 103 to become a low-temperature and low-pressure two-phase refrigerant, the heat is absorbed by the heat absorber 104 to become a low-pressure refrigerant gas, heated through the internal heat exchanger 18, and returned to the compressor 101. . At this time, the capacity of the internal heat exchanger 18 is controlled by opening and closing the respective solenoid valves. Specifically, the maximum capacity is obtained when all the solenoid valves are opened, and the capacity is changed stepwise by the number of closing the high pressure solenoid valves ABC. Further, when all the high-pressure solenoid valves ABC are closed and the low-pressure solenoid valve 19 is closed, heat exchange becomes almost impossible, so that the minimum capacity is obtained.

As described above, the capacity of the internal heat exchanger 18 can be changed from a low capacity that hardly exchanges heat to a maximum capacity.

When the capacity of the internal heat exchanger 18 is controlled to reduce the capacity of the internal heat exchanger, the heat absorber increases the heating area and decreases the heat absorbing capacity. And in the radiator, the superheat degree at the compressor suction decreases, so the discharge temperature decreases,
As the coolant temperature of the radiator decreases, the capacity decreases.

When the capacity of the internal heat exchanger is increased, the heating area of the heat absorber decreases and the heat absorbing capacity increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

By utilizing such a refrigeration cycle operation, the compressor suction temperature is set in accordance with the detection value of the heat absorber refrigerant temperature sensor 23, and the detection value of the compressor suction temperature sensor 15 is set to the set value. By controlling the opening and closing of each of the electromagnetic valves by the controller 24 so as to satisfy the above condition, the refrigeration cycle can be adjusted to an efficient state.

(Eighth Embodiment) FIG. 8 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the seventh embodiment are denoted by the same reference numerals, and detailed description is omitted. The outdoor heat exchanger 1, the expansion valve A2, the use side heat exchanger 3, the cooling / heating switching four-way valve 4, and the reversal of the refrigeration cycle between the outdoor heat exchanger 1 and the use side heat exchanger 3. A flow path switching four-way valve 10 that does not change the flow direction of the refrigerant in the expansion valve A2 and the internal heat exchanger 18; a heat exchange medium temperature sensor 6 that exchanges heat with the use side heat exchanger 3; A refrigeration cycle apparatus is configured by including a controller 24 that controls the opening and closing of each electromagnetic valve using the detection value of the heat exchange medium temperature sensor 6 as an input.

According to the above configuration, when a refrigerant that can be brought into a supercritical state by a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the compressor 101
The high-pressure and high-temperature refrigerant gas compressed by the cooling / heating switching four-way valve 4
At this time, the gas passes through the outdoor heat exchanger 1 to become a warm high-pressure refrigerant gas close to room temperature, and passes through the flow path switching four-way valve 10 to become a low-temperature high-pressure refrigerant gas at the internal heat exchanger 18. Then, the pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, and the heat is absorbed by the use-side heat exchanger 3 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas. Then, the heat is passed through the internal heat exchanger 18 and returns to the compressor 101.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. Through the flow path switching four-way valve 10 to become a low-temperature high-pressure refrigerant gas through the internal heat exchanger 18. Then, the pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, and heat is absorbed by the outdoor heat exchanger 1 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas. Then, it is heated through the internal heat exchanger 18 and returns to the compressor 101.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat sink, and the flow path switching four-way valve is provided. By passing through 10, in the internal heat exchanger 18, the flows of the high-pressure refrigerant and the low-pressure refrigerant are opposed to each other, so that heat exchange with good heat exchange efficiency can be performed.

The capacity of the internal heat exchanger 18 is controlled by opening and closing the solenoid valves. Specifically, the maximum capacity is obtained when all the solenoid valves are opened, and the capacity is changed stepwise by the number of closing the high pressure solenoid valves ABC. Further, when all the high-pressure solenoid valves ABC are closed and the low-pressure solenoid valve 19 is closed, heat exchange becomes almost impossible, so that the minimum capacity is obtained.

As described above, the capacity of the internal heat exchanger 18 can be changed from a low capacity that hardly exchanges heat to a maximum capacity.

When the capacity of the internal heat exchanger 18 is controlled to reduce the capacity of the internal heat exchanger, the heat absorption area of the heat absorber increases and the heat absorption capacity decreases. And in the radiator, the superheat degree at the compressor suction decreases, so the discharge temperature decreases,
As the coolant temperature of the radiator decreases, the capacity decreases.

When the capacity of the internal heat exchanger is increased, the heating area of the heat absorber decreases and the heat absorbing capacity increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

By using such a refrigeration cycle operation, the controller 24 controls the opening and closing of each of the solenoid valves so that the detection value of the heat exchange medium temperature sensor 6 becomes a set value. The capacity of the exchanger 3 can be adjusted.

(Embodiment 9) FIG. 9 is a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the eighth embodiment are denoted by the same reference numerals, and detailed description is omitted. The internal heat exchanger low-pressure side inlet temperature sensor 8, the internal heat exchanger low-pressure side outlet temperature sensor 9, and a controller 24 for controlling the opening and closing of each of the solenoid valves by inputting the detection values of these sensors.
To constitute a refrigeration cycle apparatus.

With the above configuration, when a refrigerant that can be brought into a supercritical state with a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the compressor 101
The high-pressure and high-temperature refrigerant gas compressed in the above-mentioned manner passes through the outdoor heat exchanger 1 at the cooling / heating switching four-way valve 4 to become a high-temperature high-pressure refrigerant gas near normal temperature, and becomes low-temperature at the internal heat exchanger 18 via the flow path switching four-way valve 10. It becomes high-pressure refrigerant gas. The pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant.
0, the heat is absorbed by the use-side heat exchanger 3 to become a low-pressure refrigerant gas.
8 and return to the compressor 101.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. Through the flow path switching four-way valve 10 to become a low-temperature high-pressure refrigerant gas through the internal heat exchanger 18. Then, the pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, and heat is absorbed by the outdoor heat exchanger 1 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas. Then, it is heated through the internal heat exchanger 18 and returns to the compressor 101.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat absorber, and the flow path switching four-way valve is provided. By passing through 10, in the internal heat exchanger 18, the flows of the high-pressure refrigerant and the low-pressure refrigerant are opposed to each other, so that heat exchange with good heat exchange efficiency can be performed.

The capacity of the internal heat exchanger 18 is controlled by opening and closing the respective solenoid valves. Specifically, the maximum capacity is obtained when all the solenoid valves are opened, and the capacity is changed stepwise by the number of closing the high pressure solenoid valves ABC. Further, when all the high-pressure solenoid valves ABC are closed and the low-pressure solenoid valve 19 is closed, heat exchange becomes almost impossible, so that the minimum capacity is obtained.

As described above, the capacity of the internal heat exchanger 18 can be changed from a low capacity that hardly exchanges heat to a maximum capacity.

When the capacity of the internal heat exchanger 18 is controlled to reduce the capacity of the internal heat exchanger, the heat absorber increases the heating area and decreases the heat absorbing capacity. And in the radiator, the superheat degree at the compressor suction decreases, so the discharge temperature decreases,
As the coolant temperature of the radiator decreases, the capacity decreases.

When the capacity of the internal heat exchanger is increased, the heating area of the heat absorber decreases and the heat absorbing capacity increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

Utilizing such a refrigeration cycle operation, the low-pressure refrigerant outlet temperature is set according to the detection value of the internal heat exchanger low-pressure side inlet temperature sensor 8, and the internal heat exchanger low-pressure side outlet temperature sensor 9 is set. The controller 24 opens and closes the solenoid valves so that the detection value is equal to the set value.
, The refrigeration cycle can be adjusted to an efficient state.

(Embodiment 10) FIG. 10 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the eighth embodiment are denoted by the same reference numerals, and detailed description is omitted. The internal heat exchanger low-pressure side inlet temperature sensor 8, the internal heat exchanger high-pressure side inlet temperature sensor 11, the compressor rotation speed detecting device 12, and the detection values of these sensors are input to open and close the solenoid valves. A refrigeration cycle device is configured by including the controller 24 for controlling.

According to the above configuration, when a refrigerant that can be brought into a supercritical state by a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the compressor 101
The high-pressure and high-temperature refrigerant gas compressed in the above-mentioned manner passes through the outdoor heat exchanger 1 at the cooling / heating switching four-way valve 4 to become a high-temperature high-pressure refrigerant gas near normal temperature, and becomes low-temperature at the internal heat exchanger 18 via the flow path switching four-way valve 10. It becomes high-pressure refrigerant gas. The pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant.
0, the heat is absorbed by the use-side heat exchanger 3 to become a low-pressure refrigerant gas.
8 and return to the compressor 101.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. Through the flow path switching four-way valve 10 to become a low-temperature high-pressure refrigerant gas through the internal heat exchanger 18. Then, the pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, and heat is absorbed by the outdoor heat exchanger 1 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas. Then, it is heated through the internal heat exchanger 18 and returns to the compressor 101.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat absorber, and the flow path switching four-way valve is provided. By passing through 10, in the internal heat exchanger 18, the flows of the high-pressure refrigerant and the low-pressure refrigerant are opposed to each other, so that heat exchange with good heat exchange efficiency can be performed.

The capacity of the internal heat exchanger 18 is controlled by opening and closing the respective solenoid valves. Specifically, the maximum capacity is obtained when all the solenoid valves are opened, and the capacity is changed stepwise by the number of closing the high pressure solenoid valves ABC. Further, when all the high-pressure solenoid valves ABC are closed and the low-pressure solenoid valve 19 is closed, heat exchange becomes almost impossible, so that the minimum capacity is obtained.

As described above, the capacity of the internal heat exchanger 18 can be changed from a low capacity that hardly exchanges heat to a maximum capacity.

When the capacity of the internal heat exchanger 18 is controlled to reduce the capacity of the internal heat exchanger, the heating area of the heat absorber increases and the heat absorbing capacity decreases. And in the radiator, the superheat degree at the compressor suction decreases, so the discharge temperature decreases,
As the coolant temperature of the radiator decreases, the capacity decreases.

When the capacity of the internal heat exchanger is increased, the heat absorption area of the heat absorber decreases and the heat absorption capacity increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

At this time, if the number of rotations of the compressor is small, the amount of circulating refrigerant decreases accordingly, and the flow rate of refrigerant decreases, so that the heat exchange time increases, and the heat exchange efficiency of the internal heat exchanger 105 increases. It is necessary to suppress the ability to improve.

Using such a refrigeration cycle operation, the high-pressure refrigerant inlet temperature is set according to the detection value of the internal heat exchanger low-pressure side inlet temperature sensor 8, and the high-pressure refrigerant inlet temperature is further set according to the rotation speed of the compressor. By correcting the set value of the temperature, by controlling the opening and closing of each solenoid valve by the controller 24 so that the detection value of the internal heat exchanger high pressure side inlet temperature sensor 11 becomes the set value this value, The refrigeration cycle can be adjusted to an efficient state.

In this embodiment, the number of revolutions of the compressor is detected by using the number-of-rotations detector, but the output of an inverter or the like or the set value may be used.

(Embodiment 11) FIG. 11 shows a cycle configuration diagram of a cooling and heating water heater according to the present invention. The same components as those in the eighth embodiment are denoted by the same reference numerals, and detailed description is omitted. Compressor suction temperature sensor 15 and compressor suction pressure sensor 1
6, a refrigerant circulating meter 17, and a controller 24 that controls the opening and closing of each of the electromagnetic valves based on the detection values of these sensors as inputs.

According to the above configuration, when a refrigerant that can be brought into a supercritical state by a radiator such as carbon dioxide is sealed and the use side heat exchanger 3 is operated as a heat absorber, the compressor 101
The high-pressure and high-temperature refrigerant gas compressed in the above-mentioned manner passes through the outdoor heat exchanger 1 at the cooling / heating switching four-way valve 4 to become a high-temperature high-pressure refrigerant gas near normal temperature, and becomes low-temperature at the internal heat exchanger 18 via the flow path switching four-way valve 10. It becomes high-pressure refrigerant gas. The pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant.
0, the heat is absorbed by the use-side heat exchanger 3 to become a low-pressure refrigerant gas, and the internal heat exchanger 1 is cooled by the cooling / heating switching four-way valve 4.
8 and return to the compressor 101.

Conversely, when the use side heat exchanger 3 is operated as a radiator, the high pressure and high temperature refrigerant gas compressed by the compressor 101 is supplied to the use side heat exchanger 3 by the cooling / heating switching four-way valve 4. Through the flow path switching four-way valve 10 to become a low-temperature high-pressure refrigerant gas through the internal heat exchanger 18. Then, the pressure is reduced by the expansion valve A2 to become a low-temperature and low-pressure two-phase refrigerant, and heat is absorbed by the outdoor heat exchanger 1 through the flow path switching four-way valve 10 to become a low-pressure refrigerant gas. Then, it is heated through the internal heat exchanger 18 and returns to the compressor 101.

As described above, the internal heat exchanger can function in the refrigeration cycle in which the use side heat exchanger 3 is operated as a radiator or a heat sink, and the flow path switching four-way valve is provided. By passing through 10, in the internal heat exchanger 18, the flows of the high-pressure refrigerant and the low-pressure refrigerant are opposed to each other, so that heat exchange with good heat exchange efficiency can be performed.

The capacity of the internal heat exchanger 18 is controlled by opening and closing the respective solenoid valves. Specifically, the maximum capacity is obtained when all the solenoid valves are opened, and the capacity is changed stepwise by the number of closing the high pressure solenoid valves ABC. Further, when all the high-pressure solenoid valves ABC are closed and the low-pressure solenoid valve 19 is closed, heat exchange becomes almost impossible, so that the minimum capacity is obtained.

As described above, the capacity of the internal heat exchanger 18 can be changed from a low capacity that hardly exchanges heat to a maximum capacity.

When the capacity of the internal heat exchanger 18 is controlled to reduce the capacity of the internal heat exchanger, the heat absorber increases the heating area and decreases the heat absorbing capacity. And in the radiator, the superheat degree at the compressor suction decreases, so the discharge temperature decreases,
As the coolant temperature of the radiator decreases, the capacity decreases.

When the capacity of the internal heat exchanger is increased, the heating area of the heat absorber decreases and the heat absorbing capacity increases. In the radiator, the degree of superheat at the suction of the compressor increases, so that the discharge temperature increases, and the capacity of the radiator increases by increasing the refrigerant temperature.

At this time, if the amount of circulating refrigerant is small, the heat exchange time is increased because the flow velocity of the refrigerant is reduced, and the heat exchange efficiency of the internal heat exchanger 105 is improved, so that it is necessary to suppress the capacity.

Using such a refrigeration cycle operation, the compressor suction temperature is set according to the detection value of the compressor suction pressure sensor 16, and the set value of the compressor suction temperature is further set according to the refrigerant circulation amount. The refrigeration cycle is adjusted to an efficient state by controlling the opening and closing of each solenoid valve by the controller 24 so that the detection value of the compressor suction temperature sensor 15 becomes the set value and this value after correction. be able to.

[0170]

As is clear from the above embodiments, according to the present invention, the capacity control range of the internal heat exchanger can be expanded, and even when the refrigerating cycle is set to the reversible cycle, the internal heat exchanger can be used. Can be provided, and a refrigeration cycle apparatus having a control method for effectively operating the internal heat exchanger of the refrigeration cycle apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a cycle configuration diagram of a refrigeration cycle apparatus according to a first embodiment of the present invention.

FIG. 2 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 3 of the present invention.

FIG. 4 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 4 of the present invention.

FIG. 5 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 5 of the present invention.

FIG. 6 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 6 of the present invention.

FIG. 7 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 7 of the present invention.

FIG. 8 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 8 of the present invention.

FIG. 9 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 9 of the present invention.

FIG. 10 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 10 of the present invention.

FIG. 11 is a cycle configuration diagram of a refrigeration cycle apparatus according to Embodiment 11 of the present invention.

FIG. 12 is a cycle configuration diagram of a conventional refrigeration cycle device.

[Explanation of symbols]

 Reference Signs List 1 outdoor heat exchanger 2 expansion valve A 3 use side heat exchanger 4 cooling / heating switching four-way valve 5 expansion valve B 6 heat exchange medium temperature 7 controller 8 internal heat exchanger low pressure side inlet temperature sensor 9 internal heat exchanger low pressure side outlet temperature Sensor 10 Flow path switching four-way valve 11 Internal heat exchanger high-pressure side inlet temperature sensor 12 Revolution detecting device 13 User side heat exchanger refrigerant temperature sensor 14 Outdoor heat exchanger refrigerant temperature sensor 15 Compressor suction temperature sensor 16 Compressor suction pressure Sensor 17 Refrigerant circulation meter 18 Internal heat exchanger 19 Low-pressure solenoid valve 20 High-pressure solenoid valve A 21 High-pressure solenoid valve B 22 High-pressure solenoid valve C 23 Heat sink refrigerant temperature sensor 24 Controller

Claims (23)

[Claims] In a refrigeration cycle apparatus comprising a compressor, an outdoor heat exchanger, an expansion mechanism, a use side heat exchanger, and an internal heat exchanger, a refrigerant that can be brought into a supercritical state during heat release is filled therein. Is divided into a first expansion mechanism section and a second expansion mechanism section and provided at the high-pressure refrigerant side entrance and exit of the internal heat exchanger, respectively. 2. The refrigeration cycle apparatus according to claim 1, wherein when the use-side heat exchanger acts as a radiator, the internal heat exchanger is connected so that the flow of the refrigerant is countercurrent. 3. The refrigeration cycle apparatus according to claim 1, wherein, when the use side heat exchanger acts as a heat absorber, the internal heat exchanger is connected so that the flow of the refrigerant becomes countercurrent. 4. A cooling / heating switching four-way valve for reversing a refrigeration cycle is provided in a pipe connecting the use side heat exchanger and the compressor suction part, and a pipe connecting the outdoor heat exchanger and the compressor discharge part, for internal heat exchange. 2. The refrigeration cycle apparatus according to claim 1, further comprising a flow path switching four-way valve for preventing the refrigerant flow direction of the internal heat exchanger from changing in the reversal of the refrigeration cycle at the inlet and outlet of the high-pressure refrigerant. 5. A refrigeration cycle apparatus comprising a compressor, an outdoor heat exchanger, a first expansion mechanism, a use-side heat exchanger, and an internal heat exchanger, wherein a refrigerant that can be in a supercritical state during heat release is filled therein. A pipe connecting the use side heat exchanger and the compressor suction section, and a pipe connecting the outdoor heat exchanger and the compressor discharge section are provided with a cooling / heating switching four-way valve for reversing a refrigeration cycle, and the internal heat exchanger is provided. A high-pressure refrigerant outlet and a high-pressure refrigerant outlet of the internal heat exchanger and the flow path switching four-way valve for preventing the refrigerant flow direction of the internal heat exchanger from changing in the reversal of the refrigeration cycle. A refrigeration cycle apparatus provided with the first expansion mechanism section between the first and second expansion mechanisms. 6. The refrigeration cycle apparatus according to claim 5, wherein a second expansion mechanism is provided at a high-pressure refrigerant inlet of the internal heat exchanger. 7. The refrigeration cycle apparatus according to claim 6, wherein the pressure reduction amount when the second expansion mechanism is fully opened is smaller than the pressure reduction amount when the expansion mechanism is fully opened. 8. The refrigeration cycle apparatus according to claim 1, further comprising temperature detecting means for a medium that exchanges heat with the refrigerant in the use-side heat exchanger, wherein the temperature is set according to the detected value. A method for controlling a refrigeration cycle apparatus, comprising: controlling a first expansion mechanism and a second expansion mechanism so that the temperature of the refrigeration cycle is adjusted to a predetermined temperature, and adjusting an internal heat exchanger capacity. 9. The method of claim 1, 2, 3, 4, 6, 7, or 8.
In the refrigeration cycle apparatus described above, a temperature detecting means for detecting a low-pressure refrigerant inlet / outlet temperature of the internal heat exchanger is provided, and the first expansion mechanism and the second expansion mechanism are controlled based on the detected values, and the internal heat exchange is performed. A method for controlling a refrigeration cycle apparatus, which comprises adjusting a capacity. 10. The refrigeration cycle apparatus according to claim 1, further comprising a temperature detecting means for detecting a high-pressure refrigerant inlet temperature and a low-pressure refrigerant inlet temperature of the internal heat exchanger, A control method for a refrigeration cycle apparatus, comprising: controlling a first expansion mechanism and a second expansion mechanism based on the detected values to adjust an internal heat exchanger capacity. 11. The refrigeration cycle apparatus according to claim 1, further comprising a temperature detecting means for detecting a refrigerant temperature at an endothermic exchange portion and at a suction of the compressor. A method for controlling a refrigeration cycle apparatus, comprising: controlling a first expansion mechanism and a second expansion mechanism by means of a control unit to adjust an internal heat exchanger capacity. 12. The refrigeration cycle apparatus according to claim 1, further comprising detection means for detecting a temperature and a pressure of a suction part of the compressor, and a first detection means for detecting the temperature and pressure of the suction part. Controlling the expansion mechanism and the second expansion mechanism,
A method for controlling a refrigeration cycle apparatus, comprising adjusting an internal heat exchanger capacity. 13. The method of claim 1, 2, 3, 4, 6, 7, 8,
In the refrigeration cycle apparatus described in 9, 10, 11 or 12, a detecting means for detecting the number of revolutions of the compressor is provided, and the first expansion mechanism and the second expansion mechanism are controlled based on the detected value, and the internal heat is controlled. A method for controlling a refrigeration cycle device, comprising adjusting an exchanger capacity. 14. The method of claim 1, 2, 3, 4, 6, 7, 8,
In the refrigeration cycle apparatus described in 9, 10, 11 or 12, a detection means for detecting a refrigerant circulation amount of the refrigeration cycle is provided, and the first expansion mechanism and the second expansion mechanism are controlled based on the detected value. A method for controlling a refrigeration cycle apparatus, comprising adjusting a heat exchanger capacity. 15. A refrigeration cycle apparatus comprising a compressor, an outdoor heat exchanger, an expansion mechanism, and a use-side heat exchanger, in which a refrigerant that can be brought into a supercritical state during heat release is sealed and decompressed by the expansion mechanism. An internal heat exchanger for exchanging heat between the high-pressure refrigerant before and the low-pressure refrigerant before suction of the compressor is provided.The internal heat exchanger includes a plurality of refrigerant circuits, and an on-off valve is provided for each of the plurality of refrigerant circuits. Refrigeration cycle device characterized by the above-mentioned. 16. A cooling / heating switching four-way valve for reversing a refrigerating cycle is provided in a pipe connecting a use side heat exchanger and a compressor suction section, and a pipe connecting an outdoor heat exchanger and the compressor discharge section. A flow connecting the side heat exchanger and the expansion mechanism and a pipe connecting the outdoor heat exchanger and the expansion mechanism so as not to change the refrigerant flow direction of the expansion mechanism when the refrigeration cycle is reversed. The refrigeration cycle apparatus according to claim 15, further comprising a four-way switching valve, and an internal heat exchanger for exchanging heat between the high-pressure refrigerant before being depressurized by the expansion mechanism and the low-pressure refrigerant before suctioning the compressor. 17. The refrigeration cycle apparatus according to claim 15, further comprising means for detecting a temperature of a medium that exchanges heat with the refrigerant in the use-side heat exchanger, wherein the on-off valve is set to a temperature set by the detected value. And controlling a capacity of an internal heat exchanger having a plurality of refrigerant circuits. 18. The refrigeration cycle apparatus according to claim 15, further comprising temperature detection means for detecting a low-pressure refrigerant inlet / outlet temperature of an internal heat exchanger having a plurality of refrigerant circuits, and an on-off valve based on the detected values. And controlling the internal heat exchanger capacity by controlling the refrigeration cycle apparatus. 19. The refrigeration cycle apparatus according to claim 15, further comprising a temperature detecting means for detecting a high-pressure refrigerant inlet temperature and a low-pressure refrigerant inlet temperature of an internal heat exchanger having a plurality of refrigerant circuits. A method for controlling a refrigeration cycle apparatus, comprising controlling an on-off valve according to a detected value to adjust an internal heat exchanger capacity. 20. The refrigeration cycle apparatus according to claim 15, further comprising a temperature detecting means for detecting a temperature of the refrigerant at the endothermic exchange portion and a refrigerant at the compressor, and controlling the on-off valve based on the detected values. A method for controlling a refrigeration cycle apparatus, comprising adjusting a heat exchanger capacity. 21. The refrigeration cycle apparatus according to claim 15, further comprising detecting means for detecting a temperature and a pressure of a suction part of the compressor, wherein the on-off valve is controlled by the detected values, and an internal heat exchanger is provided. A method for controlling a refrigeration cycle device, comprising adjusting a capacity. 22. The method of claim 15, 16, 17, 18, or 1.
The refrigeration cycle apparatus according to 9, 20, or 21,
A method for controlling a refrigeration cycle apparatus, comprising: detecting means for detecting the number of revolutions of a compressor; controlling an on-off valve based on the detected value to adjust an internal heat exchanger capacity. 23. The method of claim 15, 16, 17, 18, or 1.
The refrigeration cycle apparatus according to 9, 20, or 21,
Detecting means for detecting the refrigerant circulation amount of the refrigeration cycle is provided,
A control method for a refrigeration cycle apparatus, wherein an on-off valve is controlled based on the detected value to adjust an internal heat exchanger capacity.