JP6899960B2 - Refrigeration cycle equipment and refrigeration equipment - Google Patents

Description

The present invention relates to a refrigeration cycle device and a refrigeration device. In particular, it relates to ensuring the degree of supercooling.

Conventionally, for example, in a refrigerator (refrigerator) for refrigeration or refrigeration, which is a refrigeration cycle device, a compressor, a condenser, an expansion valve, and an evaporator are connected in order by pipes to form a basic refrigerant circuit. In addition, there are refrigeration cycle devices in which a supercooler is installed between the condenser and the expansion valve. By installing a supercooler, the refrigerant is further cooled from the saturated liquid to the supercooled state, the enthalpy difference in the evaporator is widened, the capacity is increased, the performance is improved, and the like (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2009-109065

Here, the supercooler that supercools by exchanging heat with the outdoor air (hereinafter referred to as outside air) can supercool the refrigerant to near the temperature of the outside air. However, if the temperature difference between the temperature of the refrigerant flowing out of the condenser and the temperature of the outside air is small, the degree of supercooling becomes small. If the degree of supercooling is small, the liquid refrigerant cannot flow into the expansion valve depending on the state of the piping from the supercooler to the expansion valve. Therefore, restrictions on the pipe length, pipe diameter, etc. in the refrigerant circuit are strict so as not to increase the pressure loss.

The present invention has been made against the background of the above problems, and an object of the present invention is to obtain a freezing cycle device and a freezing device capable of ensuring the supercooling degree when the supercooling degree becomes small. ..

In the refrigeration cycle apparatus according to the present invention, a compressor, a condenser, a liquid receiver, a first supercooler, a throttle device and an evaporator are connected by a refrigerant pipe, and a refrigerant containing a refrigerant having a temperature gradient is circulated. a refrigeration cycle apparatus having the circuit calculates the supercooling degree of the refrigerant circuit, by comparing the preset threshold value and the supercooling degree, and determining the control unit whether raising the condensing temperature in the condenser A supercooler inlet temperature sensor installed at the refrigerant inlet of the first supercooler to detect the temperature and an outside air temperature sensor to detect the temperature of the outside air that exchanges heat with the refrigerant in the first supercooler are provided . The control unit determines the degree of supercooling by using the temperature difference between the temperature detected by the supercooler inlet temperature sensor and the temperature detected by the outside air temperature sensor as the degree of supercooling .

Further, the refrigerating apparatus according to the present invention includes the refrigerating cycle apparatus as described above.

According to the refrigerating cycle apparatus and the refrigerating apparatus of the present invention, the control unit compares the degree of supercooling with the threshold value to determine whether or not to raise the condensation temperature of the condenser. By increasing the degree of cooling, restrictions on the pipe length, pipe diameter, etc. of the refrigerant circuit can be relaxed.

It is a figure which shows the structure of the refrigerating apparatus 1 which concerns on Embodiment 1 of this invention. It is a figure which schematically describes an example of the structure which concerns on the control part 3 which controls the refrigerating apparatus 1 which concerns on Embodiment 1 of this invention. It is a figure explaining the comparison between the refrigerant with a small temperature gradient and the refrigerant with a large temperature gradient. It is a figure which shows an example of the ph diagram of the refrigerant in the refrigerant circuit 10 of the refrigerating apparatus 1 which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the refrigerating apparatus 1 which concerns on Embodiment 2 of this invention. It is a figure explaining the flow of the refrigerant and the operation of the flow path switching device 50 in the case of the flow path A of the refrigerating apparatus 1 which concerns on Embodiment 2 of this invention. It is a figure explaining the flow of the refrigerant and the operation of the flow path switching device 50 in the case of the flow path B of the refrigerating apparatus 1 which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the refrigerating apparatus 1 which concerns on Embodiment 4 of this invention. It is a figure which shows the structure of the refrigerating apparatus 1 which concerns on Embodiment 5 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, in the following drawings, those having the same reference numerals are the same or equivalent thereto, and are common to the whole texts of the embodiments described below. In addition, the forms of the components shown in the full text of the specification are merely examples and are not limited to these descriptions. In particular, the combination of the components is not limited to the combination in each embodiment, and the components described in the other embodiments can be appropriately applied to the other embodiments. The height of temperature, pressure, etc. is not determined in relation to the absolute value, but is relatively determined in the state, operation, etc. of the system, device, or the like. In addition, when it is not necessary to distinguish or specify a plurality of devices of the same type that are distinguished by subscripts, the subscripts and the like may be omitted.

Embodiment 1.
FIG. 1 is a diagram showing a configuration of a refrigerating apparatus 1 according to a first embodiment of the present invention. The refrigerating apparatus 1 shown in FIG. 1 is a refrigerating cycle apparatus that performs a vapor compression refrigerating cycle operation. Here, the refrigerating apparatus 1 will be described as an example of the refrigerating cycle apparatus.

The refrigerating device 1 cools a room, which is a space to be cooled in a room, a warehouse, a showcase, a refrigerator, or the like. The refrigerating device 1 has a heat source side unit 100 and a user side unit 200. As shown in FIG. 1, the refrigerating apparatus 1 of the first embodiment has one heat source side unit 100 and one user side unit 200, but the number of these units is not limited. For example, the number of heat source side units 100 may be two or more. Further, the user-side unit 200 may be configured such that two or more units are connected in parallel.

In the refrigerating apparatus 1, the heat source side unit 100 and the utilization side unit 200 are connected by a liquid refrigerant extension pipe 6 and a gas refrigerant extension pipe 7, and a refrigerant circuit 10 for circulating the refrigerant is configured. In the refrigerating apparatus 1 of the first embodiment, the refrigerant filled in the refrigerant circuit 10 is a refrigerant having a large temperature gradient, which tends to reduce the degree of supercooling. In the following description, the refrigerating apparatus 1 in which the outside air and the refrigerant exchange heat with each other will be described.

The refrigerant used in the refrigerating apparatus 1 of the first embodiment is assumed to be a refrigerant having a large temperature gradient such as R463A. In the case of a refrigerant having a large temperature gradient, a temperature difference occurs between the gas saturation temperature and the liquid saturation temperature even at the same pressure. Therefore, when the average temperature of the gas saturation temperature and the liquid saturation temperature is taken as the condensation temperature, a refrigerant having a large temperature gradient can be regarded as having no temperature gradient even at the same condensation temperature. The temperature of the refrigerant flowing out of the condenser is lower. In the case of a refrigerant having a large temperature gradient, the temperature of the refrigerant flowing out of the condenser is lower than the condensation temperature, so that the degree of supercooling tends to be small.

Here, a refrigerant having a difference (temperature gradient) between the saturated gas temperature and the saturated liquid temperature at the same pressure of 3 K or more is defined as a refrigerant having a large temperature gradient. For example, the condensation temperature is 50 [° C.], and the refrigerants such as R404A and R410A have a temperature gradient of less than 1.0 K. Therefore, these refrigerants are refrigerants having a small temperature gradient. On the other hand, the refrigerant of R463A has a temperature gradient of about 5K. Further, the refrigerants such as R448A and R449A have a temperature gradient of about 3K or more. Therefore, these refrigerants have a large temperature gradient.

The user-side unit 200 is, for example, a unit installed in a room that is a cooling target space. The user-side unit 200 includes a user-side refrigerant circuit 10a, a user-side fan 43, and a user-side control unit 32, which are a part of the refrigerant circuit 10.

A user-side expansion valve 41 and a user-side heat exchanger 42 are installed on the user-side refrigerant circuit 10a. The utilization side expansion valve 41 adjusts the flow rate of the refrigerant flowing through the utilization side refrigerant circuit 10a. The user-side expansion valve 41 is composed of a throttle device such as an electronic expansion valve or an automatic temperature expansion valve, for example. Here, in the first embodiment, the utilization side expansion valve 41 is installed in the utilization side unit 200, but may be arranged in the heat source side unit 100. When the utilization side expansion valve 41 is inside the heat source side unit 100, the utilization side expansion valve 41 is arranged, for example, between the second heat exchanger 23 of the heat source side unit 100 and the liquid side closing valve 28. To.

The user-side heat exchanger 42 functions as an evaporator that evaporates the refrigerant by exchanging heat with the air in the room. The user-side heat exchanger 42 is, for example, a fin-and-tube heat exchanger having a plurality of heat transfer tubes and a plurality of fins.

Further, the user-side fan 43 is a blower that blows air to the user-side heat exchanger 42. The user-side fan 43 is arranged in the vicinity of the user-side heat exchanger 42. The user-side fan 43 includes, for example, a centrifugal fan, a multi-blade fan, and the like. The user-side fan 43 is driven by a motor (not shown). Here, the user-side fan 43 can adjust the amount of air blown to the user-side heat exchanger 42 by controlling the rotation speed of the motor.

The heat source side unit 100 is a unit that supplies heat to the user side unit 200. The heat source side unit 100 includes, for example, a heat source side refrigerant circuit 10b, a heat source side fan 27, and a heat source side control unit 31 that are a part of the refrigerant circuit 10.

A compressor 21, a first heat exchanger 22, a liquid receiver 25, a second heat exchanger 23, a liquid side closing valve 28, a gas side closing valve 29, and an accumulator 24 are installed in the heat source side refrigerant circuit 10b. .. The compressor 21 is, for example, an inverter compressor having an inverter circuit and in which inverter control is performed. Therefore, the compressor 21 can arbitrarily change the drive frequency to change the capacity (the amount of refrigerant delivered per unit time). Further, in the first embodiment, as shown in FIG. 1, an example having one compressor 21 will be described. However, depending on the size of the load of the user-side unit 200 and the like, two or more compressors 21 may be connected in parallel.

In the first embodiment, the first heat exchanger 22 functions as a condenser that condenses the refrigerant by heat exchange with the outdoor air. The first heat exchanger 22 is, for example, a fin-and-tube heat exchanger having a plurality of heat transfer tubes and a plurality of fins.

In the first embodiment, the second heat exchanger 23 functions as a first supercooler that supercools the refrigerant by exchanging heat with the outdoor air. In the refrigerating apparatus 1 of the first embodiment, the second heat exchanger 23 is integrally formed with the first heat exchanger 22. Therefore, in the refrigerating apparatus 1 of the first embodiment, a part of the heat exchanger is configured as the first heat exchanger 22, and the other part of the heat exchanger is configured as the second heat exchanger 23. Become. The second heat exchanger 23 has a smaller internal volume than the first heat exchanger 22. Here, the second heat exchanger 23 and the first heat exchanger 22 may be configured separately. In that case, a fan (not shown) for blowing air to the second heat exchanger 23 is arranged in the vicinity of the second heat exchanger 23.

The heat source side fan 27 is a blower that blows air to the first heat exchanger 22 and the second heat exchanger 23. The heat source side fan 27 is arranged in the vicinity of the first heat exchanger 22. The heat source side fan 27 includes, for example, a centrifugal fan, a multi-blade fan, and the like. The heat source side fan 27 is driven by a motor (not shown). Here, the heat source side fan 27 can adjust the amount of air blown to the first heat exchanger 22 by controlling the rotation speed of the motor.

The liquid receiver 25 is, for example, a container for storing excess liquid refrigerant. The liquid receiver 25 is arranged between the first heat exchanger 22 and the second heat exchanger 23. Here, the surplus liquid refrigerant is generated in the refrigerant circuit 10 according to, for example, the size of the load of the user-side unit 200, the condensation temperature of the refrigerant, the outside air temperature which is the outdoor temperature, the capacity of the compressor 21, and the like.

The liquid side closing valve 28 and the gas side closing valve 29 have valves that open and close, such as a ball valve, an on-off valve, and an operating valve. The liquid-side closing valve 28 and the gas-side closing valve 29 close the valves to block the inflow and outflow of the refrigerant from and to the utilization-side unit 200, for example, when the refrigerating device 1 is not operated.

Next, the control system devices and sensors included in the refrigeration device 1 of the first embodiment will be described. The heat source side unit 100 includes a heat source side control unit 31 that controls the entire refrigeration apparatus 1. The heat source side control unit 31 includes, for example, a microcomputer, a memory, and the like. Further, the user-side unit 200 includes a user-side control unit 32 that controls the user-side unit 200. The user-side control unit 32 is also configured to include, for example, a microprocessor and a memory. For example, the user-side control unit 32 and the heat source-side control unit 31 can communicate with each other to send and receive control signals.

In the refrigerating apparatus 1 according to the first embodiment, the heat source side unit 100 includes a suction temperature sensor 33a, a discharge temperature sensor 33b, a suction outside air temperature sensor 33c, a receiver outlet temperature sensor 33h, and a supercooler outlet temperature sensor 33d. doing. Further, the heat source side unit 100 has a suction pressure sensor 34a and a discharge pressure sensor 34b. Then, for example, the user-side unit 200 has a user-side heat exchange inlet temperature sensor 33e, a user-side heat exchange outlet temperature sensor 33f, and a suction air temperature sensor 33 g. The suction temperature sensor 33a, the discharge temperature sensor 33b, the suction outside air temperature sensor 33c, the receiver outlet temperature sensor 33h and the supercooler outlet temperature sensor 33d, and the suction pressure sensor 34a and the discharge pressure sensor 34b are connected to the heat source side control unit 31. Has been done. The user-side heat exchange inlet temperature sensor 33e, the user-side heat exchange outlet temperature sensor 33f, and the suction air temperature sensor 33g are connected to the user-side control unit 32.

The suction temperature sensor 33a detects the temperature of the refrigerant sucked by the compressor 21. The discharge temperature sensor 33b detects the temperature of the refrigerant discharged by the compressor 21. The liquid receiver outlet temperature sensor 33h detects the refrigerant temperature at the refrigerant outlet of the liquid receiver 25. Here, the refrigerant temperature at the refrigerant outlet of the liquid receiver 25 is the temperature of the refrigerant that has passed through the first heat exchanger 22. Further, the refrigerant temperature at the refrigerant outlet of the liquid receiver 25 is the temperature of the refrigerant at the refrigerant inlet side of the second heat exchanger 23. Therefore, the receiver outlet temperature sensor 33h also serves as a supercooler inlet temperature sensor. The supercooler outlet temperature sensor 33d detects the temperature of the refrigerant that has passed through the second heat exchanger 23. The user-side heat exchange inlet temperature sensor 33e detects the temperature of the gas-liquid two-phase refrigerant flowing into the user-side heat exchanger 42. The user-side heat exchange outlet temperature sensor 33f detects the temperature of the refrigerant flowing out from the user-side heat exchanger 42. Here, the sensor for detecting the temperature of the refrigerant is arranged, for example, in contact with the refrigerant pipe or inserted into the refrigerant pipe to detect the temperature of the refrigerant.

The suction outside air temperature sensor 33c detects the outdoor ambient temperature by detecting the temperature of the air before passing through the first heat exchanger 22. The suction air temperature sensor 33g detects the ambient temperature of the room in which the user side heat exchanger 42 is installed by detecting the temperature of the air before passing through the user side heat exchanger 42.

The suction pressure sensor 34a is arranged on the suction side of the compressor 21 and detects the pressure of the refrigerant sucked into the compressor 21. Here, the suction pressure sensor 34a may be arranged between the gas side closing valve 29 and the compressor 21. The discharge pressure sensor 34b is arranged on the discharge side of the compressor 21 and detects the pressure of the refrigerant discharged by the compressor 21.

In the first embodiment, the condensation temperature of the first heat exchanger 22 can be obtained by converting the pressure of the discharge pressure sensor 34b into the saturation temperature. Further, the condensation temperature of the first heat exchanger 22 is calculated back from the saturated liquid temperature which is the temperature detected by the receiver outlet temperature sensor 33h installed at the refrigerant outlet of the receiver 25. The saturated gas temperature can be calculated from the pressure, and the condensation temperature can be calculated from the average of the saturated gas temperature and the saturated liquid temperature. If there is either the discharge pressure sensor 34b or the receiver outlet temperature sensor 33h, the condensation temperature can be obtained from the saturated liquid temperature. The same applies to the following embodiments.

FIG. 2 is a diagram schematically showing an example of a configuration related to a control unit 3 that controls the refrigerating apparatus 1 according to the first embodiment of the present invention. The control unit 3 controls the entire refrigeration apparatus 1. The control unit 3 in the first embodiment is included in the heat source side control unit 31 in FIG.

The acquisition unit 3a acquires the temperature and pressure detected by the sensors as data based on the signals from the sensors such as the pressure sensor and the temperature sensor. The calculation unit 3b performs processing such as calculation, comparison, and determination using the data acquired by the acquisition unit 3a. The drive unit 3d drives and controls devices such as the compressor 21, valves, and fans by using the result calculated by the calculation unit 3b. The storage unit 3c stores, for example, the physical property values of the refrigerant (saturation pressure, saturation temperature, etc.), data for the calculation unit 3b to perform calculations, and the like. The calculation unit 3b can refer to or update the contents of the data stored in the storage unit 3c as needed.

Further, the control unit 3 includes an input unit 3e and an output unit 3f. The input unit 3e processes a signal related to an operation input from a remote controller, switches, etc. (not shown), or processes a signal of communication data sent from a communication means (not shown) such as a telephone line or a LAN line. To do. The output unit 3f outputs the processing result of the control unit 3 to a display means (not shown) such as an LED or a monitor, outputs to a notification means (not shown) such as a speaker, or a telephone line, a LAN line, or the like. Output to communication means (not shown). Here, when a signal including data is output to a remote location by a communication means, a communication means (not shown) having the same communication protocol is provided for both the refrigerating device 1 and the remote device (not shown). It is good to provide it.

Here, the control unit 3 has a microcomputer as described above. The microcomputer has, for example, a control arithmetic processing device such as a CPU (Central Processing Unit). The control arithmetic processing unit realizes the functions of the acquisition unit 3a, the arithmetic unit 3b, and the drive unit 3d. It also has an I / O port that manages input and output. The I / O port realizes the functions of the input unit 3e and the output unit 3f. Further, for example, a volatile storage device (not shown) such as a random access memory (RAM) capable of temporarily storing data, and a non-volatile auxiliary storage device (not shown) such as a hard disk or a flash memory capable of storing data for a long period of time. Not shown). These storage devices realize the function of the storage unit 3c. For example, the storage device has data in which the processing procedure performed by the control arithmetic processing unit is programmed. Then, the control calculation processing device executes the processing based on the data of the program, and realizes the functions of the acquisition unit 3a, the calculation unit 3b, and the drive unit 3d. However, the present invention is not limited to this, and each part may be configured by a dedicated device (hardware).

Here, in the above description, an example in which the control unit 3 is included in the heat source side control unit 31 has been described. However, it is not limited to this. For example, the control unit 3 may be included in the user side control unit 32. Further, the control unit 3 may be configured as a device separate from the heat source side control unit 31 and the user side control unit 32.

FIG. 3 is a diagram illustrating a comparison between a refrigerant having a small temperature gradient and a refrigerant having a large temperature gradient. FIG. 3A shows a ph diagram in a refrigerant having a small temperature gradient. Further, FIG. 3B shows a ph diagram in a refrigerant having a large temperature gradient.

In the case of a refrigerant having a small temperature gradient, the temperature B1 of the refrigerant on the refrigerant outflow side of the first heat exchanger 22 is substantially the same as the condensation temperature, the saturated liquid temperature, and the saturated gas temperature. Further, the temperature C1 of the refrigerant on the refrigerant outflow side of the second heat exchanger 23 is substantially the same as the outside air temperature. Then, the degree of supercooling SC1 is SC1 = B1-C1.

On the other hand, in the case of a refrigerant having a large temperature gradient, the temperature B2 of the refrigerant on the refrigerant outflow side of the first heat exchanger 22 is lower than the condensation temperature. Further, the temperature C2 of the refrigerant on the refrigerant outflow side of the second heat exchanger 23 is substantially the same as the outside air temperature. Then, the degree of supercooling SC2 is SC2 = B2-C2. From the above, SC2 <SC1 and the degree of supercooling of the refrigerant having a large temperature gradient becomes small.

FIG. 4 is a diagram showing an example of a ph diagram of the refrigerant in the refrigerant circuit 10 of the refrigerating apparatus 1 according to the first embodiment of the present invention. In the heat source side control unit 31, the supercooling degree SC obtained by the temperature difference between the temperature B related to the detection of the receiver outlet temperature sensor 33h and the temperature C related to the detection of the supercooler outlet temperature sensor 33d is set in advance. determined threshold and whether the reference subcooling degree lower than the SC _R consisting of (SC <SC _R). If it is determined that the supercooling degree SC is lower than the reference degree of supercooling SC _R, as the high-pressure side pressure of the refrigerant passing through the first heat exchanger 22 is increased, to raise the condensation temperature.

In the first embodiment, the heat source side control unit 31 controls to reduce the rotation speed of the heat source side fan 27 in order to raise the high pressure side pressure and the condensation temperature of the refrigerant. By reducing the rotation speed of the heat source side fan 27 and reducing the air volume, the amount of heat exchange between the outside air and the refrigerant in the first heat exchanger 22 is reduced, and the high pressure side pressure is increased. Therefore, the temperature B of the refrigerant on the refrigerant outflow side of the first heat exchanger 22 becomes B3, which is higher than that. The temperature C of the refrigerant on the refrigerant outflow side of the second heat exchanger 23 is substantially the same as the outside air temperature C3. Then, so-supercooling degree SC3 (= B3-C3)> SC R.

As described above, according to the refrigeration apparatus 1 of the first embodiment, when it is determined that the supercooling degree SC is lower than the reference degree of supercooling SC _R, to raise the condensation temperature of the refrigerant passing through the first heat exchanger 22 I made it. Therefore, overcooling is the temperature difference between the temperature of the refrigerant on the refrigerant outflow side of the first heat exchanger 22 and the temperature of the refrigerant on the refrigerant outflow side of the second heat exchanger 23, which is about the same as the temperature of the outside air. The degree SC can be increased. Therefore, restrictions on the pipe length, pipe diameter, and the like in the refrigerant circuit 10 can be relaxed.

In the above-mentioned example, the rotation speed of the heat source side fan 27 is lowered in order to raise the condensation temperature of the refrigerant in the first heat exchanger 22. Alternatively, the heat source side control unit 31 may control the drive frequency of the compressor 21 to be high to raise the condensation temperature. However, the drive frequency control of the compressor 21 is mainly performed based on the load on the user-side unit 200. Therefore, it is more efficient to control the rotation speed of the heat source side fan 27 for adjusting the condensation temperature.

Embodiment 2.
FIG. 5 is a diagram showing a configuration of a refrigerating apparatus 1 according to a second embodiment of the present invention. In FIG. 5, for devices and the like having the same reference numerals as those in FIG. 1, the same functions and operations as those described in the first embodiment are performed.

As shown in FIG. 5, the refrigerating device 1 of the second embodiment has a flow path switching device 50. The flow path switching device 50 is a device that switches the flow path based on an instruction from the heat source side control unit 31 and changes the refrigerant passage order between the first heat exchanger 22 and the second heat exchanger 23. Although not particularly limited in the first embodiment, in the refrigerating apparatus 1 of the second embodiment, the ratio of the internal volumes of the first heat exchanger 22 and the second heat exchanger 23 is different. Therefore, when it is desired to increase the degree of supercooling, the degree of supercooling can be increased by using the first heat exchanger 22 having a large internal volume as the supercooler. By switching the flow path by the flow path switching device 50, it is possible to select whether the first heat exchanger 22 is a supercooler or the second heat exchanger 23 is a supercooler. Here, the first heat exchanger 22 is a condenser, the second heat exchanger 23 is a supercooler, and the flow path through which the refrigerant flows is the flow path A. Further, the first heat exchanger 22 is a supercooler, the second heat exchanger 23 is a condenser, and the flow path through which the refrigerant flows is the flow path B.

The flow path switching device 50 has a three-way valve 51 and a three-way valve 52, a two-way valve 53, a two-way valve 54 and a two-way valve 55, and a check valve 56 and a check valve 57. It also has a switching pipe 58 and a switching pipe 59.

In the three-way valve 51, the refrigerant discharged from the compressor 21 flows to the first heat exchanger 22 side in the case of the flow path A, and flows to the switching pipe 58 side in the case of the flow path B. It is a valve that switches to. Further, in the case of the flow path A, the three-way valve 52 causes the refrigerant flowing out from the second heat exchanger 23 to flow to the utilization side unit 200 side, and in the case of the flow path B, flows from the switching pipe 58. It is a valve that switches the refrigerant so that it flows to the user side unit 200 side.

The two-way valve 53 is a valve that is opened in the case of the flow path A, the refrigerant flows from the first heat exchanger 22 to the liquid receiver 25, and is closed in the case of the flow path B. Further, the two-way valve 54 is a valve that is closed in the case of the flow path A and opened in the case of the flow path B so that the refrigerant flows from the second heat exchanger 23 to the liquid receiver 25. Then, the two-way valve 55 is installed in the switching pipe 59. The two-way valve 55 is a valve that is closed in the case of the flow path A and opened in the case of the flow path B so that the refrigerant flowing out of the second heat exchanger 23 flows through the switching pipe 59.

The check valve 56 stops the flow of the refrigerant from the first heat exchanger 22 side in the case of the flow path A, and allows the refrigerant from the liquid receiver 25 to pass in the case of the flow path B. In the case of the flow path A, the check valve 57 allows the refrigerant from the liquid receiver 25 to pass through, and in the case of the flow path B, stops the flow of the refrigerant from the second heat exchanger 23 side. Refrigerant flows in the switching pipe 58 and the switching pipe 59 in the case of the flow path B.

FIG. 6 is a diagram illustrating the flow of the refrigerant and the operation of the flow path switching device 50 in the case of the flow path A of the refrigerating device 1 according to the second embodiment of the present invention. In the flow path A, the refrigerant discharged from the compressor 21 passes through the three-way valve 51 and flows to the first heat exchanger 22 side. Then, the refrigerant passes through the first heat exchanger 22 and the open two-way valve 53 and flows to the liquid receiver 25. Since the two-way valve 54 is closed, the refrigerant of the liquid receiver 25 passes through the check valve 57 and flows to the second heat exchanger 23. The refrigerant that has passed through the second heat exchanger 23 passes through the three-way valve 52 and flows out from the heat source side unit 100.

FIG. 7 is a diagram illustrating the flow of the refrigerant and the operation of the flow path switching device 50 in the case of the flow path B of the refrigerating device 1 according to the second embodiment of the present invention. In the flow path B, the refrigerant discharged by the compressor 21 passes through the three-way valve 51 and flows through the switching pipe 58. Then, the refrigerant passes through the three-way valve 52 and flows to the second heat exchanger 23 side. It passes through the second heat exchanger 23 and the open two-way valve 54 and flows to the liquid receiver 25. Since the two-way valve 53 is closed, the refrigerant of the liquid receiver 25 passes through the check valve 56 and flows to the first heat exchanger 22. The refrigerant that has passed through the first heat exchanger 22 passes through the switching pipe 59 and flows out from the heat source side unit 100.

As described above, according to the refrigerating device 1 of the second embodiment, the flow path switching device 50 is provided so that the order of passing the refrigerant between the first heat exchanger 22 and the second heat exchanger 23 can be changed. I made it. Therefore, when the heat source side control unit 31 determines that the degree of supercooling is small, the internal volume of the heat exchanger serving as the supercooler can be changed to increase the degree of supercooling. Therefore, restrictions on the pipe length, pipe diameter, and the like in the refrigerant circuit 10 can be relaxed. Here, the heat source side control unit 31 switches the flow path of the flow path switching device 50 based on the degree of supercooling. For example, the flow path of the flow path switching device 50 is switched based on the type of the refrigerant. You may switch. The setting related to the type of the refrigerant should be made by the user or the like.

Here, the degree of supercooling is increased by switching the flow path with the flow path switching device 50, but the present invention is not limited to this. By arbitrarily changing the number of passes in the first heat exchanger 22 and the second heat exchanger 23, the ratio of the internal volumes may be different.

Embodiment 3.
In the first embodiment described above, the heat source side control unit 31 supercools the temperature difference between the temperature B related to the detection of the receiver outlet temperature sensor 33h and the temperature C related to the detection of the supercooler outlet temperature sensor 33d. as SC, it was determined in comparison with the reference degree of supercooling SC _R. Instead of the temperature C related to the detection of the supercooler outlet temperature sensor 33d, the outdoor ambient temperature Z related to the detection of the suction outside air temperature sensor 33c is used to calculate the supercooling degree SC with SC = BZ. The determination may be made.

Embodiment 4.
FIG. 8 is a diagram showing a configuration of a refrigerating apparatus 1 according to a fourth embodiment of the present invention. In FIG. 8, the devices having the same reference numerals as those in FIG. 1 and the like are the same as those described in the first embodiment. As shown in FIG. 8, the refrigerating apparatus 1 of the fourth embodiment further includes an inter-refrigerant supercooler 26 serving as a second supercooler in the heat source side unit 100. The inter-refrigerant supercooler 26 is installed on the downstream side of the second heat exchanger 23 in the flow of the refrigerant. The inter-refrigerant supercooler 26 is configured to include, for example, a double pipe or plate heat exchanger. The inter-refrigerant supercooler 26 is a heat exchanger that exchanges heat between the high-pressure refrigerant flowing in the heat source-side refrigerant circuit 10b and the intermediate-pressure refrigerant flowing in the bypass flow path 71.

Further, the bypass flow path 71 has a bypass flow rate adjusting device 72 and a bypass pipe 73. One end of the bypass pipe 73 is connected between the refrigerant outlet of the second heat exchanger 23 and the liquid side closing valve 28. The other end of the bypass pipe 73 is connected to the pipe on the refrigerant suction side of the compressor 21. The bypass pipe 73 branches a part of the refrigerant sent from the first heat exchanger 22 side to the utilization side heat exchanger 42 side from the heat source side refrigerant circuit 10b and bypasses it to the refrigerant suction side pipe of the compressor 21. It is a pipe. The bypass flow rate adjusting device 72 is a valve that depressurizes the refrigerant flowing through the bypass pipe 73 and adjusts the amount of the refrigerant. Then, the reduced pressure refrigerant temperature sensor 33i is installed in the bypass pipe 73 and detects the temperature of the heat exchange refrigerant that has passed through the bypass flow rate adjusting device 72.

A part of the refrigerant that has passed through the inter-refrigerant supercooler 26 is expanded by the bypass flow rate adjusting device 72 to become an intermediate pressure refrigerant. Then, heat is exchanged with the refrigerant passing through the inter-refrigerant supercooler 26. As a result, the high-pressure refrigerant that flows out of the second heat exchanger 23 and is heat-exchanged by the inter-refrigerant supercooler 26 is further supercooled. Further, the intermediate pressure refrigerant flowing in from the bypass flow rate adjusting device 72 and exchanging heat with the inter-refrigerant supercooler 26 becomes a refrigerant having a high degree of dryness, and the compressor 21 is used to lower the discharge temperature of the compressor 21. Injection is performed on the suction side.

In the refrigerating apparatus 1 of the fourth embodiment, the inter-refrigerant supercooler 26 exchanges heat with the decompressed refrigerant temperature F of the refrigerant passing through the bypass flow rate adjusting device 72. Therefore, the heat source side control unit 31 uses the temperature C related to the detection of the supercooler outlet temperature sensor 33d and the reduced pressure refrigerant temperature F related to the detection of the reduced pressure refrigerant temperature sensor 33i to supercool the SC4 = CF. Calculate the degree SC4. In the refrigerating apparatus 1 of the fourth embodiment, the temperature difference between the refrigerants flowing into the inter-refrigerant supercooler 26 is set to the degree of supercooling SC4, so that a determination based on the state of supercooling in the inter-refrigerant supercooler 26 is performed. be able to.

Embodiment 5.
FIG. 9 is a diagram showing a configuration of a refrigerating apparatus 1 according to a fifth embodiment of the present invention. In FIG. 9, the devices having the same reference numerals as those in FIGS. 1 and 8, are the same as those described in the first to fourth embodiments. As shown in FIG. 9, the refrigerating apparatus 1 of the fifth embodiment has a refrigerant heat exchanger 80. The inter-refrigerant heat exchanger 80 performs supercooling by exchanging heat between the refrigerant flowing out of the heat source side unit 100 and the refrigerant flowing in from the utilization side unit 200 to the heat source side unit 100. Here, between the refrigerant that has passed through the second heat exchanger 23 and is about to flow out of the heat source side unit 100 and the refrigerant that has flowed into the heat source side unit 100 from the user side unit 200 via the gas refrigerant extension pipe 7. Heat exchange is performed at. Since the refrigerant flowing from the user-side unit 200 to the heat source-side unit 100 is a low-pressure and low-temperature refrigerant, the degree of supercooling can be increased.

In the above-described first to fifth embodiments, the refrigerating apparatus 1 has been described as an example of the refrigerating cycle apparatus, but the present invention is not limited to this. For example, it can be applied to other refrigeration cycle devices such as air conditioners and refrigerators.

Further, in the above-described first to fifth embodiments, the refrigerant used in the refrigeration cycle apparatus has been described as being a refrigerant having a large temperature gradient. However, the configurations of Embodiments 1 to 5 can also be applied to refrigerants having a small temperature gradient and no temperature gradient.

1 Refrigerant device, 3 Control unit, 3a acquisition unit, 3b calculation unit, 3c storage unit, 3d drive unit, 3e input unit, 3f output unit, 6-component refrigerant extension pipe, 7 gas refrigerant extension pipe, 10 refrigerant circuit, 10a Side refrigerant circuit, 10b heat source side refrigerant circuit, 21 compressor, 22 first heat exchanger, 23 second heat exchanger, 24 accumulator, 25 receiver, 26 inter-refrigerant supercooler, 27 heat source side fan, 28 liquid Side closure valve, 29 gas side closure valve, 31 heat source side control unit, 32 user side control unit, 33a suction temperature sensor, 33b discharge temperature sensor, 33c suction outside air temperature sensor, 33d supercooler outlet temperature sensor, 33e user side heat Exchange inlet temperature sensor, 33f user side heat exchange outlet temperature sensor, 33 g suction air temperature sensor, 33h receiver outlet temperature sensor, 33i decompression refrigerant temperature sensor, 34a suction pressure sensor, 34b discharge pressure sensor, 41 user side expansion valve, 42 Utilization side heat exchanger, 43 Utilization side fan, 50 Flow path switching device, 51, 52 Three-way valve, 53, 54, 55 Two-way valve, 56, 57 Check valve, 58, 59 Switching piping, 71 Bypass flow path , 72 Bypass flow control device, 73 Bypass piping, 80 Refrigerant heat exchanger, 100 Heat source side unit, 200 User side unit.

Claims (8)

A refrigeration cycle device in which a compressor, a condenser, a liquid receiver, a first supercooler, a throttle device, and an evaporator are connected by a refrigerant pipe and have a refrigerant circuit for circulating a refrigerant containing a refrigerant having a temperature gradient. ,
A control unit that calculates the degree of supercooling in the refrigerant circuit, compares the degree of supercooling with a preset threshold value, and determines whether or not to raise the condensation temperature in the condenser .
A supercooler inlet temperature sensor installed at the refrigerant inlet of the first supercooler to detect the temperature, and
The first supercooler includes an outside air temperature sensor that detects the temperature of the outside air that exchanges heat with the refrigerant .
The control unit is a refrigeration cycle device that makes the determination using the temperature difference between the temperature detected by the supercooler inlet temperature sensor and the temperature detected by the outside air temperature sensor as the degree of supercooling. A refrigeration cycle device in which a compressor, a condenser, a liquid receiver, a first supercooler, a throttle device, and an evaporator are connected by a refrigerant pipe and have a refrigerant circuit for circulating a refrigerant containing a refrigerant having a temperature gradient. ,
A control unit that calculates the degree of supercooling in the refrigerant circuit, compares the degree of supercooling with a preset threshold value, and determines whether or not to raise the condensation temperature in the condenser.
A discharge pressure sensor that detects the discharge pressure of the compressor and
The first supercooler includes an outside air temperature sensor that detects the temperature of the outside air that exchanges heat with the refrigerant.
Wherein the control unit, wherein the discharge pressure sensor and the pressure detected with the temperature of the outside air temperature sensor detects and calculates the degree of supercooling, refrigerating cycle apparatus makes the determination. A fan for sending air for heat exchange with the refrigerant to the condenser is provided.
The refrigeration cycle apparatus according to claim 1 or 2 , wherein the control unit controls to lower the rotation speed of the fan and raises the condensation temperature. The refrigeration cycle apparatus according to any one of claims 1 to 3 , wherein the control unit controls to raise the drive frequency of the compressor and raises the condensation temperature. A refrigeration cycle device in which a compressor, a condenser, a liquid receiver, a first supercooler, a throttle device, and an evaporator are connected by a refrigerant pipe and have a refrigerant circuit for circulating a refrigerant containing a refrigerant having a temperature gradient. ,
A control unit that calculates the degree of supercooling in the refrigerant circuit, compares the degree of supercooling with a preset threshold value, and determines whether or not to raise the condensation temperature in the condenser.
The first heat exchanger and the second heat exchanger having different internal volumes, which are the condenser and the first supercooler,
A flow path switching device for switching the refrigerant passage order between the first heat exchanger and the second heat exchanger is provided.
The control unit, on the basis of the comparison of the supercooling degree and the threshold value, refrigeration cycle apparatus performs control for switching the flow switching device. A refrigeration cycle device in which a compressor, a condenser, a liquid receiver, a first supercooler, a throttle device, and an evaporator are connected by a refrigerant pipe and have a refrigerant circuit for circulating a refrigerant containing a refrigerant having a temperature gradient. ,
A control unit that calculates the degree of supercooling in the refrigerant circuit, compares the degree of supercooling with a preset threshold value, and determines whether or not to raise the condensation temperature in the condenser.
A supercooler outlet temperature sensor installed at the refrigerant outlet of the first supercooler to detect the temperature, and
A second supercooler that supercools the refrigerant by exchanging heat between the branched refrigerants.
A flow rate adjusting device that depressurizes one of the branched refrigerants and passes it through the second supercooler.
The flow rate adjusting device includes a reduced pressure refrigerant temperature sensor that detects the temperature of the reduced refrigerant.
Wherein the control unit, the temperature difference between supercooling outlet temperature sensor detects the temperature and the pressure reducing coolant temperature sensor and temperature detected is as the degree of supercooling, refrigerating cycle apparatus that performs the determination. The refrigeration cycle according to any one of claims 1 to 6 , further comprising an inter-refrigerant heat exchanger that exchanges heat between the refrigerant that has passed through the first supercooler and the refrigerant that has passed through the evaporator. apparatus. A refrigerating device including the refrigerating cycle device according to any one of claims 1 to 7.

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