JPH05248722A - Refrigerant control device for multi-chamber type air conditioner - Google Patents

Abstract

PURPOSE:To assure a heating capability of an indoor unit being operated without having any relation with a length of a connecting pipe and temperature of surrounding air by a method wherein a degree of opening or closing of an electrical expansion valve corresponding to a stopped indoor unit is adjusted in response to a detected temperature of a saturation temperature sensor when a few number of heating devices are operated. CONSTITUTION:In the case that the surrounding air temperature is high, only an indoor unit 109 is operated to heat and a low pressure of a compressor 103 shows a high temperature, so that the detected temperature of a saturation temperature sensor 118 is also increased, a degree of opening of instruction for each of the electrical expansion valves 106 and 107 is made lower than that of a low pressure adjusting device 1 through an electrical expansion valve control device 113, a flow rate of refrigerant flowing in the indoor units 110 and 111 is reduced and then the heating capability of the indoor unit 109 is assured. As the low pressure is increased, the detected temperature of the saturation temperature sensor 118 is also increased, resulting in that when it reaches a value more than a specified value, the degree of opening of each of the electrical expansion valves 106 and 107 is reduced by the low pressure adjusting device 1, a flow rate of the refrigerant flowing in each of the indoor units 110 and 111 not being operated can be reduced and a heating capability of the indoor unit 109 can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant control device in a refrigeration cycle of a multi-room air conditioner.

[0002]

2. Description of the Related Art In recent years, multi-room type air conditioners tend to be multi-roomed and have long pipes, and fine refrigerant flow rate control is required for product efficiency and safety.

A circuit configuration of a refrigerant control device for a multi-room air conditioner of this type will be described with reference to FIG.

As shown in the figure, a compressor 10 driven by an inverter unit 102 inside an outdoor unit 101.
3, four-way valve 104 for switching the flow path of the refrigerant, the outdoor heat exchanger 105, the electrically driven expansion valve 106 of the throttle mechanism of the refrigerant, 10
7, 108 are provided, and the electric expansion valves 106, 10 are provided.
7 and 108 are indoor units 109, 110 and 1, respectively.
It corresponds to 11. The inverter unit 102 has an indoor unit 109 that outputs an operation signal through a signal line 112,
The compressor 103 is driven by the operation command from 110, 111, and the refrigerant discharged from the compressor 103 is the four-way valve 1
04, the outdoor heat exchanger 105 during cooling,
Also, during heating, the indoor units 109, 110, 111
And the electric expansion valves 106, 107 and 108 are condensed.
It is decompressed by the indoor unit 109, 1 during cooling.
10, 111, a refrigeration cycle in which heat is exchanged as evaporating action in the outdoor heat exchanger 105 during heating and returns to the compressor 103 is formed.

In the above structure, the indoor unit 10
When 9, 110 emits a driving signal, the indoor unit 10
The operation command from 9, 110 is transmitted to the inverter unit 102 and the electric expansion valve control device 113 through the signal line 112, the inverter unit 102 drives the compressor 103, and the electric expansion valve control device 113 is operated at regular intervals. In addition, the suction pipe 1 led out to the compressor 103 from the outlet pipe 114 of the outdoor heat exchanger 105 via the saturation temperature capillary tube 115.
The saturation temperature sensor 118 attached to the bypass pipe 117 connected to the 16 and the suction temperature sensor 119 attached to the suction pipe 116 are detected, and the entire refrigeration cycle is detected by the temperature difference between the temperature sensors 118 and 119. By detecting the degree of superheat of No. 1, and transmitting the opening / closing command to the electric expansion valves 108, 107 corresponding to the indoor units 109, 110 currently operating by the signal line 120,
The opening degree of the electric expansion valve 106 corresponding to the indoor unit 111 that does not emit an operation signal and is adjusted to a proper superheat degree is completely closed during cooling to close the flow of the refrigerant to the indoor unit 111 and close the indoor unit 111. When the electric expansion valve 106 is fully closed during heating, the high-pressure gas is confined in the indoor unit 111. Therefore, the high-pressure gas becomes a liquid refrigerant due to the ambient temperature and accumulates in the inner unit 111. In order to prevent a shortage of the refrigerant in the main refrigeration cycle due to this, the liquid refrigerant accumulated in the indoor unit 111 is recovered by slightly opening the electric expansion valve 106.

[0006]

In such a conventional refrigerant control device for a multi-room air conditioner, in the case of heating operation of only the indoor unit 109, for example, the indoor units 110, 111 that do not issue other operation commands and The liquid refrigerant collects in the connection pipes 122 and 123 of the indoor units 110 and 111, and the electric expansion valves 106 and 107 corresponding to the indoor units 110 and 111 are controlled by the electric expansion valve control device 113.
The liquid refrigerant that collects in the indoor units 110 and 111 and the connection pipes 122 and 123 is recovered by slightly opening the opening of the electric expansion valves 106 and 107, so that the connection pipes 121 and 122, If 123 is a long pipe and the outside air temperature is very low, the indoor unit 110 that is stopped,
The liquid refrigerant accumulated in 111 cannot be fully recovered, the amount of refrigerant flowing in the main refrigeration cycle is insufficient, the low pressure of the compressor 103 is reduced, and the electric expansion valve control device 113 operates in order to secure an appropriate degree of superheat. Indoor unit 1 emitting
Even when the opening degree of the electric expansion valve 108 corresponding to 09 is fully opened, the pressure and temperature of the outdoor heat exchanger 105 decrease due to the shortage of the refrigerant amount, and the heating capacity of the operating indoor unit 109 decreases drastically. After that, there was a problem that the defrosting operation was started. In addition, the electric expansion valves 106 and 107 that are stopped
When the opening degree of is set large, the length of the connecting pipe is short, and when the outside air temperature is high, the indoor unit 11 that is not in operation is
On the contrary, the flow rate of the refrigerant flowing through 0 and 111 will increase,
There is also a problem that the heating capacity of the operating indoor unit 109 is reduced.

The present invention is to solve the above problems, and suppresses the accumulation of liquid refrigerant in the stopped indoor unit and the connecting pipe due to the heating operation with long piping and low outside air temperature, thereby lowering the heating capacity of the operating indoor unit, and An object of the present invention is to provide a refrigerant control device that reduces unnecessary defrosting operation.

[0008]

In order to achieve the above object, a refrigerant control device for a multi-room air conditioner according to the present invention has an inverter-controlled compressor, a four-way valve, and an outdoor heat exchanger in an outdoor unit. An electric expansion valve for refrigerant decompression corresponding to each indoor unit, a suction pipe, and a bypass pipe connected between the suction pipe and the outdoor heat exchanger outlet pipe,
The bypass pipe is provided with a capillary tube for saturation temperature detection, and the suction pipe and the bypass pipe are connected to a suction temperature sensor and a saturation temperature sensor, respectively, to the indoor unit that is issuing the operation stop signal. The opening degree of the corresponding electric expansion valve can be changed by a low pressure adjusting device that detects the temperature detected by the saturation temperature sensor.

[0009]

According to the present invention, since the saturation temperature sensor detects the saturation temperature corresponding to the low pressure of the compressor with the above-described structure, the stopped indoor unit and the connecting pipe in the heating operation with long piping and low outside air temperature are connected. Since the temperature detected by the saturation temperature sensor drops extremely when the low-pressure pressure of the compressor drops due to the accumulation of water in the compressor, the opening degree of the electric expansion valve corresponding to the indoor unit stopped due to the temperature detected by the saturation temperature sensor Is further opened via the low pressure regulator to collect the accumulated liquid refrigerant, secure the refrigerant flow rate in the main refrigeration cycle, and increase the low pressure of the compressor to secure the heating capacity of the operating indoor unit. it can.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The same reference numerals as those used in the conventional example indicate the same items, and the description thereof will be omitted.

That is, as shown in the figure, the temperature detected by the saturation temperature sensor 118 is transmitted to the low pressure adjusting device 1 through the signal line 2, and the low pressure adjusting device 1 and the electric expansion valve control device 113 are connected by the signal line 3. There is.

In the above structure, the indoor unit 109,
If the connection pipes 121, 122, 123 connecting 110, 111 and the outdoor unit 101 are long pipes and the outside air temperature is low, if the indoor unit 109 is solely operated for heating, the indoor units 110, 111 and the connection pipes are connected. The liquid refrigerant collects in 122 and 123, and the compressor 103
When the low pressure decreases, the detection temperature of the saturation temperature sensor 118 that detects the saturation temperature of the low pressure of the compressor 103 is sent to the low pressure adjusting device 1 via the signal line 2, and the low pressure adjusting device 1 controls the electric expansion valve via the signal line 3. Output to the device 113, and the electric expansion valve control device 113 outputs the electric expansion valves 106, 1
The indoor unit 1 is output so that the opening degree of 07 is further opened.
The liquid refrigerant accumulated in 10, 111 and the connection pipes 122, 123 is recovered. In addition, the connection pipes 121, 122,
When 123 is constructed shortly and the outside air temperature is high, assuming that only the indoor unit 109 is operated as described above,
Since the low-pressure pressure of the compressor 103 is high, the temperature detected by the saturation temperature sensor 118 also becomes high, and the low-pressure adjusting device 1 causes the electric expansion valves 106, 10 to operate via the electric expansion valve control device 113.
The command opening to 7 becomes small and the indoor units 110, 11
The flow rate of the refrigerant flowing through No. 1 is reduced, and the heating capacity of the indoor unit 109 in the heating operation is secured. Further, when the low pressure rises, the temperature detected by the saturation temperature sensor 118 also rises, and when the temperature reaches a certain value or more, the opening degree of the electric expansion valves 106 and 107 is reduced by the low pressure adjusting device 1 so that the indoor unit that is not operating. It is possible to reduce the flow rate of the refrigerant flowing through 110 and 111 and increase the heating capacity of the operating indoor unit 109.

As described above, according to the refrigerant control device of the embodiment of the present invention, the opening degree of the other electric expansion valve corresponding to the stopped indoor unit is detected by the temperature detected by the saturation temperature sensor during the heating operation of a small number of units. By adjusting the, the low pressure of the compressor is not reduced, regardless of the length of the connecting pipe and the outside air temperature, and the refrigerant flow rate to the indoor unit that is not operating is not unnecessarily increased. Refrigerant control is possible.

[0014]

As is apparent from the above embodiments, according to the present invention, the opening / closing degree of the electric expansion valve corresponding to the stopped indoor unit is adjusted by the temperature detected by the saturation temperature sensor during the heating operation of a small number of units. Therefore, the length of the connection pipe and
It is possible to provide a refrigerant control device for a multi-room air conditioner that can ensure the heating capacity of an operating indoor unit regardless of the outside air temperature.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a refrigerant control device for a multi-room air conditioner according to an embodiment of the present invention.

FIG. 2 is a refrigeration cycle diagram of a conventional refrigerant control device for a multi-room air conditioner.

[Explanation of symbols]

 1 Low-pressure regulator 101 Outdoor unit 103 Compressor 104 Four-way valve 105 Outdoor heat exchanger 106 Electric expansion valve 107 Electric expansion valve 108 Electric expansion valve 109 Indoor unit 110 Indoor unit 111 Indoor unit 114 Outlet pipe 115 Capillary tube for saturation temperature 116 Suction Pipe 117 Bypass pipe 118 Saturation temperature sensor 119 Suction temperature sensor

Claims (1)

[Claims] 1. A compressor controlled by an inverter in an outdoor unit, a four-way valve, an outdoor heat exchanger, an electric expansion valve for decompressing a refrigerant corresponding to each indoor unit, a suction pipe, the suction pipe, and the suction pipe. A bypass pipe connected to the outdoor heat exchanger outlet pipe is provided, and the bypass pipe is provided with a capillary tube for saturation temperature detection, and the suction pipe and the bypass pipe respectively have a suction temperature sensor and a saturation temperature. A multi-chamber type air connected to a temperature sensor, and the opening degree of the electric expansion valve corresponding to the indoor unit issuing the operation stop signal is changed by a low pressure adjusting device that detects the temperature detected by the saturation temperature sensor. Refrigerant control device for air conditioner.