JP6501878B2 - Air conditioner and operation control device - Google Patents

Description

  The present invention relates to an air conditioner that can divert existing piping and an operation control device that can control the air conditioner.

  Conventionally, as an air conditioner that can divert existing piping, for example, one that controls the operating frequency of a compressor, the opening degree of a pressure reducing device, etc. so that the pressure of the refrigerant in the existing piping does not exceed the withstand pressure reference value Are known (for example, Patent Document 1).

JP, 2002-162126, A

  However, in the air conditioner of Patent Document 1, the load capacity (operating capacity) of the indoor unit decreases during the cooling operation under an environment where the outside air temperature is higher than usual (hereinafter referred to as "high outside air temperature environment"). In this case, the pressure of the refrigerant in the existing piping is more likely to rise than in the normal cooling operation. Therefore, in the air conditioner of Patent Document 1, since the pressure of the refrigerant in the existing pipe increases the possibility of exceeding the pressure reference value, the frequency of the air conditioner abnormally stops due to the pressure abnormality increases, and the reliability of the air conditioner is increased. There is a problem that sex can not hold.

  The present invention has been made to solve the above-mentioned problems, and it is possible to suppress the pressure of the refrigerant of the existing piping to below the pressure resistance reference value even during the cooling operation under the high outside air temperature environment. An object of the present invention is to provide a conditioner and an operation control device.

In the air conditioner according to the present invention, a compressor, a heat source side heat exchanger, a pressure reducing device, and a load side heat exchanger are connected via a refrigerant pipe to circulate a refrigerant, and at least the heat source side heat exchanger is A refrigeration cycle that performs a cooling operation that functions as a radiator and the load-side heat exchanger functions as an evaporator; a heat source-side unit that accommodates the compressor, the heat source-side heat exchanger, and the pressure reducing device; accommodating the load side heat exchanger, comprising a plurality of load-side units which are connected to the heat source unit via the existing refrigerant piping, and a control device for controlling the refrigeration cycle, wherein the control device, the cooling operation Sometimes, when the outside air temperature of the outdoor air supplied to the heat source side heat exchanger exceeds the reference outside air temperature, and the total load capacity of the plurality of load side units decreases with time, the total load capacity is Fluctuation And adjusts the opening degree of the decompression device according to.

In the operation control device according to the present invention, the compressor housed in the heat source side unit, the heat source side heat exchanger, the pressure reducing device, and the plurality of loads connected to the heat source side unit via the existing refrigerant piping. The load side heat exchanger housed in the side unit is connected via a refrigerant pipe to circulate the refrigerant, and at least the heat source side heat exchanger functions as a radiator, and the load side heat exchanger is an evaporator Control an air conditioner provided with a refrigeration cycle for performing a cooling operation, and during the cooling operation, the outside air temperature of the outdoor air supplied to the heat source side heat exchanger exceeds a reference outside air temperature, and the plurality of loads In the case where the total load capacity of the side unit decreases with time, the opening degree of the pressure reducing device is adjusted in accordance with the fluctuation value of the total load capacity.

  According to the present invention, the opening degree of the heat source side pressure reducing device can be adjusted according to the reduction of the total load capacity of one or more load side units, so control is performed so that the pressure of the refrigerant of the existing piping becomes equal to or less it can. Therefore, according to the present invention, it is possible to provide a highly reliable air conditioner and operation control device capable of reducing the frequency at which the air conditioner abnormally stops due to pressure abnormality.

FIG. 2 is a schematic refrigerant circuit diagram showing an example of the air-conditioning apparatus 1 according to Embodiment 1 of the present invention. It is a flowchart which shows an example of the control processing at the time of air_conditionaing | cooling operation in the control apparatus 500 of the air conditioning apparatus 1 which concerns on Embodiment 1 of this invention. It is a flowchart which shows an example of the control processing at the time of air_conditionaing | cooling operation in the control apparatus 500 of the air conditioning apparatus 1 which concerns on Embodiment 2 of this invention.

Embodiment 1
An air conditioner 1 (refrigerating air conditioner) according to Embodiment 1 of the present invention will be described. FIG. 1 is a schematic refrigerant circuit diagram showing an example of the air conditioning apparatus 1 according to the first embodiment. In the following drawings including FIG. 1, the dimensional relationships and shapes of the respective constituent members may differ from actual ones.

  As shown in FIG. 1, the air conditioner 1 includes a heat source unit 100 (heat source unit) which is an outdoor unit, and a first load unit 200 a which is an indoor unit disposed in parallel to the heat source unit 100. And a second load side unit 200b. Between the heat source side unit 100 and the first load side unit 200a and the second load side unit 200b, a first extension refrigerant pipe 300 (liquid pipe) and a second extension refrigerant pipe 400 (gas It is connected by piping). Although two load side units are connected in FIG. 1, the number of connected load side units may be one, or three or more.

  The air conditioner 1 of the first embodiment includes a compressor 2, a heat source side heat exchanger 3, a heat source side pressure reducing device 4, a first load side pressure reducing device 5a and a second load side pressure reducing device 5b, a first The load side heat exchanger 6a and the second load side heat exchanger 6b, the refrigerant flow switching device 7, and a single system refrigeration cycle (refrigerant circuit) for circulating the refrigerant sequentially to the accumulator 8 are provided.

  The compressor 2 is a variable frequency fluid machine that is accommodated in the heat source side unit 100, compresses the sucked low-pressure refrigerant, and discharges it as a high-pressure refrigerant. The compressor 2 can use, for example, a scroll compressor whose rotational frequency is controlled by an inverter.

  The heat source side heat exchanger 3 (outdoor unit heat exchanger) is a heat exchanger that functions as a radiator (condenser) during cooling operation, and functions as an evaporator during heating operation, and is accommodated in the heat source side unit 100 There is. The heat source side heat exchanger 3 performs heat exchange between the refrigerant flowing inside the heat source side heat exchanger 3 and the outside air (for example, outdoor air) blown by the heat source side heat exchanger fan (not shown) Configured The heat source side heat exchanger 3 can be configured, for example, of a cross fin type fin-and-tube type heat exchanger composed of a heat transfer tube and a plurality of fins.

  The first heat source side refrigerant pipe 10 (outdoor machine liquid line) is accommodated in the heat source side unit 100, and one end portion is connected to the heat source side heat exchanger 3. The other end of the first heat source side refrigerant pipe 10 is a first extension refrigerant pipe connection valve 9 a (liquid operation valve) provided on the first heat source side refrigerant pipe 10, and is used as a first extension refrigerant. It is connected to the pipe 300. The first extension refrigerant pipe connection valve 9a is formed of, for example, a two-way valve such as a two-way solenoid valve capable of switching between opening and closing.

  The heat source side pressure reducing device 4 expands and reduces the pressure of the high pressure liquid refrigerant flowing from the heat source side heat exchanger 3 during the cooling operation, and causes the high pressure liquid refrigerant to flow into the first extended refrigerant pipe 300 which is an existing pipe. The heat source side pressure reducing device 4 is accommodated in the heat source side unit 100, and is provided in the first heat source side refrigerant pipe 10. The heat source side pressure reducing device 4 uses, for example, an electronic expansion valve such as a linear electronic expansion valve (LEV) whose opening degree can be adjusted in multiple stages or continuously, and is configured as an outdoor electronic expansion valve. During the heating operation, the heat source side pressure reducing device 4 further expands and decompresses the medium pressure liquid refrigerant or the two-phase refrigerant flowing from the first extended refrigerant pipe 300 into the first heat source side refrigerant pipe 10 to generate a heat source. It can be configured to flow into the side heat exchanger 3.

  The first load-side decompression device 5a and the second load-side decompression device 5b further expand and decompress the medium pressure liquid refrigerant or two-phase refrigerant flowing from the first extension refrigerant pipe 300 during the cooling operation, It is made to flow in into one load side heat exchanger 6a and the 2nd load side heat exchanger 6b, respectively. The first load-side pressure reducing device 5a is housed in the first load-side unit 200a, and the second load-side pressure-reducing device 5b is housed in the second load-side unit 200b. As the first load side pressure reducing device 5a and the second load side pressure reducing device 5b, for example, electronic expansion valves such as linear electronic expansion valves whose opening degree can be adjusted in multiple stages or continuously are used. Configured

  When the cooling operation and the heating operation in the first load unit 200a are stopped, the first load pressure reducing device 5a is adjusted to be closed. Similarly, when the cooling operation and the heating operation in the second load side unit 200b are stopped, the second load side pressure reducing device 5b is adjusted to be closed. Further, in the heating operation, the first load-side pressure reducing device 5a expands and reduces the pressure of the high-pressure liquid refrigerant flowing from the first load-side heat exchanger 6a to form a first extension refrigerant pipe which is an existing pipe. It can be configured to flow into 300. Similarly, in the heating operation, the second load-side pressure reducing device 5b expands and reduces the pressure of the high-pressure liquid refrigerant flowing in from the second load-side heat exchanger 6b to form a first extension refrigerant which is an existing pipe. It can be configured to flow into the pipe 300.

  The first load side heat exchanger 6a and the second load side heat exchanger 6b (outdoor unit heat exchanger) function as an evaporator during the cooling operation and function as a radiator during the heating operation. . The first load-side heat exchanger 6a and the second load-side heat exchanger 6b are, for example, refrigerant flowing inside the first load-side heat exchanger 6a and the second load-side heat exchanger 6b; Heat exchange with (for example, indoor air) is performed. The first load-side heat exchanger 6a and the second load-side heat exchanger 6b can be configured, for example, as a cross-fin-type fin-and-tube heat exchanger composed of a heat transfer tube and a plurality of fins. .

  The first load-side heat exchanger 6a is accommodated in the first load-side unit 200a, and the second load-side heat exchanger 6b is accommodated in the second load-side unit 200b. In the air conditioner 1 of the first embodiment, the first load side heat exchanger 6a and the second load side heat exchanger 6b are blown by air from the load side heat exchanger fan (not shown). It can be configured to supply ambient air.

  The refrigerant flow switching device 7 switches the flow direction of the refrigerant in the refrigeration cycle when switching between cooling operation and heating operation, and is accommodated in the heat source side unit 100. For example, a four-way valve is used as the refrigerant flow switching device 7.

  A fifth heat source side refrigerant pipe 18 is connected between the refrigerant flow path switching device 7 and the heat source side heat exchanger 3. A third heat source side refrigerant pipe 14 (an accumulator front pipe) is connected between the refrigerant flow switching device 7 and the refrigerant inlet of the accumulator 8. A fourth heat source side refrigerant pipe 16 is connected between the refrigerant flow switching device 7 and the discharge port of the compressor 2. The second heat source side refrigerant pipe 12 is connected between the refrigerant flow path switching device 7 and the second extension refrigerant pipe 400.

  In the refrigerant flow switching device 7, the refrigerant flows from the second heat source side refrigerant pipe 12 to the third heat source side refrigerant pipe 14 during the cooling operation, and the fourth heat source side refrigerant pipe 16 to the fifth heat source side refrigerant The refrigerant is configured to flow through the pipe 18. In the refrigerant flow switching device 7, the refrigerant flows from the fifth heat source side refrigerant pipe 18 to the third heat source side refrigerant pipe 14 in the heating operation, and from the fourth heat source side refrigerant pipe 16 to the second heat source side The refrigerant is configured to flow through the refrigerant pipe 12.

  The second heat source side refrigerant pipe 12, the third heat source side refrigerant pipe 14, the fourth heat source side refrigerant pipe 16, and the fifth heat source side refrigerant pipe 18 are accommodated in the heat source side unit 100. Further, the second heat source side refrigerant pipe 12 is connected to the second extension refrigerant pipe 400 by a second extension refrigerant pipe connection valve 9 b (gas operation valve) provided in the second heat source side refrigerant pipe 12. ing. The second extension refrigerant pipe connection valve 9 b is configured by, for example, a two-way valve such as a two-way solenoid valve capable of switching between opening and closing.

  The accumulator 8 has a refrigerant storage function for storing surplus refrigerant, and a gas / liquid that prevents a large amount of liquid refrigerant from flowing into the compressor 2 by retaining the liquid refrigerant that is temporarily generated when the operating state changes. And a separation function. The accumulator 8 is disposed on the suction pipe side of the compressor 2 and is accommodated in the heat source side unit 100.

  Next, the configuration of the bypass refrigerant circuit of the heat source side unit 100 provided in the air conditioning apparatus 1 according to Embodiment 1 will be described.

  The heat source side unit 100 is a bypass refrigerant pipe 20 (high and low pressure bypass pipe) branched from the first heat source side refrigerant pipe 10 at a position between the heat source side pressure reducing device 4 and the first extended refrigerant pipe connection valve 9a. Is equipped. The end of the bypass refrigerant pipe 20 is connected to the third heat source side refrigerant pipe 14 at a position between the refrigerant flow switching device 7 and the accumulator 8. That is, the bypass refrigerant pipe 20 is a first heat source side refrigerant pipe 10 which is a refrigerant pipe on the refrigerant outlet side of the heat source side pressure reducing device 4 and a third pipe which is a refrigerant pipe connected to the refrigerant inlet side of the accumulator 8. It is a refrigerant piping which bypasses between the heat source side refrigerant piping 14 of these.

  The bypass refrigerant pipe 20 is provided with a solenoid valve 25 which is a valve that opens or closes the flow path by power supply or power stop. The solenoid valve 25 causes the refrigerant flowing into the first heat source side refrigerant pipe 10 to flow into the accumulator 8. The first heat source side refrigerant pipe 10 has a capacity coefficient (CV value) capable of reducing the pressure of the high pressure or medium pressure refrigerant flowing into the first heat source side refrigerant pipe 10 to a low pressure. The solenoid valve 25 is configured by, for example, a two-way valve such as a two-way solenoid valve capable of switching between opening and closing.

  Next, sensors disposed in the air conditioner 1 according to Embodiment 1 will be described.

  The air conditioner 1 according to the first embodiment includes a first temperature sensor 30, a second temperature sensor 35a, a first pressure sensor 40, and a second pressure sensor 45.

  The first temperature sensor 30 is an outside air temperature sensor (outdoor temperature sensor) that detects the temperature of the outside air (outdoor air) sucked by the heat source side blower fan (not shown) and blown to the heat source side heat exchanger 3 is there. The first temperature sensor 30 is disposed, for example, on the upstream side of the heat source side blower fan (not shown). The second temperature sensor 35a is, for example, an indoor air sucked into the first load-side heat exchanger 6a by being sucked by a load-side blower fan (not shown) accommodated in the first load-side unit 200a. It can be an outside air temperature sensor (indoor unit suction temperature sensor) that detects the temperature. When the second temperature sensor 35a is configured as an outside air temperature sensor, the second temperature sensor 35a is disposed, for example, on the upstream side of the load-side blower fan (use-side blower). The third temperature sensor 35b is, for example, a room air that is sucked by a load-side blower fan (not shown) accommodated in the second load-side unit 200b and is blown to the second load-side heat exchanger 6b. It can be an outside air temperature sensor (indoor unit suction temperature sensor) that detects the temperature. When the third temperature sensor 35 b is configured as an outside air temperature sensor, the third temperature sensor 35 b is disposed, for example, on the upstream side of the load-side blower fan (use-side blower).

  The first pressure sensor 40 is a pressure sensor (intermediate pressure sensor) that detects the pressure P of the refrigerant flowing through the first heat source side refrigerant pipe 10 on the refrigerant outlet side of the heat source side pressure reducing device 4 during the cooling operation. . That is, the first pressure sensor 40 is disposed at a position of the first heat source side refrigerant pipe 10 between the heat source side pressure reducing device 4 and the first extension refrigerant pipe connection valve 9 a. The second pressure sensor 45 is a pressure sensor that detects the low pressure pressure of the joined refrigerant flowing out from the outlets of the first load side heat exchanger 6 a and the second load side heat exchanger 6 b during the cooling operation. (Low pressure pressure sensor) which detects the pressure of the refrigerant flowing out of the outlet of the heat source side heat exchanger 3 during heating operation. The second pressure sensor 45 is disposed in the third heat source side refrigerant pipe 14.

  As a material of the first temperature sensor 30, the second temperature sensor 35a, and the third temperature sensor 35b, a semiconductor (for example, a thermistor) or a metal (for example, a temperature measuring resistor) or the like is used. Further, as the first pressure sensor 40 and the second pressure sensor 45, a quartz crystal piezoelectric pressure sensor, a semiconductor sensor, a pressure transducer or the like is used. The first temperature sensor 30, the second temperature sensor 35a, and the third temperature sensor 35b may be made of the same material or different materials. The first pressure sensor 40 and the second pressure sensor 45 may be of the same type or may be of different types.

  Next, a control device 500 (operation control device) that controls the entire air conditioning apparatus 1 according to Embodiment 1 will be described.

  The control device 500 according to the first embodiment controls the operation state of the first load unit 200a and the first control unit 50 (the outdoor unit side control device) that controls the operation state of the heat source unit 100. A second control unit 55a (indoor unit control device) and a third control unit 55b (indoor unit control device) for controlling the operating state of the second load unit 200b are provided.

  The first control unit 50, the second control unit 55a, and the third control unit 55b each include a microcomputer including a CPU, a memory (for example, a ROM, a RAM, and the like), an I / O port, and the like. . The control device 500 connects the first control unit 50, the second control unit 55a, and the third control unit 55b with the communication line 58 to mutually communicate such as transmission and reception of control signals. Configured to be able to do. Communication between the first control unit 50 and the second control unit 55a and the third control unit 55b may be configured to be performed wirelessly.

  The first control unit 50 may, for example, start and stop the operation of the heat source side unit 100, adjust the opening degree of the heat source side pressure reducing device 4, open or close the solenoid valve 25, adjust the operating frequency of the compressor 2, etc. It is configured to be able to control the operating state. Further, the first control unit 50 is configured to have a storage unit (not shown) capable of storing various data such as a control target value. Further, the first control unit 50 receives an electrical signal of temperature information detected by the first temperature sensor 30, and an electrical signal of pressure information detected by the first pressure sensor 40 and the second pressure sensor 45. Configured as.

  The second control unit 55a is configured to control an operation state such as start and stop of operation of the first load side unit 200a and adjustment of the opening degree of the first load side pressure reducing device 5a. The second control unit 55a is configured to measure the load capacity Q1 (operating capacity) of the first load side unit 200a at predetermined intervals (for example, every one minute). The second control unit 55a is configured to receive an electrical signal of temperature information detected by the second temperature sensor 35a.

  The third control unit 55b is configured to control an operation state such as start and stop of operation of the second load side unit 200b, adjustment of the opening degree of the second load side pressure reducing device 5b, and the like. The third control unit 55b is configured to measure the load capacity Q2 of the second load-side unit 200b at predetermined intervals (for example, every one minute), and the second control unit 55a It is comprised so that the electrical signal of the temperature information detected by the temperature sensor 35b of 3 may be received.

The load capacity Q1 of the first load-side unit 200a measured by the second control unit 55a and the load capacity Q2 of the second load-side unit 200b measured by the third control unit 55b are the communication line 58. To the first control unit 50. In the first control unit 50, the total load capacity Q in the first load unit 200a and the second load unit 200b is calculated by the following equation (1), and stored in the storage unit of the first control unit 50. Be done.
Q = Q1 + Q2 (1)

  Next, an operation of the air conditioning apparatus 1 according to Embodiment 1 during normal cooling operation will be described.

  The high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the heat source side heat exchanger 3. The high-temperature and high-pressure gas refrigerant flowing into the heat source side heat exchanger 3 is subjected to heat exchange by releasing heat to a low-temperature medium such as outdoor air, and becomes a high-pressure liquid refrigerant. The high pressure liquid refrigerant is expanded and decompressed by the heat source side pressure reducing device 4 provided in the first heat source side refrigerant pipe 10 to become a medium pressure liquid refrigerant or a two-phase refrigerant, and passes through the first extension refrigerant pipe 300 Then, it flows into the heat source side unit 100.

  The medium pressure liquid refrigerant or two-phase refrigerant flowing into the heat source side unit 100 flows into the first load side pressure reducing device 5a and the second load side pressure reducing device 5b. The medium-pressure liquid refrigerant or two-phase refrigerant flowing into the first load-side pressure reducing device 5a and the second load-side pressure reducing device 5b is further expanded and reduced in pressure to become a low-temperature low-pressure two-phase refrigerant. The low-temperature low-pressure two-phase refrigerant flows into the first load-side heat exchanger 6a and the second load-side heat exchanger 6b, absorbs heat from a high-temperature medium such as indoor air, and evaporates to be dry. It becomes a high two-phase refrigerant or a low-temperature low-pressure gas refrigerant. The two-phase refrigerant having a high degree of dryness or the low-temperature low-pressure gas refrigerant flowing out of the first load-side heat exchanger 6a and the second load-side heat exchanger 6b is the second extended refrigerant pipe 400, the second heat source side It flows into the accumulator 8 via the refrigerant pipe 12, the refrigerant flow path switching device 7, and the third heat source side refrigerant pipe 14. The two-phase refrigerant having high dryness or the low-temperature low-pressure gas refrigerant is sucked into the compressor 2 after liquid phase components are removed by the accumulator 8. The refrigerant drawn into the compressor 2 is compressed to be a high-temperature, high-pressure gas refrigerant, and is discharged from the compressor 2. The high temperature / high pressure gas refrigerant discharged from the compressor 2 flows into the heat source side heat exchanger 3 via the fourth heat source side refrigerant piping 16, the refrigerant flow switching device 7, and the fifth heat source side refrigerant piping 18 Do. The above-described cycle is repeated in the cooling operation of the air conditioner 1.

  In the heating operation, the flow passage inside the refrigerant flow switching device 7 is switched from the solid flow passage to the dotted flow passage as shown in FIG. As a result, the high-temperature high-pressure gas refrigerant flows into the first load-side heat exchanger 6a and the second load-side heat exchanger 6b, and the heat is released to a low-temperature medium such as room air. Become. As a result, the indoor air is heated by the heat radiation of the refrigerant.

  Next, control processing in the control device 500 of the air-conditioning apparatus 1 according to Embodiment 1 will be described.

  The control device 500 of the air conditioner 1 according to the first embodiment is configured such that the outdoor air temperature of the outdoor air supplied to the heat source side heat exchanger 3 exceeds the reference outdoor air temperature during the cooling operation, and one or more load sides When the total load capacity Q of the units (the first load side unit 200a and the second load side unit 200b) decreases with time, the opening degree of the heat source side pressure reducing device 4 according to the fluctuation value of the total load capacity Q Configured to adjust.

  FIG. 2 is a flowchart showing an example of control processing during cooling operation in the control device 500 of the air conditioning apparatus 1 according to Embodiment 1. The control process of FIG. 2 may be performed constantly during the cooling operation, or may be performed as needed, for example, when a change in the outside air temperature T is detected.

  In step S11, the control device 500 determines whether the outside air temperature T detected by the first temperature sensor 30 is higher than the reference outside air temperature T0. The reference outside temperature T0 is set as a boundary value between the high outside temperature environment and the normal outside temperature environment, and is set to 52 ° C., for example. Here, the normal temperature environment means an outside air temperature environment in which the pressure of the refrigerant flowing through the existing pipe does not exceed the pressure resistance reference value due to the fluctuation of the total load capacity Q. If the outside air temperature T is less than or equal to the reference outside air temperature T0, the control process ends and the normal cooling operation is continued.

If the outside air temperature T is higher than the reference outdoor temperature T0, in step S12, the control device 500, the current in the current load capacity _{Q1 now} and second load-side unit 200b in the first load-side unit 200a load capacity _{Q2 now Is} calculated, and the present total load capacity Q _now is calculated by the following equation (2).
Q _now = Q1 _now + Q2 _now (2)

Next, in step S13, the control device 500 determines whether the current total load capacity Q _now is less than the latest total load capacity Q _last stored in the storage unit of the control device 500. If the current total load capacity Q _now is greater than or equal to the latest total load capacity Q _last , the control process ends and the normal cooling operation is continued.

If the current total load capacity Q _now is less than the latest total load capacity Q _last , in step S14, the opening degree adjustment value ΔD of the heat source side pressure reducing device 4 is calculated. The opening adjustment value ΔD is calculated using the correction coefficient K from the following equation (3).
ΔD = K × (Q _last −Q _now ) (3)

  Here, the correction coefficient K is, for example, the fluctuation value of the total load capacity Q, the fluctuation value of the pressure P detected by the first pressure sensor 40, and the opening adjustment value ΔD for canceling the fluctuation of the pressure P. It is a constant that is calculated and determined from the correlation of measured values.

  Next, in step S15, the control device 500 controls the opening degree D of the heat source side pressure reducing device 4 to open by the opening degree adjustment value ΔD, and the control process ends.

  Next, the effects of the present invention according to the first embodiment will be described.

  As described above, the air conditioner 1 according to the first embodiment includes the compressor 2, the heat source side heat exchanger 3, the pressure reducing device (the heat source side pressure reducing device 4), and the load side heat exchanger (first load side) Connecting the heat exchanger 6a and the second load-side heat exchanger 6b via a refrigerant pipe (for example, the first heat source side refrigerant pipe 10, the first extension refrigerant pipe 300, etc.) to circulate the refrigerant, At least a cooling operation in which the heat source side heat exchanger 3 functions as a radiator, and the load side heat exchangers (the first load side heat exchanger 6a and the second load side heat exchanger 6b) function as an evaporator. A heat source side unit 100 for accommodating the refrigeration cycle to be performed, the compressor 2, the heat source side heat exchanger 3, and the pressure reducing device (the heat source side pressure reducing device 4), and a load side heat exchanger (first load side heat exchanger 6a , Second load side heat exchanger 6b), existing refrigerant pipe (first extended refrigerant pipe) 00, one or more load side units (the first load side unit 200a, the second load side unit 200b) connected to the heat source side unit 100 via the second extension refrigerant pipe 400), and the refrigeration cycle are controlled Control unit 500, the outdoor temperature of the outdoor air supplied to the heat source side heat exchanger 3 exceeds the standard outside air temperature during the cooling operation, and one or more load side units (first Adjust the degree of opening of the pressure reducing device (heat source side pressure reducing device 4) according to the fluctuation value of the total load capacity when the total load capacity of the load side unit 200a and the second load side unit 200b) is reduced with time It is

  Further, the operation control apparatus (control apparatus 500) according to the first embodiment includes the compressor 2, the heat source side heat exchanger 3, and the pressure reducing device (the heat source side pressure reducing device 4) accommodated in the heat source side unit 100; One or more load side units (first load side unit 200a, second one) connected with the heat source side unit 100 via the existing refrigerant pipes (first extension refrigerant pipe 300, second extension refrigerant pipe 400) The load side heat exchanger (the first load side heat exchanger 6a, the second load side heat exchanger 6b) housed in the load side unit 200b) and the refrigerant pipe (for example, the first heat source side refrigerant pipe 10) , Through the first extension refrigerant pipe 300) to circulate the refrigerant, at least the heat source side heat exchanger 3 functions as a radiator, and the load side heat exchanger (first load side heat exchanger 6a, the second load side heat exchanger 6b) is an evaporator The air conditioner 1 is provided with a refrigeration cycle that performs a cooling operation that functions, and during the cooling operation, the outside air temperature of the outdoor air supplied to the heat source side heat exchanger 3 exceeds the reference outside air temperature, and one or more loads When the total load capacity of the side units (the first load side unit 200a and the second load side unit 200b) is reduced with time, the pressure reducing device (the heat source side pressure reducing device 4 according to the fluctuation value of the total load capacity To adjust the opening of).

  Conventionally, an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, an outdoor unit-side throttling device, and an accumulator, and an indoor unit including an indoor-side throttling device and an indoor heat exchanger are There is a refrigeration air conditioner which is connected and configured. In addition, in the conventional refrigeration air conditioning system, only the outdoor unit and the indoor unit are renewed at the time of renewal of the refrigeration air conditioning system, existing piping is diverted for gas piping and liquid piping, and existing piping (gas piping and liquid piping There is a model (an existing piping diversion model) that cleans and reuses).

  In the refrigeration air conditioning system before renewal, gas piping and liquid piping. In some cases, the pressure resistance is designed according to the refrigerant characteristics of the refrigerant having a low design pressure such as R22 or R407C. Moreover, in the refrigeration air conditioning system after updating, a refrigerant such as R410A having a design pressure higher than that of R22 or R407C may be used. Therefore, the refrigeration air conditioning system that diverts the existing piping has a configuration that can be controlled so that the pressure of the refrigerant flowing into the existing piping does not exceed the pressure resistance reference value of the gas piping and the liquid piping in the outdoor unit and the indoor unit. There is.

  For example, as a refrigerating air conditioner which diverts existing piping, a pressure sensor is attached to an outdoor unit liquid line, and there are some which detect pressure (intermediate pressure) of a refrigerant which flows into existing piping. In a refrigeration air conditioner using a pressure sensor, the refrigerant pressure detected by the pressure sensor is adjusted to a target value by adjusting the frequency of the compressor and the opening degree of the outdoor unit side throttle device attached to the outdoor unit liquid line. It is controlled to become (target intermediate pressure).

  In recent years, the environmental temperature at which the outdoor unit of the refrigeration air conditioner is installed tends to rise due to the progress of global warming or the heat island phenomenon in urban areas. In addition, the suction air temperature of the outdoor unit may rise due to a short circuit in which the blowout port and the suction port are blocked by centralized installation of the outdoor unit and the heat radiation from the outdoor unit is interrupted. Therefore, in the outdoor unit of the refrigeration air conditioning system, a configuration capable of widening the temperature of the outside air (outdoor air) available to the outdoor unit (for example, raising the allowable upper limit of the outside air temperature) is required.

  However, at the time of cooling operation under a high outside air temperature environment, the high pressure and the pressure of the refrigerant flowing into the existing piping rise, so the occurrence frequency of pressure abnormality of the refrigeration air conditioning system rises. On the other hand, when the load capacity of the indoor unit decreases during the cooling operation, the timing of deceleration of the compressor frequency is later than the timing of the reduction of the load capacity of the indoor unit, so the pressure of the refrigerant flowing into the existing piping rises Do. Therefore, when the load capacity of the indoor unit decreases during the cooling operation under the high outside air temperature environment, there is a problem that the pressure of the refrigerant flowing into the existing pipe is likely to exceed the pressure resistance reference value.

  For example, consider a refrigeration air conditioning system having five indoor units and five indoor units having the same load capacity. Here, the total load capacity in a state where all five indoor units are operating is assumed to be 100%. When the four indoor units are stopped from operating all five indoor units in the cooling operation under a high outside temperature environment, the total load capacity of the indoor units is 20%. In addition, when the four indoor units are stopped from the state where all the five indoor units are in operation, the electronic expansion valves of the stopped four indoor units are closed. Therefore, assuming that the refrigerant circulation amount in a state where all the five indoor units are operating is 100%, when the four indoor units are stopped, the refrigerant is maintained in order to maintain the pressure of the refrigerant flowing into the existing piping. It is necessary to slow down the compressor frequency so that the circulation rate is 20%. However, since the timing of deceleration of the compressor frequency is later than the timing of reduction of the load capacity of the indoor unit, the pressure of the refrigerant flowing into the existing pipe temporarily rises, and exceeds the pressure resistance reference value of the existing pipe. An anomaly will occur.

On the other hand, according to the configuration of the first embodiment, the opening degree of the heat source side pressure reducing device 4 can be controlled at the timing when the decrease of the load capacity is detected. That is, according to the configuration of the first embodiment, the opening degree of the heat source side pressure reducing device 4 can be adjusted according to the reduction of the total load capacity of one or more load side units. Therefore, according to the configuration of the first embodiment, it is possible to suppress the pressure of the refrigerant flowing through the existing pipe rising due to the reduction of the load capacity during the cooling operation under the high outside air temperature environment, and the pressure of the refrigerant flowing through the existing pipe There withstand reference value P0 (e.g., 29kg / cm ²⁾ can be controlled to be less. Therefore, according to the configuration of the first embodiment, the highly reliable air conditioner 1 and the control device 500 (operation control device) capable of reducing the frequency at which the air conditioner 1 abnormally stops due to pressure abnormality can be provided. be able to.

Second Embodiment
In the second embodiment of the present invention, an example of control processing of the solenoid valve 25 of the control device 500 according to the above-described first embodiment will be shown. FIG. 3 is a flowchart showing an example of control processing during cooling operation in the control device 500 of the air conditioning apparatus 1 according to the second embodiment.

  In the air conditioner 1 of the second embodiment, the control device 500 causes the pressure of the refrigerant flowing through the first heat source side refrigerant pipe 10 on the refrigerant outlet side of the heat source side pressure reducing device 4 to be the existing pipe during the cooling operation. When the pressure resistance reference value of the first extended refrigerant pipe 300 is exceeded, the solenoid valve 25 is configured to be opened for a certain period of time.

In step S21, in the control device 500, the pressure P of the refrigerant flowing through the first heat source side refrigerant pipe 10 on the refrigerant outlet side of the heat source side pressure reducing device 4 detected by the first pressure sensor 40 is the first It is determined whether the pressure resistance reference value P0 of the extended refrigerant piping 300 is exceeded. The pressure resistance reference value P0 is set to, for example, 29 kg / cm ² .

  If the pressure P exceeds the pressure reference value P0, the controller 500 opens the solenoid valve 25 in step S22.

  Next, in step S23, the control device 500 counts the time M during which the solenoid valve 25 is open, and determines whether a predetermined time M0 has elapsed. When the fixed time M0 has not passed, the open state of the solenoid valve 25 is maintained.

  Here, for example, when the control device 500 performs control to reduce the operating frequency of the compressor 2 to suppress the pressure P to the pressure reference value P0, the operating frequency of the reduced compressor 2 is stable. It can be time to become. For example, the fixed time M0 can be 60 seconds.

  After the predetermined time M0 has elapsed, in step S24, the control device 500 closes the solenoid valve 25 and ends the control process.

  As described above, in the air conditioner 1 according to the second embodiment, the heat source side unit 100 includes the accumulator 8 in which the heat source side unit 100 is disposed on the suction pipe side of the compressor 2 and the refrigerant flow of the pressure reducing device (the heat source side pressure reducing device 4). A bypass refrigerant pipe 20 for bypassing between the refrigerant pipe (first heat source side refrigerant pipe 10) on the outlet side and the refrigerant pipe (third heat source side refrigerant pipe 14) connected to the refrigerant inlet side of the accumulator 8 And the solenoid valve 25 provided in the bypass refrigerant pipe 20. The controller 500 controls the refrigerant pipe (first heat source side) of the refrigerant outlet side of the pressure reducing device (the heat source side pressure reducing device 4) during the cooling operation. When the pressure of the refrigerant flowing through the refrigerant pipe 10) exceeds the pressure reference value of the existing refrigerant pipe (the first extended refrigerant pipe 300), the solenoid valve 25 is opened for a certain period of time.

  The operation control apparatus (control apparatus 500) according to the second embodiment includes the accumulator 8 disposed on the suction pipe side of the compressor 2, and the refrigerant on the refrigerant outlet side of the pressure reducing device (the heat source side pressure reducing device 4). Bypass refrigerant piping 20 for bypassing between the piping (first heat source side refrigerant piping 10) and the refrigerant piping (third heat source side refrigerant piping 14) connected to the refrigerant inlet side of the accumulator 8 and bypass refrigerant The air conditioner 1 in which the heat source side unit 100 further accommodates the solenoid valve 25 provided in the pipe 20 is controlled, and the refrigerant pipe on the refrigerant outlet side of the pressure reducing device (the heat source side pressure reducing device 4) In the case where the pressure of the refrigerant flowing through the heat source side refrigerant pipe 10) in 1 exceeds the pressure resistance reference value of the existing refrigerant pipe (the first extended refrigerant pipe 300), the solenoid valve 25 is opened for a certain time. is there.

  According to the configuration of the second embodiment, the pressure of the refrigerant flowing through the first extended refrigerant pipe 300 can be reduced immediately by opening the solenoid valve 25, so that the air conditioner 1 and control with higher reliability can be achieved. A device 500 (operation control device) can be provided.

Other Embodiments
The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the above-described embodiment is not limited to the air conditioner 1 but can be used for a water heater or the like.

  Further, the above-described embodiments can be used in combination with each other.

  REFERENCE SIGNS LIST 1 air conditioner, 2 compressor, 3 heat source side heat exchanger, 4 heat source side pressure reducing device, 5 a first load side pressure reducing device, 5 b second load side pressure reducing device, 6 a first load side heat exchanger, 6b second load side heat exchanger, 7 refrigerant flow path switching device, 8 accumulator, 9a first extension refrigerant pipe connection valve, 9b second extension refrigerant pipe connection valve, 10 first heat source side refrigerant pipe, 12 Second heat source side refrigerant piping, 14 third heat source side refrigerant piping, 16 fourth heat source side refrigerant piping, 18 fifth heat source side refrigerant piping, 20 bypass refrigerant piping, 25 solenoid valve, 30 first temperature sensor , 35a second temperature sensor, 35b third temperature sensor, 40 first pressure sensor, 45 second pressure sensor, 50 first control unit, 55a second control unit, 55b third control unit, 58 communication lines, 100 heat Source side unit, 200a 1st load side unit, 200b 2nd load side unit, 300 1st extension refrigerant piping, 400 2nd extension refrigerant piping, 500 controller.

Claims (5)

A compressor, a heat source side heat exchanger, a pressure reducing device, and a load side heat exchanger are connected via a refrigerant pipe to circulate a refrigerant, and at least the heat source side heat exchanger functions as a radiator, the load side A refrigeration cycle for performing a cooling operation in which the heat exchanger functions as an evaporator;
A heat source side unit that accommodates the compressor, the heat source side heat exchanger, and the pressure reducing device;
Accommodating the load-side heat exchanger, a plurality of load-side units which are connected to the heat source unit via the existing refrigerant piping,
A controller for controlling the refrigeration cycle;
The controller is
When the outside air temperature of the outdoor air supplied to the heat source side heat exchanger exceeds the reference outside air temperature during the cooling operation, and the total load capacity of the plurality of load side units decreases with time, the total load An air conditioner, which adjusts an opening degree of the pressure reducing device according to a fluctuation value of a capacity. The heat source unit is
An accumulator disposed on the suction pipe side of the compressor;
A bypass refrigerant pipe that bypasses between a refrigerant pipe on a refrigerant outlet side of the pressure reducing device and a refrigerant pipe connected to the refrigerant inlet side of the accumulator;
And a solenoid valve provided on the bypass refrigerant pipe.
The controller is
In the cooling operation, when the pressure of the refrigerant flowing through the refrigerant pipe on the refrigerant outlet side of the pressure reducing device exceeds the pressure resistance reference value of the existing refrigerant pipe, the solenoid valve is opened for a certain period of time. The air conditioning apparatus according to Item 1. The fixed time is
When the control device performs control to reduce the operating frequency of the compressor and suppresses the pressure of the refrigerant to the pressure resistance reference value, the time until the reduced operating frequency of the compressor becomes stable state The air conditioner according to claim 2. Load-side heat exchangers accommodated in a plurality of load-side units connected to the heat source side unit through the compressor, the heat source side heat exchanger, the pressure reducing device, and the existing heat source side unit accommodated in the heat source side unit And a refrigerant pipe to circulate the refrigerant, and at least the heat source side heat exchanger functions as a radiator, and the load side heat exchanger functions as an evaporator. Control the air conditioner,
When the outside air temperature of the outdoor air supplied to the heat source side heat exchanger exceeds the reference outside air temperature during the cooling operation, and the total load capacity of the plurality of load side units decreases with time, the total load The operation control apparatus which adjusts the opening degree of the said pressure-reduction device according to the fluctuation value of a capacity | capacitance. An accumulator disposed on the suction pipe side of the compressor;
A bypass refrigerant pipe that bypasses between a refrigerant pipe on a refrigerant outlet side of the pressure reducing device and a refrigerant pipe connected to the refrigerant inlet side of the accumulator;
Controlling an air conditioner further including a solenoid valve provided in the bypass refrigerant pipe and the heat source unit;
The electromagnetic valve is opened for a certain period of time when the pressure of the refrigerant flowing through the refrigerant pipe on the refrigerant outlet side of the pressure reducing device exceeds the withstand pressure reference value of the existing refrigerant pipe during cooling operation. The operation control device described.

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