WO2016194098A1

WO2016194098A1 - Air-conditioning device and operation control device

Info

Publication number: WO2016194098A1
Application number: PCT/JP2015/065730
Authority: WO
Inventors: 周平水谷
Original assignee: 三菱電機株式会社
Priority date: 2015-06-01
Filing date: 2015-06-01
Publication date: 2016-12-08
Also published as: JPWO2016194098A1; CN107709887A; EP3306214A1; CN107709887B; JP6501878B2; EP3306214B1; EP3306214A4

Abstract

The air-conditioning device 1 according to the present invention is equipped with a control device 500 (operation control device). If, during a cooling operation, the outside air temperature of outdoor air supplied to a heat-source-side heat exchanger 3 exceeds a reference outside air temperature and the total load-carrying capacity of one or more load-side units (a first load-side unit 200a and a second load-side unit 200b) is reduced over time, the control device 500 (operation control device) adjusts the opening degree of a decompression device (heat-source-side decompression device 4) according to the variation of the total load-carrying capacity.

Description

Air conditioning apparatus and operation control apparatus

The present invention relates to an air conditioner capable of diverting existing piping and an operation control apparatus capable of controlling the air conditioner.

Conventionally, as an air conditioner capable of diverting existing piping, for example, an operation frequency of a compressor, an opening degree of a decompression device, etc. are controlled so that the pressure of the refrigerant in the existing piping does not exceed a pressure resistance reference value. Is 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 is reduced during cooling operation in an environment where the outside air temperature is higher than usual (hereinafter referred to as “high outside air temperature environment”). In this case, there is a high possibility that the pressure of the refrigerant in the existing piping will rise more than during normal cooling operation. Therefore, in the air conditioner of Patent Document 1, since the possibility that the refrigerant pressure in the existing pipe exceeds the pressure resistance reference value increases, the frequency of the air conditioner abnormally stopping due to pressure abnormality increases, and the reliability of the air conditioner is increased. There was a problem that sex could not be maintained.

The present invention has been made to solve the above-described problem, and is capable of suppressing the pressure of the refrigerant in the existing piping to less than the pressure resistance reference value even during a cooling operation in a high outside air temperature environment. It aims at providing a harmony device and an operation control device.

An air conditioner according to the present invention connects a compressor, a heat source side heat exchanger, a pressure reducing device, and a load side heat exchanger via a refrigerant pipe to circulate the refrigerant, and at least the heat source side heat exchanger includes A refrigeration cycle that functions as a radiator and performs a cooling operation in which the load-side heat exchanger functions as an evaporator, the compressor, the heat-source-side heat exchanger, and a heat-source-side unit that houses the decompression device, One or more load-side units that house a load-side heat exchanger and are connected to the heat source-side unit via an existing refrigerant pipe, and a control device that controls the refrigeration cycle, When the outdoor air temperature of the outdoor air supplied to the heat source side heat exchanger exceeds a reference outdoor air temperature during operation and the total load capacity of the one or more load side units decreases with time, the total load capacity And adjusts the opening degree of the pressure reducing device in accordance with a variation value.

Moreover, the operation control apparatus according to the present invention includes a compressor, a heat source side heat exchanger, and a decompression device housed in the heat source side unit, and one or more connected to the heat source side unit via an existing refrigerant pipe. A load side heat exchanger accommodated in the load side unit is connected via a refrigerant pipe to circulate the refrigerant. At least the heat source side heat exchanger functions as a radiator and the load side heat exchanger evaporates. Controlling an air conditioner including a refrigeration cycle that performs a cooling operation functioning as a cooler, and during the cooling operation, the outdoor air temperature of the outdoor air supplied to the heat source side heat exchanger exceeds a reference outdoor air temperature, and the one or more When the total load capacity of the load side unit decreases with time, the opening degree of the decompression device is adjusted according to the fluctuation value of the total load capacity.

According to the present invention, since 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, the pressure of the refrigerant in the existing pipe is controlled to be equal to or lower than the pressure resistance reference value. it can. Therefore, according to the present invention, it is possible to provide a highly reliable air conditioning apparatus and operation control apparatus that can reduce the frequency with which the air conditioning apparatus abnormally stops due to pressure abnormality.

It is a schematic refrigerant circuit diagram which shows an example 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 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 FIG.
An air conditioner 1 (refrigeration air conditioner) according to Embodiment 1 of the present invention will be described. FIG. 1 is a schematic refrigerant circuit diagram illustrating an example of the air-conditioning apparatus 1 according to Embodiment 1. In FIG. In the following drawings including FIG. 1, the dimensional relationship and shape of each component may be different from the actual one.

As shown in FIG. 1, the air conditioner 1 includes a heat source side unit 100 (heat source unit) that is an outdoor unit, a first load side unit 200a that is an indoor unit arranged in parallel to the heat source side unit 100, and 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 extended refrigerant pipe 300 (liquid pipe) and a second extended refrigerant pipe 400 (gas) which are existing pipes are provided. Connected by piping). In FIG. 1, two load-side units are connected, but the number of load-side units connected may be one or three or more.

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

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

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. Yes. 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 a heat source side heat exchanger fan (not shown). Configured. The heat source side heat exchanger 3 can be constituted by, for example, a cross fin type fin-and-tube heat exchanger constituted by a heat transfer tube and a plurality of fins.

The first heat source side refrigerant pipe 10 (outdoor unit liquid line) is accommodated in the heat source side unit 100, and one end is connected to the heat source side heat exchanger 3. The other end portion of the first heat source side refrigerant pipe 10 is a first extended refrigerant pipe connection valve 9a (liquid operation valve) provided on the first heat source side refrigerant pipe 10, and the first extended refrigerant. It is connected to the pipe 300. The first extended refrigerant pipe connection valve 9a is composed of, for example, a two-way valve such as a two-way solenoid valve that can be switched between open and closed.

The heat source side decompression device 4 expands and decompresses the high-pressure liquid refrigerant flowing from the heat source side heat exchanger 3 during the cooling operation, and flows it into the first extended refrigerant pipe 300 which is an existing pipe. The heat source side decompression device 4 is accommodated in the heat source side unit 100 and is provided in the first heat source side refrigerant pipe 10. 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 can be used as the heat source side pressure reducing device 4 and is configured as an outdoor electronic expansion valve. In the heating operation, the heat source side decompression 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, 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 extended refrigerant pipe 300 during the cooling operation, It is made to flow in 1 load side heat exchanger 6a and 2nd load side heat exchanger 6b, respectively. The first load-side decompression device 5a is accommodated in the first load-side unit 200a, and the second load-side decompression device 5b is accommodated in the second load-side unit 200b. The first load-side pressure reducing device 5a and the second load-side pressure reducing device 5b are, for example, electronic expansion valves such as linear electronic expansion valves whose opening degree can be adjusted in multiple stages or continuously, and are used as indoor electronic expansion valves. Composed.

In addition, when the cooling operation and the heating operation in the first load side unit 200a are stopped, the first load side 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. In addition, the first load-side decompression device 5a expands and decompresses the high-pressure liquid refrigerant flowing from the first load-side heat exchanger 6a during the heating operation, and the first extended refrigerant pipe that is an existing pipe. It can be configured to flow into 300. Similarly, during the heating operation, the second load-side decompression device 5b expands and decompresses the high-pressure liquid refrigerant flowing from the second load-side heat exchanger 6b, and is a first extended refrigerant that 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) are heat exchangers that function as an evaporator during cooling operation and function as a radiator during heating operation. . The first load side heat exchanger 6a and the second load side heat exchanger 6b are, for example, a refrigerant flowing inside the first load side heat exchanger 6a and the second load side heat exchanger 6b, and the outside air It is configured to exchange heat with (for example, room air). The 1st load side heat exchanger 6a and the 2nd load side heat exchanger 6b can be constituted as a fin and tube type heat exchanger of the cross fin type constituted by a heat exchanger tube and a plurality of fins, for example. .

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. Moreover, in the air conditioning apparatus 1 according to the first embodiment, the first load side heat exchanger 6a and the second load side heat exchanger 6b are blown by air from a fan for load side heat exchanger (not shown). It can be configured to supply outside air.

The refrigerant flow switching device 7 switches the refrigerant flow direction in the refrigeration cycle when switching between the cooling operation and the heating operation, and is accommodated in the heat source 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 switching device 7 and the heat source side heat exchanger 3. A third heat source side refrigerant pipe 14 (pipe before the accumulator) 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. A second heat source side refrigerant pipe 12 is connected between the refrigerant flow switching device 7 and the second extended refrigerant pipe 400.

During the cooling operation, the refrigerant flow switching device 7 causes the refrigerant to flow from the second heat source side refrigerant pipe 12 to the third heat source side refrigerant pipe 14, and from 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. Further, in the heating operation, the refrigerant flow switching device 7 causes the refrigerant to flow from the fifth heat source side refrigerant pipe 18 to the third heat source side refrigerant pipe 14, 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. The second heat source side refrigerant pipe 12 is connected to the second extended refrigerant pipe 400 by a second extended refrigerant pipe connection valve 9b (gas operation valve) provided in the second heat source side refrigerant pipe 12. ing. The second extended refrigerant pipe connection valve 9b is composed of, for example, a two-way valve such as a two-way solenoid valve that can be switched between open and closed.

The accumulator 8 is a gas / liquid that prevents a large amount of liquid refrigerant from flowing into the compressor 2 by retaining a refrigerant storage function that stores excess refrigerant and liquid refrigerant that is temporarily generated when the operating state changes. It has 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 / 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. It has. 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 that is a refrigerant pipe on the refrigerant outlet side of the heat source side decompression device 4 and a refrigerant pipe that is connected to the refrigerant inlet side of the accumulator 8. This is a refrigerant pipe that bypasses the heat source side refrigerant pipe 14.

The bypass refrigerant pipe 20 is provided with an electromagnetic valve 25 that is a valve that opens or closes the flow path when power is supplied or stopped. The solenoid valve 25 causes the refrigerant that has flowed into the first heat source side refrigerant pipe 10 to flow into the accumulator 8. It has a capacity coefficient (CV value) that can reduce 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 electromagnetic valve 25 is configured by a two-way valve such as a two-way electromagnetic valve capable of switching between opening and closing, for example.

Next, the sensor arranged 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) that is sucked by a heat source side fan (not shown) and blown to the heat source side heat exchanger 3. is there. The 1st temperature sensor 30 is arrange | positioned, for example in the upstream of the heat-source side ventilation fan (not shown). For example, the second temperature sensor 35a is sucked in by a load-side blower fan (not shown) housed in the first load-side unit 200a and is sent to the first load-side heat exchanger 6a. It can be an outside air temperature sensor (indoor unit intake temperature sensor) that detects the temperature. When the 2nd temperature sensor 35a is comprised as an outside temperature sensor, the 2nd temperature sensor 35a is arrange | positioned at the upstream of a load side ventilation fan (use side air blower), for example. For example, the third temperature sensor 35b is sucked in by a load-side fan (not shown) housed in the second load-side unit 200b and is sent to the second load-side heat exchanger 6b. It can be an outside air temperature sensor (indoor unit intake temperature sensor) that detects the temperature. When the 3rd temperature sensor 35b is comprised as an outside temperature sensor, the 3rd temperature sensor 35b is arrange | positioned, for example in the upstream of a load side ventilation fan (use side air 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 decompression 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 extended refrigerant pipe connection valve 9a. During the cooling operation, the second pressure sensor 45 flows out from the outlets of the first load side heat exchanger 6a and the second load side heat exchanger 6b and detects the low pressure of the merged refrigerant. It is a (low pressure sensor) and detects the pressure of the refrigerant flowing out from 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 resistance temperature detector) is used. Further, as the first pressure sensor 40 and the second pressure sensor 45, a crystal piezoelectric pressure sensor, a semiconductor sensor, a pressure transducer, or the like is used. In addition, the 1st temperature sensor 30, the 2nd temperature sensor 35a, and the 3rd temperature sensor 35b may be comprised with the same material, and may be comprised with a different material. Also, the first pressure sensor 40 and the second pressure sensor 45 may be made of the same type or different types.

Next, a control device 500 (operation control device) that performs overall control of the 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 control unit 50 (outdoor unit side control device) that controls the operation state of the heat source side unit 100 and the first load side unit 200a. A second control unit 55a (indoor unit side control device) and a third control unit 55b (indoor unit side control device) that controls the operating state of the second load side unit 200b are provided.

The first control unit 50, the second control unit 55a, and the third control unit 55b include a microcomputer that includes a CPU, a memory (eg, ROM, RAM, etc.), 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 a communication line 58 to communicate with each other such as transmission and reception of control signals. Configured to be able to do. Note that communication between the first control unit 50 and the second control unit 55a and the third control unit 55b may be performed wirelessly.

For example, the first control unit 50 starts and stops the operation of the heat source side unit 100, adjusts the opening degree of the heat source side decompression device 4, opens or closes the electromagnetic valve 25, adjusts the operation frequency of the compressor 2, and the like. It is configured to be able to control the operating state. The first control unit 50 is configured to have a storage unit (not shown) that can store various data such as a control target value. The first control unit 50 also 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 follows.

The second control unit 55a is configured to control operation states such as start and stop of the operation of the first load-side unit 200a and adjustment of the opening degree of the first load-side decompression 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 a predetermined interval (for example, every 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 the operation state such as the start and stop of the operation of the second load side unit 200b and the adjustment of the opening degree of the second load side decompression device 5b. The third control unit 55b is configured to measure the load capacity Q2 of the second load-side unit 200b at a predetermined interval (for example, every 1 minute), and the second control unit 55a 3 is configured to receive an electrical signal of temperature information detected by the temperature sensor 35b.

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. Is transmitted to the first control unit 50 via. In the first control unit 50, the total load capacity Q in the first load side unit 200 a and the second load side unit 200 b is calculated by the following formula (1) and stored in the storage unit of the first control unit 50. Is done.
Q = Q1 + Q2 (1)

Next, the operation during normal cooling operation of the air-conditioning apparatus 1 according to Embodiment 1 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 that has flowed into the heat source side heat exchanger 3 is heat-exchanged 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 depressurized by the heat source-side decompression 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 extended refrigerant pipe 300. Then, it flows into the heat source side unit 100.

The medium-pressure liquid refrigerant or two-phase refrigerant that has flowed into the heat source side unit 100 flows into the first load-side decompression device 5a and the second load-side decompression device 5b. The medium-pressure liquid refrigerant or two-phase refrigerant flowing into the first load-side decompression device 5a and the second load-side decompression device 5b is further expanded and decompressed to become a low-temperature and low-pressure two-phase refrigerant. The low-temperature and 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 room air, and evaporates to dryness. It becomes a high two-phase refrigerant or a low-temperature and low-pressure gas refrigerant. The two-phase refrigerant having a high dryness or the low-temperature and low-pressure gas refrigerant that has flowed out of the first load-side heat exchanger 6a and the second load-side heat exchanger 6b is supplied to the second extended refrigerant pipe 400, the second heat source side. The refrigerant flows into the accumulator 8 via the refrigerant pipe 12, the refrigerant flow switching device 7, and the third heat source side refrigerant pipe 14. The two-phase refrigerant having a high degree of dryness or the low-temperature and low-pressure gas refrigerant is sucked into the compressor 2 after the liquid phase component is removed by the accumulator 8. The refrigerant sucked into the compressor 2 is compressed to become a high-temperature and high-pressure gas refrigerant and is discharged from the compressor 2. The high-temperature and 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 pipe 16, the refrigerant flow switching device 7, and the fifth heat source side refrigerant pipe 18. To do. In the cooling operation of the air conditioner 1, the above cycle is repeated.

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

Next, the control process 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-conditioning apparatus 1 according to Embodiment 1 is configured such that the outdoor air temperature supplied to the heat source side heat exchanger 3 exceeds the reference outdoor air temperature during 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 all the time during the cooling operation, or may be performed at any time when a change in the outside air temperature T is detected, for example.

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

When the outside air temperature T exceeds the reference outside air temperature T0, in step S12, the control device 500 causes the current load capacity Q1 _now in the first load side unit 200a and the current load capacity Q2 _now in the second load side unit 200b. And the current total load capacity _Qnow is calculated by the following equation (2).
Q _now = Q1 _now + Q2 _now (2)

Next, in step S <_b> 13, the control device 500 determines whether or not 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 apparatus 500. When the current total load capacity Q _now is equal to or greater than the latest total load capacity Q _last , the control process is terminated and normal cooling operation is continued.

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

Here, the correction coefficient K is, for example, a fluctuation value of the total load capacity Q, a fluctuation value of the pressure P detected by the first pressure sensor 40, and an 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 D of the heat source side decompression device 4 to be opened by the opening adjustment value ΔD, and the control process ends.

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

As described above, the air-conditioning apparatus 1 according to Embodiment 1 includes the compressor 2, the heat source side heat exchanger 3, the pressure reducing device (heat source side pressure reducing device 4), and the load side heat exchanger (first load side). The heat exchanger 6a and the second load side heat exchanger 6b) are connected via a refrigerant pipe (for example, the first heat source side refrigerant pipe 10, the first extended refrigerant pipe 300, etc.) to circulate the refrigerant, At least cooling operation in which the heat source side heat exchanger 3 functions as a radiator and the load side heat exchanger (the first load side heat exchanger 6a and the second load side heat exchanger 6b) functions as an evaporator. The refrigeration cycle to be performed, the compressor 2, the heat source side heat exchanger 3, the heat source side unit 100 housing the pressure reducing device (heat source side pressure reducing device 4), and the load side heat exchanger (first load side heat exchanger 6a). , The second load-side heat exchanger 6b), and the existing refrigerant pipe (the first extended refrigerant distribution). 300, one or more load side units (first load side unit 200a, second load side unit 200b) connected to the heat source side unit 100 via the second extended refrigerant pipe 400) and the refrigeration cycle are controlled. The control device 500 includes a control device 500 for controlling the outdoor air temperature of the outdoor air supplied to the heat source side heat exchanger 3 during the cooling operation to exceed a reference outdoor air temperature, and one or more load side units (first When the total load capacity of the load side unit 200a and the second load side unit 200b) decreases with time, the opening degree of the decompression device (heat source side decompression device 4) is adjusted according to the fluctuation value of the total load capacity To do.

The operation control device (control device 500) according to the first embodiment includes a compressor 2, a heat source side heat exchanger 3, and a pressure reducing device (heat source side pressure reducing device 4) housed in the heat source side unit 100. One or more load-side units (first load-side unit 200a, second load) connected to the heat-source-side unit 100 via existing refrigerant pipes (first extended refrigerant pipe 300, second extended refrigerant pipe 400) The load side heat exchanger (first load side heat exchanger 6a, second load side heat exchanger 6b) accommodated in the load side unit 200b) is connected to a refrigerant pipe (for example, the first heat source side refrigerant pipe 10). The first extended refrigerant pipe 300 or the like) 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) And controlling the air conditioner 1 having a refrigeration cycle that performs a cooling operation that functions as the outside air temperature of the outdoor air supplied to the heat source side heat exchanger 3 during the cooling operation exceeds the reference outside air temperature, and one or more When the total load capacity of the load 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) according to the fluctuation value of the total load capacity. The opening degree of 4) is adjusted.

Conventionally, an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, an outdoor unit side throttle device, and an accumulator, and an indoor unit including an indoor side throttle unit and an indoor heat exchanger are connected by gas piping and liquid piping. There is a refrigeration air conditioner that is connected and configured. In addition, in the conventional refrigeration air conditioner, when the refrigeration air conditioner is updated, only the outdoor unit and the indoor unit are updated, and the existing piping (gas piping and liquid piping) is used for the gas piping and liquid piping. ) Is cleaned and reused (existing piping diversion model).

In the refrigeration air conditioner before renewal, gas and liquid piping are not used. The pressure resistance may be designed in accordance with the refrigerant characteristics of a refrigerant having a low design pressure such as R22 or R407C. In the refrigerating and air-conditioning apparatus after the update, a refrigerant such as R410A having a higher design pressure than R22 or R407C may be used. Therefore, the refrigeration air conditioner that diverts 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 liquid piping in the outdoor unit and indoor unit. Yes.

For example, as a refrigerating and air-conditioning apparatus that diverts existing piping, there is one that attaches a pressure sensor to an outdoor unit liquid line and detects the pressure (intermediate pressure) of refrigerant flowing into the existing piping. In a refrigeration air conditioner using a pressure sensor, the refrigerant pressure detected by the pressure sensor is adjusted to the 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. (Target intermediate pressure) is controlled.

Recently, due to the progress of global warming or the urban heat island phenomenon, the environmental temperature where the outdoor unit of the refrigeration air conditioner is installed tends to increase. Further, the intake air temperature of the outdoor unit may rise due to a short circuit in which the outlet and the suction port are blocked due to the concentrated installation of the outdoor unit and the heat radiation from the outdoor unit is blocked. Therefore, the outdoor unit of the refrigeration air conditioner is required to have a configuration capable of widening the temperature of the outside air (outdoor air) that can be used by the outdoor unit (for example, increasing the allowable upper limit value of the outside air temperature).

However, during the cooling operation in a high outside air temperature environment, the high pressure and the pressure of the refrigerant flowing into the existing pipes increase, so the frequency of occurrence of pressure abnormalities in the refrigeration air conditioner increases. On the other hand, when the load capacity of the indoor unit decreases during the cooling operation, the pressure of the refrigerant flowing into the existing pipe rises because the timing of deceleration of the compressor frequency is delayed from the timing of decrease of the load capacity of the indoor unit To do. Therefore, when the load capacity of the indoor unit is reduced during the cooling operation under a high outside air temperature environment, there is a problem that the possibility that the pressure of the refrigerant flowing into the existing pipe exceeds the pressure resistance reference value is increased.

For example, consider a refrigeration / air-conditioning apparatus having five indoor units connected and having five indoor units with the same load capacity. Here, the total load capacity in a state where all five indoor units are in operation is 100%. When four indoor units are stopped from a state in which all five indoor units are operated during a cooling operation under a high outside air temperature environment, the total load capacity of the indoor units is 20%. Moreover, when four indoor units stop from the state in which all five indoor units are in operation, the electronic expansion valves of the four stopped indoor units are closed. Therefore, assuming that the refrigerant circulation amount in a state in which all five indoor units are in operation is 100%, the refrigerant pressure that flows into the existing piping is maintained when the four indoor units are stopped. It is necessary to decelerate the compressor frequency so that the circulation amount becomes 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 piping temporarily rises, exceeds the pressure resistance reference value of the existing piping, Abnormality will occur.

On the other hand, according to the structure of this Embodiment 1, the opening degree of the heat-source side decompression device 4 can be controlled at the timing which detected the reduction | decrease of load capacity. That is, according to the configuration of the first embodiment, the opening degree of the heat source side decompression 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 an increase in the pressure of the refrigerant flowing through the existing pipe due to the reduction of the load capacity during the cooling operation in a high outside air temperature environment, and the pressure of the refrigerant flowing through the existing pipe Can be controlled to be equal to or lower than the withstand voltage reference value P0 (for example, 29 kg / cm ² ). Therefore, according to the configuration of the first embodiment, it is possible to provide a highly reliable air conditioner 1 and control device 500 (operation control device) that can reduce the frequency with which the air conditioner 1 abnormally stops due to pressure abnormality. be able to.

Embodiment 2. FIG.
In the second embodiment of the present invention, an example of the control process of the electromagnetic valve 25 of the control device 500 according to the above-described first embodiment will be described. FIG. 3 is a flowchart illustrating an example of a control process during cooling operation in the control device 500 of the air-conditioning apparatus 1 according to Embodiment 2.

In the air conditioner 1 according to the second embodiment, the control device 500 is configured so that 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 decompression apparatus 4 is the existing pipe during the cooling operation. When the pressure resistance reference value of a certain first extended refrigerant pipe 300 is exceeded, the electromagnetic valve 25 is configured to be opened for a certain 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 decompression device 4 detected by the first pressure sensor 40 is the first pressure sensor 40. It is determined whether or not the pressure resistance reference value P0 of the extended refrigerant pipe 300 is exceeded. The pressure resistance reference value P0 is set to 29 kg / cm ² , for example.

When the pressure P exceeds the pressure resistance reference value P0, the control device 500 opens the electromagnetic valve 25 in step S22.

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

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

After a predetermined time M0 has elapsed, in step S24, the control device 500 closes the electromagnetic 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 disposed on the suction pipe side of the compressor 2 and the refrigerant flow of the decompression device (heat source side decompression device 4). Bypass refrigerant pipe 20 that bypasses between the refrigerant pipe on the outlet side (first heat source side refrigerant pipe 10) and the refrigerant pipe (third heat source side refrigerant pipe 14) connected to the refrigerant inlet side of the accumulator 8. And a solenoid valve 25 provided in the bypass refrigerant pipe 20, and the control device 500 has a refrigerant pipe (first heat source side) on the refrigerant outlet side of the pressure reducing apparatus (heat source side pressure reducing apparatus 4) during the cooling operation. When the pressure of the refrigerant flowing through the refrigerant pipe 10) exceeds the pressure resistance reference value of the existing refrigerant pipe (first extended refrigerant pipe 300), the electromagnetic valve 25 is opened for a certain period of time.

Further, the operation control device (control device 500) according to the second embodiment includes an accumulator 8 disposed on the suction pipe side of the compressor 2 and a refrigerant on the refrigerant outlet side of the decompression device (heat source side decompression device 4). A bypass refrigerant pipe 20 that bypasses between the pipe (first heat source side refrigerant pipe 10) and a refrigerant pipe (third heat source side refrigerant pipe 14) connected to the refrigerant inlet side of the accumulator 8, and a bypass refrigerant The air conditioner 1 that further accommodates the electromagnetic valve 25 provided in the pipe 20 in the heat source side unit 100 is controlled, and the refrigerant pipe (first pipe) on the refrigerant outlet side of the pressure reducing apparatus (heat source side pressure reducing apparatus 4) during cooling operation. When the pressure of the refrigerant flowing through the first heat source side refrigerant pipe 10) exceeds the pressure resistance reference value of the existing refrigerant pipe (first extended refrigerant pipe 300), the electromagnetic valve 25 is opened for a certain period of time. is there.

According to the configuration of the second embodiment, since the pressure of the refrigerant flowing through the first extended refrigerant pipe 300 can be immediately reduced by opening the electromagnetic valve 25, the air conditioner 1 and the 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 can be made. For example, the above-described embodiment is not limited to the air conditioner 1 and can be used for a water heater or the like.

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

1 air conditioner, 2 compressor, 3 heat source side heat exchanger, 4 heat source side pressure reducing device, 5a first load side pressure reducing device, 5b second load side pressure reducing device, 6a first load side heat exchanger, 6b second load side heat exchanger, 7 refrigerant flow switching device, 8 accumulator, 9a first extended refrigerant pipe connection valve, 9b second extended refrigerant pipe connection valve, 10 first heat source side refrigerant pipe, 12 2nd heat source side refrigerant pipe, 14 3rd heat source side refrigerant pipe, 16 4th heat source side refrigerant pipe, 18 5th heat source side refrigerant pipe, 20 bypass refrigerant pipe, 25 solenoid valve, 30 1st 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, 5 Communication lines, 100 heat-source side unit, 200a first load unit, 200b second load unit, 300 first extension refrigerant pipe, 400 second extension refrigerant pipe, 500 controller.

Claims

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 the refrigerant, at least the heat source side heat exchanger functions as a radiator, and the load side A refrigeration cycle that performs cooling operation in which the heat exchanger functions as an evaporator, and
A heat source side unit that houses the compressor, the heat source side heat exchanger, and the pressure reducing device;
One or more load side units that house the load side heat exchanger and are connected to the heat source side unit via an existing refrigerant pipe;
A control device for controlling the refrigeration cycle,
The controller is
In the cooling operation, when the outside air temperature of the outdoor air supplied to the heat source side heat exchanger exceeds a reference outside air temperature, and the total load capacity of the one or more load side units decreases with time, the total An air conditioner that adjusts the opening of the decompression device in accordance with a fluctuation value of a load capacity.
The heat source unit is
An accumulator disposed on the suction pipe side of the compressor;
A bypass refrigerant pipe that bypasses between the refrigerant pipe on the refrigerant outlet side of the decompressor and the refrigerant pipe connected to the refrigerant inlet side of the accumulator;
A solenoid valve provided in the bypass refrigerant pipe;
The controller is
During cooling operation, when the pressure of the refrigerant flowing through the refrigerant pipe on the refrigerant outlet side of the decompression device exceeds the pressure resistance reference value of the existing refrigerant pipe, the electromagnetic valve is opened for a certain period of time. Item 2. The air conditioner according to Item 1.
A compressor, a heat source side heat exchanger, and a decompression device housed in the heat source side unit, and a load side heat exchange housed in one or more load side units connected to the heat source side unit via an existing refrigerant pipe A refrigerating cycle for performing a cooling operation in which 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 equipped,
In the cooling operation, when the outside air temperature of the outdoor air supplied to the heat source side heat exchanger exceeds a reference outside air temperature, and the total load capacity of the one or more load side units decreases with time, the total An operation control device that adjusts an opening degree of the pressure reducing device in accordance with a fluctuation value of a load capacity.
An accumulator disposed on the suction pipe side of the compressor;
A bypass refrigerant pipe that bypasses between the refrigerant pipe on the refrigerant outlet side of the decompressor and the refrigerant pipe connected to the refrigerant inlet side of the accumulator;
Controlling an air conditioner that further accommodates an electromagnetic valve provided in the bypass refrigerant pipe in the heat source side unit;
In the cooling operation, the solenoid valve is opened for a certain time when the pressure of the refrigerant flowing through the refrigerant pipe on the refrigerant outlet side of the decompression device exceeds the pressure resistance reference value of the existing refrigerant pipe. The operation control device described.