阅读说明：本技术 热源侧单元以及制冷循环装置 (Heat source-side unit and refrigeration cycle device ) 是由 铃木康太 有井悠介 石川智隆 于 2019-04-02 设计创作，主要内容包括：本发明的热源侧单元(100A)与负载侧单元(200A)连接,从而形成供含有三氟碘甲烷(CF3I)的制冷剂进行循环的制冷循环装置。喷射回路(4)使从过冷却热交换器(14)流出的制冷剂的一部分向压缩机(11)的喷射口(P1)流入。过冷却热交换器(14)使从冷凝器(12)流出的制冷剂与在喷射回路(4)中流动的制冷剂进行热交换。温度传感器(46)检测压缩机(11)的排出温度。控制装置(3)基于检测到的压缩机(11)的排出温度,将制冷剂的温度控制在100℃以下。(A heat source side unit (100A) and a load side unit (200A) are connected to form a refrigeration cycle device in which a refrigerant containing trifluoroiodomethane (CF3I) circulates. The injection circuit (4) causes a part of the refrigerant flowing out of the supercooling heat exchanger (14) to flow into an injection port (P1) of the compressor (11). The supercooling heat exchanger (14) exchanges heat between the refrigerant flowing out of the condenser (12) and the refrigerant flowing through the injection circuit (4). A temperature sensor (46) detects the discharge temperature of the compressor (11). The control device (3) controls the temperature of the refrigerant to be 100 ℃ or lower based on the detected discharge temperature of the compressor (11).)

1. A heat source side unit connected to the load side unit to form a refrigeration cycle device for circulating a refrigerant containing trifluoroiodomethane (CF3I),

the heat source-side unit is characterized by comprising:

a compressor that compresses the refrigerant;

a condenser that condenses the refrigerant discharged from the compressor;

a subcooling heat exchanger; and

an injection circuit configured to cause a part of the refrigerant flowing out of the supercooling heat exchanger to flow into an injection port of the compressor,

the supercooling heat exchanger exchanges heat between the refrigerant flowing out of the condenser and the refrigerant flowing in the injection circuit,

the heat source-side unit further includes:

a temperature sensor that detects a discharge temperature of the compressor; and

a control device that controls a temperature of the refrigerant to 100 ℃ or lower based on the detected discharge temperature of the compressor.

2. A heat source side unit according to claim 1,

the heat source side unit includes a flow rate adjustment device that adjusts a flow rate of the refrigerant flowing to the injection circuit,

the control device controls the flow rate adjustment device when the discharge temperature detected by the temperature sensor increases above a threshold value.

3. The heat source side unit as set forth in claim 2, wherein

The flow adjusting device is an electronic expansion valve,

the control device increases the opening degree of the electronic expansion valve when the discharge temperature detected by the temperature sensor increases to the threshold value or more.

4. A heat source side unit according to claim 1,

the heat source-side unit includes a fan that blows air toward the condenser,

the control device increases the rotation speed of the fan when the discharge temperature detected by the temperature sensor increases above a threshold value.

5. A heat source side unit according to claim 1,

the heat source side unit includes:

a flow rate adjusting device that adjusts a flow rate of the refrigerant flowing to the injection circuit; and

a fan that blows air toward the condenser,

the control device increases the rotation speed of the fan when the discharge temperature detected by the temperature sensor increases above a first threshold value,

the control device may control the flow rate adjustment device to increase the flow rate of the refrigerant flowing to the injection port of the compressor when the discharge temperature detected by the temperature sensor increases to a second threshold value or more, which is greater than the first threshold value, after the rotation speed of the fan is increased.

6. A heat source side unit according to claim 1,

the control device decreases the driving frequency of the compressor when the discharge temperature detected by the temperature sensor increases above a threshold value.

7. A heat source side unit according to claim 1,

the control device stops the compressor when the discharge temperature detected by the temperature sensor increases above a threshold value.

8. A heat source side unit according to claim 1,

the control means decreases the driving frequency of the compressor when the discharge temperature detected by the temperature sensor increases above a first threshold value,

the control device stops the compressor when the discharge temperature detected by the temperature sensor increases to a second threshold value or more that is greater than the first threshold value after the driving frequency of the compressor is decreased.

9. A heat source side unit according to claim 1,

the control device increases the flow rate of the refrigerant flowing to the injection port of the compressor and decreases the driving frequency of the compressor when the discharge temperature detected by the temperature sensor increases to a threshold value or more.

10. A heat source side unit according to claim 1,

the control device increases the flow rate of the refrigerant flowing to the injection port of the compressor and decreases the driving frequency of the compressor when the discharge temperature detected by the temperature sensor increases to a first threshold or more,

the control device stops the compressor when the discharge temperature detected by the temperature sensor increases to a second threshold value or more greater than the first threshold value after increasing the flow rate of the refrigerant flowing to the injection port of the compressor and decreasing the driving frequency of the compressor.

11. A heat source side unit according to claim 1,

the control device increases the flow rate of the refrigerant flowing to the injection port of the compressor when the discharge temperature detected by the temperature sensor increases to a first threshold value or more,

the control device decreases the driving frequency of the compressor when the discharge temperature detected by the temperature sensor increases to a second threshold value or more that is greater than the first threshold value after increasing the flow rate of the refrigerant flowing to the injection port of the compressor.

12. A heat source side unit according to claim 1,

the control device increases the flow rate of the refrigerant flowing to the injection port of the compressor when the discharge temperature detected by the temperature sensor increases to a first threshold value or more,

the control device decreases the driving frequency of the compressor when the discharge temperature detected by the temperature sensor increases to a second threshold value greater than the first threshold value or more after increasing the flow rate of the refrigerant flowing to the injection port of the compressor,

the control device stops the compressor when the discharge temperature detected by the temperature sensor increases to a third threshold value or more that is greater than the second threshold value after the driving frequency of the compressor is decreased.

13. A heat source side unit according to claim 7, 8, 10 or 12,

the heat source-side unit includes a fan that blows air toward the condenser,

the control device increases the rotation speed of the fan after stopping the compressor.

14. A refrigeration cycle device is characterized by comprising:

a heat source side unit as set forth in any one of claims 1 to 13; and

a load side unit connected with the heat source side unit.

15. A refrigeration cycle device is characterized by comprising:

a first refrigerant circuit for circulating a first refrigerant; and

a second refrigerant circuit for circulating a second refrigerant,

the first refrigerant containing trifluoroiodomethane (CF3I), the second refrigerant not containing trifluoroiodomethane (CF3I),

the first refrigerant circuit includes:

a first compressor that compresses the first refrigerant;

a first condenser that condenses the first refrigerant discharged from the first compressor;

a subcooling heat exchanger; and

an injection circuit configured to flow a part of the first refrigerant flowing out of the supercooling heat exchanger into an injection port of the first compressor,

the supercooling heat exchanger exchanges heat between the first refrigerant flowing out of the first condenser and the first refrigerant flowing in the injection circuit,

the first refrigerant circuit further includes:

a first decompression device that decompresses the first refrigerant supercooled in the supercooling heat exchanger; and

a first evaporator that evaporates the first refrigerant decompressed in the first decompression device,

the second refrigerant circuit includes:

a second compressor that compresses the second refrigerant;

a second condenser that condenses the second refrigerant discharged from the second compressor;

a second decompressing device that decompresses the second refrigerant condensed in the second condenser; and

a second evaporator that evaporates the second refrigerant decompressed in the second decompressing device,

the first evaporator and the second condenser constitute a cascade condenser that exchanges heat between the first refrigerant and the second refrigerant,

the refrigeration cycle device further includes:

a temperature sensor that detects a discharge temperature of the first compressor; and

a control device that controls a temperature of the first refrigerant to 100 ℃ or lower based on the detected discharge temperature of the first compressor.

Technical Field

The present invention relates to a heat source side unit and a refrigeration cycle device.

Background

As a countermeasure against global warming, a refrigeration cycle apparatus using a refrigerant having a small global warming potential is known. For example, patent document 1 describes a refrigeration cycle apparatus using an HFC mixed refrigerant (for example, R410A) containing trifluoroiodomethane (CF 3I).

Patent document 1: japanese laid-open patent publication No. 11-228947

When the temperature of trifluoroiodomethane (CF3I) exceeds 100 ℃, it reacts with water to produce harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

As a result, the proportion of trifluoroiodomethane (CF3I) in the HFC mixed refrigerant decreases, and therefore, the characteristics of the HFC mixed refrigerant may change, which may degrade the performance of the refrigeration cycle apparatus. In addition, when the refrigerant pipe is damaged, harmful by-products may leak into the room.

Disclosure of Invention

Accordingly, an object of the present invention is to provide a heat source side unit and a refrigeration cycle apparatus capable of preventing trifluoroiodomethane (CF3I) contained in a refrigerant from reacting with water to generate harmful by-products.

A heat source side unit according to the present invention is connected to a load side unit to form a refrigeration cycle apparatus in which a refrigerant containing trifluoroiodomethane (CF3I) circulates, and includes: a compressor that compresses a refrigerant; a condenser for condensing the refrigerant discharged from the compressor; a subcooling heat exchanger; and an injection circuit configured to cause a part of the refrigerant flowing out of the supercooling heat exchanger to flow into an injection port of the compressor. The supercooling heat exchanger exchanges heat between the refrigerant flowing out of the condenser and the refrigerant flowing through the injection circuit. The heat source-side unit further includes: a temperature sensor that detects a discharge temperature of the compressor; and a control device for controlling the temperature of the refrigerant to be 100 ℃ or lower based on the detected discharge temperature of the compressor.

According to the present invention, it is possible to prevent trifluoroiodomethane (CF3I) contained in the refrigerant from reacting with water to generate harmful by-products.

Drawings

Fig. 1 is a schematic diagram showing an example of the configuration of a refrigeration cycle apparatus 1000 according to embodiment 1.

Fig. 2 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 1.

Fig. 3 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 2.

Fig. 4 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 3.

Fig. 5 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 4.

Fig. 6 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 5.

Fig. 7 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 6.

Fig. 8 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 7.

Fig. 9 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 8.

Fig. 10 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 9.

Fig. 11 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 10.

Fig. 12 is a schematic diagram showing an example of the configuration of a refrigeration cycle apparatus 1000A according to embodiment 11.

Detailed Description

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

Embodiment 1.

Fig. 1 is a schematic diagram showing an example of the configuration of a refrigeration cycle apparatus 1000 according to embodiment 1. As shown in fig. 1, the refrigeration cycle apparatus 1000 includes a heat source side unit 100 and a load side unit 200. The refrigeration cycle is formed by connecting the heat source side unit 100 and the load side unit 200 by refrigerant pipes. In the example shown in fig. 1, 1 load side unit 200 is provided, but the present invention is not limited to this. For example, 2 or more load-side units 200 may be connected in parallel. When a plurality of load-side units 200 are provided, the load-side units 200 may all have the same capacity, or may have different capacities.

The heat-source-side unit 100 includes a compressor unit 110, a condenser unit 120, and a control device 3. The compressor unit 110 and the condenser unit 120 are connected by refrigerant pipes 10a and 10 b.

The compressor unit 110 includes a compressor 11, an accumulator 13, a supercooling heat exchanger 14, an injection circuit 4, and a flow rate adjusting device 15. The condenser unit 120 includes a condenser 12 and a fan 12a.

The compressor 11 sucks a low-temperature and low-pressure refrigerant, and compresses the sucked refrigerant to a high-temperature and high-pressure state. The compressor 11 is a scroll compressor, and an injection port P1 is provided at an intermediate pressure portion of the compression chamber. A bypass pipe 16 of the injection circuit 4 branched from the main circuit at the outlet side of the supercooling heat exchanger 14 is connected to the injection port P1. The injection circuit 4 is configured to cause a part of the refrigerant flowing out of the supercooling heat exchanger 14 to flow into the injection port P1 of the compressor 11. In the example shown in fig. 1, 1 compressor 11 is provided, but the present invention is not limited to this, and for example, 2 or more compressors 11 may be connected in parallel in accordance with the load of the load side unit 200.

As the compressor 11, for example, an inverter compressor is used in which the driving frequency is changed to control the refrigerant delivery amount per unit time, that is, the capacity. In this case, a compressor inverter board for changing the driving frequency is mounted on the heat source side unit 100, and the driving frequency of the compressor 11 is controlled by the control device 3.

The condenser 12 is connected to the discharge side of the compressor 11 via a refrigerant pipe 10 a. The condenser 12 exchanges heat between a fluid such as air and a refrigerant. The condenser 12 performs heat exchange between the refrigerant and a fluid (water or air, refrigerant or brine, etc.) to condense the refrigerant.

Fan 12a blows air to condenser 12. The rotation speed of the fan 12a is controlled by the control device 3.

The accumulator 13 is connected to an outlet side of the condenser 12 of the condenser unit 120 via a refrigerant pipe 10 b. The accumulator 13 temporarily accumulates the refrigerant flowing out of the condenser 12 and separates the liquid refrigerant from the gas refrigerant.

The supercooling heat exchanger 14 is connected to the condenser 12 via the refrigerant pipe 10b and the accumulator 13, and supercools the refrigerant flowing out of the condenser 12. The supercooling heat exchanger 14 exchanges heat between the refrigerant flowing through the main circuit portion flowing out of the condenser 12 and the refrigerant flowing through the injection circuit 4 branched from the main circuit.

The flow rate adjusting device 15 adjusts the flow rate of the refrigerant that branches from the outlet side of the supercooling heat exchanger 14 to the injection circuit 4 and flows to the injection circuit 4, based on the control of the control device 3. As the flow rate adjusting device 15, for example, an electronic expansion valve is used.

The heat source side unit 100 further includes a discharge pressure sensor 41, an intake pressure sensor 42, a discharge temperature sensor 46, an inlet temperature sensor 44, and an outlet temperature sensor 45.

The discharge pressure sensor 41 is provided on the discharge side of the compressor 11. The discharge pressure sensor 41 detects the discharge pressure of the refrigerant discharged from the compressor 11.

The discharge temperature sensor 46 is provided on the discharge side of the compressor 11. The discharge temperature sensor 46 detects a temperature (hereinafter, discharge temperature) Td of the refrigerant discharged from the compressor 11.

The suction pressure sensor 42 is provided on the suction side of the compressor 11. The suction pressure sensor 42 detects a suction pressure of the refrigerant sucked into the compressor 11.

The inlet temperature sensor 44 detects the temperature of the refrigerant flowing into the supercooling heat exchanger 14.

The load-side unit 200 and the compressor unit 110 of the heat source-side unit 100 are connected by refrigerant pipes 10c and 10 d. The load-side unit 200 includes a pressure reducer 21 and an evaporator 22.

The pressure reducing device 21 reduces the pressure of the refrigerant supercooled in the supercooling heat exchanger 14, expands the refrigerant, and adjusts the flow rate of the refrigerant. As the pressure reducing device 21, for example, an electronic expansion valve or a temperature expansion valve is used.

The evaporator 22 exchanges heat between a fluid such as air and a refrigerant. The evaporator 22 absorbs heat from the refrigerant decompressed and expanded by the decompression device 21 and evaporates the refrigerant. As the evaporator 22, for example, a fin-tube type heat exchanger having a heat transfer tube and a plurality of fins is used.

Next, the operation of the refrigeration cycle apparatus 1000 will be described.

When the refrigeration cycle apparatus 1000 starts operating, the compressor 11 is first driven. The gas refrigerant compressed by the compressor 11 to have a high temperature and a high pressure is discharged from the compressor 11 and flows into the condenser 12.

The gas refrigerant flowing into the condenser 12 is condensed by heat exchange with air, water, or the like, and becomes a low-temperature and high-pressure liquid refrigerant. The low-temperature and high-pressure liquid refrigerant flows through the main circuit portion in the supercooling heat exchanger 14. The refrigerant discharged from the supercooling heat exchanger 14 flows through the injection circuit 4 branched from the main circuit, and flows through the supercooling heat exchanger 14 to the injection circuit portion. In the supercooling heat exchanger 14, the refrigerant flowing through the main circuit portion exchanges heat with the refrigerant flowing through the injection circuit portion. The refrigerant in the injection circuit 4 flows into the injection port P1 of the compressor 11. The amount of refrigerant flowing into the injection port P1 is controlled by the flow rate adjusting device 15.

In the present embodiment, since a refrigerant (for example, R466A) containing trifluoroiodomethane (CF3I) is used, the controller 3 controls the temperature of the refrigerant to be equal to or lower than the temperature (100 ℃) at which trifluoroiodomethane (CF3I) reacts with water.

As in the conventional art, the control device 3 controls the flow rate adjusting device 15 based on the outside air temperature, the temperature of the refrigerant discharged from the compressor 11, the degree of superheat of the refrigerant, or the like. For example, the controller 3 opens the flow rate adjusting device 15 when the outside air temperature is equal to or higher than a set value, and closes the flow rate adjusting device 15 when the outside air temperature is lower than the set value. Alternatively, the control device 3 opens the flow rate adjustment device 15 when the temperature of the refrigerant discharged from the compressor 11 is equal to or higher than a set value, and closes the flow rate adjustment device 15 when the temperature of the refrigerant discharged from the compressor 11 is lower than the set value. Alternatively, the control device 3 opens the flow rate adjusting device 15 when the degree of superheat of the refrigerant is equal to or greater than a set value, and closes the flow rate adjusting device 15 when the degree of superheat of the refrigerant is less than the set value.

In embodiment 1, the control device 3 controls the flow rate adjusting device (electronic expansion valve) 15 based on the outside air temperature, the temperature of the refrigerant discharged from the compressor 11, the degree of superheat of the refrigerant, or the like, and increases the opening degree of the flow rate adjusting device (electronic expansion valve) 15 when the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to a threshold value THA (100 ℃ - Δ TA) or more, thereby increasing the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11. The increase in the opening degree of the flow rate adjusting device 15 may be a constant value. Alternatively, the increase amount of the opening degree of the flow rate adjustment device 15 may be increased as the difference between the discharge temperature Td and the threshold THA is increased.

The threshold value THA can be set to a value slightly smaller than the temperature (100 ℃) at which trifluoroiodomethane (CF3I) reacts with water, taking into account the control compliance of the flow rate adjusting device 15 and the overshoot of the compressed gas temperature.

The threshold value THA can be set in consideration of safety and efficiency. That is, the threshold THA can be set to the following value: when the discharge temperature Td of the compressor 11 increases to the threshold value THA or more without reducing the performance of the refrigeration cycle device 1000 as much as possible, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃ or less by increasing the opening degree of the flow rate adjusting device 15.

Fig. 2 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 1.

In step S101, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S102, when the discharge temperature Td of the compressor 11 increases to the threshold THA (100 ═ Δ TA) or more, the process proceeds to step S103.

In step S103, the control device 3 increases the opening degree of the flow rate adjusting device 15 to increase the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor 11. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

As described above, according to the present embodiment, when the discharge temperature Td of the compressor 11 is equal to or higher than the threshold THA, the discharge temperature Td of the compressor 11 at the maximum temperature in the refrigeration cycle is controlled to be equal to or lower than 100 ℃ by increasing the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 2.

The control device 3 increases the rotation speed of the fan 12a when the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to or above a threshold THB (═ 100 ℃ to Δ TB). The amount of increase in the rotation speed of the fan 12a may also be a constant value. Alternatively, the amount of increase in the rotation speed of the fan 12a may be increased as the difference between the discharge temperature Td and the threshold THB is increased.

The threshold THB can be set in consideration of the safety plane and the efficiency plane. That is, the threshold THB can be set to the following value: when the discharge temperature Td of the compressor 11 increases to the threshold value THB or higher without reducing the performance of the refrigeration cycle device 1000 as much as possible, the rotation speed of the fan 12a is increased, whereby the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

Fig. 3 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 2.

In step S201, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S202, when the discharge temperature Td of the compressor 11 increases to the threshold THB (100 — Δ TB) or more, the process proceeds to step S203.

In step S203, the control device 3 increases the rotation speed of the fan 12a to lower the temperature of the refrigerant at the outlet of the condenser 12. As a result, the temperature of the refrigerant flowing through the injection port P1 of the compressor 11 is lowered, and as a result, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

As described above, according to the present embodiment, when the discharge temperature Td of the compressor 11 is equal to or higher than the threshold THB, the rotation speed of the fan 12a is increased, whereby the discharge temperature Td of the compressor 11 at the highest temperature in the refrigeration cycle is controlled to be 100 ℃. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 3.

The control device 3 increases the rotation speed of the fan 12a when the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to or above a threshold THC (═ 100 ℃ to Δ TC). After increasing the rotation speed of the fan 12a, when the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to a threshold value THA (100 ℃ - Δ TA) or more, the control device 3 increases the opening degree of the flow rate adjustment device 15, thereby increasing the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11. Wherein, Delta TC is more than Delta TA, THA is more than THC. Here, the threshold THC is a first threshold, and the threshold THA is a second threshold.

The increase in the opening degree of the flow rate adjusting device 15 may be a constant value. Alternatively, the increase amount of the opening degree of the flow rate adjusting device 15 may be increased as the difference between the discharge temperature Td and the threshold THA is increased. The amount of increase in the rotation speed of the fan 12a may also be a constant value. Alternatively, the amount of increase in the rotation speed of the fan 12a may be increased as the difference between the discharge temperature Td and the threshold THC is increased.

The threshold value THA can be set in consideration of safety and efficiency. That is, the threshold THA can be set to the following value: when the discharge temperature Td of the compressor 11 increases to the threshold value THA or more without reducing the performance of the refrigeration cycle device 1000 as much as possible, the opening degree of the flow rate adjusting device 15 is increased, whereby the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

The threshold THC can be set to a value as follows: in the previous stage when the discharge temperature Td of the compressor 11 increases to the threshold value THA or more, the temperature of the refrigerant flowing into the injection port P1 of the compressor 11 can be lowered by the fan 12a.

Fig. 4 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 3.

In step S301, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S302, when the discharge temperature Td of the compressor 11 increases to or above the threshold THC (═ 100 ℃ to Δ TC: the first threshold), the process proceeds to step S303.

In step S303, the control device 3 increases the rotation speed of the fan 12a to lower the temperature of the refrigerant at the outlet of the condenser 12. This reduces the temperature of the refrigerant flowing through the injection port P1 of the compressor 11, and as a result, the discharge temperature Td of the compressor 11 can be reduced.

In step S304, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46. When the discharge temperature Td of the compressor 11 increases to or above the threshold THA (═ 100 ℃ to Δ TA: the second threshold), the process proceeds to step S305. Wherein, Delta TC is more than Delta TA, THA is more than THC.

In step S305, the control device 3 increases the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor 11 by increasing the opening degree of the flow rate adjustment device 15. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

As described above, according to the present embodiment, when the discharge temperature Td of the compressor 11 increases to the threshold value THC or more, the rotation speed of the fan 12a is increased, and thereafter, when the discharge temperature Td of the compressor 11 increases to the threshold value THA or more, the opening degree of the flow rate adjusting device 15 is increased to increase the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11, thereby controlling the discharge temperature Td of the compressor 11, which is the highest temperature in the refrigeration cycle, to 100 ℃. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 4.

The control device 3 decreases the driving frequency of the compressor 11 when the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to the threshold value THD (═ 100 ℃ to Δ Td) or more. The amount of reduction in the driving frequency of the compressor 11 may also be a constant value. Alternatively, the reduction amount of the drive frequency of the compressor 11 may be increased as the difference between the discharge temperature Td and the threshold THD is increased.

The threshold value THD can be set in consideration of safety and efficiency. That is, the threshold THD can be set to the following value: when the discharge temperature Td of the compressor 11 increases to the threshold value THD or more without reducing the performance of the refrigeration cycle device 1000 as much as possible, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃ or less by reducing the driving frequency of the compressor 11.

Fig. 5 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 4.

In step S701, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S702, when the discharge temperature Td of the compressor 11 increases to the threshold value THD (100 — Δ Td) or more, the process proceeds to step S703.

In step S703, the control device 3 decreases the driving frequency of the compressor 11. This can reduce the discharge temperature Td of the compressor 11. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

As described above, according to the present embodiment, when the discharge temperature Td of the compressor 11 increases to the threshold value THD or more, the drive frequency of the compressor 11 is reduced, whereby the discharge temperature Td of the compressor 11 at the highest temperature in the refrigeration cycle is controlled to 100 ℃. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 5.

THE control device 3 stops THE compressor 11 when THE discharge temperature Td of THE compressor 11 detected by THE discharge temperature sensor 46 increases to or above a threshold value he (═ 100 ℃ to Δ TE).

THE threshold value he can be set in consideration of safety and efficiency. That is, THE threshold value he can be set to THE following value: when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he or more without reducing THE performance of THE refrigeration cycle device 1000 as much as possible, THE discharge temperature Td of THE compressor 11 can be controlled to a temperature of 100 ℃ or less by stopping THE compressor 11.

After stopping the compressor 11, the control device 3 increases the rotation speed of the fan 12a. This can suppress a temperature rise of the high-temperature gas compressed by the compressor 11 when the pressure of the condenser 12 is reduced and the compressor 11 restarts operation.

Fig. 6 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 5.

In step S801, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S802, when THE discharge temperature Td of THE compressor 11 increases to or above THE threshold value he (═ 100 ℃ to Δ TE), THE process proceeds to step S803.

In step S803, the control device 3 stops the compressor 11. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

As described above, according to THE present embodiment, when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he or more, THE compressor 11 is stopped, whereby THE discharge temperature Td of THE compressor 11 at THE highest temperature in THE refrigeration cycle is controlled to 100 ℃. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 6.

The control device 3 decreases the driving frequency of the compressor 11 when the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to the threshold value THF (100 ℃ - Δ TF) or more. The amount of reduction in the driving frequency of the compressor 11 may also be a constant value. Alternatively, the reduction amount of the drive frequency of the compressor 11 may be increased as the difference between the discharge temperature Td and the threshold value THF is increased.

After THE drive frequency of THE compressor 11 is reduced, THE control device 3 stops THE compressor 11 when THE discharge temperature Td of THE compressor 11 detected by THE discharge temperature sensor 46 increases to THE threshold value he or more. After stopping the compressor 11, the control device 3 increases the rotation speed of the fan 12a.

Here, THE threshold THF is a first threshold, and THE threshold he is a second threshold.

THE threshold value he can be set in consideration of safety and efficiency. That is, THE threshold value he can be set to THE following value: when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he or more without reducing THE performance of THE refrigeration cycle device 1000 as much as possible, THE discharge temperature Td of THE compressor 11 can be controlled to a temperature of 100 ℃ or less by stopping THE compressor 11.

The threshold THF can be set to the following value: in THE previous stage when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he or more, THE discharge temperature Td of THE compressor 11 can be reduced by reducing THE driving frequency of THE compressor 11.

Fig. 7 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 6.

In step S401, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S402, when the discharge temperature Td of the compressor 11 increases to the threshold value THF (100 ℃ - Δ TF: first threshold value) or more, the process proceeds to step S403.

In step S403, the control device 3 decreases the driving frequency of the compressor 11. This can reduce the discharge temperature Td of the compressor 11.

In step S404, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46. When THE discharge temperature Td of THE compressor 11 increases to THE threshold value he (100 c —. Δ TE: THE second threshold value) or more regardless of whether THE drive frequency of THE compressor 11 is decreased, THE process proceeds to step S405.

In step S405, the control device 3 stops the compressor 11. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

In step S406, the control device 3 increases the rotation speed of the fan 12a to decrease the pressure of the condenser 12. This can suppress a temperature rise of the compressed high-temperature gas when the compressor 11 restarts operation.

As described above, according to THE present embodiment, THE drive frequency of THE compressor 11 is reduced when THE discharge temperature Td of THE compressor 11 increases to THE threshold value THF or higher, and thereafter, THE compressor 11 is stopped when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he or higher, whereby THE discharge temperature Td of THE compressor 11 at THE highest temperature in THE refrigeration cycle can be controlled to 100 ℃. Thereby, the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle is made not to exceed 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 7.

When the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to or above the threshold THG (═ 100 ℃ to Δ TG), the control device 3 increases the opening degree of the flow rate adjustment device 15, increases the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11, and decreases the drive frequency of the compressor 11.

The increase in the opening degree of the flow rate adjusting device 15 may be a constant value. Alternatively, the amount of increase in the opening degree of the flow rate adjustment device 15 may be increased as the difference between the discharge temperature Td and the threshold THG is increased. The amount of reduction in the driving frequency of the compressor 11 may also be a constant value. Alternatively, the reduction amount of the drive frequency of the compressor 11 may be increased as the difference between the discharge temperature Td and the threshold THG is increased.

The threshold THG can be set in consideration of the safety back surface and the efficiency back surface. That is, the threshold THG can be set to the following value: when the discharge temperature Td of the compressor 11 increases to or above the threshold THG without reducing the performance of the refrigeration cycle device 1000 as much as possible, the opening degree of the flow rate adjusting device 15 is increased to increase the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11 and to reduce the driving frequency of the compressor 11, thereby making it possible to control the discharge temperature Td of the compressor 11 to a temperature of 100 ℃.

Fig. 8 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 7.

In step S901, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S902, when the discharge temperature Td of the compressor 11 increases to or above the threshold THG (═ 100 ℃ to Δ TG), the process proceeds to step S903.

In step S903, the control device 3 increases the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor 11 and decreases the driving frequency of the compressor 11 by increasing the opening degree of the flow rate adjustment device 15. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

As described above, according to the present embodiment, when the discharge temperature Td of the compressor 11 increases to the threshold THG or more, the opening degree of the flow rate adjusting device 15 is increased to increase the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11 and the drive frequency of the compressor 11 is decreased, thereby controlling the discharge temperature Td of the compressor 11, which is the highest temperature in the refrigeration cycle, to 100 ℃. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 8.

When the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to or above the threshold THH (═ 100 ℃ to Δ TG), the control device 3 increases the opening degree of the flow rate adjustment device 15, increases the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11, and decreases the drive frequency of the compressor 11. The increase in the opening degree of the flow rate adjusting device 15 may be a constant value. Alternatively, the amount of increase in the opening degree of the flow rate adjustment device 15 may be increased as the difference between the discharge temperature Td and the threshold THH is increased. The amount of reduction in the driving frequency of the compressor 11 may also be a constant value. Alternatively, the larger the difference between the discharge temperature Td and the threshold THH, the larger the amount of reduction in the drive frequency of the compressor 11 is.

THE control device 3 increases THE flow rate of THE refrigerant flowing to THE injection port P1 of THE compressor 11 and decreases THE driving frequency of THE compressor 11, and then stops THE compressor 11 when THE discharge temperature Td of THE compressor 11 detected by THE discharge temperature sensor 46 increases to THE threshold value he or more. After stopping the compressor 11, the control device 3 increases the rotation speed of the fan 12a. Here, THE threshold THH is a first threshold, and THE threshold he is a second threshold.

THE threshold value he can be set in consideration of THE safety back surface and THE efficiency back surface. That is, THE threshold value he can be set to THE following value: when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he or more without reducing THE performance of THE refrigeration cycle device 1000 as much as possible, THE discharge temperature Td of THE compressor 11 can be controlled to a temperature of 100 ℃ or less by stopping THE compressor 11.

The threshold THH can be set to the following value: in THE previous stage when THE discharge temperature Td of THE compressor 11 is increased to THE threshold value he or more, THE opening degree of THE flow rate adjusting device 15 is increased, so that THE flow rate of THE refrigerant flowing to THE injection port P1 of THE compressor 11 is increased, and THE drive frequency of THE compressor 11 is decreased, whereby THE discharge temperature Td of THE compressor 11 can be decreased.

Fig. 9 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 8.

In step S501, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S502, when the discharge temperature Td of the compressor 11 increases to or above the threshold THH (100 ℃ to Δ TH: first threshold), the process proceeds to step S503.

In step S503, the control device 3 increases the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor 11 and decreases the driving frequency of the compressor 11 by increasing the opening degree of the flow rate adjustment device 15. This can reduce the discharge temperature Td of the compressor 11.

In step S504, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46. THE process proceeds to step S505 when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he (100 c — Δ TE: THE second threshold value) or more, regardless of whether THE flow rate of THE low-temperature refrigerant flowing to THE injection port P1 of THE compressor 11 is increased or not and THE driving frequency of THE compressor 11 is decreased.

In step S505, the control device 3 stops the compressor 11. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

In step S506, the control device 3 increases the rotation speed of the fan 12a to decrease the pressure of the condenser 12. This can suppress a temperature rise of the compressed high-temperature gas when the compressor 11 restarts operation.

As described above, according to THE present embodiment, when THE discharge temperature Td of THE compressor 11 increases to THE threshold THH or more, THE opening degree of THE flow rate adjusting device 15 is increased to increase THE flow rate of THE refrigerant flowing to THE injection port P1 of THE compressor 11 and to lower THE driving frequency of THE compressor 11, and then, when THE discharge temperature Td of THE compressor 11 increases to THE threshold thee or more, THE compressor 11 is stopped, whereby THE discharge temperature Td of THE compressor 11 at THE highest temperature in THE refrigeration cycle is controlled to 100 ℃. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 9.

When the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to or above the threshold THI (═ 100 ℃ to Δ TI), the control device 3 increases the opening degree of the flow rate adjustment device 15, thereby increasing the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11. The increase in the opening degree of the flow rate adjusting device 15 may be a constant value. Alternatively, the amount of increase in the opening degree of the flow rate adjusting device 15 may be increased as the difference between the discharge temperature Td and the threshold THI is increased.

The control device 3 increases the flow rate of the refrigerant flowing through the injection port P1 of the compressor 11, and then decreases the driving frequency of the compressor 11 when the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to a threshold value THJ (100 ℃ - Δ TJ) or more. The amount of reduction in the driving frequency of the compressor 11 may also be a constant value. Alternatively, the reduction amount of the drive frequency of the compressor 11 may be increased as the difference between the discharge temperature Td and the threshold THJ is increased. Here, the threshold THI is a first threshold, and the threshold THJ is a second threshold.

The threshold THJ can be set in consideration of the safety back surface and the efficiency back surface. That is, the threshold THJ can be set to the following value: when the discharge temperature Td of the compressor 11 increases to the threshold value THJ or more without reducing the performance of the refrigeration cycle device 1000 as much as possible, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃ or less by reducing the driving frequency of the compressor 11.

The threshold THI can be set to the following value: in the previous stage when the discharge temperature Td of the compressor 11 increases to the threshold value THJ or more, the opening degree of the flow rate adjustment device 15 is increased to increase the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11, thereby enabling the discharge temperature Td of the compressor 11 to be decreased.

Fig. 10 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 9.

In step S1001, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S1002, when the discharge temperature Td of the compressor 11 increases to or above the threshold THI (═ 100 ℃ to Δ TI: the first threshold), the process proceeds to step S1003.

In step S1003, the control device 3 increases the opening degree of the flow rate adjusting device 15 to increase the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor 11.

In step S1004, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46. The process proceeds to step S1005 when the discharge temperature Td of the compressor 11 increases to the threshold value THJ (100 c to Δ TJ: the second threshold value) or more, regardless of whether the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor 11 is increased or not.

In step S1005, the control device 3 decreases the driving frequency of the compressor 11. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

As described above, according to the present embodiment, when the discharge temperature Td of the compressor 11 increases to the threshold THI or more, the opening degree of the flow rate adjusting device 15 is increased to increase the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11, and thereafter, when the discharge temperature Td of the compressor 11 increases to the threshold THJ or more, the drive frequency of the compressor 11 is decreased to control the discharge temperature Td of the compressor 11 having the highest temperature in the refrigeration cycle to 100 ℃. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 10.

When the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to or above the threshold value THK (═ 100 ℃ to Δ TK), the control device 3 increases the opening degree of the flow rate adjustment device 15, thereby increasing the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11. The increase in the opening degree of the flow rate adjusting device 15 may be a constant value. Alternatively, the amount of increase in the opening degree of the flow rate adjustment device 15 may be increased as the difference between the discharge temperature Td and the threshold THK is increased.

The control device 3 increases the flow rate of the refrigerant flowing through the injection port P1 of the compressor 11, and then decreases the driving frequency of the compressor 11 when the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46 increases to a threshold value THL (100 ℃ ═ Δ TL) or more. The amount of reduction in the driving frequency of the compressor 11 may also be a constant value. Alternatively, the reduction amount of the drive frequency of the compressor 11 may be increased as the difference between the discharge temperature Td and the threshold THL is increased.

After THE drive frequency of THE compressor 11 is decreased, THE control device 3 stops THE compressor 11 when THE discharge temperature Td of THE compressor 11 detected by THE discharge temperature sensor 46 increases to a threshold value he (100 c — Δ TE) or more. After stopping the compressor 11, the control device 3 increases the rotation speed of the fan 12a.

Here, THE threshold THK is a first threshold, THE threshold THK is a second threshold, and THE threshold he is a second threshold.

THE threshold value he can be set in consideration of THE safety back surface and THE efficiency back surface. That is, THE threshold value he can be set to THE following value: when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he or more without reducing THE performance of THE refrigeration cycle device 1000 as much as possible, THE discharge temperature Td of THE compressor 11 can be controlled to a temperature of 100 ℃ or less by stopping THE compressor 11.

The threshold THL can be set to the following value: in THE previous stage when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he or more, THE discharge temperature Td of THE compressor 11 can be reduced by reducing THE driving frequency of THE compressor 11.

The threshold THK can be set to the following value: in the previous stage when the discharge temperature Td of the compressor 11 increases to the threshold THL or more, the discharge temperature Td of the compressor 11 can be decreased by increasing the flow rate of the refrigerant flowing to the injection port P1 of the compressor 11.

Fig. 11 is a flowchart showing a procedure of controlling the temperature of the refrigerant in the refrigeration cycle apparatus according to embodiment 10.

In step S601, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46.

In step S602, when the discharge temperature Td of the compressor 11 increases to the threshold value THK (100 ℃ - Δ TK: first threshold value) or more, the process proceeds to step S603.

In step S603, the control device 3 can increase the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor 11 by increasing the opening degree of the flow rate adjusting device 15.

In step S604, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46. The process proceeds to step S605 when the discharge temperature Td of the compressor 11 increases to the threshold THL (100 ℃ - Δ TL: second threshold) or more, regardless of whether the flow rate of the low-temperature refrigerant flowing to the injection port P1 of the compressor 11 is increased.

In step S605, the control device 3 decreases the driving frequency of the compressor 11.

In step S606, the control device 3 acquires the discharge temperature Td of the compressor 11 from the discharge temperature sensor 46. THE process proceeds to step S607 when THE discharge temperature Td of THE compressor 11 increases to THE threshold value he (100 c — Δ TE: THE third threshold value) or more, regardless of whether THE flow rate of THE low-temperature refrigerant flowing to THE injection port P1 of THE compressor 11 is increased or not and THE driving frequency of THE compressor 11 is decreased.

In step S607, the control device 3 stops the compressor 11. Thereby, the discharge temperature Td of the compressor 11 can be controlled to a temperature of 100 ℃.

In step S608, the control device 3 increases the rotation speed of the fan 12a to decrease the pressure of the condenser 12. This can suppress a temperature rise of the compressed high-temperature gas when the compressor 11 restarts operation.

As described above, according to THE present embodiment, when THE discharge temperature Td of THE compressor 11 increases to THE threshold THK or more, THE opening degree of THE flow rate adjustment device 15 is increased to increase THE flow rate of THE refrigerant flowing to THE injection port P1 of THE compressor 11, then, when THE discharge temperature Td of THE compressor 11 increases to THE threshold THL or more, THE drive frequency of THE compressor 11 is decreased, and then, when THE discharge temperature Td of THE compressor 11 increases to THE threshold thee or more, THE compressor 11 is stopped, whereby THE discharge temperature Td of THE compressor 11 at THE maximum temperature in THE refrigeration cycle can be controlled to 100 ℃. This makes it possible to keep the temperature of the refrigerant (e.g., R466A) containing trifluoroiodomethane (CF3I) in the refrigeration cycle at 100 ℃. As a result, it is possible to prevent trifluoroiodomethane (CF3I) from reacting with water to generate harmful by-products such as hydrogen fluoride, hydrogen iodide, and carbonyl fluoride.

Embodiment 11.

Fig. 12 is a schematic diagram showing an example of the configuration of a refrigeration cycle apparatus 1000A according to embodiment 11.

The refrigeration cycle apparatus 1000A includes a heat source-side unit 100A and a load-side unit 200A. The heat-source-side unit 100A includes a compressor unit 110, a condenser unit 120, and a control device 3, as in embodiment 1. The heat source side unit 100A further includes a heat exchange unit 130.

The heat exchange unit 130 includes a compressor 53, a cascade condenser 57, and a pressure reducing device 21.

The compressor unit 110 and the condenser unit 120 are connected by refrigerant pipes 10b and 10 a. The compressor unit 110 and the heat exchange unit 130 are connected by refrigerant pipes 10c and 10 d.

The load-side unit 200A includes a pressure reducer 52 and an evaporator 54.

The load side unit 200A and the heat exchange unit 130 are connected by refrigerant pipes 10e and 10f.

The refrigeration cycle apparatus 1000A includes a first refrigerant circuit 91 on the high-stage side and a second refrigerant circuit 92 on the low-stage side.

As in embodiment 1, the first refrigerant circuit 91 includes a compressor (first compressor) 11, a condenser (first condenser) 12, an accumulator 13, a supercooling heat exchanger 14, a flow rate adjusting device 15, an injection circuit 4, a pressure reducing device (first pressure reducing device) 21, and an evaporator (first evaporator) 22. The first refrigerant circuit 91 circulates the high-stage-side refrigerant (first refrigerant). As in embodiment 1, the high-stage-side refrigerant is a refrigerant (e.g., R466A) containing trifluoroiodomethane (CF 3I).

The second refrigerant circuit 92 includes a compressor (second compressor) 53, a condenser (second condenser) 56, a pressure reducing device (second pressure reducing device) 52, and an evaporator (second evaporator) 54. The second refrigerant circuit 92 circulates a low-stage-side refrigerant (second refrigerant). The low-stage-side refrigerant is a refrigerant that causes a disproportionation reaction, such as HFO-1123 refrigerant.

The compressor 53 sucks a low-temperature and low-pressure refrigerant, and compresses the sucked refrigerant into a high-temperature and high-pressure state.

The condenser 56 is connected to the discharge side of the compressor 53. The condenser 56 exchanges heat between a fluid such as air and the refrigerant. The condenser 56 performs heat exchange between the refrigerant and a fluid (water or air, refrigerant or brine, etc.) to condense the refrigerant.

The decompression device 52 decompresses and expands the refrigerant, and adjusts the flow rate of the refrigerant. As the pressure reducing device 52, for example, an electronic expansion valve or a temperature expansion valve can be used.

The evaporator 54 exchanges heat between a fluid such as air and a refrigerant. The evaporator 54 absorbs heat from the refrigerant decompressed and expanded by the decompression device 52 and evaporates the refrigerant. As the evaporator 54, for example, a fin-tube type heat exchanger having a heat transfer tube and a plurality of fins can be used.

The condenser 56 on the low-stage side and the evaporator 22 on the high-stage side constitute a cascade condenser 57. In the cascade condenser 57, the low-stage-side refrigerant flowing through the low-stage-side condenser 56 exchanges heat with the high-stage-side refrigerant flowing through the high-stage-side evaporator 22.

In embodiment 11, the control device 3 can control the discharge temperature Td of the compressor 11 to a temperature of 100 ℃ or lower based on the discharge temperature Td of the compressor 11 detected by the discharge temperature sensor 46, as in embodiments 1 to 10.

In the present embodiment, even if the temperature of the refrigerant on the high-stage side exceeds 100 ℃ in the heat source-side unit 100A, since the by-product is generated by trifluoroiodomethane (CF3I), since the refrigerant not containing trifluoroiodomethane (CF3I) is circulated in the indoor load-side unit 200A, the by-product generated in the indoor load-side unit 200A can be prevented from leaking.

All the embodiments disclosed herein are to be considered as examples, and are not intended to limit the present invention. The scope of the present invention is defined not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

Description of the reference numerals

A control device; a spray circuit; 10a, 10b, 10c, 10d, 10e, 10f. 12. 56.. a condenser; a fan; a reservoir; a subcooling heat exchanger; a flow regulating device; bypass piping; 21. a pressure relief device; 22. an evaporator; discharging the pressure sensor; a suction pressure sensor; an outside air temperature sensor; an inlet temperature sensor; 45.. an outlet temperature sensor; a cascade condenser; a first refrigerant circuit; 92.. a second refrigerant circuit; 100. a heat source side unit; 200. a load side unit; a compressor unit; a condenser unit; a heat exchange unit; 1000. a refrigerating and air conditioning apparatus.