JP2014190565A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the humidity of cooled air while suppressing an increase in energy consumption.SOLUTION: An air conditioner includes a heater 11 that causes heat exchange between air cooled by a low-pressure heat exchanger 7 and gas-phase refrigerant generated in a decompression process of a decompression device 5. The air cooled by the low-pressure heat exchanger 7 thereby exchanges heat with the gas-phase refrigerant generated in the decompression process of the decompression device 5. Therefore, the air cooled and dehumidified by the low-pressure heat exchanger 7 can be heated by heat released when the gas-phase refrigerant is cooled. Accordingly, the air cooled and dehumidified by using the refrigerant that does not contribute to cooling the air can be heated. It is therefore possible to reduce the humidity of the cooled air while suppressing an increase in energy consumption.

Description

  The present invention relates to an air conditioner using a vapor compression refrigerator.

  An air conditioner using a vapor compression refrigerator includes, for example, a compressor, an outdoor heat exchanger, a decompressor such as a capillary tube, and an indoor heat exchanger, as described in Patent Document 1. Then, the refrigerant decompressed by the decompressor is heat-exchanged with the air blown into the room by the indoor heat exchanger, and the air is cooled.

JP-A-5-302760

  For example, in an air conditioner for cooling an electric heating element such as a computer, it is not preferable that the relative humidity (hereinafter simply referred to as humidity) of the cooled air is high. Therefore, usually, indoor air is cooled to a dew point by an indoor heat exchanger, moisture in the air is condensed to reduce absolute humidity, and then the air is heated to an appropriate temperature to reduce humidity.

  By the way, when an electric heater such as a sheathed heater is used as a heating source for heating the cooled air, in addition to energy for cooling and dehumidifying the air, energy for heating the air is also required. The energy consumption of the device increases.

  In view of the above points, an object of the present invention is to reduce the humidity of cooled air while suppressing an increase in energy consumption.

  In order to achieve the above object, the present invention provides a high-pressure heat exchanger (3) for cooling a refrigerant and a high-pressure cooled by a high-pressure heat exchanger (3) in an air conditioner using a vapor compression refrigerator. A decompressor (5) for decompressing the refrigerant, a low-pressure heat exchanger (7) for evaporating the low-pressure refrigerant decompressed by the decompressor (5), and a high-pressure heat exchanger (3) side by compressing the refrigerant And a heater (11) for exchanging heat with the air cooled by the low-pressure heat exchanger (7) and the refrigerant extracted from the middle of the decompression of the decompression device (5). Features.

  Thus, in the present invention, the air cooled by the low-pressure heat exchanger (7) and the refrigerant extracted from the decompression device (5) in the middle of the decompression are heat-exchanged, and thus released when the refrigerant is cooled. The air cooled and dehumidified by the low-pressure heat exchanger (7) can be heated by the heat generated.

Therefore, since air can be heated using the refrigerant | coolant which does not contribute to cooling of air, the humidity of the cooled air can be reduced, suppressing the increase in energy consumption.
Incidentally, the reference numerals in parentheses for each of the above means are examples showing the correspondence with the specific means described in the embodiments described later, and the present invention is indicated by the reference numerals in the parentheses of the above respective means. It is not limited to specific means.

It is a mimetic diagram of a vapor compression refrigeration machine concerning a 1st embodiment of the present invention. It is a control system block diagram of the vapor compression refrigeration machine concerning a 1st embodiment of the present invention. It is a control flowchart of the vapor compression refrigeration machine concerning a 1st embodiment of the present invention. It is a schematic diagram of the vapor compression refrigerator which concerns on 2nd Embodiment of this invention.

  The “embodiment of the invention” described below shows an example of the embodiment. In other words, the invention specific items described in the claims are not limited to the specific means and structures shown in the following embodiments.

  The present embodiment is an air conditioner using a vapor compression refrigerator that is operated at a pressure whose high-pressure side pressure is lower than the critical pressure of the refrigerant. And a vapor compression refrigerator cools electric heating elements, such as a computer, indirectly by cooling indoor air.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that at least one member or part described with at least a reference numeral is provided, except for cases where “plural”, “two or more” and the like are omitted.

(First embodiment)
1. Configuration of Vapor Compression Refrigerator, etc. As shown in FIG. 1, a vapor compression refrigeration machine 1 according to this embodiment includes a high pressure heat exchanger 3, a decompression device 5, a low pressure heat exchanger 7, a compression device 9, and a heater. 11 etc. The high-pressure heat exchanger 3 cools the high-pressure refrigerant (hereinafter also referred to as discharge refrigerant) discharged from the compression device 9.

  That is, the high-pressure heat exchanger 3 cools the discharged refrigerant by exchanging heat between the outdoor air and the discharged refrigerant. In this embodiment, the pressure of the discharged refrigerant is smaller than the critical pressure of the refrigerant. For this reason, the discharged refrigerant in the gas phase is cooled and condensed (liquefied) by the high-pressure heat exchanger 3.

  The decompression device 5 decompresses the high-pressure refrigerant cooled by the high-pressure heat exchanger 3. The decompression device 5 includes a first decompression device 5A and a second decompression device 5B. The first decompression device 5A and the second decompression device 5B are connected in series via the first gas-liquid separator 13A. That is, the decompression device 5 decompresses the refrigerant flowing out of the high pressure heat exchanger 3 in two stages.

  The degree of supercooling of the refrigerant flowing out from the high-pressure heat exchanger 3 is 0 (zero) or small. For this reason, the refrigerant decompressed by the first decompression device 5A is in a gas-liquid two-phase state. The gas-liquid two-phase refrigerant flowing out from the first decompression device 5A is separated into a gas-phase refrigerant and a gas-phase refrigerant by the first gas-liquid separator 13A.

  The liquid phase refrigerant separated and extracted by the first gas-liquid separator 13A is further decompressed by the second decompression device 5B. And the low pressure heat exchanger 7 evaporates the low pressure liquid phase refrigerant decompressed by the second decompression device 5B. That is, in the low-pressure heat exchanger 7, the air supplied to the room and the refrigerant decompressed by the decompression device 5 are heat-exchanged to evaporate (vaporize) the liquid-phase refrigerant, thereby cooling the air. .

  The gas phase refrigerant separated and extracted by the first gas-liquid separator 13 </ b> A is introduced into the heater 11. The heater 11 exchanges heat between the gas-phase refrigerant, that is, the refrigerant decompressed by the first decompression device 5A and the air cooled by the low-pressure heat exchanger 7 (hereinafter referred to as cooling air).

  For this reason, the refrigerant that has flowed into the heater 11 is cooled by the cooling air to condense or decrease in temperature. The cooling air is heated by condensation heat or sensible heat radiated from the refrigerant. That is, the heater 11 exchanges heat with the air cooled by the low-pressure heat exchanger 7 and the refrigerant being decompressed by the decompression device 5.

  A second gas-liquid separator 13 </ b> B is provided on the refrigerant outflow side of the heater 11. In the 2nd gas-liquid separator 13B, the refrigerant | coolant which flowed out from the heater 11 is isolate | separated into a gaseous-phase refrigerant | coolant and a liquid phase refrigerant | coolant, and a liquid phase refrigerant | coolant is stored.

  The liquid phase side of the second gas / liquid separator 13B and the gas phase side of the first gas / liquid separator 13A communicate with each other via the refrigerant passage 13C. A check valve 13D is provided in the refrigerant passage 13C. The check valve 13D allows the refrigerant to flow from the second gas-liquid separator 13B to the first gas-liquid separator 13A, and the refrigerant flows from the first gas-liquid separator 13A to the second gas-liquid separator 13B. To stop.

  The compression device 9 compresses the refrigerant decompressed by the decompression device 5 and discharges it to the high-pressure heat exchanger 3 side. The compression device 9 includes a first compression device 9A and a second compression device 9B. The first compressor 9A sucks and compresses the refrigerant flowing out from the low-pressure heat exchanger 7.

  The second compression device 9B sucks and compresses the refrigerant decompressed by the first decompression device 5A. That is, the first injection unit 15A causes the refrigerant evaporated in the heater 11, that is, the gas-phase refrigerant flowing out from the second gas-liquid separator 13B, to be injected into the compression device 9 in the compression process.

  The second injection unit 15B injects the gas-phase refrigerant from the refrigerant decompressed by the first decompression device 5A to the compression device 9 in the compression process by bypassing the heater 11. Then, the refrigerant discharged from the first compressor 9A and the refrigerant discharged from the second compressor 9B merge and flow into the high-pressure heat exchanger 3.

  The first injection part 15A is provided with a check valve 15C. The second injection portion 15B is provided with a check valve 15D. Both check valves 15C and 15D prevent the refrigerant from flowing back from the suction side of the second compression device 9B to the first pressure reduction device 5A side.

  A first valve 17A for opening and closing the refrigerant passage is provided in the refrigerant passage from the outlet of the first decompression device 5A to the first injection portion 15A. A second valve 17B that opens and closes the refrigerant passage is provided in the refrigerant passage from the outlet of the first pressure reducing device 5A to the second injection portion 15B.

  The first valve 17A and the second valve 17B are controlled to be opened and closed by an injection control device 17C. The injection control device 17C closes the other valve when opening one of the first valve 17A and the second valve 17B, and opens the other valve when closing one of the valves.

  After determining whether or not it is necessary to heat the cooling air, the injection control device 17C opens the first valve 17A and closes the second valve 17B when it is determined that heating is necessary. And Thereby, the cooling air is heated by the heater 11.

  When it is determined that heating is not necessary, the injection controller 17C closes the first valve 17A and opens the second valve 17B. Thereby, the cooling air is blown into the room as it is without being heated by the heater 11.

  Therefore, in the vapor compression refrigerator 1 according to the present embodiment, the gas-phase refrigerant is compressed in the compression device 9 in the compression process regardless of which of the first injection unit 15A and the second injection unit 15B is operated. Will be injected. That is, the vapor compression refrigerator 1 according to the present embodiment operates as a so-called “gas injection refrigerator” regardless of which injection unit is operated.

  The liquid-phase refrigerant stored in the first gas-liquid separator 13A and the liquid-phase refrigerant stored in the second gas-liquid separator 13B are evaporated and vapor compressed when the cooling load increases. It circulates in the type refrigerator 1. For this reason, the amount of circulating refrigerant increases and the refrigeration capacity increases.

2. About the decompression device The first decompression device 5A includes a variable throttle device (not shown), a first decompression device controller 5D, and the like. The variable throttle device has an electric actuator (not shown) that changes and adjusts the throttle opening. The first pressure reducing device controller 5D controls the operation of the actuator to change the throttle opening of the first pressure reducing device 5A.

  The second decompression device 5B includes a variable throttle device (not shown), a temperature detector 5E, a second decompression device controller 5F, and the like. The variable throttle device has an electric actuator (not shown) that changes and adjusts the throttle opening.

  The temperature detector 5E detects the temperature of the refrigerant flowing out from the low pressure heat exchanger 7. Based on the temperature detected by the temperature detector 5E, the second decompression device control unit 5F has a predetermined degree of heating that has a value of 0 or more for the degree of heating of the refrigerant flowing out of the low-pressure heat exchanger 7. The throttle opening degree of the second decompression device 5B is controlled so as to be a value.

3. Example of Control of Vapor Compression Refrigerator 3.1 Outline of Control Device Injection control device 17C, first decompression device control unit 5D and second decompression device control unit 5F, and first compression device 9A and second compression device 9B The control part which controls the operation | movement of 1 is integrated in the one control apparatus 21, as shown in FIG.

  The control device 21 is configured by a microcomputer having a CPU, a ROM, a ROM, and the like. And the control apparatus 21 performs control according to the program previously memorize | stored in non-volatile memory | storage parts, such as ROM.

  Detection signals output from the temperature detector 5E, the blown air temperature detector 23A, and the blown air relative humidity detector 23B are input to the control device 21. The control device 21 uses the detection signals output from the detectors 5E, 23A, and 23B according to the above program, and the first compression device 9A, the second compression device 9B, the first decompression device 5A, and the second decompression device 5B. The operation of the first valve 17A and the second valve 17B is controlled.

  The blown air temperature detector 23A detects the temperature of the air that has passed through the heater 11, that is, the air blown into the room. The blown air relative humidity detector 23B detects the relative humidity of the air blown into the room.

  Hereinafter, the temperature of the air detected by the blown air temperature detector 23 </ b> A is referred to as “blown air temperature”. The temperature of the air detected by the blowing air relative humidity detector 23B is referred to as “blowing air humidity”.

3.2 Control Example by Control Device The control flow shown in FIG. 3 starts when a start switch (not shown) of the vapor compression refrigerator 1 is turned on, and stops when the start switch is shut off. When the start switch is turned on, a program for executing the control flow is read and executed by the control device 21 (CPU).

  When the control flow is started, first, whether or not the vapor compression refrigerator 1 is currently operating in the reheating mode, that is, the first valve 17A is open and the second valve 17B is closed. In step S1, it is determined whether or not the compression device 9 is operating.

  When it is determined that the engine is not operating in the reheat heating mode (S1: NO), it is determined whether or not the blown air temperature is equal to or lower than a predetermined temperature (S3). “Predetermined temperature” does not mean strictly a specific temperature but also includes a range having a width with respect to the specific temperature. In the present embodiment, for example, the predetermined temperature is 18 ° C., and the range is about ± 0.5 ° C. Hereinafter, the predetermined temperature is referred to as a target blown air temperature.

  When it is determined that the blown air temperature is higher than the target blown air temperature (S3: NO), the rotational speed of the first compressor 9A is increased by a predetermined rotational speed from the current rotational speed (S5). When it is determined that the blown air temperature is equal to or lower than the target blown air temperature (S3: YES), the rotational speed of the first compressor 9A is decreased by a predetermined rotational speed from the current rotational speed (S13).

  When S5 or S13 ends, it is determined whether or not the blown air humidity is equal to or higher than a predetermined upper limit value of a relative humidity range (S7). The “predetermined relative humidity range” is a value set in advance for each blown air temperature, and is stored in the ROM in the form of a map or a function value. Hereinafter, the “upper limit value of the predetermined relative humidity range” is referred to as a target upper limit humidity. The “lower limit value of the predetermined relative humidity range” is referred to as a target lower limit humidity.

  When it is determined that the blown air humidity is lower than the target upper limit humidity (S7: NO), S1 is executed again. When it is determined that the blown air humidity is equal to or higher than the target upper limit humidity (S7: YES), the first valve 17A is opened, the second valve 17B is closed, and the low pressure heat exchanger 7 is passed. The rotation speed of the first compressor 9A is controlled so that the air temperature becomes a target dew point (hereinafter referred to as a target dew point) (S9).

  The target dew point is a temperature determined based on the blown air temperature and the blown air humidity. In other words, the ROM stores in advance a map or function indicating the relationship between the blown air temperature, blown air humidity, and dew point. Whether or not the temperature of the air that has passed through the low-pressure heat exchanger 7 is actually the target dew point is determined by comparing the dew point estimated from the blown air temperature and the blown air humidity with the target dew point.

  Next, after the throttle opening degree of the first pressure reducing device 5A is controlled so that the blown air temperature becomes the target blown air temperature (S11), S1 is executed again. When it is determined that the engine is operating in the reheat heating mode (S1: YES), it is determined whether or not the blown air temperature is equal to or lower than the target blown air temperature (S15).

  When it is determined that the blown air temperature is higher than the target blown air temperature (S15: NO), the throttle opening of the first pressure reducing device 5A is smaller than the current throttle opening (S17). Thereby, since the temperature of the refrigerant | coolant which flows in into the heater 11 falls, the reheating capability falls from now.

  Next, it is determined whether the blown air humidity is equal to or higher than the target upper limit humidity (S19). When it is determined that the blown air humidity is lower than the target upper limit humidity (S19: NO), S1 is executed again. When it is determined that the blown air humidity is equal to or higher than the target upper limit humidity (S19: YES), the first compression is performed so that the temperature of the air that has passed through the low-pressure heat exchanger 7 becomes the dew point by the same method as S9. The rotation speed of the device 9A is controlled (S21).

  Thereafter, after the throttle opening degree of the first pressure reducing device 5A is controlled so that the blown air temperature becomes the target blown air temperature (S23), S1 is executed again. When it is determined in S15 that the blown air temperature is equal to or lower than the target blown air temperature (S15: YES), the throttle opening of the first pressure reducing device 5A is larger than the current throttle opening (S25). . Thereby, since the temperature of the refrigerant | coolant which flows in into the heater 11 rises, reheating capability rises from now.

  Next, it is determined whether the blown air humidity is equal to or lower than the target lower limit humidity (S27). When it is determined that the blown air humidity is higher than the target lower limit humidity (S27: NO), S1 is executed again.

  When it is determined that the blown air humidity is equal to or lower than the target lower limit humidity (S27: YES), the rotational speed of the first compressor 9A is closed with the first valve 17A closed and the second valve 17B opened. Is smaller than the current state (S29), S1 is executed again.

  Thereby, the refrigerant bypasses the heater 11 and is injected into the compression process of the compression device 9. The second compression device 9B is controlled such that the discharge pressure of the second compression device 9B and the discharge pressure of the first compression device 9A are the same pressure.

4). Features of the Vapor Compression Refrigerating Machine According to the Present Embodiment In the present embodiment, a heater 11 is provided that exchanges heat between the air cooled by the low-pressure heat exchanger 7 and the gas-phase refrigerant generated in the decompression process of the decompression device 5. It is characterized by that.

  Thereby, in this embodiment, since heat is exchanged with the air cooled in the low pressure heat exchanger 7 and the gas phase refrigerant generated in the pressure reducing process of the pressure reducing device 5, the gas phase refrigerant is released when cooled. The air that has been cooled and dehumidified in the low-pressure heat exchanger 7 can be heated by the generated heat.

  Therefore, since the air that has been cooled and dehumidified can be heated using the refrigerant that does not contribute to the cooling of the air, the humidity of the cooled air can be reduced while suppressing an increase in energy consumption.

This embodiment is characterized by including a first injection portion 15A that injects the refrigerant evaporated in the heater 11 into the compression device 9 in the compression process.
Thereby, in this embodiment, it becomes possible to function as a so-called “injection refrigerator” in which the gas-phase refrigerant is injected into the compression process. Accordingly, it is possible to improve the efficiency of the vapor compression refrigerator as with the injection refrigerator.

  In the present embodiment, the second injection unit 15B that injects the gas-phase refrigerant extracted from the decompression unit 5 during the decompression process to the compression unit 9 in the compression process, bypassing the heater 11, and the first injection unit 15A and the second injection unit. One of the portions 15B is selectively operated.

  Thereby, in this embodiment, the injection refrigerator using the refrigerant evaporated by the heater 11 and the normal injection refrigerator are selectively switched. Accordingly, it is possible to efficiently select the case where heating is required and the case where heating is not required, and to efficiently operate the air conditioner.

(Second Embodiment)
In the present embodiment, when it is estimated that the pressure ratio of the second compression device 9B falls below a predetermined pressure ratio (for example, 1.2) set in advance, the second compression device 9B is stopped. The refrigerant flowing out of the high-pressure heat exchanger 3 is led to the second decompression device 5B by bypassing the first decompression device 5A and the first gas-liquid separator 13A.

  The “pressure ratio” refers to the ratio between the discharge pressure and the suction pressure of the compressor. The predetermined pressure ratio (hereinafter referred to as the “minimum limit pressure ratio”) is a pressure ratio determined by the specifications of each compressor, and a pressure ratio at which the compressor cannot be operated at a pressure ratio smaller than the pressure ratio. Say.

  As shown in FIG. 4, in this embodiment, a bypass circuit L1, a third valve 23A, and a check valve 23C are provided. The bypass circuit L1 is a refrigerant path that guides the refrigerant flowing out of the high-pressure heat exchanger 3 to the second decompression device 5B by bypassing the first decompression device 5A and the first gas-liquid separator 13A.

  The check valve 32C prevents the refrigerant from flowing back to the second compressor 9B from the discharge side of the second compressor 9B. The third valve 23A opens and closes the bypass circuit L1. A valve control unit 23B that controls opening and closing of the third valve 23A is integrated with the control device 21.

  That is, the control device 21 sets the rotation speed of the second compression apparatus 9B (hereinafter, this rotation speed is referred to as a command rotation speed) so that the discharge pressure of the second compression apparatus 9B and the discharge pressure of the first compression apparatus 9A become the same pressure. .) Control.

  When the control device 21 determines that the pressure ratio of the second compression device 9B is lower than the limit minimum pressure ratio at the command rotational speed, the control device 21 stops the second compression device 9B and first The third valve 23A is opened simultaneously with closing the valve 17A and the second valve 17B.

  When the control device 21 determines that the pressure ratio of the second compression device 9B is equal to or greater than the limit minimum pressure ratio, the control device 21 closes the third valve 23A and closes the second compression device 9B. The first valve 17A and the second valve 17B are controlled in the same manner as in the first embodiment.

  In the above description, the pressure ratio of the second compression device 9B is estimated from the rotational speed or the like. However, the present embodiment is not limited to this, and the pressure ratio of the second compression device 9B is determined by other methods. It may be estimated or detected.

(Other embodiments)
In the above-described embodiment, the first compression device 9A and the second compression device 9B are arranged in parallel to the refrigerant flow, but the present invention is not limited to this, and the first compression device 9A. And the second compression device 9B may be arranged in series with respect to the refrigerant flow.

  When the first compression device 9A and the second compression device 9B are arranged in series with respect to the refrigerant flow, the first compression device 9A and the second compression device 9B are configured by a single compression device. May be.

  In the above embodiment, the refrigerant pressure on the high pressure side is lower than the critical pressure of the refrigerant. However, the present invention is not limited to this, and supercritical refrigeration in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant. It can also be applied to machines. In the supercritical refrigerator, the high-pressure heat exchanger 3 does not condense the refrigerant.

  In the above-described embodiment, the first gas-liquid separator 13A and the second gas-liquid separator 13B are provided, but the present invention is not limited to this. That is, the first gas-liquid separator 13 </ b> A may be eliminated and a gas-liquid two-phase refrigerant may be introduced into the heater 11. The second gas-liquid separator 13B may be eliminated, and the opening degree of the first valve 17A may be controlled so that the degree of heating of the refrigerant flowing out of the heater 11 becomes 0 or more.

  In the above-described embodiment, the compression device 9 is configured by a plurality of compressors. However, the present invention is not limited to this, and the compression device 9 is configured by a single compressor or the like having an injection port. May be. In addition, the format of the compression apparatus 9 is not ask | required. That is, any method such as a reciprocating method, a rotary method, a vane method, a scroll method, or the like may be used.

  Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 ... Vapor compression refrigerator 3 ... High pressure heat exchanger 5 ... Pressure reducing device 5A ... First pressure reducing device 5B ... Second pressure reducing device 5D ... First pressure reducing device controller 5E ... Temperature detector 5F ... For second pressure reducing device Control part 7 ... Low pressure heat exchanger 9 ... Compression device 9A ... First compression device 9B ... Second compression device 11 ... Heater 13A ... First gas-liquid separator 13B ... Second gas-liquid separator 13C ... Refrigerant passage 13D ... Check valve 13 ... Second pressure reducing device 15A ... First injection portion 15B ... Second injection portion 15C ... Check valve 15D ... Check valve 17A ... First valve 17B ... Second valve 17C ... Injection control device

Claims (5)

In an air conditioner using a vapor compression refrigerator,
A high-pressure heat exchanger that cools the refrigerant;
A decompression device for decompressing the high-pressure refrigerant cooled in the high-pressure heat exchanger;
A low-pressure heat exchanger that evaporates the low-pressure refrigerant decompressed by the decompression device;
A compression device that compresses the refrigerant and discharges the refrigerant to the high-pressure heat exchanger side;
An air conditioner comprising: air cooled by the low-pressure heat exchanger; and a heater for exchanging heat with refrigerant extracted from the middle of the decompression of the decompression device.   The air conditioner according to claim 1, further comprising a first injection unit that injects the refrigerant evaporated in the heater into the compression device in a compression process. A second injection unit for injecting the gas phase refrigerant extracted from the decompression device of the decompression device into the compression device in a compression process by bypassing the heater;
The air conditioner according to claim 2, further comprising: an injection control device that selectively activates one of the first injection unit and the second injection unit. Equipped with a blown air relative humidity detector that detects the relative humidity of the air blown into the room,
The injection control device operates the first injection unit when the detected relative humidity detected by the blown air relative humidity detector is equal to or higher than a preset relative humidity, and the detected relative humidity is the relative humidity. The air conditioner according to claim 3, wherein the second injecting unit is actuated when the ratio is less than 4. It has a blown air temperature detector that detects the temperature of air blown into the room,
The decompressor includes a first decompressor and a second decompressor,
A part of the refrigerant decompressed by the first decompression device is guided to the first injection part,
During operation of the first injection unit, the throttle opening of the first pressure reducing device is controlled so that the temperature of the air detected by the blown air temperature detector becomes a predetermined temperature set in advance. The air conditioner according to claim 4.