JP2012236577A - Refrigerating cycle device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a temperature of a battery by heating the battery, regarding a refrigerating cycle device having a gas injection mechanism.SOLUTION: The gas injection type refrigerating cycle device 2 includes a first pressure reducer 23 and an intermediate heat exchanger 24 between a condenser 22 and a gas-liquid separator 25. The intermediate heat exchanger 24 provides heat exchange between the battery 4 and a refrigerant. A control device 5 controls a valve opening of the first pressure reducer 23 so that an intermediate pressure of the refrigerant downstream of the first pressure reducer 23 becomes a target one. The control device 5 controls the opening of the first pressure reducer 23 so as to cool the battery 4 when the temperature of the battery 4 exceeds an optimal temperature range. The control device 5 controls the opening of the first pressure reducer 23 so as to heat the battery 4 when the temperature of the battery 4 becomes less than the optimal temperature range. The control device 5 controls the first pressure reducer 23 so as to increase the intermediate pressure as a heating quantity required for the battery 4 increases.

Description

  The present invention relates to a refrigeration cycle apparatus including a gas injection mechanism.

  Patent Document 1 proposes that a refrigeration cycle device of an air conditioner mounted on a vehicle is used for temperature adjustment of an electric device. In particular, this technique uses an refrigeration cycle apparatus having a gas injection mechanism to cool an electrical device with an intermediate pressure of the refrigeration cycle apparatus.

  Patent Document 2 proposes cooling an electric device such as an inverter with an intermediate pressure of a refrigeration cycle apparatus (heat pump cycle) having a gas injection mechanism. Further, in this apparatus, it has been proposed to adjust the intermediate pressure according to the amount of heat generated by the electrical equipment.

JP-A-9-290622 JP-A-11-34640

  In the above prior art, the electrical equipment is only cooled down. That is, the heat exchanger for cooling the electrical equipment is placed between the first throttle and the gas-liquid separator. And the temperature of a refrigerant | coolant is adjusted to temperature lower than the cooling water etc. of a heat exchanger by adjusting the refrigerant | coolant pressure after a 1st aperture_diaphragm | restriction with a 1st and 2nd aperture_diaphragm | restriction. For this reason, it is only possible to cool the electrical equipment.

  By the way, there is known an electric vehicle equipped with an electric motor for movement, that is, traveling, and further equipped with a battery for supplying electric power to the electric motor. For example, an electric vehicle (EV) that runs only by an electric motor, a hybrid vehicle (HV) equipped with an internal combustion engine and an electric motor, or a hybrid vehicle (plug-in hybrid vehicle: PHV) that can be charged from an external power source is known as an electric vehicle. It has been. A battery mounted on an electric vehicle generates heat due to Joule heat or the like. For this reason, it is cooled by mounting a cooling device such as a dedicated blower. Such batteries required fine temperature control. In particular, in the case of a lithium ion battery, it is necessary to maintain the battery temperature at about 10 ° C. to 40 ° C. in order to bring out the desired performance. In such a device, not only cooling but also heating the device is required.

  In order to meet such a demand, it is conceivable to provide a heat exchanger on the high-pressure side of the refrigeration cycle apparatus to warm the electrical equipment. However, in the case of a battery, the necessary temperature range is about 10 ° C to 40 ° C. For this reason, if the refrigerant on the high-pressure side of the refrigeration cycle apparatus is used as it is, there is a possibility that the temperature becomes too high.

  This invention is made | formed in view of the said problem, The objective is to provide the refrigeration cycle apparatus for vehicles which can control the temperature of the vehicle-mounted electric equipment.

  Another object of the present invention is to provide a vehicular refrigeration cycle apparatus that can not only cool electrical equipment but also heat electrical equipment.

  The present invention employs the following technical means to achieve the above object.

  The invention according to claim 1 is connected to the compressor via a compressor (21) having a suction port (21a) for low-pressure refrigerant and a gas injection port (21b), and a gas injection passage (29). A gas-liquid separator (25), a decompressor (23) that depressurizes the high-pressure refrigerant and supplies it to the gas-liquid separator, and is provided between the decompressor and the gas-liquid separator. A replaceable intermediate heat exchanger (24, 224, 324) and a control means (5) for controlling the decompressor so that the electric device is heated by the intermediate pressure refrigerant flowing through the intermediate heat exchanger. Features. According to this configuration, the electric device can be heated by the refrigeration cycle apparatus including the gas injection mechanism. For this reason, the temperature of the electrical equipment can be adjusted by the refrigeration cycle apparatus.

  The control means (5) controls the decompressor (23) so as to control the intermediate pressure (Pm) of the refrigerant in the intermediate heat exchanger to the target pressure (Pmc, Pmh). It is characterized by. According to this configuration, the electric device is heated by controlling the intermediate pressure of the refrigeration cycle apparatus to the target pressure.

  In the invention according to claim 3, the control means (5) sets the target pressure in accordance with the necessary heating amount necessary for adjusting the temperature of the electric device within a temperature range suitable for the electric device to operate. It is characterized by doing. According to this configuration, the target pressure is set according to the required heating amount. For this reason, the temperature of an electric equipment can be adjusted in the temperature range suitable for an electric equipment to operate | move.

  The invention described in claim 4 is characterized in that the control means (5) sets the target pressure higher as the required heating amount becomes larger. According to this configuration, the target pressure is set higher as the required heating amount increases. For this reason, the temperature of the refrigerant | coolant in an intermediate heat exchanger becomes high. As a result, the electric device can be heated quickly.

  In the invention according to claim 5, the control means (5) sets the target pressure so that the temperature of the refrigerant in the intermediate heat exchanger falls within a temperature range suitable for the operation of the electric device. Features. According to this configuration, the temperature of the refrigerant in the intermediate heat exchanger is controlled within a temperature range suitable for operating the electric device. As a result, excessive heating of the electric device is suppressed.

  The invention according to claim 6 is characterized in that the control device includes a liquid back prevention control means (655) for reducing the amount of heat exchange between the intermediate heat exchanger and the electric device when the liquid back to the compressor is detected. And According to this configuration, when the liquid back to the compressor is detected, the heat exchange amount in the intermediate heat exchanger is reduced. By reducing the amount of heat exchange, condensation of the refrigerant in the intermediate heat exchanger is suppressed, and liquid back is suppressed. As a result, liquid compression due to the liquid back is suppressed.

  Note that the reference numerals in parentheses described in the claims and the above-described means indicate the correspondence with the specific means described in the embodiments described later as one aspect, and are technical terms of the present invention. It does not limit the range.

1 is a block diagram illustrating a vehicle refrigeration cycle apparatus according to a first embodiment to which the present invention is applied. It is a Mollier diagram which shows the cooling control state by the refrigeration cycle apparatus for vehicles of 1st Embodiment. It is a Mollier diagram which shows the heating control state by the refrigeration cycle apparatus for vehicles of 1st Embodiment. It is a block diagram which shows the refrigerating-cycle apparatus for vehicles which concerns on 2nd Embodiment to which this invention is applied. It is a block diagram which shows the refrigerating-cycle apparatus for vehicles which concerns on 3rd Embodiment to which this invention is applied. It is a block diagram which shows the refrigerating-cycle apparatus for vehicles which concerns on 4th Embodiment to which this invention is applied. It is a block diagram which shows the refrigerating-cycle apparatus for vehicles which concerns on 5th Embodiment to which this invention is applied. It is a block diagram which shows the refrigerating-cycle apparatus for vehicles which concerns on 6th Embodiment to which this invention is applied. It is a Mollier diagram which shows the liquid back state of the refrigeration cycle apparatus for vehicles.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

(First embodiment)
FIG. 1 is a block diagram showing a vehicle refrigeration cycle apparatus according to a first embodiment to which the present invention is applied. The vehicle is provided with a vehicle air conditioner 1 for adjusting the temperature in the passenger compartment. The air conditioner 1 includes a refrigeration cycle device 2 for a vehicle mounted on the vehicle. The refrigeration cycle apparatus 2 is mainly used for cooling the air supplied into the passenger compartment. The refrigeration cycle apparatus 2 may provide a heat pump cycle that heats the air supplied to the passenger compartment. The vehicle is provided with a motor 3 as a power source for driving the vehicle. The motor 3 drives the drive wheels of the vehicle. The vehicle is provided with a battery 4 for supplying power to the motor 3. The battery 4 is a secondary battery. The battery 4 is an electrochemical device mounted on the vehicle. The battery 4 is an electric device mounted on the vehicle. The battery 4 is provided by, for example, a lithium ion battery. The refrigeration cycle apparatus 2 is configured to be able to exchange heat with the battery 4. The refrigeration cycle device 2 is a device for the air conditioner 1 and also a battery temperature adjusting device for adjusting the temperature of the battery 4. The vehicle is provided with a control device 5 that controls the refrigeration cycle apparatus 2.

  The refrigeration cycle apparatus 2 includes a compressor 21, a condenser 22, a first decompressor 23, an intermediate heat exchanger 24 for electrical equipment, a gas-liquid separator 25, a second decompressor 26, and evaporation. Instrument 27. The refrigeration cycle provided by the refrigeration cycle apparatus 2 is also called a gas injection cycle. The compressor 21, the condenser 22, the first pressure reducer 23, the gas-liquid separator 25, the second pressure reducer 26, and the evaporator 27 are arranged on the main refrigerant circuit 28 in the above order. A gas injection passage 29 is provided between the gas-liquid separator 25 and the compressor 21.

The compressor 21 sucks low-pressure refrigerant and pressurizes it to discharge the high-pressure refrigerant.
The compressor 21 is a gas injection type compressor that introduces an intermediate-pressure gas refrigerant in an intermediate stage of the compression process. The compressor 21 includes a low-pressure refrigerant suction port 21a, a gas injection port 21b for introducing a medium-pressure refrigerant, and a pressurized refrigerant discharge port 21c. The compressor 21 has a first compression stage and a second compression stage, and has a gas injection port 21b between the first compression stage and the second compression stage. The condenser 22 is a radiator that radiates heat from the high-pressure refrigerant discharged from the compressor 21. The condenser 22 condenses the refrigerant by dissipating the high-pressure refrigerant. The condenser 22 condenses the refrigerant by exchanging heat with air outside the passenger compartment.

  The first pressure reducer 23 depressurizes the high-pressure refrigerant output from the condenser 22 to an intermediate pressure. The first decompressor 23 decompresses the high-pressure refrigerant and supplies the intermediate-pressure refrigerant to the intermediate heat exchanger 24 and the gas-liquid separator 25. An intermediate pressure refrigerant is obtained by the first pressure reducer 23. The first pressure reducer 23 is a valve whose opening degree can be adjusted. The opening degree of the first decompressor 23 is adjusted by the control device 5.

  An intermediate heat exchanger 24 for adjusting the temperature of the battery 4 as an electric device mounted on the vehicle is provided downstream of the first decompressor 23. The intermediate heat exchanger 24 is provided between the first pressure reducer 23 and the gas-liquid separator 25, and is configured to be able to exchange heat with electrical equipment. The intermediate heat exchanger 24 provides direct or indirect heat exchange between the intermediate pressure refrigerant and the electrical equipment.

  The intermediate heat exchanger 24 includes a first heat exchanger 24a, a heat transport medium circulation system 24b, and a second heat exchanger 24c. The first heat exchanger 24a provides heat exchange between the refrigerant and the heat transport medium. The circulation system 24b provides a circulation passage through which the heat transport medium circulates between the first heat exchanger 24a and the second heat exchanger 24c. For example, water can be used as the heat transport medium. The circulation system 24b provides heat transport between the battery 4 and the intermediate pressure refrigerant. The circulation system 24b enables heat transfer in both directions, ie, heat transfer from the battery 4 to the intermediate pressure refrigerant and heat transfer from the intermediate pressure refrigerant to the battery 4. The circulation system 24b enables both cooling of the battery 4 by the intermediate pressure refrigerant and heating of the battery 4 by the intermediate pressure refrigerant. The second heat exchanger 24c provides heat exchange between the battery 4 and the heat transport medium.

  A gas-liquid separator 25 is provided downstream of the intermediate heat exchanger 24. The gas-liquid separator 25 separates the liquid refrigerant and the gas refrigerant. The gas-liquid separator 25 is connected to the compressor 21 via a gas injection passage 29. Further, the gas-liquid separator 25 is connected to the second decompressor 26 via the main refrigerant circuit 28. The gas-liquid separator 25 supplies the gas refrigerant to the compressor 21 and supplies the liquid refrigerant to the second decompressor 26. The intermediate heat exchanger 24 is disposed between the first pressure reducer 23 and the gas-liquid separator 25.

  A second decompressor 26 is provided downstream of the gas-liquid separator 25 on the main refrigerant circuit 28. The second pressure reducer 26 reduces the intermediate pressure refrigerant to a low pressure for air conditioning. An evaporator 27 is provided downstream of the second decompressor 26. The evaporator 27 is an endothermic heat exchanger that absorbs heat from the refrigerant. The evaporator 27 cools the air supplied to the vehicle interior by exchanging heat with the air supplied to the vehicle interior.

  The control device 5 is provided by a microcomputer provided with a computer-readable storage medium. The storage medium stores a computer-readable program. The storage medium can be provided by a memory. The program is executed by the control device 5 to cause the control device 5 to function as a device described in this specification, and to cause the control device 5 to function so as to execute the control method described in this specification. The means provided by the control device 5 can also be called a functional block or module that achieves a predetermined function.

  The air conditioner 1 can include a plurality of sensors as a plurality of detection means for detecting the operating state of the refrigeration cycle apparatus 2. One of the plurality of sensors is a pressure sensor 53. The pressure sensor 53 detects the intermediate pressure Pm. The pressure sensor 53 provides intermediate pressure detection means for detecting the intermediate pressure Pm.

  The air conditioner 1 can include a plurality of sensors as a plurality of detection means for detecting the state of the battery 4, for example, the temperature state. One of the plurality of sensors is a temperature sensor 54. The temperature sensor 54 detects the temperature Tb of the battery 4. The temperature sensor 54 is installed in the container (battery pack) of the battery 4. The temperature sensor 54 provides battery temperature detection means for detecting the temperature Tb of the battery 4. The temperature sensor 54 is also a device temperature detection means for detecting the temperature Tb of the electrical device to be temperature controlled.

  The control device 5 controls the first pressure reducer 23 so that the refrigeration cycle device 2 functions for air conditioning in the passenger compartment. Furthermore, the control device 5 controls the first pressure reducer 23 so that the refrigeration cycle device 2 functions to adjust the temperature of the battery 4. The control device 5 provides control means for controlling the first pressure reducer 23 so that the battery 4 is heated by the intermediate pressure refrigerant flowing in the intermediate heat exchanger 24. Further, the control device 5 controls the first decompressor 23 so that the refrigeration cycle device 2 functions for air conditioning in the passenger compartment and for adjusting the temperature of the battery 4.

  The control device 5 includes a cooling control unit 51 and a heating control unit 52. The cooling control means 51 controls the first decompressor 23 so as to cool the battery 4. The cooling control means 51 controls the opening of the first decompressor 23 to a relatively small opening so that a low temperature that can cool the battery 4 in the intermediate heat exchanger 24 is obtained. The cooling control means 51 adjusts the opening of the first pressure reducer 23 so that the intermediate pressure Pm becomes a relatively low pressure so that a low temperature capable of cooling the battery 4 in the intermediate heat exchanger 24 is obtained. . The heating control means 52 controls the first decompressor 23 so as to heat the battery 4. The heating control means 52 controls the opening of the first decompressor 23 to a relatively large opening so that a high temperature capable of heating the battery 4 in the intermediate heat exchanger 24 is obtained. The heating control means 52 adjusts the opening of the first pressure reducer 23 so that the intermediate pressure Pm becomes a relatively high pressure so that a high temperature capable of heating the battery 4 in the intermediate heat exchanger 24 is obtained. .

  The battery 4 of this embodiment exhibits high performance when the temperature of the battery 4 is within a predetermined optimum temperature range. The optimum temperature range is, for example, between 10 ° C and 40 ° C. The control device 5 controls the first decompressor 23 so that the temperature of the battery 4 is maintained in the optimum temperature range. The control device 5 feedback-controls the first pressure reducer 23 so that the intermediate pressure Pm becomes a predetermined cooling target pressure Pmc or a heating target pressure Pmh. The temperature of the battery 4 is detected by the temperature sensor 54. The intermediate pressure Pm is detected by the pressure sensor 53. When the temperature of the battery 4 is within the optimum temperature range, the control device 5 operates the refrigeration cycle device 2 as a gas injection cycle, and controls the first decompressor 23 so as to function mainly for air conditioning in the passenger compartment. .

  FIG. 2 is a Mollier diagram showing a cooling control state by the vehicle refrigeration cycle apparatus of the first embodiment. The refrigerant temperature at the cooling target pressure Pmc is sufficiently lower than the temperature of the battery 4. In this embodiment, when the temperature of the battery 4 exceeds 40 ° C. which is the upper limit temperature, the control by the cooling control means 51 is executed. Therefore, the refrigerant temperature at the cooling target pressure Pmc is lower than 40 ° C. As a result, the battery 4 is cooled and cooled by the refrigeration cycle apparatus 2.

  FIG. 3 is a Mollier diagram showing a heating control state by the vehicle refrigeration cycle apparatus of the first embodiment. The refrigerant temperature at the heating target pressure Pmh is sufficiently higher than the temperature of the battery 4. In this embodiment, when the temperature of the battery 4 falls below 10 ° C. which is the lower limit temperature, the control by the heating control means 52 is executed. Therefore, the refrigerant temperature at the heating target pressure Pmh is higher than 10 ° C. As a result, the battery 4 is heated and warmed by the refrigeration cycle apparatus 2.

  2 and 3, the pressure in the intermediate heat exchanger 24 and the liquid refrigerant pressure and the gas refrigerant pressure downstream of the gas-liquid separator 25 are illustrated as different pressures. This is a device on the Mollier diagram. It has been edited to facilitate understanding of the positions and functions of 22, 23, 24, 25, 26, and 27.

  In this embodiment, an intermediate pressure of 0.4 MPa to 0.8 MPa can be obtained downstream of the first pressure reducer 23, and a refrigerant temperature of 10 ° C. to 30 ° C. can be obtained in the range of the intermediate pressure. A refrigerant is used.

  The control device 5 (cooling control means 51) controls the first decompressor 23 to cool the battery 4 when the temperature of the battery 4 exceeds 40 ° C. The cooling control means 51 feedback-controls the first pressure reducer 23 so that the intermediate pressure Pm becomes a predetermined cooling target pressure Pmc.

  When the temperature of the battery 4 falls below 10 ° C., the control device 5 (heating control means 52) controls the first pressure reducer 23 so as to heat the battery 4. The heating control means 52 feedback-controls the first pressure reducer 23 so that the intermediate pressure Pm becomes a predetermined heating target pressure Pmh.

  The control device 5 sets a target pressure in accordance with a necessary heating amount necessary for adjusting the temperature of the battery 4 within an optimum temperature range suitable for the operation of the battery 4. The heating target pressure Pmh can be set so that the intermediate pressure Pm increases as the necessary heating amount necessary to maintain the temperature of the battery 4 in the optimum temperature range increases. The necessary heating amount can be given by the difference between the temperature of the battery 4 detected by the temperature sensor 54 and the target temperature. The target temperature can be a temperature value within the optimum temperature range, and can be, for example, 25 ° C. The heating target pressure Pmh is set higher as the temperature of the battery 4 becomes lower than the target temperature. Thereby, the temperature of the refrigerant in the intermediate heat exchanger 24 is maintained higher than the temperature of the battery 4. Furthermore, since the temperature of the refrigerant increases as the temperature of the battery 4 becomes lower than the target temperature, the temperature of the battery 4 can be quickly adjusted to the target temperature.

  The control device 5 sets the target pressure so that the temperature of the refrigerant in the intermediate heat exchanger 24 falls within the optimum temperature range suitable for the operation of the battery 4. That is, the heating target pressure Pmh is set to be equal to or lower than a predetermined upper limit pressure. The upper limit pressure of the heating target pressure Pmh is set to a pressure value at which the refrigerant temperature at the intermediate pressure becomes a temperature equal to or lower than the upper limit value of the optimum temperature range of the battery 4. Specifically, the upper limit pressure of the heating target pressure Pmh can be set to about 0.8 MPa at which the refrigerant temperature becomes 30 ° C., which is lower than 40 ° C., which is the upper limit temperature of the battery 4. Thereby, excessive heating of the battery 4 can be avoided. The cooling target pressure Pmc can also be set similarly to the heating target pressure Pmh. That is, the variable ranges of the target pressures Pmc and Pmh can be set so that the refrigerant temperature range obtained in the variable ranges is within the optimum temperature range of the battery 4.

  According to this embodiment, the battery 4 can be cooled by the refrigeration cycle apparatus 2, and the battery 4 can be heated by the refrigeration cycle apparatus 2. For this reason, the temperature of the battery 4 can be maintained in a predetermined temperature range.

(Second Embodiment)
FIG. 4 is a block diagram showing a vehicle refrigeration cycle apparatus according to a second embodiment to which the present invention is applied. In the first embodiment, the intermediate heat exchanger 24 that uses water as a heat transport medium is employed. Instead, this embodiment employs an intermediate heat exchanger 224 that uses air as a heat transport medium. The battery 204 is configured to be able to exchange heat with air. The intermediate heat exchanger 224 includes a first heat exchanger 224a and a blower 224b. The first heat exchanger 224a provides heat exchange between the intermediate-pressure refrigerant and air. The blower 224 b supplies the air that has passed through the first heat exchanger 224 a to the battery 204. Also in this configuration, the intermediate heat exchanger 224 can cool the battery 204 and can heat the battery 204.

(Third embodiment)
FIG. 5 is a block diagram showing a vehicle refrigeration cycle apparatus according to a third embodiment to which the present invention is applied. In the said embodiment, the intermediate heat exchanger 24 using a heat transport medium was employ | adopted. Instead, this embodiment employs an intermediate heat exchanger 324 that provides direct heat exchange between the intermediate pressure refrigerant and the battery 4. The intermediate heat exchanger 324 includes a pipe 324 b that is provided downstream of the first pressure reducer 23 and reaches the battery 4. Further, the intermediate heat exchanger 324 includes a heat exchanger 324c that provides heat exchange between the battery 4 and the refrigerant. Also in this configuration, the intermediate heat exchanger 324 can cool the battery 4 and can heat the battery 4.

(Fourth embodiment)
FIG. 6 is a block diagram showing a vehicle refrigeration cycle apparatus according to a fourth embodiment to which the present invention is applied. In the above embodiment, the temperature sensor 54 is disposed so as to directly detect the temperature of the battery 4. Instead, in this embodiment, the temperature sensor 454 detects the temperature of water that is a heat transport medium. The temperature sensor 454 is provided in the piping of the circulation system 24b and detects the temperature of the heat transport medium. The temperature of the heat transport medium corresponds to the temperature of the battery 4. Therefore, the temperature sensor 454 indirectly detects the temperature of the battery 4. Also in this configuration, the intermediate heat exchanger 324 can cool the battery 4 and can heat the battery 4.

(Fifth embodiment)
FIG. 7 is a block diagram showing a vehicle refrigeration cycle apparatus according to a fifth embodiment to which the present invention is applied. In the above embodiment, the intermediate pressure Pm downstream of the first pressure reducer 23 is controlled to the target pressures Pmc and Pmh. Instead, the dryness χ (chi) of the refrigerant downstream of the first pressure reducer 23 is detected. This dryness is controlled to the target dryness. The dryness χ corresponds to the ratio of vapor refrigerant (gas refrigerant) in the gas-liquid mixed refrigerant downstream of the first pressure reducer 23. The dryness χ corresponds to the amount of vapor on the isobaric line between the saturated vapor line and the saturated liquid line, as shown in FIG. The air conditioner 1 includes a dryness calculation unit 553 instead of the pressure sensor 53. The dryness calculating means 553 includes a plurality of detecting means for detecting the operating state of the refrigeration cycle apparatus 2 necessary for calculating the dryness χ.

  For example, the dryness calculating means 553 includes a discharge pressure sensor and a discharge temperature sensor that detect the state of the refrigerant discharged from the compressor 21. Further, the dryness calculating means 553 can include a density sensor that detects the refrigerant density at the intermediate pressure, a rotation speed sensor that detects the rotation speed of the compressor, and a capacity sensor that detects the discharge volume of the compressor. The circulation amount of the refrigerant is calculated from the refrigerant density at the intermediate pressure, the discharge volume of the compressor 21, and the rotation speed. Further, the dryness calculating means 553 can include a temperature sensor and an air volume sensor for detecting the heat radiation amount in the condenser 22. The dryness calculating means 553 calculates the dryness χ from these detected values. Instead of the dryness χ, the enthalpy or wetness of the refrigerant may be calculated.

  The control device 5 controls the first pressure reducer 23 so that the dryness χ of the refrigerant becomes the target dryness according to the heating amount or cooling amount required in the intermediate heat exchanger 24. Also in this configuration, the intermediate heat exchanger 24 can cool the battery 4 and can heat the battery 4.

(Sixth embodiment)
FIG. 8 is a block diagram showing a vehicle refrigeration cycle apparatus according to a sixth embodiment to which the present invention is applied. In the said embodiment, the refrigerating-cycle apparatus 2 was utilized also as a battery temperature control apparatus. In addition to this, in this embodiment, when the refrigeration cycle apparatus 2 is used as a battery temperature adjusting device, a protection means for protecting the refrigeration cycle apparatus 2 from liquid compression is adopted.

  FIG. 9 is a Mollier diagram showing the liquid back state of the vehicle refrigeration cycle apparatus. When the battery 4 is heated by the intermediate pressure Pm, the amount of heat released from the refrigerant, that is, the heating amount of the battery 4 may be too large. In this case, the refrigerant after the intermediate heat exchanger 24 has a low enthalpy, and most of the refrigerant may become a liquid phase refrigerant. In this case, the gas-liquid separator 25 is filled with the liquid refrigerant, and the liquid refrigerant may flow into the gas injection passage 29. Such a phenomenon is called liquid back. When the liquid back is generated, liquid compression occurs in the compressor 21 and the compressor 21 may be damaged.

  The control device 5 includes liquid back prevention control means 655 as protection means. The liquid back prevention control means 655 includes a plurality of detection means for detecting the operating state of the refrigeration cycle apparatus 2 necessary for detecting a liquid back. Furthermore, the control device 5 includes a limiting unit 656 for adjusting the heat load in the intermediate heat exchanger 24, that is, the amount of heat exchange between the battery 4 and the refrigerant in the intermediate heat exchanger 24, and particularly reducing the amount of heat exchange. . The restricting means 656 can be provided by a pump 656 that regulates the flow rate of the heat transport medium in the circulation system 24b. The liquid back prevention control unit 655 reduces the amount of heat exchange between the intermediate heat exchanger 24 and the battery 4 when the liquid back to the compressor 21 is detected. By reducing the heat exchange amount, the condensation of the refrigerant in the intermediate heat exchanger 24 is suppressed, and the liquid back is suppressed. As a result, liquid compression due to the liquid back is suppressed.

  For example, the liquid back prevention control unit 655 can include a sensor that detects the pressure and / or temperature of the refrigerant on the discharge side of the compressor 21. The sign of liquid compression can be detected by the temperature drop of the refrigerant discharged from the compressor 21. The liquid back prevention control means 655 controls the pump 656 so as to reduce the heat load in the intermediate heat exchanger 24 when the above-mentioned index related to the temperature of the discharged refrigerant is out of the predetermined value range mapped in advance. To do. That is, when the temperature of the discharged refrigerant falls below the specified value due to the liquid back to the compressor 21, the rotational speed of the pump 656 is reduced and the flow rate is reduced. Thereby, the amount of heat exchange in the intermediate heat exchanger 24 is limited, and excessive liquefaction of the refrigerant is prevented. For this reason, the gas-liquid separator 25 can supply the gas refrigerant to the gas injection passage 29 again.

  In this embodiment, the rotational speed of the pump 656 is reduced. However, in the configuration of the second embodiment, the rotational speed of the blower 224b may be reduced.

  According to this embodiment, the temperature of the battery 4 can be maintained in a predetermined temperature range, and the refrigeration cycle apparatus 2 can be protected from liquid compression.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. The structure of the said embodiment is an illustration to the last, Comprising: The scope of the present invention is not limited to the range of these description. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  For example, in the above embodiment, the cooling control means 51 controls the intermediate pressure Pm to the cooling target pressure Pmc. Instead of this, the first pressure reducer 23 may be controlled so that the degree of supercooling downstream of the condenser 22 is controlled to the cooling target value. The degree of supercooling is also called a subcool, and is indicated by the symbol SC in FIG.

  In the above embodiment, the refrigeration cycle apparatus 2 is used for both cooling and heating of the battery 4. Instead of this, the refrigeration cycle apparatus 2 may be used only for heating the battery 4. In this case, the battery 4 may be cooled by an air cooling structure using air outside the passenger compartment or air inside the passenger compartment.

  Further, the means and functions provided by the control device can be provided by software only, hardware only, or a combination thereof. For example, the control device may be configured by an analog circuit.

  DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner, 2 Vehicle refrigeration cycle apparatus, 21 Compressor, 22 Condenser, 23 1st decompressor, 24 Intermediate heat exchanger, 24a 1st heat exchanger, 24b Circulation system, 24c 2nd heat exchanger , 25 Gas-liquid separator, 26 Second decompressor, 27 Evaporator, 3 Motor, 4 Battery, 5 Control device, 51 Cooling control means, 52 Heating control means, 53 Pressure sensor (intermediate pressure detection means), 54 Temperature sensor (Equipment temperature detection means), 204 battery, 205 blower, 224 intermediate heat exchanger, 224a first heat exchanger, 224b blower, 324 intermediate heat exchanger, 324b pipe, 324c heat exchanger, 454 temperature sensor, 553 dryness Calculation means, 655 Liquid back prevention control means, 656 pump.

Claims (6)

A compressor (21) having a low-pressure refrigerant suction port (21a) and a gas injection port (21b);
A gas-liquid separator (25) connected to the compressor via a gas injection passage (29);
A decompressor (23) for decompressing the high-pressure refrigerant and supplying it to the gas-liquid separator;
An intermediate heat exchanger (24, 224, 324) provided between the pressure reducer and the gas-liquid separator and capable of exchanging heat with the electric device (4);
The vehicle refrigeration cycle apparatus comprising: control means (5) for controlling the decompressor so that the electric device is heated by the intermediate-pressure refrigerant flowing through the intermediate heat exchanger.   The said control means (5) controls the said pressure reduction device (23) so that the intermediate pressure (Pm) of the refrigerant | coolant in the said intermediate heat exchanger may be controlled to target pressure (Pmc, Pmh). The vehicle refrigeration cycle apparatus according to 1.   The control means (5) sets the target pressure in accordance with a necessary heating amount necessary for adjusting the temperature of the electric device within a temperature range suitable for the electric device to operate. The vehicle refrigeration cycle apparatus according to claim 2.   The said control means (5) sets the said target pressure high, so that the said required heating amount becomes large, The refrigeration cycle apparatus for vehicles of Claim 3 characterized by the above-mentioned.   The said control means (5) sets the said target pressure so that the temperature of the refrigerant | coolant in the said intermediate heat exchanger may become in the temperature range suitable for the said electric equipment to operate | move. The vehicle refrigeration cycle apparatus according to any one of claims 2 to 4.   The said control apparatus is equipped with the liquid back prevention control means (655) which reduces the heat exchange amount of the said intermediate heat exchanger and the said electric equipment, if the liquid back to the said compressor is detected. The refrigeration cycle device for a vehicle according to any one of claims 5 to 6.

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