JP6167891B2 - Heat pump cycle device. - Google Patents

Description

  The present invention relates to a heat pump cycle apparatus.

  Patent Document 1 discloses a refrigeration cycle apparatus in which an evaporator is arranged inside (inside the room) of a refrigerated refrigeration warehouse, and a radiator is arranged outside (outside the room) to cool the inside air using the evaporator. Is described.

  This refrigeration cycle apparatus includes a refrigerant circuit in which refrigerant circulates in the order of a compressor, an outdoor radiator, an expansion valve (throttle), and an indoor evaporator, and frost detection means for detecting the frost formation amount of the indoor evaporator. I have. Then, in order to suppress the growth of frost generated on the surface of the indoor evaporator, a target evaporation temperature that does not cause insufficient cooling capacity is determined according to the detection result of the frosting detection means, and the refrigerant in the indoor evaporator is determined. The rotation speed of the compressor is adjusted so that the evaporation temperature becomes the target evaporation temperature. Furthermore, this refrigeration cycle apparatus is provided with dew point temperature detecting means for detecting the dew point temperature of the internal air, and determines the target evaporation temperature described above according to the detected dew point temperature.

JP 2012-52758 A

  By the way, in the heat pump cycle apparatus in which the refrigerant circulates and flows in the order of the compressor, the radiator, the throttle, and the evaporator, the evaporator (outdoor evaporator) is disposed outside the room, and the object to be heated is heated by the radiator. Under outdoor temperature and high humidity conditions, with the progress of the heating operation, frosting occurs in the outdoor evaporator, and there is a problem that the heat dissipation capability of the radiator is reduced.

  Therefore, in such a heat pump cycle device, a configuration in which the refrigerant discharge capacity of the compressor is adjusted so that the temperature of the outdoor evaporator becomes a temperature at which frost formation can be suppressed is considered (hereinafter, this configuration is referred to as a study example). ). According to this, since the temperature of the outdoor evaporator is a temperature at which frost formation can be suppressed during the heating operation, frost formation of the outdoor evaporator can be suppressed.

  However, in this study example, the evaporation temperature of the refrigerant in the outdoor evaporator is limited and the refrigerant discharge capacity of the compressor is also limited, so that both the heat absorption amount of the outdoor evaporator and the compression work of the compressor are reduced. It will be restricted. For this reason, compared with the case where the temperature of an outdoor evaporator is not made into the temperature which can suppress frost formation, in the examination example, the thermal radiation capability of a heat sink falls remarkably. The heat dissipation capability of the radiator is the sum of the heat absorption amount of the outdoor evaporator and the compression work amount of the compressor.

  An object of this invention is to provide the heat pump cycle apparatus which can suppress the frost formation of an outdoor evaporator, suppressing the fall of the thermal radiation capability of a radiator in view of the said point.

In order to achieve the above object, in the invention described in claim 1,
Compressors (11, 21) for compressing and discharging the sucked refrigerant;
A radiator (12, 61, 71) for dissipating the refrigerant discharged from the compressor to heat the object to be heated;
A first throttle (13) for depressurizing the refrigerant that has flowed out of the radiator by narrowing the refrigerant flow path;
An outdoor evaporator (14) which is disposed outside and evaporates the refrigerant decompressed by the first throttle by heat exchange with the outside air;
A second throttle (15) for depressurizing the refrigerant that has flowed out of the outdoor evaporator and flowing into the compressor by narrowing the refrigerant flow path ;
A refrigerant flow path for allowing the refrigerant decompressed by the second throttle to flow into the compressor without passing through a heat exchanger that exchanges heat between the refrigerant and a fluid different from the refrigerant ,
When the refrigerant decompressed by the second throttle flows into the compressor without passing through the heat exchanger, the second throttle has a throttle opening at which the temperature of the outdoor evaporator becomes a temperature at which frost formation can be suppressed. In addition, the compressor is characterized in that the refrigerant discharge capability is adjusted so that the radiator exhibits a desired heat dissipation capability.

  In the present invention, in order to suppress the frost formation of the outdoor evaporator, the temperature of the outdoor evaporator is set to a temperature at which frost formation can be suppressed by the second throttle, and compression is performed so that the radiator exhibits a desired heat dissipation capability. The refrigerant discharge capacity of the machine is adjusted. In this case, the heat absorption amount of the outdoor evaporator is limited in the same manner as in the above-described study example, but the compression work amount of the compressor is not limited as in the study example. In this case, as compared with the examination example when the temperature of the outdoor evaporator is set to the same temperature as the present invention, the compression work of the compressor increases as the suction pressure of the compressor by the second throttle decreases. Since the specific enthalpy of the refrigerant discharged from the compressor increases, the heat dissipation capability of the radiator can be improved (see FIG. 7).

  Therefore, according to this invention, compared with the example of examination, frost formation of an outdoor evaporator can be suppressed, suppressing the fall of the thermal radiation capability of a radiator.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a whole lineblock diagram of the heat pump cycle device of a 1st embodiment. It is a figure which shows the refrigerant circuit at the time of the cooling operation of the heat pump cycle apparatus of 1st Embodiment. It is a figure which shows the refrigerant circuit at the time of the heating operation of the heat pump cycle apparatus of 1st Embodiment. It is a flowchart which shows the control processing which the electronic controller of 1st Embodiment performs. It is a figure for demonstrating the target outdoor heat exchanger temperature TOO used in the case of determination of the opening degree of a 2nd aperture_diaphragm | restriction in step S17 in FIG. It is a figure for demonstrating the determination method of the aperture opening degree of the 2nd aperture_diaphragm | restriction in step S17 in FIG. It is a Mollier diagram which shows the state of the refrigerant | coolant at the time of each heating operation of 1st Embodiment and the comparative example. It is a figure for demonstrating the target outdoor heat exchanger temperature TOO used in the case of determination of the aperture opening degree of the 2nd aperture_diaphragm | restriction at the time of heating operation of 2nd Embodiment. It is a whole block diagram of the heat pump cycle apparatus of 3rd Embodiment. It is a flowchart which shows the control processing which the electronic control apparatus of 3rd Embodiment performs. It is a figure which shows the refrigerant circuit at the time of the heating operation of the heat pump cycle apparatus of 3rd Embodiment. It is a whole block diagram of the heat pump cycle apparatus of 4th Embodiment. It is a whole block diagram of the heat pump cycle apparatus of 5th Embodiment. It is a whole block diagram of the heat pump cycle apparatus of 6th Embodiment. It is a figure which shows the 2nd aperture_diaphragm | restriction of other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
As shown in FIG. 1, in this embodiment, the heat pump cycle device 10 according to the present invention is applied to a vehicle air conditioner 1 mounted on an electric vehicle that obtains driving force for traveling from a traveling electric motor. Yes. This heat pump cycle device 10 fulfills the function of cooling or heating the vehicle interior air blown into the vehicle interior, which is the air conditioning target space, in the vehicle air conditioner 1.

  Therefore, as shown in FIG. 2, the heat pump cycle device 10 has a refrigerant circuit in a cooling mode (cooling operation) for cooling the air blown in the vehicle interior to cool the vehicle interior, and air blown in the vehicle interior as shown in FIG. It is configured to be able to switch between a refrigerant circuit in a heating mode (heating operation) in which air is heated to heat the vehicle interior. Moreover, in the heat pump cycle apparatus 10 of this embodiment, the normal CFC-type refrigerant | coolant is employ | adopted as a refrigerant | coolant, and the subcritical refrigeration cycle in which the pressure of a high pressure refrigerant | coolant does not exceed the critical pressure of a refrigerant | coolant is comprised.

  As shown in FIG. 1, the heat pump cycle apparatus 10 includes a compressor 11, an indoor condenser 12, a first throttle 13, an outdoor heat exchanger 14, a second throttle 15, a three-way valve 16, and indoor evaporation. A container 17, an accumulator 18, and an electronic control unit 40.

  The compressor 11 is disposed in the vehicle bonnet, sucks the refrigerant in the heat pump cycle device 10, compresses it, and discharges it. The fixed displacement type compression mechanism with a fixed discharge capacity is driven to rotate by an electric motor. It is configured as an electric compressor. The operation (rotation speed) of the electric motor of the compressor 11 is controlled by a control signal output from the electronic control unit 40.

  The inlet side of the indoor condenser 12 is connected to the discharge port side of the compressor 11. The indoor condenser 12 is disposed in a casing 31 that forms an air passage for air blown into the vehicle interior in the indoor air conditioning unit 30. The indoor condenser 12 is a radiator that heats the discharged refrigerant and heats the blown air in the vehicle as a heating target by exchanging heat between the high-pressure discharged refrigerant discharged from the compressor 11 and the blown air in the vehicle. is there.

  The inlet side of the first throttle 13 is connected to the outlet side of the indoor condenser 12. The first throttle 13 depressurizes the refrigerant that has flowed out of the indoor condenser 12 by restricting the cross-sectional area of the refrigerant flow path that guides the refrigerant that has flowed out of the indoor condenser 12 to the outdoor heat exchanger 14 during heating operation. Depressurizing means. The first throttle 13 is configured to be able to change the flow path cross-sectional area of the refrigerant flow path. Specifically, the first throttle 13 is an electric that is configured to include a valve body that can change the throttle opening and an electric actuator that includes a stepping motor that changes the throttle opening of the valve body. This is a variable aperture mechanism of the type. In the first throttle 13, the throttle opening degree of the valve body is increased or decreased by a control signal output from the electronic control device 40. The first throttle 13 of the present embodiment has a fully open function that hardly exerts a pressure reducing action by fully opening the throttle opening of the valve body.

  The inlet side of the outdoor heat exchanger 14 is connected to the outlet side of the first throttle 13. The outdoor heat exchanger 14 is disposed inside the vehicle bonnet, that is, outside the vehicle compartment, and exchanges heat between the refrigerant flowing through the inside and the outside air blown by the blower fan 14a. More specifically, the outdoor heat exchanger 14 functions as an evaporator that evaporates the low-pressure refrigerant during the heating operation and exerts an endothermic effect, and functions as a radiator that radiates the high-pressure refrigerant during the cooling operation. The blower fan 14a is an electric blower in which the operation rate, that is, the rotation speed (the amount of blown air) is controlled by a control voltage output from the control device.

  The inlet side of the second throttle 15 is connected to the outlet side of the outdoor heat exchanger 14. The second throttle 15 reduces the refrigerant flowing out of the outdoor heat exchanger 14 by restricting the cross-sectional area of the refrigerant flow path through which the refrigerant flowing out of the outdoor heat exchanger 14 flows during cooling operation and heating operation. Depressurizing means. The second throttle 15 is an electric variable throttle mechanism similar to the first throttle 13, and the throttle opening degree of the valve body is increased or decreased by a control signal output from the electronic control device 40. Similar to the first diaphragm 13, the second diaphragm 15 also has a fully open function. The first throttle 13 and the second throttle 15 are not limited to a configuration in which the throttle opening can be continuously changed, and may be configured to be able to change the throttle opening in a stepwise manner.

  The outlet side of the second throttle 15 is connected to the inlet side of the indoor evaporator 17 and the inlet side of the accumulator 18 via a three-way valve 16. The three-way valve 16 includes a refrigerant flow path that guides the refrigerant flowing out of the second throttle 15 to the indoor evaporator 17, and a refrigerant flow path that guides the refrigerant flowing out of the second throttle 15 to the accumulator 18 bypassing the indoor evaporator 17. It is the refrigerant | coolant flow path switching means which switches. The three-way valve 16 is an electric three-way valve whose operation is controlled by a control voltage output from the electronic control unit 40.

  The indoor evaporator 17 is disposed upstream of the indoor condenser 12 in the casing 31 of the indoor air conditioning unit 30. The indoor evaporator 17 absorbs and evaporates the refrigerant by heat exchange between the refrigerant circulating in the interior and the air blown into the vehicle interior during the cooling operation, and cools the air blown into the vehicle interior by the heat absorption effect (cooling). Heat exchanger). The inlet side of the accumulator 18 is connected to the refrigerant outlet side of the indoor evaporator 17.

  The accumulator 18 is a gas-liquid separator that separates the gas-liquid refrigerant flowing into the accumulator 18 and stores excess refrigerant in the cycle. The suction side of the compressor 11 is connected to the gas-phase refrigerant outlet of the accumulator 18. Accordingly, the accumulator 18 functions to prevent the compressor 11 from being compressed by suppressing the suction of the liquid phase refrigerant into the compressor 11.

  Next, the indoor air conditioning unit 30 will be described. The indoor air-conditioning unit 30 blows the temperature-adjusted vehicle interior air into the vehicle interior, and is disposed inside the instrument panel (instrument panel) at the foremost portion of the vehicle interior to form a casing 31 thereof. It is comprised by accommodating the air blower 32, the above-mentioned indoor condenser 12, the indoor evaporator 17, etc. in the inside.

  The casing 31 forms an air passage for the air blown into the passenger compartment therein, and is formed of a resin having a certain degree of elasticity and excellent in strength. An inside / outside air switching device 33 for switching and introducing vehicle interior air (inside air) and outside air is disposed on the most upstream side of the air flow of the vehicle interior blown air in the casing 31.

  On the downstream side of the air flow of the inside / outside air switching device 33, a blower 32 that blows air sucked through the inside / outside air switching device 33 toward the vehicle interior is arranged. The blower 32 is an electric blower that drives a centrifugal multiblade fan with an electric motor, and the number of rotations (air flow rate) is controlled by a control voltage output from the electronic control unit 40.

  On the downstream side of the air flow of the blower 32, the indoor evaporator 17 and the indoor condenser 12 are arranged in this order with respect to the flow of the air blown into the vehicle interior. Further, a bypass passage 34 is formed in the casing 31 to allow the blown air that has passed through the indoor evaporator 17 to flow around the indoor condenser 12.

  Further, an air passage switching door 35 is disposed on the downstream side of the air flow in the indoor evaporator 17 and on the upstream side of the air flow in the indoor condenser 12. The air passage switching door 35 switches an air passage that passes through the indoor condenser 12 and a bypass passage 34 as an air passage through which the blown air after passing through the indoor evaporator 17 flows. The air passage switching door 35 is driven by a servo motor (not shown), and its operation is controlled by a control signal output from the electronic control unit 40.

  Although not shown in the drawings, an opening that is connected to an air outlet provided in the passenger compartment is provided in the most downstream portion of the air flow of the casing 31. The blown air whose temperature has been adjusted by the indoor evaporator 17 or the indoor condenser 12 is blown out from the blowout port into the vehicle interior, which is the air-conditioning target space, through the opening.

  The heat pump cycle device 10 also includes a first refrigerant temperature sensor 41, a refrigerant pressure sensor 42, and an outdoor heat exchanger 14 that detect the temperature and pressure of the outlet refrigerant of the indoor condenser 12 (inlet refrigerant of the first throttle 13), respectively. A second refrigerant temperature sensor 43 that detects the temperature of the outlet refrigerant (inlet refrigerant of the second throttle 15), an outside air temperature sensor 44 that detects the temperature and humidity of the outside air flowing into the outdoor heat exchanger 14, respectively, an outside air humidity sensor 45, and the like It has. Each sensor 41, 42, 43, 44, 45 is connected to the input side of the electronic control device 40, and a detection signal of each sensor is input to the electronic control device 40.

  The electronic control unit 40 is composed of a known microcomputer including a CPU, ROM, RAM and the like and its peripheral circuits, and performs various calculations and processing based on a control program stored in the ROM, and is connected to the output side. The control means controls the operation of the various control target devices 11, 13, 14a, 15, 16, 32, 35 and the like.

  On the input side of the electronic control unit 40, in addition to the above-described sensors, an inside air sensor that detects the vehicle interior temperature Tr, an outside air sensor that detects the outside air temperature Tam, a solar radiation sensor that detects the amount of solar radiation Ts in the vehicle interior, Various control sensors such as an indoor evaporator temperature sensor for detecting the indoor evaporator temperature Te are connected. The indoor evaporator temperature sensor detects the fin temperature of the indoor evaporator 17 or the air temperature after passing through the indoor evaporator 17 as Te.

  Further, an operation panel (not shown) disposed near the instrument panel in the front part of the vehicle interior is connected to the input side of the electronic control unit 40, and operation signals from various operation switches provided on the operation panel are input. . As various operation switches provided on the operation panel, an air conditioner switch, a temperature setting switch for setting the passenger compartment temperature, and the like are provided.

  Next, control processing executed by the electronic control device 40 will be described. For example, the electronic control device 40 repeatedly executes the control process shown in the flowchart of FIG. 4 until the operation stop of the vehicle air conditioner 1 is requested after the operation start of the vehicle air conditioner 1 is requested by the operation panel. . The processing at each step in FIG. 4 constitutes means for realizing each function.

  First, in step S1 of FIG. 4, the electronic control unit 40 reads the detection signals from the above-described sensors and the operation signals of the operation panel.

  Subsequently, in step S2, a target blowing temperature TAO, which is a target temperature of air blown into the vehicle interior, is determined based on the values of the detection signal and the operation signal read in step S1, and the target of the indoor evaporator temperature Te is determined. A target indoor evaporator temperature TEO, which is a temperature, is determined. TAO is the vehicle interior set temperature Tset set by the temperature setting switch, the vehicle interior temperature Tr detected by the internal air sensor, the outdoor air temperature Tam detected by the external air temperature sensor, and the solar radiation amount Ts detected by the solar radiation sensor. Based on a predetermined calculation formula. Also, TEO is determined based on TAO with reference to a control map stored in advance in electronic control device 40.

  Subsequently, the operation mode is determined in steps S3 and S4.

  Specifically, in step S3, it is determined whether or not the air conditioner switch (A / CSW) on the operation panel is turned on. This air-conditioner switch is a switch for the occupant to set whether or not the vehicle interior blown air is cooled by the indoor evaporator 17. If it is determined that the air conditioner switch is not ON (NO), the process proceeds to step S12, and the operation mode is determined to be the heating operation. On the other hand, if it is determined that the air conditioner switch is ON (YES), the process proceeds to step S4.

  In step S4, it is determined whether or not the difference (TAO-Tam) between the target blowing temperature TAO and the outside air temperature Tam is smaller than the reference temperature α. This α is, for example, 0 ° C. When it is determined that TAO is higher than Tam and TAO-Tam is higher than α (NO), the heating request degree is high, so the process proceeds to step S12 and the operation mode is determined to be the heating operation. On the other hand, if it is determined that TAO is lower than Tam and TAO-Tam is lower than α (YES), the cooling request degree is high, so the process proceeds to step S5 and the operation mode is determined to be the cooling operation.

  When the operation mode is determined to be the cooling operation in step S5, the operation state of each control target device is determined in steps S6 to S10 so that the cooling operation illustrated in FIG. 2 is executed.

  Specifically, in step S6, the opening direction of the three-way valve 16 is determined as the B direction. That is, in order to set the refrigerant flow direction in the three-way valve 16 to the B direction, the connection port for the B direction of the three-way valve 16 is opened and the connection port for the A direction is closed.

  Subsequently, in step S7, the position of the air passage switching door 35 is determined to be a position where the air passage of the indoor condenser 12 is fully closed and the bypass passage 34 is fully opened.

  Subsequently, in step S8, the rotational speed of the compressor 11 is determined so that the indoor evaporator temperature Te detected by the indoor evaporator temperature sensor approaches the target indoor evaporator temperature TEO.

  Subsequently, in step S9, the opening degree of the first diaphragm 13 is determined to be fully open (fixed). This is to suppress deterioration in cycle efficiency due to flow path pressure loss.

  Subsequently, in step S10, the throttle opening of the second throttle 15 is determined as a desired control opening. This desired control opening degree is determined in advance so that the supercooling degree SC_cool of the refrigerant flowing into the second throttle 15 (second throttle inlet refrigerant) approaches the maximum coefficient of performance COP of the cycle. It is a throttle opening degree set so that it may approach SCO_cool. SC_cool is calculated from the difference between the refrigerant saturation temperature corresponding to the inlet refrigerant pressure of the second throttle 15 detected by the refrigerant pressure sensor 42 and the inlet refrigerant temperature of the second throttle 15 detected by the second refrigerant temperature sensor 43. The At this time, since the first throttle 13 is fully opened, the refrigerant pressure sensor 42 can detect the inlet refrigerant pressure of the second throttle 15.

  In step S11, a control signal or a control voltage is output from the electronic control unit 40 to the control target device so as to obtain the control state determined as described above.

  Thereby, in the cooling operation, as indicated by the arrows in FIG. 2, the refrigerant discharged from the compressor 11 is converted into the indoor condenser 12, the first throttle 13 (full opening degree), the outdoor heat exchanger 14, the second A refrigerant circuit is formed in which the throttle 15 (control opening), the indoor evaporator 17, and the accumulator 18 flow in this order and return to the compressor 11. At this time, since the air passage of the indoor condenser 12 is closed by the air passage switching door 35, the refrigerant that has flowed into the indoor condenser 12 does not substantially dissipate heat to the air blown into the vehicle interior. leak. For this reason, the vehicle interior air cooled by the indoor evaporator 17 is blown out into the vehicle interior.

  On the other hand, when the operation mode is determined to be the heating operation in step S12, the operation state of each control target device is determined in steps S13 to S so that the heating operation illustrated in FIG. 3 is executed.

  Specifically, in step S13, the opening direction of the three-way valve 16 is determined as the A direction. That is, in order to set the refrigerant flow in the A direction, the connection port in the B direction of the three-way valve 16 is closed and the connection port in the A direction is opened.

  Subsequently, in step S14, the position of the air passage switching door 35 is determined to be a position where the air passage of the indoor condenser 12 is fully opened and the bypass passage 34 is fully closed.

  Subsequently, in step S15, the rotational speed of the compressor 11 is determined so that the indoor condenser temperature Tav approaches the target blowing temperature TAO. In the present embodiment, the refrigerant saturation temperature calculated based on the outlet refrigerant pressure PH of the indoor condenser 12 detected by the refrigerant pressure sensor 42 is used as Tav. When Tav is lower than TAO, the rotational speed of the compressor 11 is made higher than the rotational speed (previous value) determined previously, and when Tav is higher than TAO, the rotational speed of the compressor 11 is made lower than the previous value. .

  Subsequently, in step S16, the throttle opening of the first throttle 13 is determined as a desired control opening. This desired control opening is the throttle opening that is set so that the degree of supercooling SC_hot of the refrigerant flowing into the first throttle 13 approaches the target subcooling degree SCO_hot that is set in advance so that COP approaches the maximum value. It is. SC_hot is calculated from the difference between the refrigerant saturation temperature corresponding to the inlet refrigerant pressure of the first throttle 13 detected by the refrigerant pressure sensor 42 and the inlet refrigerant temperature of the first throttle 13 detected by the first refrigerant temperature sensor 41. The

  Subsequently, in step S17, the throttle opening of the second throttle 15 is determined as a desired control opening. This desired control opening is a throttle opening that is set so that the outdoor heat exchanger temperature To becomes the target outdoor heat exchanger temperature TOO. TOO is a temperature at which the outdoor heat exchanger 14 does not frost, and is determined according to the dew point temperature Tdp of the outside air.

  Specifically, as shown in FIG. 5, TOO is set to a temperature equal to or higher than Tdp. That is, TOO [° C.] = Tdp [° C.] (temperature on a straight line shown in FIG. 5) or TOO [° C.] = Tdp + Z [° C.] (temperature on a straight line shown in a dashed line in FIG. 5) And Z is a fixed value, for example, Z = 1 ° C. When TOO is set to a temperature lower than Tdp, To becomes a temperature lower than Tdp, and condensed water resulting from frosting adheres to the surface of the outdoor heat exchanger 14 (condensed water adhesion in FIG. 5). region). On the other hand, if TOO is set to a temperature equal to or higher than Tdp, To becomes a temperature equal to or higher than Tdp, and adhesion of condensed water to the surface of the outdoor heat exchanger 14 can be prevented, and frost formation on the outdoor heat exchanger 14 is prevented. Can be prevented.

  In this embodiment, the detected temperature of the second refrigerant temperature sensor 43 that detects the temperature of the outlet refrigerant of the outdoor heat exchanger 14 is used as To. Tdp is calculated from the outside air temperature and the outside air humidity detected by the outside air temperature sensor 44 and the outside air humidity sensor 45 as dew point temperature detecting means.

  In the determination of the throttle opening of the second throttle 15, when the control process shown in FIG. 4 is executed for the first time, the throttle opening (initial value) is determined to be a full opening (initial value = full opening). In the second and subsequent control processes, the throttle opening is determined to be the sum of the previous throttle opening (previous value) and the throttle opening manipulated variable (throttle opening = previous value + operated amount).

  Here, the aperture opening operation amount is determined as shown in FIG. The vertical axis in FIG. 6 indicates the throttle opening operation amount. When the operation amount is larger than 0, it means that the throttle opening is enlarged, and when the operation amount is smaller than 0, the throttle opening degree is increased. Means to reduce. When TOO-To is larger than 0, that is, when the detected To is lower than TOO, the amount of opening reduction (y1 in FIG. 6) corresponding to the magnitude of TOO-To (x1 in FIG. 6). Is the throttle opening manipulated variable. In this case, the opening degree of the second diaphragm 15 is reduced, so that To increases and approaches the TOO. On the other hand, when TOO-To is smaller than 0, that is, when To exceeds TOO, the opening enlargement amount (y2 in FIG. 6) corresponding to the magnitude of TOO-To (x2 in FIG. 6) is This is the throttle opening manipulated variable. In this case, the opening degree of the second diaphragm 15 is increased, so that To is lowered and brought closer to TOO.

  In step S11, a control signal or a control voltage is output from the electronic control unit 40 to the control target device so as to obtain the control state determined as described above.

  Thereby, in the heating operation, as indicated by the arrows in FIG. 3, the refrigerant discharged from the compressor 11 is converted into the indoor condenser 12, the first throttle 13 (control opening), the outdoor heat exchanger 14, the second A refrigerant circuit is formed which flows in the order of the throttle 15 (control opening) and the accumulator 18 and returns to the compressor 11.

  In this heating operation, since the refrigerant does not flow into the indoor evaporator 17, the air blown into the vehicle interior is not cooled by the indoor evaporator 17, and the air blown into the vehicle interior that has passed through the indoor evaporator 17 is heated by the indoor condenser 12. And blown out into the passenger compartment. At this time, since the refrigerant discharge capacity of the compressor 11 is adjusted as in step S15, the indoor condenser 12 exhibits a desired heating capacity.

  In this heating operation, the outdoor heat exchanger 14 functions as an outdoor evaporator, and heat is absorbed from the outside air by the heat exchange between the outside air and the refrigerant, so that the refrigerant evaporates. At this time, the temperature of the outdoor heat exchanger 14 is adjusted by the second throttle 15 as in step S17.

  As described in step S <b> 17, since the initial opening of the second throttle 15 is set to fully open, the throttle opening is basically fully opened. However, when the temperature To of the outdoor heat exchanger 14 is lower than the dew point temperature Tdp, the throttle opening is reduced so that the target temperature TOO is equal to or higher than Tdp. Thereby, the refrigerant | coolant pressure in the outdoor heat exchanger 14 rises, and the temperature To of the outdoor heat exchanger 14 becomes the temperature more than Tdp. Thus, since the outdoor heat exchanger 14 is set to a temperature at which frost formation does not occur, frost formation is prevented.

  Here, this embodiment and the comparative example 1 are compared. In Comparative Example 1, with respect to the heat pump cycle device 10 of the present embodiment, the opening degree of the second throttle 15 is fully opened so that the second throttle 15 does not exert a pressure reducing action during heating operation, and the outdoor heat exchanger 14 is changed so that the rotational speed of the compressor 11 is controlled so that the temperature To 14 becomes a temperature at which frost formation does not occur. The comparative example 1 corresponds to the examination example described in the column of the problem to be solved by the above-described invention.

  In this comparative example 1, in order to suppress frost formation of the outdoor heat exchanger 14 during heating operation, the temperature of the outdoor heat exchanger 14 is adjusted to a temperature at which frost formation can be suppressed by adjusting the rotation speed of the compressor 11. Therefore, the heat absorption amount of the outdoor heat exchanger 14 and the compression work amount of the compressor 11 are limited. For this reason, compared with the case where the temperature of the outdoor heat exchanger 14 is not made into the temperature which can suppress frost formation, the heating capability of the indoor condenser 12 falls remarkably.

  In contrast, in the present embodiment, as described above, during the heating operation, the opening degree of the second throttle 15 is adjusted and the indoor condensation is performed so that the temperature of the outdoor heat exchanger 14 becomes a temperature at which frost does not form. The rotation speed of the compressor 11 is adjusted so that the compressor 12 exhibits a desired heating capacity. For this reason, in this embodiment, although the heat absorption amount of the outdoor heat exchanger 14 is restrict | limited similarly to the comparative example 1, the compression work amount of the compressor 11 does not receive a restriction | limiting like the comparative example 1. FIG.

  As shown in FIG. 7, in the present embodiment, the suction of the compressor 11 by the second throttle 15 is compared with Comparative Example 1 in which the target outdoor heat exchanger temperature TOO is set to the same temperature as the present embodiment. As the pressure decreases, the amount of compression work of the compressor 11 increases and the specific enthalpy of the refrigerant discharged from the compressor 11 increases, so that the heating capacity of the indoor condenser 12 can be improved. That is, according to this embodiment, compared with the comparative example 1, the indoor condenser 12 can exhibit a large heating capability.

  Therefore, according to this embodiment, compared with the comparative example 1, it can suppress the frost formation of an outdoor evaporator, suppressing the fall of the heating capability of the indoor condenser 12. FIG.

  Moreover, in this embodiment, the 2nd aperture_diaphragm | restriction 15 used as a pressure reduction means at the time of air_conditionaing | cooling operation is utilized as an aperture | diaphragm | squeeze for making the temperature of the outdoor heat exchanger 14 into a temperature which does not frost at the time of heating operation. For this reason, according to this embodiment, the increase in the components of the heat pump cycle can be suppressed.

(Second Embodiment)
In the present embodiment, the method for determining the throttle opening of the second throttle 15 during the heating operation is changed with respect to the first embodiment. Only this change will be described below.

  In the first embodiment, as shown in FIG. 5, the target outdoor heat exchanger temperature TOO is always set to a temperature equal to or higher than Tdp regardless of the numerical value of the dew point temperature Tdp of the outside air. 8, when Tdp is less than 0 ° C., TOO is set to a temperature equal to or higher than Tdp (TOO [° C.] = Tdp [° C.] or TOO [° C.] = Tdp + Z [° C.]), and Tdp is 0 When the temperature is higher than or equal to ° C., TOO is set to 0 ° C. (TOO [° C.] = 0 [° C.]). Here, when Tdp is 0 ° C. or higher, the TOO is set to 0 ° C. If the dew point temperature Tdp is 0 ° C. or higher, that is, if it is higher than the freezing point of water, condensed water is formed on the surface of the outdoor heat exchanger 14. Even if it adheres, it freezes and does not lead to frost formation.

  Therefore, the electronic control unit 40 controls the opening degree of the second throttle 15 so that the temperature of the outdoor heat exchanger 14 is equal to or higher than Tdp when Tdp is lower than 0 ° C., and when Tdp is equal to or higher than 0 ° C. The throttle opening degree of the second throttle 15 is controlled so that the temperature of the outdoor heat exchanger 14 becomes 0 ° C. or higher. Thus, according to the present embodiment, when Tdp is 0 ° C. or higher, TOO is set to 0 ° C., so that the limit of the refrigerant evaporation temperature in the outdoor heat exchanger 14 during heating operation is minimized. You can stay.

(Third embodiment)
As shown in FIG. 9, the heat pump cycle device 10 of the present embodiment changes the compressor 11 to a compressor 21 having an intermediate pressure port with respect to the configuration of the heat pump cycle device 10 of the first embodiment. A liquid separator 22, a third throttle 23, an intermediate pressure refrigerant flow path 24, and the like are added.

  The compressor 21 includes a compression chamber for compressing refrigerant, a discharge port 21a for discharging compressed high-pressure refrigerant, a suction port 21b for sucking low-pressure refrigerant in the heat pump cycle, and an intermediate for introducing intermediate-pressure refrigerant in the heat pump cycle. And a pressure port 21c. The intermediate pressure port 21 c is in communication with the compression chamber, and the intermediate pressure refrigerant in the heat pump cycle flows into a place in the middle of the refrigerant compression process in the compressor 21.

  The gas-liquid separator 22 is disposed between the first throttle 13 and the outdoor heat exchanger 14. The gas-liquid separator 22 is for separating the gas-liquid refrigerant that has passed through the first throttle 13 and is of a centrifugal type.

  The third throttle 23 is a decompression unit that decompresses the liquid-phase refrigerant separated by the gas-liquid separator 22. The third aperture 23 is a fixed aperture mechanism with a fixed aperture opening.

  The intermediate pressure refrigerant flow path 24 is a refrigerant flow path for guiding the gas-phase refrigerant separated by the gas-liquid separator 22 to the intermediate pressure port 21 c of the compressor 21.

  Further, the heat pump cycle device 10 of the present embodiment includes a first on-off valve 25 that opens and closes the intermediate pressure refrigerant flow path 24, a third throttle bypass flow path 26 that flows the refrigerant bypassing the third throttle 23, and a third And a second opening / closing valve 27 for opening and closing the throttle bypass flow path 26. Each of the first on-off valve 25 and the second on-off valve 27 is an electromagnetic valve whose opening / closing operation is controlled by a control voltage output from the electronic control unit 40.

  In the present embodiment, the electronic control device 40 executes the control process shown in the flowchart of FIG. In the flowchart shown in FIG. 10, Step S21 is added after Step S6, Step S22 is added after Step S13, and Step S15 is added to the flowchart of FIG. 4 described in the first embodiment. Steps S23 and S24 are added between step S17.

  In this embodiment, when the operation mode is determined to be the cooling operation in step S5, step S21 is performed in addition to steps S6 to S10. In step S21, it is determined that the first on-off valve 25 is closed and the second on-off valve 27 is opened. As a result, the refrigerant does not flow through the intermediate pressure refrigerant flow path 24 and the third throttle 23.

  In step S11, a control signal or a control voltage is output from the electronic control unit 40 to the control target device so that the control state determined in steps S6, S21, and S7 to S10 is obtained. Thereby, during the cooling operation, the same refrigerant circuit as that during the cooling operation of the first embodiment is formed.

  When the operation mode is determined to be the heating operation in step S12, step S22 is performed in addition to steps S13 to S17. In step S22, it is determined that the first on-off valve 25 is opened and the second on-off valve 27 is closed. As a result, the refrigerant flows through the intermediate pressure refrigerant flow path 24 and the third throttle 23.

  Then, in step S23 after step S15, it is determined whether or not the heating capacity of the indoor condenser 12 is insufficient while the rotation speed of the compressor 21 is maximum. Specifically, it is determined whether or not the rotational speed of the compressor 21 is MAX and TAO-Tav> β. TAO is the target blowing temperature, Tav is the indoor condenser temperature, and β is a predetermined value (for example, 0 ° C.).

  At this time, if at least one of the rotational speed of the compressor 21 = MAX and insufficient heating capacity is not satisfied, a negative (NO) determination is made, the process proceeds to step S16, and the entrance of the first throttle 13 is performed as in the first embodiment. The throttle opening degree of the first throttle 13 is determined so that the supercooling degree SC_hot of the refrigerant becomes the target supercooling degree SCO_hot. On the other hand, if the rotation speed of the compressor 21 is MAX and the heating capacity is insufficient, an affirmative (YES) determination is made, the process proceeds to step S24, and the throttle opening of the first throttle 13 is set so that Tav approaches TAO. decide. If Tav is lower than TAO, the throttle opening is increased from the throttle opening (previous value) determined in the previous control process. If Tav exceeds TAO, the throttle opening determined in the previous control process The throttle opening is smaller than the previous value. Thus, in the present embodiment, the control target of the throttle opening of the first throttle 13 is switched depending on whether the heating capacity is insufficient.

  Thereafter, in step S17, the aperture of the second aperture 15 is determined as in the first embodiment. Note that, similarly to the second embodiment, the opening degree of the second diaphragm 15 may be determined. In step S11, a control signal or a control voltage is output from the electronic control unit 40 to the control target device so as to obtain the control state determined as described above.

  Thereby, in this embodiment, as shown in FIG. 11, a gas injection cycle is comprised at the time of heating operation. That is, the high-pressure refrigerant discharged from the discharge port 21 a of the compressor 21 is condensed by the indoor condenser 12, and the condensed high-pressure refrigerant is reduced to the intermediate pressure by the first throttle 13. The intermediate-pressure refrigerant that has flowed out of the first throttle 13 is separated into a gas-phase refrigerant and a liquid-phase refrigerant by the gas-liquid separator 22. The intermediate-pressure liquid phase refrigerant separated by the gas-liquid separator 22 is decompressed to a low pressure by the third throttle 23, evaporated by the outdoor heat exchanger 14, and the evaporated low-pressure refrigerant is compressed by the second throttle 15. The pressure is reduced to the suction pressure 21 and is sucked into the suction port 21 b of the compressor 21 through the accumulator 18. On the other hand, the intermediate-pressure gas-phase refrigerant separated by the gas-liquid separator 22 is guided to the intermediate-pressure port 21c of the compressor 21 via the intermediate-pressure refrigerant flow path 24, and merges with the refrigerant in the middle of the compression process. .

  According to this embodiment, in addition to the effect of 1st Embodiment, there exist the following two effects.

  The first effect is that it is possible to eliminate the need for component changes such as improvement of component heat resistance accompanying an increase in discharge refrigerant temperature. In this embodiment, during heating operation, in the compression process of the compressor 21, the superheated gas in the middle of the compression process and the saturated gas injected from the intermediate pressure port 21c are mixed, so that the compression work is increased. Moreover, it is because an excessive temperature rise of the refrigerant discharged from the discharge port 21a can be suppressed. In the present embodiment, since the injected refrigerant amount is added to the refrigerant circulation amount sucked from the suction port 21b and the refrigerant flow rate is increased, compared with the case where no intermediate-pressure gas-phase refrigerant is introduced into the compressor. Thus, the compression work can be increased.

  The second effect is that, when the desired heating capacity cannot be obtained, the electronic control unit 40 can solve the shortage of the heating capacity by increasing the opening of the first throttle 13.

  That is, in the present embodiment, during the heating operation, as in steps S15 and S16, basically, the rotational speed of the compressor 21 is controlled so that a desired heating capacity is exhibited, and COP is maximized. In addition, the opening degree of the first throttle 13 is controlled.

  Then, as in steps S23 and S24, when the desired heating capacity is insufficient while the rotation speed of the compressor 21 is maximum, the opening of the first throttle 13 is increased so that Tav approaches TAO. . As a result, the amount of refrigerant injected from the intermediate pressure port 21c increases, and the amount of compression work from the intermediate pressure to the high pressure can be further increased. Thereby, the heating capacity can be increased, and the shortage of the heating capacity can be solved.

  The first effect is not limited to the two-stage expansion cycle as in the present embodiment, but may be a one-stage expansion cycle, a two-stage compression cycle, or the like as long as the intermediate-pressure gas-phase refrigerant is introduced into the compressor. It is also exhibited in other heat pump cycle devices. That is, in this embodiment, the high-pressure refrigerant flowing out from the indoor condenser 12 is decompressed and expanded with two throttles to the evaporation pressure (two-stage expansion cycle), but the high-pressure refrigerant is decompressed and expanded with one throttle to the evaporation pressure. May be better (one stage expansion cycle). Further, in this embodiment, the intermediate-pressure gas-phase refrigerant is introduced into the compression chamber of the compressor and mixed with the superheated gas in the middle of the compression process, but has a low-stage compression section and a high-stage compression section. In the case of using the stage compressor, the intermediate-pressure gas-phase refrigerant may be mixed with the gas refrigerant discharged from the low-stage compression section, and the mixed refrigerant may be sucked into the high-stage compression section ( Two-stage compression cycle).

(Fourth embodiment)
As shown in FIG. 12, the heat pump cycle device 10 of the present embodiment changes the configuration of the heat pump cycle device 10 of the first embodiment from the three-way valve 16 in FIG. A diaphragm 52 is added. This embodiment can also be applied to the second and third embodiments.

  The on-off valve 51 is arranged in a refrigerant flow path that guides the refrigerant flowing out from the second throttle 15 to the accumulator 18 by bypassing the indoor evaporator 17 and opens and closes the refrigerant flow path. The opening / closing valve 51 is an electromagnetic valve whose opening / closing operation is controlled by a control voltage output from the electronic control unit 40.

  The cooling throttle 52 is disposed in a refrigerant flow path that guides the refrigerant that has flowed out of the second throttle 15 to the indoor evaporator 17, and the outdoor heat is reduced by reducing the flow sectional area of the refrigerant flow path during cooling operation. It is a decompression means for decompressing the refrigerant flowing out of the exchanger. The cooling throttle 52 is an electric variable throttle mechanism similar to the first throttle 13, and has a fully-closed function in order to block the refrigerant flow path during heating operation.

  In this embodiment, the control process shown in FIG. 4 described in the first embodiment is changed as follows.

  When the operation mode is determined to be the cooling operation in step S5 of FIG. 4 and the operating state of each control target device is determined in steps S6 to S10, step S6 and step S10 are changed. In step S6, it is determined to close the on-off valve 51. In step S10, the throttle opening of the second throttle 15 is determined to be fully open, and the throttle opening of the cooling throttle 52 is determined to be a desired control opening. This desired control opening is a control opening for bringing the COP close to the maximum value, as in the determination of the opening of the second throttle 15 in step S10 described in the first embodiment.

  Thereby, in the cooling operation, the refrigerant discharged from the compressor 11 is supplied to the indoor condenser 12, the first throttle 13 (fully opened opening), the outdoor heat exchanger 14, the second throttle 15 (fully opened opening), and for cooling. A refrigerant circuit is formed which flows in the order of the throttle 52 (control opening), the indoor evaporator 17, and the accumulator 18 and returns to the compressor 11.

  Further, when the operation mode is determined to be the heating operation in step S12 of FIG. 4 and the operating state of each control target device is determined in steps S13 to S17, step S13 is changed. In step S13, it is determined to open the on-off valve 51, and the throttle opening of the cooling throttle 52 is determined to be fully closed. Thereby, in the heating operation, the same refrigerant circuit as that in the heating operation of the first embodiment is formed.

  According to this embodiment, in addition to the effect which 1st Embodiment has, there exists the following effect. That is, in the present embodiment, the cooling throttle 52 is disposed on the side closer to the indoor evaporator 17 than the second throttle 15 in the refrigerant flow path from the outdoor heat exchanger 14 to the indoor evaporator 17. For this reason, the length of the refrigerant flow path through which the low-temperature and low-pressure refrigerant flows is shortened as compared with the case where the refrigerant flowing out of the outdoor heat exchanger 14 is decompressed by the second throttle 15 during the cooling operation to be a low-temperature and low-pressure refrigerant. it can. Thereby, the heat loss to the outside air when the low-temperature and low-pressure refrigerant flows through the refrigerant flow path can be reduced.

(Fifth embodiment)
As shown in FIG. 13, the heat pump cycle device 10 of the present embodiment is obtained by changing the indoor condenser 12 to a water refrigerant heat exchanger 61 with respect to the heat pump cycle device 10 of the first embodiment. This embodiment is applicable to any of the second to fourth embodiments.

  The water-refrigerant heat exchanger 61 exchanges heat between the high-pressure discharged refrigerant discharged from the compressor 11 and water to radiate the discharged refrigerant, and heats the water as a heating target (heating heat exchange). And constitutes the hot water circuit 60 together with the heater core 62. The hot water circuit 60 is a circuit that circulates water (hot water) that has exchanged heat with a refrigerant, and is configured by connecting a water refrigerant heat exchanger 61 and a heater core 62 in a ring shape with piping. As water here, ethylene glycol aqueous solution is used, for example.

  The heater core 62 is disposed in the casing 31 of the indoor air conditioning unit 30 on the downstream side of the air flow from the indoor evaporator 17. The heater core 62 is a heating heat exchanger that heats the vehicle interior air by heat exchange between the hot water and the vehicle interior air.

  In the present embodiment, during the heating operation, the water refrigerant heat exchanger 61 exchanges heat between the high-pressure discharged refrigerant discharged from the compressor 11 and water to heat the water to warm water, and the heater core 62 warms and Heating is performed by exchanging heat with the indoor blowing air and heating the blowing air inside the vehicle interior.

  According to the present embodiment, the indoor air conditioning unit 30 mounted on the electric vehicle is mounted on a vehicle that obtains driving force for driving the vehicle from an internal combustion engine (engine), and heats the air blown into the vehicle interior using engine cooling water as a heat source. A general indoor air conditioning unit equipped with a heater core can be employed without significant changes.

(Sixth embodiment)
As shown in FIG. 14, in the present embodiment, the heat pump cycle device 10 according to the present invention is applied to a heat pump hot water heater 2. In the heat pump cycle device 10 of the present embodiment, carbon dioxide is employed as the refrigerant, and a supercritical refrigeration cycle in which the pressure of the high-pressure refrigerant is equal to or higher than the critical pressure of the refrigerant is configured.

  The heat pump cycle device 10 of the present embodiment includes a compressor 11, a water / refrigerant heat exchanger 71, a first throttle 13, an outdoor heat exchanger 14, a second throttle 15, an accumulator 18, and an electronic control device 40. And.

  The water-refrigerant heat exchanger 71 is connected to the hot water supply tank 72 by piping, and hot water in the hot water supply tank 72 is configured to circulate between the water / refrigerant heat exchanger 71 and the hot water supply tank 72. . The water-refrigerant heat exchanger 71 exchanges heat between the high-pressure discharged refrigerant discharged from the compressor 11 and hot water supply to dissipate the discharged refrigerant, and heats the hot water as a heating target (for heating Heat exchanger).

  As with the heating operation of the first embodiment, the electronic control unit 40 controls the rotational speed of the compressor 11, the throttle opening of the first throttle 13, and the second throttle 15 during the heating operation of the first embodiment. Control the throttle opening. Thereby, the refrigerant discharged from the compressor 11 is in the order of the water-refrigerant heat exchanger 71, the first throttle 13 (control opening), the outdoor heat exchanger 14, the second throttle 15 (control opening), and the accumulator 18. A refrigerant circuit that flows and returns to the compressor 11 is formed. At this time, hot water is heated by exchanging heat with the refrigerant in the water / refrigerant heat exchanger 71. Further, the refrigerant evaporates by exchanging heat with the outside air in the outdoor heat exchanger 14. Therefore, the outdoor heat exchanger 14 of this embodiment is an outdoor evaporator.

  Also in the present embodiment, during the water heating operation, the rotational speed of the compressor 11 and the throttle opening of the second throttle 15 are controlled in the same manner as in the first embodiment. The frost formation of the outdoor heat exchanger 14 can be suppressed while suppressing a decrease in capacity.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope described in the claims as follows.

  (1) In each of the embodiments described above, the electronic control unit 40 controls the throttle opening of the second throttle 15 so that the temperature of the outdoor heat exchanger 14 is not frosted during the heating operation. The throttle opening degree of the second throttle 15 may be controlled so as to be a temperature at which frost formation can be suppressed. The temperature at which frost formation can be suppressed is a temperature slightly lower than the dew point temperature.

  (2) In each of the above embodiments, the second refrigerant temperature sensor 43 is used as the temperature detecting means for detecting the temperature To of the outdoor evaporator 14, and the temperature To of the outdoor evaporator 14 is detected by the second refrigerant temperature sensor 43. However, as the temperature detecting means for detecting the temperature To of the outdoor evaporator 14, a temperature sensor for detecting the surface temperature of the fins and tubes of the outdoor evaporator 14 or the inside of the outdoor evaporator 14 is used. A pressure sensor that detects the pressure of the refrigerant or the outlet refrigerant may be used. In these cases, the temperature detected by the temperature sensor or the refrigerant temperature calculated from the pressure detected by the pressure sensor is used as the temperature To of the outdoor evaporator 14.

  (3) In each of the above embodiments, the temperature detecting means for detecting the temperature To of the outdoor evaporator 14 is used, and the detected temperature To becomes the target temperature Too of the outdoor evaporator 14 determined according to the dew point temperature Tdp. As described above, the electronic control unit 40 controls the throttle opening of the second throttle. For example, the target of the outdoor evaporator 14 in which the pressure of the internal refrigerant or the outlet refrigerant of the outdoor evaporator 14 is determined according to the dew point temperature. You may control the opening degree of a 2nd aperture_diaphragm | restriction so that it may become the target pressure value corresponding to temperature. In short, in the present invention, the physical quantity detecting means for detecting the physical quantity related to the temperature of the outdoor evaporator 14 is used, and the detected value corresponds to the target temperature of the outdoor evaporator 14 determined according to the dew point temperature. Thus, the electronic control unit 40 may control the aperture of the second aperture.

  (4) In each of the above embodiments, the refrigerant pressure sensor 42 is used as the temperature detecting means for detecting the temperature Tav of the indoor condenser 12, and the outlet refrigerant pressure PH of the indoor condenser 12 is used as the temperature Tav of the indoor condenser 12. Although the refrigerant saturation temperature calculated based on the temperature of the indoor condenser 12 is used as a temperature detecting means for detecting the temperature Tav of the indoor condenser 12, a temperature sensor for detecting the surface temperature of the fins and tubes of the indoor condenser 12 is used. A temperature sensor that detects the air temperature after passing through the condenser 12 may be used. In these cases, a temperature sensor for detecting the temperature Tav of the indoor condenser 12 is required in addition to the refrigerant pressure sensor 42 used for opening control of the second throttle 15. For this reason, from the viewpoint of reducing the number of sensors, it is preferable to use the refrigerant pressure sensor 42 as temperature detecting means for detecting the temperature of the outdoor evaporator 14 as in the first embodiment.

  Moreover, in each said embodiment, although the temperature detection means which detects the temperature Tav of the indoor condenser 12 was used and the refrigerant | coolant discharge capability of the compressor 11 was controlled so that the detected temperature Tav became the target blowing temperature TAO, For example, the electronic control unit 40 may control the refrigerant discharge capacity of the compressor 11 so that the pressure of the internal refrigerant or the outlet refrigerant of the indoor condenser 12 becomes a target pressure value corresponding to a desired heating capacity. In short, in the present invention, the physical quantity detection means for detecting the physical quantity related to the heating capacity in the indoor condenser 12 is used, and the refrigerant of the compressor 11 is set so that the detected value becomes a target value corresponding to the desired heating capacity. What is necessary is just to control discharge capacity.

  (5) In each of the above embodiments, an electric compressor is employed as the compressor, but a compressor other than the electric compressor may be employed. For example, a variable displacement compressor using an internal combustion engine as a drive source may be employed. Examples of the case where such a compressor is employed include a case where a heater core and an indoor condenser are used in combination in a vehicle air conditioner mounted on a hybrid vehicle, and the indoor condenser is used during operation of the internal combustion engine. .

  (6) In each of the above embodiments, a variable throttle mechanism is employed as the second throttle 15. However, if the second throttle 15 is not used as a pressure reducing means during cooling operation, the second throttle 15 may be a fixed throttle. May be adopted. In this case, as shown in FIG. 15, a bypass channel 81 that bypasses the second throttle 15 and an open / close valve 82 that opens and closes the bypass channel 81 are provided. During the heating operation or the heating operation, the on-off valve 82 is closed so that the refrigerant is decompressed by the second throttle 15. Further, the throttle opening degree of the second throttle 15 at this time is set to a throttle opening degree at which the temperature of the outdoor heat exchanger 14 becomes a temperature at which frost formation can be suppressed under a predetermined condition, thereby enabling the first embodiment. Has the same effect as. When a fixed throttle is employed as the second throttle 15, the open / close state of the on-off valve 82 may be switched intermittently so that the temperature of the outdoor heat exchanger 14 becomes a temperature at which frost formation can be suppressed.

  (7) In each of the above embodiments, the outside air temperature sensor 44 and the outside air humidity sensor 45 are used as the dew point temperature detecting means. However, a dew point temperature sensor that can directly detect the dew point temperature may be used.

  (8) The above embodiments are not irrelevant to each other, and can be appropriately combined unless the combination is clearly impossible. In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes.

11 Compressor 12 Indoor condenser (heat radiator)
13 First throttle 14 Outdoor heat exchanger (outdoor evaporator)
15 Second aperture 40 Electronic control device (control means)
21 Compressor 61 Water refrigerant heat exchanger (radiator)
71 Water refrigerant heat exchanger (heat radiator)

Claims (4)

Compressors (11, 21) for compressing and discharging the sucked refrigerant;
A radiator (12, 61, 71) for dissipating the refrigerant discharged from the compressor and heating the object to be heated;
A first throttle (13) for depressurizing the refrigerant flowing out of the radiator by narrowing the refrigerant flow path;
An outdoor evaporator (14) that is disposed outside and evaporates the refrigerant decompressed by the first throttle by heat exchange with the outside air;
A second throttle (15) for depressurizing the refrigerant that has flowed out of the outdoor evaporator to flow into the compressor by narrowing the refrigerant flow path ;
A refrigerant flow path that allows the refrigerant decompressed by the second throttle to flow into the compressor without passing through a heat exchanger that exchanges heat between the refrigerant and a fluid different from the refrigerant ,
When the refrigerant decompressed by the second throttle flows into the compressor without passing through the heat exchanger, the second throttle has a temperature at which the temperature of the outdoor evaporator can suppress frost formation. The heat pump cycle device is characterized in that the refrigerant discharge capacity is adjusted so that the compressor exhibits a desired heat radiation capacity. The second throttle is configured to be able to change the throttle opening,
Control means (40) for controlling the refrigerant discharge capacity of the compressor and the throttle opening of the second throttle;
The control means controls the throttle opening of the second throttle so that the temperature of the outdoor evaporator becomes a temperature at which frost formation can be suppressed, and so that the radiator exhibits a desired heat dissipation capability. The heat pump cycle device according to claim 1, wherein the refrigerant discharge capacity of the compressor is controlled. Dew point temperature detecting means (44, 45) for detecting the dew point temperature of the outside air flowing into the outdoor evaporator;
Temperature detecting means (43) for detecting the temperature of the outdoor evaporator,
The control means determines the temperature (To) detected by the temperature detecting means according to the dew point temperature (Tdp) detected by the dew point temperature detecting means in order to suppress frost formation of the outdoor evaporator. The heat pump cycle device according to claim 2, wherein a throttle opening degree of the second throttle is controlled so as to be a target temperature (TOO). When the dew point temperature detected by the dew point temperature detecting means is lower than the freezing point of water, the control means sets the target temperature to a temperature equal to or higher than the dew point temperature, and when the dew point temperature is equal to or higher than the freezing point of water, The heat pump cycle device according to claim 3, wherein the target temperature is set to a freezing point of water.

Images