JP6589242B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner using a heat pump cycle.

  In a vehicle that does not include an engine such as an electric vehicle, an air conditioner that performs a heating operation using a heat pump cycle may be used (for example, see Patent Document 1).

  This type of vehicle air conditioner includes a heat pump cycle in which refrigerant is circulated while changing between a gas phase and a liquid phase to transfer heat energy, and a refrigerant and an air conditioner in an indoor heat exchanger (evaporator and condenser) of the heat pump cycle. An air-conditioning unit that exchanges heat with air and blows conditioned air adjusted in temperature and humidity into the vehicle interior, and a control device that controls the heat pump cycle and air-conditioning unit according to switch operations and changes in detected temperature by passengers And.

  The heat pump cycle compresses and discharges the refrigerant, introduces the high-temperature and high-pressure refrigerant discharged from the compressor, passes the heat of the refrigerant with the conditioned air in the air conditioning unit, and passes through the condenser A first expansion valve that decompresses the expanded refrigerant to expand, an outdoor heat exchanger that exchanges heat of the introduced refrigerant with the outside air, and a second expansion valve that decompresses and expands the refrigerant that has passed through the outdoor heat exchanger And an evaporator that introduces the low-temperature and low-pressure refrigerant that has passed through the second expansion valve and exchanges heat of the refrigerant with the conditioned air in the air-conditioning unit.

  The air conditioning unit includes a heat removal unit that removes heat from the conditioned air, a heating unit that heats the conditioned air, conditioned air that passes through the heating unit, and conditioned air that bypasses the heating unit. And an air mix device for adjusting the ratio. A heat pump cycle evaporator is disposed in the heat removal unit, and a heat pump cycle capacitor is disposed in the heating unit.

The control device selects one of a plurality of operation modes in accordance with a switch operation by the occupant, a change in detected temperature, and the like, and performs an air conditioning operation in accordance with the selected operation mode. The operation mode includes, for example, the following.
(1) Cooling operation mode An operation mode in which the refrigerant discharged from the compressor is sequentially flowed in the order of the outdoor heat exchanger, the second expansion valve, and the evaporator, and returned to the suction portion of the compressor to perform heat removal by the evaporator.
(2) Heating operation mode (non-dehumidifying heating operation mode)
An operation mode in which the refrigerant discharged from the compressor is sequentially flowed in the order of the condenser, the first expansion valve, and the outdoor heat exchanger, and returned to the suction portion of the compressor to perform heating in the condenser.
(3) Dehumidification heating operation mode An operation mode in which the refrigerant discharged from the compressor is sequentially flowed in the order of the condenser, the first expansion valve, and the evaporator, and returned to the suction portion of the compressor to perform heat removal by the evaporator and heating by the condenser. .

  By the way, in the dehumidifying and heating operation mode described above, dehumidification and heating are performed on the conditioned air by an evaporator and a condenser. In the heat pump cycle, for example, the heating capacity of the condenser is increased by increasing the rotation speed of the compressor. If it tries to do so, since the heat removal capability of the evaporator is also increased at this time, it is difficult to appropriately raise the temperature of the conditioned air.

  For this reason, as a countermeasure, it is considered to arrange another heating device such as a PTC (Positive Temperature Coefficient) heater in addition to the condenser of the heat pump cycle in the heating unit in the air conditioning unit. In this case, heating of the conditioned air is performed by a heating device different from the evaporator while performing dehumidification by the evaporator of the heat pump cycle. As a result, it is possible to appropriately raise the temperature of the conditioned air without causing an excessive cooling capacity of the evaporator.

JP 2009-202735 A

  The above-described vehicle air conditioner has a dehumidifying and heating operation mode in which heat removal by an evaporator and heating by a heating device are executed. In the dehumidifying and heating operation mode, it is desired to introduce the refrigerant discharged from the compressor directly into the outdoor heat exchanger without introducing it into the condenser. That is, it is desirable to provide a bypass passage that bypasses the condenser and connects the discharge portion of the compressor and the outdoor heat exchanger, and directly introduces the refrigerant discharged from the compressor to the outdoor heat exchanger through the bypass passage. In this case, since the heat removal capability of the evaporator can be controlled independently during the dehumidifying heating operation, the humidity and temperature of the conditioned air can be more appropriately controlled.

However, even in the case of a vehicle air conditioner adopting such a configuration, when the operation mode transitions from the dehumidifying and heating operation mode to the non-dehumidifying heating operation mode, the conditioned air passes through the low-temperature condenser, thereby There is a concern that the comfort of the car is impaired.
That is, in the case of the above vehicle air conditioner, in the dehumidifying and heating operation mode, since the high-temperature and high-pressure refrigerant is not introduced into the condenser, the condenser itself is cooled. For this reason, when the operation mode is switched to the non-dehumidification heating operation mode after the dehumidification heating mode continues for a long time, the conditioned air hits the condenser before being sufficiently heated by the refrigerant, and the conditioned air becomes cold air and enters the vehicle interior. It will be blown out.

  Therefore, the present invention is intended to provide a vehicle air conditioner that can enhance the comfort of passengers during the air conditioning operation.

The vehicle air conditioner according to the present invention employs the following configuration in order to solve the above problems.
That is, the vehicle air conditioner according to the present invention includes a heat pump cycle (for example, the heat pump cycle 12 of the embodiment) that circulates a refrigerant while changing the gas phase and a liquid phase to move heat energy, and an air intake port. An air conditioning unit (for example, the air conditioning unit 11 of the embodiment) that adjusts at least one of the temperature and humidity of the conditioned air taken in from the vehicle and blows the adjusted conditioned air into the vehicle interior, and the heat pump cycle and the An air conditioner for a vehicle including a control device (for example, the control device 13 of the embodiment) that controls the air conditioning unit, wherein the heat pump cycle compresses and discharges the refrigerant (for example, the compressor of the embodiment) 21) and a refrigerant which introduces the refrigerant discharged from the compressor and exchanges heat of the refrigerant with conditioned air. A heat exchanger (for example, the condenser 55 of the embodiment), a first expansion valve (for example, the first expansion valve 22 of the embodiment) that decompresses and expands the refrigerant that has passed through the condenser, and heat of the introduced refrigerant is An outdoor heat exchanger (for example, the outdoor heat exchanger 24 of the embodiment) that exchanges heat with the second expansion valve (for example, the second expansion of the embodiment) that decompresses and expands the refrigerant that has passed through the outdoor heat exchanger. Valve 29), an evaporator that introduces the refrigerant that has passed through the second expansion valve, and exchanges the cold heat of the refrigerant with conditioned air (for example, the evaporator 53 of the embodiment), the condenser, and the first expansion valve. Via the heating air-conditioning main passage (for example, the heating air-conditioning main passage 41 of the embodiment) connecting the discharge section of the compressor and the outdoor heat exchanger, bypassing the condenser and the first expansion valve. Before The outdoor heat exchanger passes through a first bypass passage (for example, the first bypass passage 42 in the embodiment) that connects the discharge portion of the compressor and the outdoor heat exchanger, the second expansion valve, and the evaporator. The outdoor heat exchanger bypasses the main passage for heat removal air conditioning (for example, the main passage for heat removal air conditioning 43 of the embodiment), the second expansion valve, and the evaporator connecting the compressor and the suction portion of the compressor. And a second bypass passage (for example, the second bypass passage 44 of the embodiment) that connects the suction portion of the compressor, and the air conditioning unit includes a duct (for example, of the embodiment) A duct 51), a heat removal unit (for example, the heat removal unit 35 of the embodiment) that removes the conditioned air that has flowed into the duct, and a heating unit (for example, an implementation type) that heats the conditioned air that has flowed into the duct. Heating unit 36), an air mixing device that adjusts the ratio of conditioned air that passes through the heating unit and conditioned air that bypasses the heating unit in the duct (for example, the air mixing door 54 of the embodiment), The evaporator is provided in the heat removal part, the condenser and the heating device (for example, the PTC heater 56 of the embodiment) separate from the condenser are provided in the heating part, and the operation The mode is at least a cooling operation mode in which the refrigerant discharged from the compressor flows in the order of the outdoor heat exchanger and the main passage for heat removal air conditioning and returns to the compressor, and the refrigerant discharged from the compressor is A non-dehumidifying heating operation mode in which the main passage for heating and air conditioning, the outdoor heat exchanger, and the second bypass passage are flowed in this order and returned to the compressor; and the compressor The refrigerant discharged from the first bypass passage, the outdoor heat exchanger, and the main passage for heat removal air conditioning are returned to the compressor, and the dehumidification heating operation mode for operating the heating device is performed. In addition, the control device prohibits mode transition from the dehumidifying and heating operation mode to the non-dehumidifying and heating mode when operating in the dehumidifying and heating operation mode.

In the cooling operation mode, the refrigerant discharged from the compressor is introduced into the outdoor heat exchanger, and the refrigerant exchanges heat with the outside air in the outdoor heat exchanger. The refrigerant that has passed through the outdoor heat exchanger passes through the second expansion valve of the heat removal air conditioning main passage, is introduced into the evaporator, and is returned from the evaporator to the suction portion of the compressor. At this time, the low-temperature and low-pressure refrigerant introduced into the evaporator is vaporized by heat exchange with the conditioned air, and the conditioned air is removed by the refrigerant. From the air conditioning unit, the conditioned air removed by the evaporator is blown out into the passenger compartment.
In the non-dehumidifying heating operation mode, the refrigerant discharged from the compressor passes through the condenser and the first expansion valve in the heating air conditioning main passage and is introduced into the outdoor heat exchanger, and passes through the second bypass passage 44 from the outdoor heat exchanger. To return to the compressor suction. At this time, the high-temperature and high-pressure refrigerant introduced into the condenser is condensed by exchanging heat with the conditioned air, and the conditioned air is heated by receiving the heat of the refrigerant. In the air conditioning unit, the conditioned air is heated by the condenser without being removed by the evaporator. Heated conditioned air is blown out from the air conditioning unit into the passenger compartment.
In the dehumidifying and heating operation mode, the refrigerant discharged from the compressor is introduced into the outdoor heat exchanger through the first bypass passage, and the refrigerant passing through the outdoor heat exchanger passes through the second expansion valve of the main passage for heat removal air conditioning. After passing through and being introduced into the evaporator, it is returned from the evaporator to the suction part of the compressor. At this time, the low-temperature and low-pressure refrigerant introduced into the evaporator is vaporized by heat exchange with the conditioned air, and the conditioned air is removed by the refrigerant to remove moisture. On the other hand, the conditioned air is heated by the heating device when passing through the heating device in the air conditioning unit. As a result, the dehumidified heated air is blown out from the air conditioning unit into the passenger compartment.
Here, when the vehicle air conditioner is operating in the dehumidifying and heating operation mode, the high-temperature and high-pressure refrigerant is not introduced into the condenser of the heat pump cycle. For this reason, when the operation in the dehumidifying and heating operation mode continues, the condenser is cooled, and when the transition is made from this state to the non-dehumidifying heating operation mode, the conditioned air is cooled by the cooled condenser immediately after the transition. However, in the vehicle air conditioner according to the present invention, the control device prohibits the transition from the dehumidifying heating operation mode to the non-dehumidifying heating operation mode, so that the conditioned air cooled by the condenser is prevented from being blown into the vehicle interior. can do.

The heat pump cycle includes a passage switching unit (for example, in the embodiment) that switches a passage connecting the outdoor heat exchanger and the suction portion side of the compressor to either the heat removal air conditioning main passage or the second bypass passage. The passage switching unit closes the heat removal air-conditioning main passage during the mode transition from the cooling operation mode to the non-dehumidification heating operation mode and opens the second bypass passage. When opening, the structure which has an opening degree adjustment valve (for example, heating valve 32 of embodiment) which can increase the opening degree of the said 2nd bypass passage in steps may be sufficient.
In the cooling operation mode, when the outdoor heat exchanger and the suction portion of the compressor are connected through the heat removal air conditioning main passage, the differential pressure before and after the second expansion valve in the heat removal air conditioning main passage increases. Yes. For this reason, at this time, the pressure of the refrigerant inside the outdoor heat exchanger is relatively large with respect to the pressure on the suction portion side of the compressor. On the other hand, when the outdoor heat exchanger and the suction part of the compressor are connected through the second bypass passage in the non-dehumidifying heating operation mode, the pressure inside the outdoor heat exchanger is almost the same as the suction part of the compressor. Is maintained at a low pressure. For this reason, if the second bypass passage is suddenly opened during the transition from the cooling operation mode to the non-dehumidifying heating operation mode, the high-pressure refrigerant in the outdoor heat exchanger suddenly escapes to the suction portion side of the compressor, causing abnormal noise. May occur. In this vehicle air conditioner, since the passage switching unit has an opening adjustment valve, and the opening adjustment valve can open the opening of the second bypass passage in stages, the opening adjustment is performed at the initial stage of passage switching. The valve can be opened once with a small opening area. As a result, when the passage is switched, the pressure difference between the outdoor heat exchanger and the suction portion of the compressor is reduced stepwise, and the high-pressure refrigerant in the outdoor heat exchanger suddenly escapes to the suction portion side of the compressor. Generation of abnormal noise can be suppressed.

The heat pump cycle includes a passage switching unit (for example, in the embodiment) that switches a passage connecting the outdoor heat exchanger and the suction portion side of the compressor to either the heat removal air conditioning main passage or the second bypass passage. The second expansion valve is configured such that the passage switching unit closes the main passage for heat removal air conditioning when the mode is changed from the cooling operation mode to the non-dehumidifying heating operation mode. When opening the second bypass passage, it may be configured to have an opening adjustment mechanism that can increase the valve opening more than the valve opening during normal use.
If the second bypass passage is suddenly opened during the transition from the cooling operation mode to the non-dehumidifying heating operation mode, the high-pressure refrigerant in the outdoor heat exchanger suddenly escapes to the suction portion side of the compressor and generates noise. There is a possibility. In this vehicle air conditioner, since the second bypass valve has an opening adjustment mechanism that can increase the valve opening more than the valve opening during normal use, the passage switching unit is for heat removal air conditioning. When the main passage is closed and the second bypass passage is opened, the second bypass valve increases the valve opening so that the pressure on the upstream side and the pressure on the downstream side of the second expansion valve can be quickly brought close to each other. For this reason, when the passage is switched, it is possible to suppress the generation of abnormal noise due to the high-pressure refrigerant in the outdoor heat exchanger that suddenly escapes to the suction portion side of the compressor.

  According to the present invention, since the control device prohibits the transition from the dehumidifying and heating operation mode to the non-dehumidifying and heating operation mode, the cooled conditioned air is prevented from being blown into the vehicle interior during the heating operation, and the air conditioning operation is being performed. The passenger comfort can be improved.

It is a block diagram of the vehicle air conditioner which concerns on one Embodiment of this invention, and is a figure which shows the action | operation at the time of air_conditionaing | cooling operation mode. It is a block diagram of the vehicle air conditioner which concerns on one Embodiment of this invention, and is a figure which shows the action | operation at the time of non-dehumidification heating operation mode. It is a block diagram of the vehicle air conditioner which concerns on one Embodiment of this invention, and is a figure which shows the action | operation at the time of a strong cooling operation mode. It is a block diagram of the vehicle air conditioner which concerns on one Embodiment of this invention, and is a figure which shows the action | operation at the time of dehumidification heating operation mode. It is a block diagram of the vehicle air conditioner which concerns on one Embodiment of this invention, and is a figure which shows the action | operation at the time of a defrost operation mode.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each figure, the dark dot portion in the flow path indicates a portion where the refrigerant is at a high pressure, and the thin dot portion in the flow path indicates a portion where the refrigerant is at a low pressure.
1-5 is a block diagram of the vehicle air conditioner 10 which concerns on this embodiment, and is a figure which shows the operation state at each operation mode.
The vehicle air conditioner 10 according to the present embodiment is mounted on, for example, an electric vehicle that does not include an engine (internal combustion engine) as a vehicle drive source. The vehicle air conditioner 10 includes a heat pump cycle 12 that circulates a refrigerant while changing it into a gas phase and a liquid phase to move heat energy, and an air conditioner that adjusts at least one of the temperature and humidity of the conditioned air and blows it into the vehicle interior. A unit 11 and a control device 13 for controlling the heat pump cycle 12 and the air conditioning unit 11 are provided.

  The air conditioning unit 11 has a duct 51 through which conditioned air flows. Inside the duct 51, a blower 52, an evaporator 53, an air mix door 54, a PTC (Positive Temperature Coefficient) heater 56, a capacitor 55, Is arranged.

  The duct 51 has an air intake port 57 located on the upstream side in the flow direction of the conditioned air, and an air outlet 58 located on the downstream side. The blower 52, the evaporator 53, the air mix door 54, the PTC heater 56, and the condenser 55 are arranged in this order from the upstream side to the downstream side in the flow direction of the conditioned air.

  The blower 52 is driven in accordance with, for example, a drive voltage applied by control by the control device 13, and conditioned air (at least one of internal air and external air) taken into the duct 51 through the air intake port 57 To send to.

  The evaporator 53 performs heat exchange between the low-temperature and low-pressure refrigerant that has flowed into the interior and the conditioned air that passes through the surroundings (air that flows through the duct 51), and the surroundings of the evaporator 53 by heat absorption when the refrigerant evaporates. Cool the conditioned air that passes through. The evaporator 53 is provided in the heat removal part 35 located downstream of the blower 52 in the duct 51.

  The condenser 55 can dissipate heat with a high-temperature and high-pressure refrigerant that passes through the inside thereof, and heats the conditioned air that passes around the condenser 55.

  The PTC heater 56 is disposed at a position downstream of the evaporator 53 in the duct 51 and upstream of the capacitor 55. The PTC heater 56 incorporates a PTC element whose resistance value increases as the temperature rises, and heats the conditioned air passing around the PTC heater 56. The PCT heater 56 is provided in the heating unit 36 that is located downstream of the evaporator 53 in the duct 51 together with the condenser 55.

  The air mix door 54 can be rotated by a driving means (not shown) that is driven by the control of the control device 13. Specifically, the air mix door 54 includes a heating position (see FIGS. 2 and 5) that opens a ventilation path (heating path) toward the heating unit (PTC heater 56 and condenser 55) in the duct 51. , And a cooling position (see FIG. 3) that opens a ventilation path (cooling path) that bypasses the heating unit 36 (PTC heater 56 and condenser 55). In addition, the air mix door 54 is rotated between the heating position and the cooling position, thereby adjusting the ratio of the conditioned air passing through the heating unit 36 and the conditioned air bypassing the heating unit 36. The temperature of the conditioned air blown out from the outlet 58 into the vehicle compartment is adjusted.

  The heat pump cycle 12 includes the evaporator 53 and the condenser 55, the compressor 21, the shutoff valve 34, the first expansion valve 22, the bypass valve 23, the outdoor heat exchanger 24, the cooling valve 26, the receiver tank 25, the sub condenser 27, and the cooling. Auxiliary heat exchanger 31, second expansion valve 29, heating valve 32, and gas-liquid separator 33, and these constituent members are connected via a refrigerant flow path.

  The compressor 21 has a suction part connected to the gas-liquid separator 33 and a discharge part connected to the condenser 55 side. The compressor 21 is driven by the driving force of the driving means driven by the control of the control device 13, sucks mainly the gas component of the refrigerant from the gas-liquid separator 33, compresses the refrigerant, It discharges to the condenser 55 side as a high-pressure refrigerant.

The first expansion valve 22 is a throttle valve whose opening degree can be adjusted by the control of the control device 13, mainly when decompressing the refrigerant discharged from the condenser 55 during the heating operation, And it discharges to the outdoor heat exchanger 24 as a low-pressure gas-liquid two-phase (liquid phase rich) spray-like refrigerant.
A passage from the discharge portion of the compressor 21 to the first expansion valve 22 via the condenser 55 is a heating air-conditioning main passage 41.

  Between the compressor 21 and the condenser 55 in the heating air-conditioning main passage 41, a shut-off valve 34 that is opened and closed under the control of the control device 13 is interposed. In addition, a portion between the compressor 21 and the shutoff valve 34 in the heating / air conditioning main passage 41 is connected to a downstream portion of the first expansion valve 22 via a first bypass passage 42. A bypass valve 23 that is controlled to be opened and closed by the control device 13 is interposed in the first bypass passage 42.

  When the bypass valve 23 is closed and the shutoff valve 34 is opened under the control of the control device 13, the refrigerant discharged from the condenser 55 passes through the condenser 55 and the first expansion valve 22 in the heating air-conditioning main passage 41. And flows into the outdoor heat exchanger 24. On the other hand, when the shut-off valve 34 is closed and the bypass valve 23 is opened by the control device 13, the refrigerant discharged from the condenser 55 passes through the first bypass passage 42 and is in an outdoor heat exchanger in a high temperature / high pressure state. 24.

  The outdoor heat exchanger 24 exchanges heat between the refrigerant flowing into the interior and the outdoor atmosphere. The outdoor heat exchanger 24 can absorb heat from the outdoor atmosphere by a low-temperature and low-pressure refrigerant that passes through the interior mainly during the heating operation, and vaporizes the refrigerant by absorbing heat from the outdoor atmosphere. The outdoor heat exchanger 24 can dissipate heat to the outdoor atmosphere by a high-temperature and high-pressure refrigerant that passes through the interior mainly when the cooling operation is performed, and cools the refrigerant by releasing heat to the outdoor atmosphere.

  The cooling valve 26 is installed on the heat removal air-conditioning main passage 43 connected to the downstream portion of the outdoor heat exchanger 24 in the refrigerant flow path, and is controlled to be opened and closed by the control device 13. The cooling valve 26 is mainly opened when the cooling operation is performed, and is mainly closed when the heating operation is performed.

  The receiver tank 25 is installed on the downstream side of the cooling valve 26 in the main passage 43 for heat removal air conditioning. The receiver tank 25 stores excess refrigerant out of the refrigerant that has passed through the outdoor heat exchanger 24 and has flowed into the main passage 43 for heat removal air conditioning mainly during cooling operation.

  The sub condenser 27 is installed on the downstream side of the receiver tank 25 in the heat removal air conditioning main passage 43, and exchanges heat between the refrigerant flowing into the interior and the outdoor atmosphere.

  The second expansion valve 29 is disposed on the upstream side of the evaporator 53 in the main passage 43 for heat removal air conditioning. The second expansion valve 29 is configured by an electromagnetic throttle valve whose valve opening degree is controlled by the control device 13. The second expansion valve 29 decompresses the refrigerant passing through the heat removal air conditioning main passage 43 and expands it, and then supplies it to the evaporator 53 as a low temperature and low pressure gas-liquid two-phase (vapor-phase rich) spray refrigerant. Discharge. The second expansion valve 29 has an opening adjustment mechanism (not shown) that can increase the valve opening more than the valve opening during normal use by an electromagnetic throttle valve.

The auxiliary heat exchanger 31 for cooling is between the upstream portion located on the upstream side of the second expansion valve 29 and the downstream portion located on the downstream side of the evaporator 53 in the main passage 43 for heat removal air conditioning. It is arranged to straddle. The cooling auxiliary heat exchanger 31 performs heat exchange between the upstream portion and the downstream portion described above during the cooling operation, and cools the refrigerant in the upstream portion before flowing into the evaporator 53.
In addition, the main passage 43 for heat removal air conditioning in this embodiment is the cooling valve 26, the receiver tank 25, the sub condenser 27, the auxiliary heat exchanger 31 for cooling, the second expansion valve 29, from the downstream portion of the outdoor heat exchanger 24. This is a passage connected to the gas-liquid separator 33 via the evaporator 53.

The heating valve 32 is installed on a second bypass passage 44 that bypasses the heat removal air conditioning main passage 43 and connects the downstream portion of the outdoor heat exchanger 24 and the gas-liquid separator 33. The heating valve 32 is configured by an electromagnetic opening degree adjusting valve capable of opening / closing the second bypass passage 44 and adjusting the opening degree in multiple stages. The heating valve 32 is controlled by the control device 13. The heating valve 32 is mainly opened when the heating operation is performed, and is mainly closed when the cooling operation is performed.
The heating valve 32, together with the cooling valve 26, switches the passage connecting the outdoor heat exchanger 24 and the suction portion side of the compressor 21 to either the heat removal air conditioning main passage 43 or the second bypass passage 44. Part.

  The gas-liquid separator 33 is disposed between the junction 46 that connects the downstream end of the heat removal air conditioning main passage 43 and the downstream end of the second bypass passage 44 and the suction portion of the compressor 21. The gas-liquid separator 33 separates the refrigerant that has flowed in from the merging portion 46 into gas and liquid, stores an excess liquid component (liquid phase) of the refrigerant, and compresses mainly the gas component (gas phase) of the refrigerant. 21 inhale.

  Further, the vehicle air conditioner 10 according to the present embodiment has a plurality of operation modes, and any one of the operation modes is selected and executed according to a switch operation by the driver, a change in detected temperature of each part, or the like. . The vehicle air conditioner 10 has the following operation modes.

(A) Cooling operation mode As shown in FIG. 1, the refrigerant discharged from the compressor 21 is supplied to the heating / air conditioning main passage 41 (the condenser 55 and the first expansion valve 22), the outdoor heat exchanger 24, and the heat removal air conditioning. An operation mode in which the main passage 43 (the second expansion valve 29 and the evaporator 53) flows in this order and is returned to the compressor 21. In this operation mode, the opening area of the first expansion valve 22 is enlarged.
When the operation is performed in this operation mode, the conditioned air passing through the duct 51 of the air conditioning unit 11 is removed by the evaporator 53, and the conditioned air is blown out from the air outlet 58 into the vehicle interior. The temperature of the conditioned air blown out from the air outlet 58 into the vehicle compartment is controlled by opening control of the air mix door 54.

(B) Non-dehumidifying heating operation mode As shown in FIG. 2, the refrigerant discharged from the compressor 21 is supplied to the heating air-conditioning main passage 41 (the condenser 55 and the first expansion valve 22), the outdoor heat exchanger 24, the first Operation mode in which the two bypass passages 44 are flowed in order and returned to the compressor 21.
When the operation is performed in this operation mode, the conditioned air passing through the duct 51 of the air conditioning unit 11 is heated by the condenser 55, and the conditioned air is blown out from the air outlet 58 into the vehicle interior. Also in this case, the temperature of the conditioned air blown out from the air outlet 58 into the vehicle compartment is controlled by opening control of the air mix door 54.

(C) Strong cooling operation mode As shown in FIG. 3, the refrigerant discharged from the compressor 21 is supplied to the first bypass passage 42, the outdoor heat exchanger 24, the heat removal air conditioning main passage 43 (the second expansion valve 29, and , And the evaporator 53) are flowed in this order to return to the compressor 21.
When the operation is performed in this operation mode, the conditioned air passing through the duct 51 of the air conditioning unit 11 is removed by the evaporator 53, and the conditioned air is blown out from the air outlet 58 into the vehicle interior. In this operation mode, since the refrigerant discharged from the compressor 21 is directly introduced into the outdoor heat exchanger 24 without passing through the condenser 55 and the first expansion valve 22, the heat removal capability of the evaporator 53 is efficiently increased. Can do.

(D) Dehumidification heating operation mode As shown in FIG. 4, the refrigerant | coolant discharged from the compressor 21 is made into the 1st bypass channel 42, the outdoor heat exchanger 24, the main channel | path 43 for a heat removal air conditioning (2nd expansion valve 29, and , And the evaporator 53) in this order to return to the compressor 21, and the PTC heater 56 (heating device) is operated.
When the operation is performed in this operation mode, the conditioned air passing through the duct 51 of the air conditioning unit 11 is removed by the evaporator 53 and then heated by the PTC heater 56, and the conditioned air is passed through the air outlet 58 from the vehicle interior. Is blown out. In this operation mode, the heat removal capability by the evaporator 53 and the heating capability by the PTC heater 56 can be appropriately controlled independently. The temperature of the conditioned air blown out from the air outlet 58 into the vehicle compartment is controlled by opening control of the air mix door 54.

(E) Defrosting operation mode The opening area of the first expansion valve 22 in the heating / air-conditioning main passage 41 is enlarged, and the refrigerant discharged from the compressor 21 in this state is used as the heating / air-conditioning main passage 41 as shown in FIG. An operation mode in which the passage 41 (the condenser 55 and the first expansion valve 22), the outdoor heat exchanger 24, and the second bypass passage 44 are sequentially flowed and returned to the compressor 21.
When the operation is performed in this operation mode, the high-temperature and high-pressure refrigerant discharged from the compressor 21 passes through the first expansion valve 22 and is introduced into the outdoor heat exchanger 24 with a relatively high temperature. Thereby, the frost adhering to the outdoor heat exchanger 24 by the heat | fever of the refrigerant | coolant introduced into the outdoor heat exchanger 24 is removed.

  The control device 13 basically selects and executes one of the above-described operation modes according to a switch operation by the driver, a change in the detected temperature of each part, or the like. Further, when another operation mode is selected while operating in any one of the operation modes, the operation mode is basically changed to the selected operation mode. However, when operating in the dehumidifying heating operation mode, the control device 13 prohibits mode transition from the dehumidifying heating operation mode to the non-dehumidifying heating operation mode. At this time, the operation in the dehumidifying and heating operation mode is continued regardless of the selection of the non-dehumidifying and heating operation mode. However, the air mix door 54 is fixed to the heating position and the like from the air outlet 58 to the vehicle interior. The temperature of the conditioned air that is blown out is increased.

  In addition, when the control device 13 changes the mode from the cooling operation mode to the non-dehumidifying heating operation mode, when the heat removal air conditioning main passage 43 is closed and the second bypass passage 44 is opened, the opening degree of the second bypass passage 44 is stepped. The opening degree of the heating valve 32 is controlled so as to increase. Specifically, the control device 13 opens the heating valve 32 with a small opening at the initial stage of opening the second bypass passage 44, and then increases the opening of the heating valve 32 after a predetermined time has elapsed. Thereby, the high-pressure refrigerant in the outdoor heat exchanger 24 gently flows in the direction of the gas-liquid separator 33 in the initial stage of opening the second bypass passage 44 with a small opening area, and the outdoor heat exchanger 24 and the gas-liquid separator The pressure difference between the 33 suction parts is reduced.

  In addition, when the control device 13 changes the mode from the cooling operation mode to the non-dehumidifying heating operation mode, when the heat removal air conditioning main passage 43 is closed and the second bypass passage 44 is opened, the valve opening degree of the second expansion valve 29 is increased. The valve opening degree of the second expansion valve 29 is controlled so as to be larger than the valve opening degree during normal use. Specifically, the control device 13 increases the valve opening degree of the second expansion valve 29 at the initial stage of switching of the passage, and when the pressure difference before and after the second expansion valve 29 becomes small, the second expansion valve 29 29 is returned to the valve opening during normal use. Thereby, the pressure difference between the outdoor heat exchanger 24 and the suction part of the gas-liquid separator 33 is reduced early.

As described above, when the vehicle air conditioner 10 according to the present embodiment is operating in the dehumidifying heating operation mode, the control device 13 prohibits mode transition from the dehumidifying heating operation mode to the non-dehumidifying heating operation mode. It has become. For this reason, it is possible to prevent the cooled conditioned air from being blown into the vehicle interior by rapidly switching the operation mode from the dehumidifying and heating operation mode to the non-dehumidifying and heating operation mode.
That is, since the high-temperature and high-pressure refrigerant is not introduced into the condenser 55 when operating in the dehumidifying and heating operation mode, the condenser 55 is cooled when the operation in the dehumidifying and heating operation mode continues, and the non-dehumidifying heating operation mode is changed from this state. When the transition is made, the conditioned air is cooled by the cooled condenser 55 immediately after the transition, but in the vehicle air conditioner 10 according to the present embodiment, the control device 13 prohibits such a transition of the operation mode. Thus, it is possible to suppress the cooled conditioned air from being blown into the passenger compartment.
Therefore, when the vehicle air conditioner 10 according to the present embodiment is employed, it is possible to improve the comfort of the passenger during the air conditioning operation.

  Further, in the vehicle air conditioner 10 according to the present embodiment, the heating valve 32 interposed in the second bypass passage 44 can adjust the opening degree of the second bypass passage 44 stepwise. Since it is configured by a valve, the opening degree of the second bypass passage 44 can be increased stepwise by the heating valve 32 under the control of the control device 13 during the mode transition from the cooling operation mode to the non-dehumidifying heating operation mode. . For this reason, at the initial stage of switching from the cooling operation mode to the non-dehumidifying heating operation mode, the high-pressure refrigerant in the outdoor heat exchanger 24 is gently passed through the heating valve 32 to the suction portion side of the gas-liquid separator 33 to The pressure difference between the exchanger 24 and the suction part of the gas-liquid separator 33 can be reduced. Therefore, in the vehicle air conditioner 10 according to the present embodiment, the high-pressure refrigerant in the outdoor heat exchanger 24 is separated through the heating valve 32 during the mode transition from the cooling operation mode to the non-dehumidifying heating operation mode. It is possible to prevent an abnormal noise from being generated by suddenly pulling out to the suction portion side of the container 33. Therefore, when this configuration is adopted, the comfort of the passenger during the air conditioning operation can be enhanced.

  Furthermore, in the vehicle air conditioner 10 according to the present embodiment, the second expansion valve 29 interposed in the heat removal air conditioning main passage 43 can increase the valve opening more than the valve opening during normal use. Since it has a possible opening adjustment mechanism, the valve opening of the second expansion valve 29 is controlled by the control device 13 when the mode is changed from the cooling operation mode to the non-dehumidifying heating operation mode. Can be increased. For this reason, at the initial stage of switching from the cooling operation mode to the non-dehumidifying heating operation mode, the pressure difference between the outdoor heat exchanger 24 and the suction portion of the gas-liquid separator 33 is reduced early through the second expansion valve 29. Can do. Therefore, at the time of the mode transition from the cooling operation mode to the non-dehumidifying heating operation mode, the high-pressure refrigerant in the outdoor heat exchanger 24 suddenly escapes to the suction portion side of the gas-liquid separator 33 through the heating valve 32, thereby It is possible to prevent abnormal noise from occurring. Therefore, when this configuration is adopted, the comfort of the passenger during the air conditioning operation can be enhanced.

In addition, this invention is not limited to said embodiment, A various design change is possible in the range which does not deviate from the summary. For example, in the above-described embodiment, the PTC heater 56 is employed as a heating device disposed with the condenser 55 in the heating unit 36 in the air conditioning unit 11. However, the heating device is not limited to the PTC heater 56, and water heating is performed. Other devices such as a heater can also be employed.
In the above embodiment, the heating valve 32 is controlled so that the opening degree increases stepwise at the time of the mode transition from the cooling operation mode to the non-dehumidifying heating operation mode, and the valve opening degree is during normal use. The second expansion valve 29 is controlled so as to be larger than the valve opening, but either one of these controls may be used.

DESCRIPTION OF SYMBOLS 10 ... Vehicle air conditioner 11 ... Air conditioning unit 12 ... Heat pump cycle 13 ... Control device 21 ... Compressor 22 ... 1st expansion valve 24 ... Outdoor heat exchanger 26 ... Cooling valve (passage switching part)
29 ... second expansion valve 32 ... heating valve (passage switching unit, opening adjustment valve)
35 ... Heat removal section 36 ... Heating section 41 ... Heating air conditioning main passage 42 ... First bypass passage 43 ... Heat removal air conditioning main passage 44 ... Second bypass passage 51 ... Duct 53 ... Evaporator 54 ... Air mix door (air mix) apparatus)
55 ... Capacitor 56 ... PTC heater (heating device)

Claims (3)

A heat pump cycle in which refrigerant is circulated while changing the gas phase and liquid phase to transfer heat energy;
An air conditioning unit that adjusts at least one of the temperature and humidity of the conditioned air taken from the air intake, and blows the adjusted conditioned air into the vehicle interior;
A control device for controlling the heat pump cycle and the air conditioning unit according to an operation mode;
A vehicle air conditioner comprising:
The heat pump cycle is
A compressor that compresses and discharges the refrigerant;
A condenser for introducing the refrigerant discharged from the compressor and exchanging heat of the refrigerant with conditioned air;
A first expansion valve that decompresses and expands the refrigerant that has passed through the condenser;
An outdoor heat exchanger for exchanging heat of the introduced refrigerant with the outside air,
A second expansion valve that decompresses and expands the refrigerant that has passed through the outdoor heat exchanger;
An evaporator that introduces the refrigerant that has passed through the second expansion valve and exchanges the cold heat of the refrigerant with conditioned air;
A main passage for heating and air conditioning that connects the discharge section of the compressor and the outdoor heat exchanger via the condenser and the first expansion valve;
A first bypass passage that bypasses the condenser and the first expansion valve and connects a discharge portion of the compressor and the outdoor heat exchanger;
Via the second expansion valve and the evaporator, a main passage for heat removal air conditioning that connects the outdoor heat exchanger and the suction portion of the compressor;
A second bypass passage that bypasses the second expansion valve and the evaporator and connects the outdoor heat exchanger and the suction portion of the compressor,
The air conditioning unit is
A duct through which conditioned air passes;
A heat removal unit for removing heat from the conditioned air flowing into the duct;
A heating section for heating the conditioned air flowing into the duct;
An air mix device that adjusts a ratio of conditioned air that passes through the heating unit in the duct and conditioned air that bypasses the heating unit;
The evaporator is provided in the heat removal unit, the capacitor and the heating device different from the capacitor are provided in the heating unit,
The operation mode is at least:
A cooling operation mode in which the refrigerant discharged from the compressor flows in the order of the outdoor heat exchanger and the main passage for heat removal air conditioning and returns to the compressor;
A non-dehumidifying heating operation mode in which the refrigerant discharged from the compressor flows in the order of the heating air-conditioning main passage, the outdoor heat exchanger, and the second bypass passage and returns to the compressor;
A dehumidifying heating operation mode in which the refrigerant discharged from the compressor flows in the order of the first bypass passage, the outdoor heat exchanger, and the main passage for heat removal air conditioning and returns to the compressor, and the heating device is operated. Including,
The control device prohibits mode transition from the dehumidifying and heating operation mode to the non-dehumidifying and heating mode when operating in the dehumidifying and heating mode. The heat pump cycle has a passage switching portion that switches a passage connecting the outdoor heat exchanger and the suction portion side of the compressor to either the heat removal air conditioning main passage or the second bypass passage,
When the mode switching from the cooling operation mode to the non-dehumidifying heating operation mode is performed, the passage switching unit opens the second bypass passage when the main passage for heat removal air conditioning is closed and the second bypass passage is opened. The vehicle air-conditioning apparatus according to claim 1, further comprising an opening adjustment valve capable of increasing the pressure stepwise. The heat pump cycle has a passage switching portion that switches a passage connecting the outdoor heat exchanger and the suction portion side of the compressor to either the heat removal air conditioning main passage or the second bypass passage,
When the passage switching unit closes the heat removal air conditioning main passage and opens the second bypass passage at the time of mode transition from the cooling operation mode to the non-dehumidifying heating operation mode, The vehicle air conditioner according to claim 1 or 2, further comprising an opening adjustment mechanism capable of increasing the valve opening more than the valve opening during use.

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