JP2015104932A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently agitate warm air retained in a ceiling and cool air retained on a floor in a vehicle in heating operation with simple constitution.SOLUTION: An air conditioner 1 for a vehicle comprises: a refrigeration cycle circuit 10 in which a compressor 11, a flow passage switcher 12, a heat source side heat exchanger 13, a throttle device 15 and a use side heat exchanger 16 are connected by refrigerant piping, and which performs cooling operation and heating operation by switching the flow passage switcher 12; and a control part 20 for controlling so as to supply the cool air into the vehicle 2 from the ceiling 4 of the vehicle 2 by switching the flow passage switcher 12 so that the refrigeration cycle circuit 10 becomes a refrigerant flow passage in cooling operation, when defrosting operation of the heat source side heat exchanger 13 is performed during heating operation.

Description

  The present invention relates to a vehicle air conditioner mounted on a vehicle.

  2. Description of the Related Art Conventionally, a heat pump type vehicle air conditioner mounted on a vehicle ceiling in a train or the like has a structure in which a compressor, a blower, and the like are arranged in a casing, and cool air or hot air blows out from the ceiling into the vehicle. Yes. Due to the characteristics of the air, cold air convects downward and warmed air convects upward, so that cold air accumulates at the feet and warm air tends to accumulate on the ceiling. Thus, various methods for stirring warm air accumulated on the ceiling have been proposed (see, for example, Patent Documents 1 and 2). Patent Document 1 discloses a vehicle air conditioner that is driven by an in-vehicle fan attached to the ceiling when the temperature of the ceiling exceeds a set temperature. Patent Document 2 discloses a vehicle air conditioner that switches air outlets so that cool air supplied from an air conditioner blows out from the ceiling side and warm air blows out from the floor side.

JP-A-62-216861 Japanese Utility Model Publication No. 61-131367

  However, as in Patent Document 1, when the air in the vehicle is agitated by driving the indoor blower, the warm air accumulated on the ceiling is only blown downward, so that the agitation cannot be performed efficiently. . As a result, the warm air blown out from the air conditioner is directly sucked into the air conditioner (short circuit), causing an abnormal increase in the refrigerant pressure, etc., and the compressor and the air conditioner are stopped. It becomes the situation that cannot be heated. Moreover, when the cold air and the warm air are supplied from different outlets as in Patent Document 2, a structure for switching and a structure for guiding the warm air to the floor side are required, and the structure becomes complicated.

  The present invention has been made to solve the above-described problems, and provides a vehicle air conditioner that can efficiently stir warm air accumulated on a ceiling and cold air accumulated on a floor during heating operation with a simple configuration. To get.

  The vehicle air conditioner of the present invention is installed on the roof of a vehicle, sucks air in the vehicle from a suction port formed in a ceiling in the vehicle, and cools air in the vehicle from a blowout port formed in the ceiling in the vehicle. Or a vehicle air conditioner that supplies warm air, wherein the compressor, the flow path switch, the heat source side heat exchanger, the expansion device, and the use side heat exchanger are connected by a refrigerant pipe, Refrigeration cycle circuit that performs cooling operation and heating operation by switching the flow path switch, and when the defrosting operation of the heat source side heat exchanger is performed during the heating operation, the refrigeration cycle circuit is in the cooling operation And a control unit that controls the channel switch so that the cool air is supplied from the ceiling of the vehicle into the vehicle.

  According to the vehicle air conditioner of the present invention, the cold air supplied from the indoor blower during the defrosting operation is supplied into the vehicle from the ceiling outlet, so that the cold air blown out from the outlet has accumulated on the ceiling. Since the air is guided downward along with the warm air, the warm air accumulated on the ceiling and the cold air accumulated on the floor can be efficiently stirred without adding a new configuration.

1 is a schematic diagram of a vehicle equipped with a vehicle air conditioner according to Embodiment 1 of the present invention. It is a schematic diagram which shows the mode in the vehicle of the air conditioning apparatus for vehicles of FIG. It is a schematic diagram which shows the mode in the vehicle of the air conditioning apparatus for vehicles of FIG. It is a refrigerant circuit figure which shows an example of the refrigerating cycle circuit in the air conditioning apparatus for vehicles of FIG. It is a cross-sectional schematic diagram which shows the mode in the vehicle of the conventional air conditioning apparatus for vehicles. It is a schematic diagram which shows the air conditioning apparatus for vehicles which concerns on Embodiment 2 of this invention. It is a flowchart which shows the operation example of the air conditioning apparatus for vehicles of FIG.

Embodiment 1. FIG.
Embodiments of a vehicle air conditioner according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of a vehicle on which a vehicle air conditioner is mounted, and FIGS. 2 and 3 are schematic views showing the interior of the vehicle air conditioner of FIG. 1, with reference to FIGS. The vehicle air conditioner 1 will be described. The vehicle air conditioner 1 is a vehicle air conditioner mounted on the roof 3 of the vehicle 2, and is installed on the roof 3 of the vehicle 2. A ceiling 4, which is a decorative surface, is installed on the roof 3 side of the vehicle 2. The ceiling 4 receives a suction port 5 for sucking air in the vehicle 2, and cool air or warm air supplied from the vehicle air conditioner 1. An air outlet 6 that blows out into the vehicle 2 is formed. Note that the roof 3 of the vehicle 2 is formed with an opening that leads to the inlet 5 and the outlet 6. The vehicle air conditioner 1 sucks air in the vehicle 2 from the suction port 5 and supplies cold air or warm air from the air outlet 6 into the vehicle 2.

  FIG. 4 is a refrigerant circuit diagram illustrating an example of a refrigeration cycle circuit in the vehicle air conditioner of FIG. The vehicle air conditioner 1 is a heat pump type air conditioner capable of cooling operation and heating operation, and includes a compressor 11, a heat source side heat exchanger 13, an outdoor blower 14, and a use side heat exchanger 16 as refrigerant pipes. And a refrigeration cycle circuit 10 connected at.

  The compressor 11 is composed of, for example, a vane compressor or a screw compressor, and sucks and compresses the refrigerant. The flow path switch 12 is made up of a four-way valve, for example, and is connected to the discharge side of the compressor 11. The flow path switch 12 connects the discharge side of the compressor 11 and the heat source side heat exchanger 13 during the cooling operation, and also connects the use side heat exchanger 16 and the suction side of the compressor 11. Set on the road. On the other hand, the flow path switch 12 connects the discharge side of the compressor 11 and the use side heat exchanger 16 during heating operation, and also connects the heat source side heat exchanger 13 and the suction side of the compressor 11 to the heating flow. Set on the road.

  The heat source side heat exchanger 13 performs heat exchange between the refrigerant and the outside air, functions as a condenser that condenses and liquefies the refrigerant during the cooling operation, and an evaporator that evaporates and vaporizes the refrigerant during the heating operation. Function as. The heat source side heat exchanger 13 is blown from the outdoor blower 14. The expansion device 15 functions as a pressure reducing valve or an expansion valve that adjusts the pressure of the refrigerant, and is connected between the heat source side heat exchanger 13 and the use side heat exchanger 16. The use-side heat exchanger 16 performs heat exchange between the refrigerant and the outside air, functions as a condenser that condenses and liquefies the refrigerant during cooling operation, and functions as an evaporator that evaporates and vaporizes the refrigerant during heating operation. To do. Further, as shown in FIG. 3, the vehicle air conditioner 1 sucks air in the vehicle 2 from the suction port 5 and supplies the air to the use side heat exchanger 16, and heat is exchanged in the use side heat exchanger 16. It has an indoor blower 17 that supplies cool air or warm air from the blowout port 6 into the vehicle 2.

  The flow of the refrigerant during the cooling operation of the vehicle air conditioner 1 will be described with reference to FIGS. First, the refrigerant is compressed to high temperature and high pressure in the compressor 11 and flows into the heat source side heat exchanger 13. The refrigerant flowing into the heat source side heat exchanger 13 exchanges heat with the outside air taken in by the outdoor blower 14 and is condensed and liquefied. The condensed and liquefied refrigerant flows into the use side heat exchanger 16. The refrigerant flowing into the use side heat exchanger 16 is decompressed by the expansion device 15 and is changed to a refrigerant in a low-pressure two-phase state. After that, the refrigerant exchanges heat with the air in the vehicle 2 by the use side heat exchanger 16 to be evaporated and gasified. At this time, cold air after heat exchange is supplied from the blower outlet 6 into the vehicle 2 by the indoor blower 17. Thereafter, the evaporated gas refrigerant is again sucked into the compressor 11 from the use side heat exchanger 16.

  Next, the flow of the refrigerant during the heating operation of the vehicle air conditioner 1 will be described with reference to FIGS. 1 to 4. First, the refrigerant is compressed to a high temperature and a high pressure in the compressor 11 and flows into the use side heat exchanger 16. In the use side heat exchanger 16, the refrigerant is heat-exchanged with the air in the vehicle 2 to be condensed and liquefied. At this time, warm air after heat exchange is supplied from the blower outlet 6 into the vehicle 2 by the indoor blower 17. Thereafter, the condensed and liquefied refrigerant flows into the heat source side heat exchanger 13 through the expansion device 15. The refrigerant that has flowed into the heat source side heat exchanger 13 exchanges heat with the outside air taken in by the outdoor blower 14 to be evaporated and gasified. Then, the evaporated gas refrigerant is again sucked into the compressor 11 from the use side heat exchanger 16.

  As shown in FIG. 1, the vehicle air conditioner 1 includes a control unit 20 that controls switching between cooling operation and heating operation and the operation of the refrigeration cycle circuit 10 during operation. In particular, the control unit 20 has a function of controlling the refrigeration cycle circuit 10 so that the defrosting operation of the heat source side heat exchanger is performed when the heating operation is performed. In addition, the start timing of the defrost operation at the time of heating operation can use well-known methods, such as every fixed period, for example. Here, the control unit 20 switches the flow path switch 12 so that the refrigeration cycle circuit 10 becomes a refrigerant flow path during the cooling operation during the defrosting operation so that the cold air is supplied from the ceiling 4 into the vehicle 2. (Reverse cycle defrost).

  Then, as shown in FIG. 3, the cold air heat-exchanged with the refrigerant in the use side heat exchanger 16 flows into the vehicle 2 from the air outlet 6. The cold air flowing into the vehicle 2 from the ceiling 4 generates an air flow toward the floor 7 with warm air accumulated on the ceiling 4 side. Thereby, the air in the vehicle 2 can be stirred.

  At this time, the control unit 20 controls the indoor blower 17 so that air is blown into the vehicle 2 during the above-described defrosting operation. Thereby, in addition to the stirring of the air in the vehicle 2 by cold air, the stirring by the indoor blower 17 can be performed, so that the stirring of the air in the vehicle 2 can be performed more effectively. In particular, the control unit 20 has a function of adjusting the air blowing intensity by the indoor blower 17 and controls the air blowing intensity of the indoor blower 17 to be weak during the defrosting operation. Then, when the indoor blower 17 at the time of the defrosting operation performs a low speed operation, the air in the vehicle 2 can be agitated while maintaining passenger comfort without overcooling the inside of the vehicle 2 by blowing.

  According to the first embodiment, the indoor blower 17 is driven during the defrosting operation, and the cool air blown into the vehicle 2 and the warm air accumulated in the ceiling 4 are sent downward from the air outlet 6 to stir the air in the vehicle 2. It is possible to suppress a decrease in heating efficiency due to a short circuit. That is, as shown in FIG. 5 of the related art, when only the indoor blower 17 is driven, the warm air accumulated on the ceiling 4 is only blown downward, so that efficient stirring cannot be performed. On the other hand, in the vehicle air conditioner 1, as shown in FIG. 3, a defrosting operation by reverse cycle defrost is performed so that the cold air flows from the air outlet 6 into the vehicle 2. Efficient air agitation can be performed without any problems.

Embodiment 2. FIG.
FIG. 6 is a schematic view showing a vehicle air conditioner according to Embodiment 2 of the present invention. The vehicle air conditioner 100 will be described with reference to FIG. In the vehicle air conditioner 100 of FIG. 6, parts having the same configurations as those of the vehicle air conditioner 1 of FIGS. 1 to 5 are denoted by the same reference numerals and description thereof is omitted. The vehicle air conditioner 100 of FIG. 6 is different from the vehicle air conditioner 1 of FIGS. 1 to 5 in that the defrosting operation is performed based on the ceiling temperature Tr of the ceiling 4 and the floor temperature Tf of the floor 7 in the vehicle 2. Is to control the start timing.

  Specifically, the vehicle air conditioner 100 includes a ceiling temperature detection sensor 101 that detects the temperature of the ceiling 4 in the vehicle 2 as the ceiling temperature Tr, and a floor temperature detection sensor that detects the temperature of the floor 7 as the floor temperature Tf. 102. The ceiling temperature Tr and the floor temperature Tf detected by the ceiling temperature detection sensor 101 and the floor temperature detection sensor 102 are sent to the control unit 20. And control part 120 is controlled to start defrosting operation by reverse cycle defrost, when difference delta T between ceiling temperature Tr and floor temperature Tf is larger than preset temperature threshold Tref at the time of heating operation. In addition, the control part 120 may control the defrost operation based on the difference (DELTA) T mentioned above while controlling the start of a defrost operation for the removal of normal frost formation. Moreover, you may control the control part 120 to drive the indoor air blower 17 like the said Embodiment 1 during the defrost operation.

  FIG. 7 is a flowchart showing an operation example of the vehicle air conditioner in FIG. 6, and an operation example of the vehicle air conditioner will be described with reference to FIGS. 6 and 7. First, when the heating operation is started, the ceiling temperature detection sensor 101 detects the ceiling temperature Tr, and the floor temperature detection sensor 102 detects the floor temperature Tf (step ST11). Thereafter, the control unit 20 calculates a difference ΔT between the ceiling temperature Tr and the floor temperature Tf, and determines whether or not the difference ΔT is larger than the set temperature threshold Tref (step ST12). When the difference ΔT is larger than the set temperature threshold value Tref, it is determined that there is a possibility that the heating efficiency may be reduced, and the defrosting operation by the reverse cycle defrost is started (step ST13). At this time, as shown in the first embodiment, the indoor blower 17 may be driven to blow air into the vehicle 2. Then, after the defrosting operation for a predetermined period is performed, the refrigerant flow path of the refrigeration cycle circuit 10 is switched to the refrigerant flow path during the heating operation, and the heating operation is restarted (step ST14).

  In this way, when the start timing of the defrosting operation is controlled based on the difference ΔT between the ceiling 4 and the floor 7 in the vehicle 2, the vehicle 2 is in a state where a short circuit may occur. Since the air in the vehicle 2 can be agitated using the cool air supplied from the air outlet 6, it is possible to reliably prevent a short circuit due to warm air accumulating on the ceiling 4. Moreover, since air is stirred using cold air as in the first embodiment, efficient air stirring can be performed without adding a new configuration.

  The embodiment of the present invention is not limited to the first and second embodiments. For example, in the first and second embodiments, the case where the cold air is directly blown into the vehicle 2 at the time of the defrosting operation is illustrated. A heating means for heating within a lower temperature range may be provided. And the control parts 20 and 120 may operate | move a heating means simultaneously with a defrost operation, and when it blows off cold air from the blower outlet 6 at the time of a defrost operation, you may make it blow out after heating cold air with a heating means. Thereby, when the cold air at the time of the cold air defrosting operation is blown out into the room as it is, the air in the vehicle 2 can be stirred while suppressing the cold air from lowering the temperature in the vehicle 2.

  7 illustrates the case where the start timing of the defrosting operation is controlled based on the difference ΔT, but the defrosting operation is performed when the difference ΔT becomes smaller than a predetermined threshold after the defrosting operation. May be controlled to end. Thereby, supply of the cold air more than necessary into the vehicle 2 can be prevented.

  DESCRIPTION OF SYMBOLS 1,100 Air conditioning apparatus for vehicles, 2 Vehicles, 3 Roofs, 4 Ceilings, 5 Suction ports, 6 Air outlets, 7 Floors, 10 Refrigeration cycle circuit, 11 Compressor, 12 Flow path switch, 13 Heat source side heat exchanger , 14 outdoor blower, 15 throttle device, 16 utilization side heat exchanger, 17 indoor blower, 20, 120 control unit, 101 ceiling temperature detection sensor, 102 floor temperature detection sensor, Tf floor temperature, Tr ceiling temperature, Tref set temperature Threshold, ΔT difference.

Claims (5)

A vehicle that is installed on the roof of a vehicle, sucks air in the vehicle from a suction port formed in a ceiling in the vehicle, and supplies cool air or warm air to the vehicle from a blowout port formed in the ceiling in the vehicle An air conditioner for use,
The compressor, the flow path switch, the heat source side heat exchanger, the expansion device, and the use side heat exchanger are connected by refrigerant piping, and cooling operation and heating operation are performed by switching the flow path switch. A refrigeration cycle circuit for performing
When the defrosting operation of the heat source side heat exchanger is performed during the heating operation, the vehicle is switched by switching the flow path switch so that the refrigeration cycle circuit becomes a refrigerant flow path during cooling operation. A vehicle air conditioner comprising: a control unit that controls the cool air to be supplied into the vehicle from the ceiling of the vehicle. An indoor blower that blows cool air or warm air heat-exchanged with the refrigerant in the use side heat exchanger from the outlet into the vehicle;
The vehicle air conditioner according to claim 1, wherein the control unit drives the indoor blower when performing a defrosting operation.   The said control part has a function which adjusts the operating speed of the said indoor air blower, Comprising: When performing a defrost operation, it controls so that the said indoor air blower may drive at low speed. 2. The vehicle air conditioner according to 2. A ceiling temperature sensor for detecting a ceiling temperature in the vehicle as a ceiling temperature;
A floor temperature sensor that detects a floor temperature in the vehicle as a floor temperature; and
In the heating operation, when the difference between the ceiling temperature detected by the ceiling temperature sensor and the floor temperature detected by the floor temperature sensor is larger than a set temperature threshold, The vehicle air conditioner according to any one of claims 1 to 3, which starts a defrosting operation. A refrigerant temperature sensor for detecting a refrigerant temperature flowing into the heat source side heat exchanger during heating operation;
2. The controller is configured to start the defrosting operation when the refrigerant temperature detected by the refrigerant temperature sensor is lower than a set refrigerant threshold value during heating operation. The vehicle air conditioner of any one of -3.

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