JP5984479B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicular air conditioner that can remove fogging of a window glass of a vehicle and reduce wasteful exhaust heat, in particular, an existing refrigeration cycle and a hot water cycle arranged in parallel therewith. The present invention relates to a vehicle air conditioner that can also be used for an air conditioning unit.

As a conventional vehicle air conditioner that uses a refrigeration cycle and a hot water cycle provided in parallel therewith, as shown in FIG. 7, a heat pump type cooling device 100 having a first circulation path through which a first refrigerant circulates. And a heating circulation device 200 having a second circulation path through which the second refrigerant circulates, the heat pump type cooling device 100, the compressor 101 that compresses the first refrigerant, and the first refrigerant. A capacitor 102 that dissipates heat to the second refrigerant, an expansion device 103 that expands the first refrigerant, and an evaporator 104 that exchanges heat between the expanded first refrigerant and air. Pump 201 that circulates the second refrigerant in heating circulation device 200, heater core 202 that heats the air by exchanging heat between the second refrigerant and air, and a radiator that radiates the heat of the second refrigerant (Heat dissipation ) 203, a bypass passage 204 for bypassing the radiator 203, and a passage switching valve 205 for switching the passage between the radiator side and the bypass passage. 301, the evaporator 104, and the heater core 202 are disposed, and during heating operation, the second refrigerant is caused to flow through the bypass passage 204, and the air heated by the heater core 202 is supplied into the vehicle interior. (See Patent Document 1).
In such a configuration, since a heater core using hot water can be used, there is an advantage that a conventional air conditioning unit can be used as it is.

  Conventionally, the compressor is driven when the outside air temperature is higher than a preset first level, and the compressor is driven when the outside air temperature is between the first level and a second level lower than the first level. When the outside air temperature is lower than the second level, 100% outside air is introduced to prevent the occurrence of fogging on the inner surface of the glass. Is also known (see Patent Document 2).

JP 2008-230594 A Japanese Patent Publication No.62-14411

By the way, as shown in FIG. 7A, when the former configuration is used for the dehumidifying heating operation in which the air that has passed through the evaporator 104 is heated (reheated) by the heater core 202 and is supplied to the passenger compartment. Since the heat of the refrigerant can be transferred to the second refrigerant by the condenser 102 and can be radiated by the heater core 202, waste heat exhausted by the condenser 102 can be prevented and energy can be used effectively. If the state is left as it is, as shown in FIG. 7B, heat is gradually accumulated in the second circulation path, and the heat is excessively accumulated.
In such a state, heat transfer from the heat pump type cooling device 100 to the heating circulation device 200 via the condenser 102 becomes difficult, and the heat dissipation function by the condenser 102 is reduced, so that the first refrigerant is sufficiently cooled. Since the expansion device is throttled so that a predetermined degree of superheat is obtained in the evaporator 104, the refrigerant flow rate to the evaporator 104 is reduced, and sufficient dehumidification capability cannot be ensured. Further, since the heat radiation by the capacitor 102 is not sufficiently performed, the pressure of the high-pressure line in the first circulation path increases.

For this reason, the second circulation path cannot be removed from an excessive heat storage state, and the dehumidifying function by the evaporator 104 cannot be sufficiently obtained, so that the window glass may be fogged.
Therefore, in order to eliminate such inconvenience, the second refrigerant is caused to flow through the radiator 203 provided in the second circulation path, and the second refrigerant is radiated by the radiator 203 so that the second circulation path is excessively discharged. It is effective to avoid heat storage.
However, even if excessive heat storage in the second circulation path is avoided by heat radiation from the radiator 203 and the dehumidifying function by the evaporator 104 can be secured, the dew point temperature of the air that has passed through the evaporator 104 is usually from the viewpoint of preventing the evaporator 104 from freezing. When it is around 2 ° C. and the temperature of the air outside the passenger compartment is sufficiently lower than the dew point temperature of the air that has passed through the evaporator (for example, −5 ° C.), there is a concern that the window glass may still be fogged.

  Therefore, as shown in the latter prior art, it is effective to introduce low-temperature outside air with a relatively small amount of water, thereby reducing the amount of heat absorbed by the evaporator. By adopting such a configuration, the amount of heat transferred from the first refrigerant to the second refrigerant via the condenser 102 is reduced (because the amount of heat input to the second circulation path can be reduced). In addition, heat is less likely to be stored in the second circulation path, and the introduction of air with a small amount of moisture makes it possible to reduce the relative humidity of the passenger compartment air and prevent fogging of the window glass.

  By the way, when the outside air temperature is low, the interior temperature of the air conditioner is also low at the initial stage of operation of the air conditioner. Therefore, even if the inside air introduction ratio is increased, cold air is introduced into the ventilation passage. The endothermic amount of is reduced. In addition, when the outside air temperature is low, there is a request to heat the air as much as possible. Therefore, the amount of heat released by the heater core 202 increases, and excessive heat is not accumulated in the second circulation path. For this reason, heat is not accumulated as much as the radiator 203 has to be used. Therefore, as shown in FIG. 8, when the outside air temperature is equal to or lower than a predetermined temperature (−α ° C.), there is no requirement to use the radiator.

  In addition, when high-temperature outside air is introduced, particularly in rainy weather, the window glass may become cloudy. However, if the outside air temperature falls below a predetermined temperature (β ° C), Even when the relative humidity is high, the amount of moisture contained in the outside air is small, so that the outside air is taken into the vehicle interior to lower the relative humidity of the vehicle interior air, and the fogging of the window glass can be effectively removed or prevented.

  However, taking outside air into the passenger compartment when the outside air temperature is low can remove or prevent fogging of the window glass, and exhausts the passenger compartment air heated by the air conditioner to the outside of the passenger compartment. It is also to dissipate heat energy.

  As shown in FIG. 8, there is a competing section in which an outside air temperature region where heat is radiated using the radiator 203 and an outside air temperature region where an anti-fogging effect due to the introduction of outside air is desired overlap.

  Here, heat dissipation by the radiator is an exhaust heat method that does not contribute to prevention of window fogging, whereas introduction of low temperature outside air is an exhaust heat method that contributes to prevention of window fogging as described above. When it is in the section and it is desired to avoid excessive heat storage in the second circulation path, it is desirable to increase the outside air introduction ratio in preference to the heat radiation by the radiator.

  And when using the vehicle air conditioner provided with the heat pump type cooling device and the heating circulation device mentioned above, while avoiding excessive heat storage of the heating circulation device, ensuring window clearness and wasteful exhaustion. It is required to prevent heat as much as possible and to make heating operation and dehumidification operation more efficient, thereby contributing to improvement of fuel consumption.

  The present invention has been made in view of such circumstances, and while avoiding excessive heat storage in the heating circulation cycle, the heat radiation of the radiator and the introduction of outside air are linked to ensure window clearness and wasteful waste heat. The main object is to provide a vehicle air conditioner that can prevent the above-described problems.

  In order to solve the above problems, a vehicle air conditioner and a vehicle air conditioning control method according to the present invention include a first circulation cycle in which a first heat medium circulates and a second cycle in which a second heat medium circulates. A circulation cycle; and an air conditioning unit having an air passage inside. The first circulation cycle includes a compressor in which the first heat medium compresses the first heat medium, and the compressed first heat medium. A heat exchanger that transfers the heat of one heat medium to the second heat medium, an expansion device that expands the first heat medium, the first heat medium expanded by the expansion device, and the blower An evaporator that cools the air in the passage, and the compressor can be circulated in this order, and the second circulation cycle includes the pump, the heat exchanger, and the second heat medium. Heater core that dissipates heat and heats air in the air passage, front It is configured so that it can circulate in the order of the pump, and is provided between the heater core and the pump, or between the pump and the heat exchanger, and dissipates the heat of the second heat medium to the outside of the passenger compartment. A radiator that bypasses the radiator, a flow rate adjusting means that adjusts a flow rate of the second heat medium that flows through the radiator and the bypass channel, and the heat exchanger or the heat exchanger A temperature detecting means for detecting the temperature of the second heat medium between the heater core and the air conditioning unit, wherein the air-conditioning unit introduces the vehicle interior air and the vehicle exterior air into the air passage. In the case where the intake device for adjusting air, the blower for blowing the air introduced through the intake device, the evaporator and the heater core are arranged, the intake device And the compressor and the pump are operated, and when the temperature of the second heat medium exceeds the first predetermined temperature, the introduction ratio of outside air in the vehicle is relatively increased, When the temperature of the second heat medium exceeds a second predetermined temperature that is higher than the first predetermined temperature, the flow rate adjusting unit causes the second heat medium to flow through the radiator, or the radiator The flow rate of the second heat medium that is passed through is increased.

  Therefore, until the temperature of the second heat medium exceeds the first predetermined temperature, the inside air introduction rate is relatively high, the amount of heat absorbed by the evaporator is increased, and the temperature of the second heat medium is increased early. In addition, since the outside air introduction rate is increased after the temperature of the second heat medium exceeds the first predetermined temperature, the amount of heat absorbed by the evaporator can be suppressed. For this reason, it is possible to prevent excessive heat input to the second circulation cycle in which heat has already been sufficiently stored. Further, by increasing the outside air introduction rate, it is possible to reduce the moisture content of the air introduced into the blower passage, reduce the relative humidity of the cabin interior air, and prevent window fogging.

Further, when the flow rate adjusting means exceeds the second predetermined temperature, the flow rate of the second heat medium flows to the radiator or the flow rate of the second heat medium to flow to the radiator increases. Even if heat is not released from the radiator immediately, or the amount of heat released from the radiator does not increase, priority can be given to increasing the outside air introduction rate to prevent window fogging, and limited energy is effective for heating operation. It can be used.
If excessive heat input to the second circulation cycle cannot be suppressed even if the outside air introduction rate is increased, the second heat medium is radiated by the radiator, thereby increasing the temperature of the second heat medium. And can be maintained within an appropriate temperature range.

  Therefore, the flow rate adjusting means does not flow the second heat medium through the radiator or flows the second heat medium through the radiator until the temperature of the second heat medium exceeds the second predetermined temperature. It is preferable not to increase the flow rate of the heat medium. By adopting such a configuration, exhaust heat operation that does not contribute to prevention of window fogging is prohibited until the second heat medium reaches the second predetermined temperature. Alternatively, the increase in the amount of exhaust heat is prohibited, and the limited energy can be more reliably used for the heating operation.

When the temperature of the second heat medium exceeds the first predetermined temperature and then falls below a third predetermined temperature lower than the first predetermined temperature, the intake device introduces vehicle exterior air. It is preferable that the ratio is relatively reduced.
In such a configuration, since the introduction ratio of the outside air introduction rate decreases after the temperature falls below the third predetermined temperature, a hysteresis is provided between the first predetermined temperature and the third predetermined temperature, and the intake device hunting is performed. Can be prevented. Moreover, it can prevent that the temperature of a 2nd heat medium falls too much, can maintain a 2nd heat medium at high temperature, and can maintain heating performance.

Furthermore, the flow rate adjusting means, when the temperature of the second heat medium exceeds the second predetermined temperature and then falls below a fourth predetermined temperature lower than the second predetermined temperature, It is preferable that the flow rate of the second heat medium that does not flow through the radiator or the flow of the second heat medium that flows through the radiator is reduced.
In such a configuration, since the flow rate of the second heat medium flowing through the radiator after being lower than the fourth predetermined temperature is reduced, a hysteresis is provided between the fourth predetermined temperature and the second predetermined temperature, The hunting of the flow rate adjusting means can be prevented, and the temperature of the second heat medium can be prevented from excessively decreasing to maintain the second heat medium at a high temperature, thereby maintaining the heating performance.

The vehicle interior humidity detection means for detecting the humidity of the vehicle interior air, the vehicle interior temperature detection means for detecting the temperature of the vehicle interior air, the vehicle exterior humidity detection means for detecting the humidity of the vehicle exterior air, and the vehicle exterior air A vehicle exterior temperature detecting means for detecting the temperature of the vehicle interior, and a computing means, wherein the computing means computes the dew point temperature of the passenger compartment air from the humidity of the passenger compartment air and the temperature of the passenger compartment air, The dew point temperature of the vehicle exterior air is calculated from the humidity of the vehicle exterior air and the temperature of the vehicle exterior air, and the relative increase in the introduction ratio of the vehicle exterior air by the intake device is greater than the vehicle interior air. This should be done when the dew point temperature is low.
In such a configuration, since the relative increase in the proportion of the outside air is performed when the dew point temperature of the outside air is lower than the inside air, the clear window effect can be surely obtained. .

  Further, it is desirable that the intake device relatively increase the introduction ratio of outside air in the vehicle compartment when in the dehumidifying heating operation mode. For example, if the ratio of outside air in the passenger compartment is increased in the cooling mode in which the temperature of the outside air is high, warm air is introduced into the air passage, and the temperature of the air from the air conditioner rises, which is not appropriate. Increasing the proportion of the air outside the passenger compartment sometimes is appropriate because it can prevent excessive heat input to the second circulation cycle and prevent window fogging.

As described above, according to the present invention, in the intake device of the air conditioning unit, the compressor of the first circulation cycle and the pump of the second circulation cycle are operated, and the temperature of the second heat medium is the first. When the predetermined temperature of 1 is exceeded, the introduction ratio of outside air in the passenger compartment is relatively increased, and the flow rate adjusting means has a second predetermined temperature in which the temperature of the second heat medium is higher than the first predetermined temperature. When the temperature is exceeded, the second heat medium is allowed to flow to the radiator or the flow rate of the second heat medium that is allowed to flow to the radiator is increased. Therefore, until the first predetermined temperature is exceeded, The temperature of the second heat medium can be increased early by increasing the amount of heat, and the amount of heat absorbed by the evaporator can be suppressed after exceeding the first predetermined temperature. In addition, excessive heat input to the second circulation cycle that has already been sufficiently stored can be prevented, and the moisture content of the air introduced into the blower passage can be reduced to effectively prevent window fogging. .
Also, priority should be given to an operation for increasing the outside air introduction rate that does not immediately release heat from the radiator even if the first predetermined temperature is exceeded, and can prevent excessive heat input to the second circulation cycle and prevent window fogging. Therefore, it is possible to ensure window clearness and prevent waste heat exhaustion, and to effectively use limited energy for heating operation. In addition, if excessive heat input to the second circulation cycle cannot be suppressed even if the outside air introduction rate is increased, heat is dissipated by the radiator, so the temperature rise of the second heat medium is suppressed and It is possible to maintain the temperature range.

  Here, until the temperature of the second heat medium exceeds the second predetermined temperature, the second heat medium is not allowed to flow to the radiator, or the flow rate of the second heat medium that is allowed to flow to the radiator is not increased. Thus, until the temperature of the second heat medium exceeds the second predetermined temperature, the exhaust heat operation that does not contribute to the prevention of window fogging is prohibited, and the limited energy can be used more reliably for the heating operation. It becomes.

  In addition, when the temperature of the second heat medium exceeds the first predetermined temperature and then falls below a third predetermined temperature lower than the first predetermined temperature, the intake device introduces outside air in the passenger compartment. By relatively reducing the ratio, hunting of the intake device can be prevented, and the temperature of the second heat medium can be prevented from excessively decreasing to raise the temperature of the second heat medium (hot water). It is possible to maintain and maintain the heating performance.

  Further, when the temperature of the second heat medium exceeds the second predetermined temperature and then falls below a fourth predetermined temperature lower than the second predetermined temperature, the flow rate adjusting means causes the second heat medium to be a radiator. Do not flow, or by reducing the flow rate of the second heat medium flowing to the radiator, hunting of the flow rate adjusting means can be prevented, the temperature of the second heat medium is prevented from excessively decreasing, Moreover, it becomes possible to maintain the heating performance by maintaining the second heat medium (warm water) at a high temperature.

In addition, by making the relative increase in the introduction ratio of the vehicle exterior air by the intake device performed when the dew point temperature of the vehicle exterior air is lower than the vehicle interior air, the window clear effect can be reliably obtained. It becomes possible.
In addition, by making the intake device perform a relative increase in the introduction ratio of the outside air in the vehicle compartment in the dehumidifying and heating operation mode, it is possible to reliably obtain the window clearing effect.

FIG. 1 is a diagram showing an overall configuration of a vehicle air conditioner according to the present invention. FIG. 2 is a perspective view showing a heat exchanger that transfers the heat of the first heat medium to the second heat medium according to the present invention. FIG. 3 is a flowchart showing an example of a control operation by the control unit of FIG. FIG. 4 is a characteristic diagram showing a relationship between a switching threshold value of the flow rate of the radiator with respect to the temperature of the second heat medium and a switching threshold value of the outside air introduction rate of the intake device. FIG. 5 is a characteristic diagram showing a first example of the relationship between the second heat medium temperature, the inside / outside air introduction ratio, the radiator heat release, the window glass temperature and the dew point temperature after the dehumidifying and heating operation is started. is there. FIG. 6 is a characteristic diagram showing a second example of the relationship between the second heat medium temperature, the inside / outside air mixing ratio, the radiator heat dissipation, the window glass temperature and the dew point temperature after the dehumidifying and heating operation is started. is there. FIG. 7 is an explanatory diagram for explaining a conventional vehicle air conditioner and its problems. FIG. 8 is a diagram showing temperature conditions in which anti-fogging is effective due to the introduction of outside air by the intake device, and temperature conditions in which heat radiation by the radiator is effective.

Embodiments of a vehicle air conditioner according to the present invention will be described below with reference to the drawings.
FIG. 1 shows a vehicle air conditioner according to the present invention. The vehicle air conditioner includes a first circulation cycle 1 in which a first heat medium circulates and a second circulation in which a second heat medium circulates. It has a cycle 2 and an air conditioning unit 4 having an air passage 3 inside.

In the first circulation cycle 1, a refrigerant such as a hydrofluorocarbon (HFC) system or CO2 is used as the first heat medium, and the compressor 5 that compresses the first heat medium and the compressed first heat medium A heat exchanger 6 that transfers the heat of the heat to a second heat medium, which will be described later, an expansion device 7 that expands the first heat medium, and the first heat medium expanded by the expansion device 7 to evaporate and blow the air passage 3. And an evaporator 8 for cooling the air.
Therefore, the first heat medium (refrigerant) circulates in the order of the compressor 5, the heat exchanger 6, the expansion device 7, the evaporator 8, and the compressor 5, and then radiates heat in the heat exchanger 6 and in the evaporator 8. The heat absorption is repeated.

The second circulation cycle 2 uses a liquid medium such as warm water or coolant as the second heat medium when circulating in the cycle, and the heat exchanger circulates the second heat medium and the heat exchanger. 6, a heater core 11 that radiates heat of the second heat medium (heat exchange of the second heat medium with air) and heats the air in the air passage 3, the pump 10, and the heat exchanger 6 , A radiator 12 that radiates heat of the second heat medium to the outside of the passenger compartment, a bypass passage 13 through which the second heat medium flows around the radiator, and the radiator 12 and the bypass passage 13 And a flow rate adjusting valve 14 that adjusts the flow rate of the second heat medium that flows to and a heat medium temperature detection sensor 15 that detects the temperature of the second heat medium.
Therefore, the second heat medium (warm water) is circulated in the order of the pump 10, the heat exchanger 6, the heater core 11, and the pump 10, and repeats heat absorption in the heat exchanger 6 and heat dissipation in the heater core 11. In addition, the portion led to the radiator 12 through the flow rate control valve 14 is radiated by the radiator 12.

  For example, as shown in FIG. 2, the heat exchanger 6 includes a first heat medium inflow port 21 and an outflow port 22, and a second heat medium inflow port 23 and an outflow port 24. Even if the tube plates 25 to be stacked are configured by alternately stacking the tube plates through which the first heat medium flows and the tube plates through which the second heat medium flows, the stacked tube plates 25 The passage through which the first heat medium flows and the passage through which the second heat medium flow may be provided adjacent to each other, and heat exchange is performed between the first heat medium and the second heat medium. By moving the heat of the first heat medium to the second heat medium, the second heat medium is heated.

  The air conditioning unit 4 is provided with an intake device 31 that adjusts the introduction ratio of vehicle interior air and vehicle exterior air on the most upstream side, and is introduced to the downstream side of the intake device 31 via the intake device 31. The blower 32 sends the air to the downstream side of the blower passage 3 and blows the air into the vehicle compartment via a blow-off port (not shown), and the evaporator 8 and the heater core 11 are arranged on the downstream side of the blower 32. .

  The intake device 31 is configured such that the introduction ratio is adjusted by adjusting the opening of the inside air inlet 33 and the outside air inlet 34 by the intake door 35. Therefore, the inside air and the outside air introduced through the intake device 31 are sent to the evaporator 8 and the heater core 11 by the rotation of the blower 32, where they are dehumidified and heat-exchanged to be supplied into the vehicle interior from a desired outlet. It has become.

  The evaporator 8 is disposed upstream of the heater core 11 in the air flow direction in the air conditioning unit, and an air mix door 36 is provided between the downstream side of the evaporator 8 and the upstream side of the heater core 11. The air mix door 36 can be displaced from a position (full hot position: opening degree 100%) where the air flow rate of the heater core 11 is maximum to a position (full cool position: opening degree 0%) where the airflow volume is minimum. By adjusting the opening degree, the ratio of the air passing through the heater core 11 and the air bypassing can be adjusted.

  The compressor 5, the pump 10, the intake door 35, the air mix door 36, and the flow rate adjusting valve 14 are controlled by a control signal from the control unit 40. The control unit 40 is a publicly known unit including an input circuit including an A / D converter and a multiplexer, an arithmetic processing circuit including a ROM, a RAM, a CPU, and an output circuit including a drive circuit. A refrigerant temperature signal from the heat medium temperature detection sensor 15 for detecting the temperature of the vehicle heat medium, a vehicle interior air humidity sensor 41 for detecting the humidity of the vehicle interior air, and a vehicle interior air temperature sensor 42 for detecting the temperature of the vehicle interior air. , A signal from the outside air humidity sensor 43 that detects the humidity of the outside air and a signal from the outside air temperature sensor 44 that detects the temperature of the outside air are input, and are determined in advance based on these various signals. Processing is performed according to a predetermined program.

  In this example, the heat medium temperature detection sensor 15 is installed between the heat exchanger 6 and the heater core 11 in the second circulation cycle 2, and the temperature of the second heat medium immediately after flowing out of the heat exchanger 6. Is reflected. Although not shown, the heat medium temperature detection sensor 15 may be disposed in the heat exchanger 6 to detect the temperature of the second heat medium flowing out of the heat exchanger 6. Any of them is a part where the temperature of the second heat medium is high in the second circulation cycle 2, and is suitable as a part for grasping the temperature state of the circulation cycle.

  Next, of the control operations by the control unit 40, a specific control operation example of the inside / outside air introduction ratio by the intake device 31 and the flow rate adjustment to the radiator by the flow rate control valve 14 will be described based on the flowchart shown in FIG.

  First, when the air conditioner is operated, the control unit 40 performs initial setting such as setting the control flag F1 used in the program to zero (step 50). Thereafter, whether or not there is a request for dehumidifying and heating operation is determined by the operation of the occupant or by automatic setting based on the heat load in the passenger compartment (step 52), and it is determined that there is no request for the dehumidifying and heating operation. In this case, the control proceeds to another control process without performing this control (step 54), and then the determination in step 52 is repeated again.

  On the other hand, if it is determined in step 52 that there is a request for the dehumidifying heating operation, in step 56, the ratio of the outside air by the intake device is relatively reduced to make the inside air rich state the heating capacity. And the flow rate control valve 14 is adjusted so that the second heat medium does not flow to the radiator 12 or flows in order to increase the temperature of the second heat medium in the second circulation cycle as soon as possible. The flow rate of the second heat medium flowing through the radiator 12 is reduced.

  Thereafter, the detected temperature of the second heat medium detected by the heat medium temperature detection sensor 15, the detected humidity and detected temperature of the vehicle interior air detected by the vehicle interior air humidity sensor 41 and the vehicle interior air temperature sensor 42, the exterior of the vehicle interior The detected humidity and detected temperature of the vehicle exterior air detected by the air humidity sensor 43 and the vehicle exterior air temperature sensor 44 are input (step 58). In step 60, the temperature of the second heat medium is set to the first predetermined temperature ( It is determined whether the temperature is higher than the conventional radiator drive determination temperature).

  If it is determined that the temperature of the second heat medium is equal to or lower than the first predetermined temperature (conventional radiator drive determination temperature), is the control flag F1 set to “1” (second) Whether or not the temperature of the heating medium once becomes higher than the first predetermined temperature and then becomes equal to or lower than the first predetermined temperature is determined (step 62).

  In the initial stage of the dehumidifying and heating operation, the temperature of the second heat medium has not yet reached the first predetermined temperature. Therefore, the control flag F1 is in the zero state by the initial setting in step 50. Then, the process proceeds to another control process 54, and then returns to step 52.

If it is determined in step 60 that the temperature of the second heat medium is higher than the first predetermined temperature, the control flag is set to “1” (step 64), and the dew point temperature of the vehicle exterior air is It is determined whether or not the dew point temperature of the passenger compartment air is lower, that is, whether or not introduction of the passenger compartment outside air is effective in order to prevent fogging of the inner surface of the window glass (step 66).
In this determination, the dew point temperature of the vehicle interior air is calculated from the detected humidity and detected temperature of the vehicle interior air input in step 58, and the vehicle exterior air is calculated from the humidity of the vehicle exterior air and the temperature of the vehicle exterior air. The dew point temperature is calculated and the results are compared.

  As a result of the determination, when it is determined that the dew point temperature of the vehicle interior air is higher than the dew point temperature of the vehicle interior air, it is not effective to introduce the vehicle exterior air in order to prevent the fogging of the window glass from fogging the inner surface. Therefore, while maintaining the current setting state, the process proceeds to another control process of step 68, and then proceeds to step 70 to determine whether or not there is a request for dehumidifying heating operation, and the request for dehumidifying heating operation is still If there is, the process proceeds to step 58. If it is determined that there is no request for the dehumidifying and heating operation, the process proceeds to another control process of step 54, and then returns to step 52.

  On the other hand, when it is determined in step 66 that the dew point temperature of the vehicle interior air is lower than the dew point temperature of the vehicle interior air, the vehicle exterior air is introduced to prevent fogging of the inner surface of the window glass. Is effective, the intake device 31 relatively increases the proportion of the air outside the passenger compartment and increases the amount of outside air introduced with a small amount of water (step 72).

  Thus, until the first predetermined temperature is exceeded, the outside air introduction ratio is relatively decreased by step 56 (because the inside air introduction rate is relatively increased), so the amount of heat absorbed by the evaporator increases. It becomes possible to raise the temperature of the second heat medium at an early stage. Moreover, since the external air introduction ratio relatively increases after the first predetermined temperature is exceeded, the endothermic amount of the evaporator can be suppressed. For this reason, it is possible to prevent excessive heat input to the second circulation cycle via the heat exchanger 6, and it is possible to reduce the humidity of the air introduced into the air passage and prevent window fogging. It becomes.

  Thereafter, it is determined whether or not the temperature of the second heat medium has become higher than a second predetermined temperature that is higher than the first predetermined temperature (step 74), and the second heat medium is still the first heat medium. If the control flag F1 is set to “2”, it is determined that the temperature is between the second heat medium and the second heat medium (the second heat medium has become higher than the second predetermined temperature). It is determined whether or not there is a history (step 76).

If it is not F1 = 2, the temperature of the second heat medium has not yet reached the second predetermined temperature. Therefore, in step 78, the second heat medium is not allowed to flow to the radiator or is already in the radiator. If it is flowing to the radiator, do not increase the flow rate to the radiator.
As a result, even if the second heat medium exceeds the first predetermined temperature, priority can be given to the operation of increasing the outside air introduction rate that does not immediately release heat from the radiator and can prevent window fogging, and has limited energy. Can be effectively used for heating operation.

On the other hand, if it is determined in step 74 that the temperature of the second heat medium is higher than the second predetermined temperature, the control flag is set to “2” (step 80), and the second Since excessive heat is accumulated in the circulation cycle, the flow control valve 14 is controlled so that the second heat medium flows to the radiator 12 or, if already flowing, to the radiator 12. The flow rate to the radiator 12 by the flow rate control valve 14 is adjusted so as to increase the flow rate (step 82). Then, after the above process, the process proceeds to another control process of step 68 and then returns to step 70.
As a result, when excessive heat input to the second circulation cycle cannot be suppressed even if the outside air introduction rate is increased, the second heat is suppressed by radiating heat with the radiator, thereby suppressing the temperature rise of the second heat medium. It becomes possible to maintain the medium in an appropriate temperature range.

In Step 76, when it is determined that the control flag F1 is set to “2” (the second predetermined temperature after the temperature of the second heat medium becomes higher than the second set temperature). If lower than the second predetermined temperature, it is determined whether or not the second heat medium has fallen below a fourth predetermined temperature lower than the second predetermined temperature (step 84). If it is determined that the temperature is lower than the predetermined temperature, the second heat medium is not passed through the radiator 12 or the flow rate of the second heat medium passed through the radiator 12 is decreased (step 86).
Thereby, it is possible to prevent the temperature of the second heat medium from being excessively lowered, maintain the second heat medium at a high temperature, and maintain the heating performance.
Thereafter, the process proceeds to another control process of step 68 and returns to step 70. In Step 84, when it is determined that the second heat medium is not lower than the fourth predetermined temperature, the state in which the second heat medium flows to the radiator in Step 82 or the state in which the flow rate to the radiator is increased is maintained. Then, after the other control processing of step 68, the process returns to step 70 again.

By the above control, when the temperature of the second heat medium decreases and becomes lower than the first predetermined temperature after the second heat medium once becomes higher than the first predetermined temperature, the control flag F1 Is set to 1, the process proceeds from step 62 to step 88, where it is determined whether or not the temperature of the second heat medium is lower than a third predetermined temperature set to a temperature lower than the first predetermined temperature. If it is determined that the temperature of the second heat medium has fallen below the third predetermined temperature, the temperature of the second heat medium is lowered and there is a concern about a decrease in heating capacity. In order to ensure, the intake device 31 relatively reduces the introduction ratio of the outside air according to the temperature of the second heat medium (step 90).
Thereby, it is possible to prevent the temperature of the second heat medium from excessively decreasing, maintain the second heat medium at a high temperature, and maintain the heating performance.

  Therefore, in the above-described control, the flow rate control to the radiator 12 and the control of the outside air introduction rate by the intake device 31 are performed as shown in FIG. 4 according to the temperature of the second heat medium. 31, when the temperature of the second heat medium exceeds the first predetermined temperature, the outside air introduction ratio is relatively increased, and the temperature is lower than the third predetermined temperature lower than the first predetermined temperature. In this case, the introduction ratio of outside air in the passenger compartment is relatively reduced, and a hysteresis is provided between the first predetermined temperature and the third predetermined temperature, and the movement of the intake door 35 of the intake device 31 is Hunting is prevented from occurring. Further, in the flow control to the radiator 12, when the temperature of the second heat medium exceeds the second predetermined temperature, the flow to the radiator 12 is relatively increased, and the second predetermined temperature is increased. When the temperature falls below a fourth predetermined temperature lower than the temperature, the flow rate to the radiator 12 is relatively decreased, and a hysteresis is provided between the second predetermined temperature and the fourth predetermined temperature. Hunting is prevented from occurring in the flow rate control (operation of the flow rate control valve 14). The fourth predetermined temperature is set higher than the first predetermined temperature, and the second predetermined temperature and the second predetermined temperature are higher than the hysteresis set between the first predetermined temperature and the third predetermined temperature. Since the hysteresis set between the predetermined temperature of 4 is in a high temperature range, the outside air introduction rate seems to increase early in the relatively low temperature region from the viewpoint of preventing window fogging. In order to maintain the high temperature of the second heat medium, the flow rate to the radiator is switched between increasing and decreasing in a relatively high temperature region, thereby preventing window fogging and unnecessary waste heat. Can be effectively achieved.

  Next, in the above-described configuration, the inside / outside air introduction ratio by the intake device 31 accompanying the temperature change of the second heat medium during the dehumidifying heating operation, the presence / absence of heat radiation by the radiator 12, the temperature and dew point temperature inside the vehicle interior of the window In the following, the change in the temperature of the second heat medium shown in FIG. 5 will be described.

First, immediately after the compressor 5 and the pump 10 are operated (and the blower 22 is also operated accordingly) and the dehumidifying and heating operation is started, in step 56, the intake device 31 makes the relative ratio of the outside air in the passenger compartment relatively. Therefore, the second heat medium does not flow through the radiator 12 (or the flow rate is decreased when it is flowing), so that the inside / outside air introduction ratio becomes rich in the inside air, and the temperature of the vehicle interior air increases. Since the amount of heat absorbed by the evaporator 8 increases, the amount of heat input to the second circulation cycle 2 increases.
For this reason, the temperature of the 2nd heat carrier of the 2nd circulation cycle 2 rises early, and the surface temperature and dew point temperature inside a window glass also rise gradually in connection with this.
Even if the temperature of the second heat medium is equal to or lower than the first predetermined temperature, if the temperature of the second heat medium rises, in step 56, the introduction ratio of the outside air in the vehicle is relatively small. It may be increased to contribute to prevention of fogging of the window glass.

  When the temperature of the second heat medium exceeds the first predetermined temperature and the dew point temperature of the vehicle exterior air is lower than the dew point temperature of the vehicle interior air, the intake device The introduction ratio of the outside air in the passenger compartment increases according to the temperature (step 72), suppresses an increase in the surface temperature inside the glass, and lowers the dew point temperature of the air inside the glass. By increasing the introduction ratio of the outside air in the passenger compartment, the heat absorption amount of the evaporator 8 is suppressed, and excessive heat input to the second circulation cycle is prevented.

When the temperature of the second heat medium further exceeds the first predetermined temperature, in step 72, the introduction ratio of outside air in the passenger compartment is set to 100% according to the temperature of the second heat medium. Increase until the dew point temperature of the air inside the glass is lowered.
At this stage, heat dissipation by the radiator 12 is not yet performed, and the introduction ratio of outside air in the passenger compartment is increased in preference to the heat dissipation by the radiator 12.

Thereafter, when the temperature of the second heat medium further rises and exceeds the second predetermined temperature in spite of the adjustment of the outside air introduction ratio, the second circulation cycle 2 is excessively stored. Therefore, the heat release by the radiator 12 is started in step 82 (or the flow rate to the radiator 12 is increased to increase the heat release amount), and the heat accumulated in the second circulation cycle 2 is actively released. .
As a result, when the temperature of the second heat medium gradually decreases and falls below the fourth predetermined temperature, in step 86, the heat dissipation by the radiator 12 is stopped (or the flow rate to the radiator 12 is reduced). To reduce the amount of heat released) and minimize the exhaust heat that does not contribute to fogging of the window glass to maintain the heating performance.

Moreover, with respect to the temperature change of the second heat medium shown in FIG. 6, the inside / outside air introduction ratio by the intake device, the presence or absence of heat radiation by the radiator, and the changes in the glass temperature and the dew point temperature are as follows.
That is, after the compressor 5 and the pump 10 are operated (and the blower 22 is also operated accordingly) and the dehumidifying and heating operation is started, until the temperature of the second heat medium exceeds the first predetermined temperature, The inside / outside air introduction ratio by the intake device 31, the presence / absence of heat radiation by the radiator 12, and the changes in the glass temperature and the dew point temperature change in the same manner as in FIG. 5, but the temperature of the second heat medium exceeds the first predetermined temperature. As a result of increasing the outdoor air introduction ratio later, when the temperature of the second heat medium gradually decreases and falls below the third predetermined temperature, the introduction ratio of outside air in the vehicle compartment is relatively reduced in step 90. The temperature of the second heat medium is prevented from excessively decreasing, the second heat medium (warm water) is maintained at a high temperature, and the heating performance is maintained.

  Thereafter, when the temperature of the second heat medium rises again and exceeds the first predetermined temperature, the introduction ratio of the outside air in the passenger compartment increases in step 72, the heat absorption amount of the evaporator 8 is suppressed, and The dew point temperature of the air inside the window glass is lowered, and the window glass is hardly fogged. Thereby, if the temperature of the second heat medium is lowered again, the same processing is performed thereafter.

  In this example, since the temperature of the second heat medium does not exceed the second predetermined temperature, heat radiation by a radiator that has been conventionally performed is not performed, and it is useless that does not contribute to the clearing of the window glass. It is possible to avoid exhaust heat.

  As described above, the configuration of the vehicle air conditioner of FIG. 1 has been described as an example, but other configurations may be adopted as long as they do not depart from the gist of the present invention. For example, although the example which provided the radiator 12 between the pump 10 and the heat exchanger 6 of the 2nd circulation cycle 2 was shown, the radiator 12 may be provided between the heater core 11 and the pump 10. . Moreover, although the example which provided the flow volume adjustment valve 14 between the pump 10 and the radiator 12 was shown, you may make it provide between the radiator 12 and the heat exchanger 6. FIG.

DESCRIPTION OF SYMBOLS 1 1st circulation cycle 2 2nd circulation cycle 3 Air supply passage 4 Air conditioning unit 5 Compressor 6 Heat exchanger 7 Expansion device 8 Evaporator 10 Pump 11 Heater core 12 Radiator 13 Bypass flow path 14 Flow rate adjustment valve 15 Heat medium temperature detection sensor 31 Intake device 32 Blower 41 Car interior humidity sensor 42 Car interior temperature sensor 43 Car interior humidity sensor 44 Car interior temperature sensor

Claims (12)

A first circulation cycle in which the first heat medium circulates, a second circulation cycle in which the second heat medium circulates, and an air conditioning unit having an air passage inside.
In the first circulation cycle, the first heat medium is a compressor that compresses the first heat medium, and heat that moves the heat of the compressed first heat medium to the second heat medium. An exchanger, an expansion device that expands the first heat medium, an evaporator that evaporates the first heat medium expanded by the expansion device and cools the air in the air passage, and the compressor can be circulated in this order. Configured,
In the second circulation cycle, the second heat medium circulates in the order of a pump, the heat exchanger, a heater core that radiates heat from the second heat medium and heats the air in the air passage, and the pump. And a radiator that is provided between the heater core and the pump, or between the pump and the heat exchanger, and dissipates heat of the second heat medium to the outside of the passenger compartment. A bypass flow path that bypasses the radiator, a flow rate adjusting means that adjusts a flow rate of the second heat medium that flows through the radiator and the bypass flow path, and the heat exchanger or between the heat exchanger and the heater core. And a temperature detecting means for detecting the temperature of the second heat medium.
The air conditioning unit includes an intake device that adjusts an introduction ratio of vehicle interior air and vehicle exterior air to the air passage, a blower that blows air introduced through the intake device, the evaporator, and the heater core. In the vehicle air conditioner configured by arranging
When the compressor and the pump are operated and the temperature of the second heat medium exceeds a first predetermined temperature, the intake device relatively increases the introduction ratio of outside air in the vehicle compartment,
When the temperature of the second heat medium exceeds a second predetermined temperature that is higher than the first predetermined temperature, the flow rate adjusting unit causes the second heat medium to flow through the radiator, or the radiator The vehicle air conditioner is characterized in that the flow rate of the second heat medium flowing through the vehicle is increased. The flow rate adjusting means does not flow the second heat medium to the radiator or flows the second heat medium to the radiator until the temperature of the second heat medium exceeds the second predetermined temperature. The vehicle air conditioner according to claim 1, wherein the flow rate of the medium is not increased.
When the temperature of the second heat medium exceeds the first predetermined temperature and then falls below a third predetermined temperature lower than the first predetermined temperature, the intake device reduces the introduction ratio of outside air in the vehicle compartment. It decreases relatively.
The vehicle air conditioner according to claim 1 or 2. The flow rate adjusting means is
When the temperature of the second heat medium exceeds the second predetermined temperature and then falls below a fourth predetermined temperature lower than the second predetermined temperature, the second heat medium is not allowed to flow to the radiator. Or the flow volume of the said 2nd heat medium sent through the said radiator is reduced. The vehicle air conditioner in any one of the Claims 1 thru | or 3 characterized by the above-mentioned. Vehicle interior humidity detection means for detecting the humidity of the vehicle interior air, vehicle interior temperature detection means for detecting the temperature of the vehicle interior air, vehicle exterior humidity detection means for detecting the humidity of the vehicle interior air, and the temperature of the vehicle exterior air A vehicle exterior temperature detecting means for detecting
The calculating means calculates a dew point temperature of the passenger compartment air from the humidity of the passenger compartment air and the temperature of the passenger compartment air, and also calculates a dew point temperature of the passenger compartment air from the humidity of the passenger compartment outdoor air and the temperature of the passenger compartment outdoor air. Calculate the dew point temperature,
The relative increase in the introduction ratio of the outside air by the intake device is performed when the dew point temperature of the outside air is lower than the inside air. Air conditioner for vehicles. The vehicle air conditioner according to any one of claims 1 to 5, wherein the intake device relatively increases the outdoor air introduction ratio in a dehumidifying and heating operation mode. A first circulation cycle in which the first heat medium circulates, a second circulation cycle in which the second heat medium circulates, and an air conditioning unit having an air passage inside.
In the first circulation cycle, the first heat medium is a compressor that compresses the first heat medium, and heat that moves the heat of the compressed first heat medium to the second heat medium. An exchanger, an expansion device that expands the first heat medium, an evaporator that evaporates the first heat medium expanded by the expansion device and cools the air in the air passage, and the compressor can be circulated in this order. Configured,
In the second circulation cycle, the second heat medium circulates in the order of a pump, the heat exchanger, a heater core that radiates heat from the second heat medium and heats the air in the air passage, and the pump. And a radiator that is provided between the heater core and the pump, or between the pump and the heat exchanger, and dissipates heat of the second heat medium to the outside of the passenger compartment. A bypass flow path that bypasses the radiator, a flow rate adjusting means that adjusts a flow rate of the second heat medium that flows through the radiator and the bypass flow path, and the heat exchanger or between the heat exchanger and the heater core. And a temperature detecting means for detecting the temperature of the second heat medium.
The air conditioning unit includes an intake device that adjusts an introduction ratio of vehicle interior air and vehicle exterior air to the air passage, a blower that blows air introduced through the intake device, the evaporator, and the heater core. In a vehicle air-conditioning control method using a vehicle air-conditioning apparatus configured by arranging
When the compressor and the pump are operated and the temperature of the second heat medium exceeds a first predetermined temperature, the intake device relatively increases the introduction ratio of outside air in the vehicle compartment,
When the temperature of the second heat medium exceeds a second predetermined temperature that is higher than the first predetermined temperature, the flow rate adjusting unit causes the second heat medium to flow through the radiator, or the radiator An air conditioning control method for a vehicle, characterized by increasing a flow rate of the second heat medium that flows through the vehicle. The flow rate adjusting means does not flow the second heat medium to the radiator or flows the second heat medium to the radiator until the temperature of the second heat medium exceeds the second predetermined temperature. The vehicle air conditioning control method according to claim 7, wherein the flow rate of the medium is not increased. When the temperature of the second heat medium exceeds the first predetermined temperature and then falls below a third predetermined temperature lower than the first predetermined temperature, the intake device reduces the introduction ratio of outside air in the passenger compartment. The vehicle air conditioning control method according to claim 7 or 8, wherein the vehicle air conditioning control method is relatively reduced. The flow rate adjusting means is
When the temperature of the second heat medium exceeds the second predetermined temperature and then falls below a fourth predetermined temperature lower than the second predetermined temperature, the second heat medium is not allowed to flow to the radiator. Or the flow volume of the said 2nd heat medium sent to the said radiator is reduced. The vehicle air-conditioning control method in any one of Claims 7 thru | or 9 characterized by the above-mentioned.
The vehicle air conditioner includes vehicle interior humidity detection means for detecting the humidity of the vehicle interior air, vehicle interior temperature detection means for detecting the temperature of the vehicle interior air, and vehicle exterior humidity detection means for detecting the humidity of the vehicle exterior air. And a vehicle exterior temperature detection means for detecting the temperature of the vehicle exterior air, and a calculation means,
The calculating means calculates a dew point temperature of the passenger compartment air from the humidity of the passenger compartment air and the temperature of the passenger compartment air, and also calculates a dew point temperature of the passenger compartment air from the humidity of the passenger compartment outdoor air and the temperature of the passenger compartment outdoor air. Calculate the dew point temperature,
The relative increase in the introduction ratio of outside air by the intake device is performed when the dew point temperature of the outside air is lower than the inside air. Vehicle air conditioning control method. The vehicle air conditioning control method according to any one of claims 7 to 11, wherein the intake device relatively increases the introduction ratio of outside air in the vehicle in a dehumidifying and heating operation mode.

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