JP6519283B2 - Vehicle air conditioner - Google Patents

Description

  The present invention relates to a vehicle air conditioner.

  Patent Document 1 discloses a vehicle air conditioner. In this vehicle air conditioner, both the exhaust heat of the engine and the heating by the refrigeration cycle (heat pump) are used as a heat source for heating the vehicle interior. The exhaust heat usage of the engine is limited to such an extent that it does not affect the warm-up of the engine. On the other hand, the heat quantity which is insufficient for the adjustment of the vehicle interior temperature is compensated by driving the heat pump.

JP 2011-73668 A

  By the way, in a hybrid vehicle that obtains traveling drive power from an engine and a traveling electric motor, when the traveling speed is zero, the engine is stopped, fuel consumption is suppressed, and fuel consumption is improved. Even in the hybrid vehicle, the vehicle air conditioner uses exhaust heat of the engine to heat the vehicle interior. However, in the case of a vehicle air conditioner, when the water temperature of the engine cooling water or the heater water temperature is low, the engine is driven for heating even if the traveling speed is zero, so there is room for improvement in fuel efficiency improvement. The

  An object of the present invention is to provide a vehicular air-conditioning system capable of shortening the driving time of an engine for heating and improving the fuel consumption of the vehicle in consideration of the above fact.

A vehicle air conditioner according to the invention described in claim 1 comprises a first circulation passage for circulating exhaust heat of an engine by a heat medium, and a heater core connected in parallel to the first circulation passage for heating a vehicle interior. a second circulation path for circulating the heat medium different heat pump or an electric heater of the heat is the heat generation source to a heat exchanger for transferring the heat medium from said engine, first circulation path and the second circulation path And a first detection unit for detecting a first temperature of the heat medium circulated in the first circuit, and a second temperature of the heat medium circulated in the second circuit. When the first temperature does not reach the heater intermittent allowance temperature set to a temperature higher than the temperature at which the engine is warmed up, the first circulation path and the second circulation path are not connected. Where the first temperature is equal to or higher than the heater intermittent allowance temperature and equal to or higher than the second temperature To a controller for executing a switching it to connect to the first circulation path and the second circulation path to the switching unit, wherein the heater intermittent permission temperature is the temperature of the air blown into the passenger compartment through the heater core The temperature required for the heat medium circulated in the second circuit to reach the target value .

  A vehicle air conditioner according to claim 1 comprises a first circulation passage and a second circulation passage for circulating a heat medium. The first circulation path circulates the exhaust heat of the engine by the heat medium, for example, to warm up the engine. The second circulation path is connected in parallel to the first circulation path, and circulates the heat medium through the heater core for heating the vehicle interior and the heat exchanger for transferring the heat of the heat generation source to the heat medium.

  Here, the vehicle air conditioner according to claim 1 includes a switching unit, a first detection unit, a second detection unit, and a controller. The first detection unit detects a first temperature of the heat medium circulated in the first circulation path. The controller performs switching of the switching unit when the first temperature does not reach the heater intermittent allowance temperature, and disconnects the first circulation path and the second circulation path. Therefore, the heat medium can be circulated independently in each of the first circuit and the second circuit. As a result, warm-up of the engine is performed by effectively using exhaust heat of the engine in the first circuit, and heat is transferred from the heat generation source to the heat medium through the heat exchanger in the second circuit. The heat medium is circulated to the heater core to heat the vehicle interior. Therefore, since the engine is not driven to heat the heat medium circulated in the second circuit, the driving time of the engine for heating is eliminated.

  On the other hand, when the first temperature is equal to or higher than the heater intermittent allowance temperature and equal to or higher than the second temperature, the controller performs switching of the switching unit and connects the first circulation path and the second circulation path. For this reason, the heat medium of the first circulation path flows to the second circulation path, and the heat medium to which the exhaust heat of the engine is transmitted circulates through the heater core, so that the passenger compartment can be heated. And since 1st temperature is made more than 2nd temperature, the drive time of the engine for heating becomes short.

  The vehicle air conditioner described in claim 1 has an excellent effect that the driving time of the engine for heating can be shortened and the fuel efficiency of the vehicle can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram explaining the system configuration | structure of the vehicle air conditioner which concerns on one Embodiment. It is a flowchart explaining the operation | movement method of the vehicle air conditioner shown by FIG. It is a block diagram corresponding to Drawing 1 of a vehicular air-conditioning system in which a plurality of circulation paths are in an operation state independently, respectively. It is a block diagram corresponding to Drawing 1 of the air-conditioner for vehicles in which a plurality of circulation paths are in operation as one system. It is a figure which shows the relationship of the temperature of the thermal medium, engine rotation speed, and time in the vehicle air conditioner which concerns on one Embodiment. It is a figure corresponding to Drawing 5 which shows a relation of temperature of a heat carrier, engine number of rotations, and time in an air-conditioner for vehicles concerning a comparative example.

(Configuration of air conditioner for vehicle)
The example applied to the hybrid vehicle of illustration abbreviation | omission is demonstrated about the vehicle air conditioner which concerns on one embodiment of this invention using FIGS. 1-6.

  As shown in FIG. 1, the automotive air conditioner 10 according to the present embodiment includes a plurality of circulation paths including a first circulation path 20 and a second circulation path 30. The first circulation passage 20 is in the form of a closed loop including an engine 22 as an internal combustion engine. The first circulation path 20 is configured to circulate heat generated by driving the engine 22 as exhaust heat. The first circulation passage 20 is mainly used to cool the engine 22, but is used to warm up the engine 22 using exhaust heat at the time of starting the engine 22 or the like. Specifically, the first circulation passage 20 includes a circulation pipe 24 for circulating, for example, engine cooling water as a heat medium, and a first circulation pump 26 provided on the upstream side of the circulation pipe 24 for forcibly circulating the engine cooling water. And have. The upstream end of the circulation pipe 24 is connected to an outlet 22A of the engine 22 from which the engine cooling water flows. The downstream end of the circulation pipe 24 is connected to the inlet 22B of the engine 22 into which the circulatingly returned engine cooling water is introduced.

  The first circulation passage 20 includes a first detection unit 28 between the outlet 22 </ b> A of the engine 22 and the first circulation pump 26. As the first detection unit 28, a water temperature sensor that detects the temperature (first temperature) of engine cooling water circulated in the first circulation passage 20 immediately after the start of circulation is used.

  On the other hand, the second circulation passage 30 is in the form of a closed loop including a heater core 32 for heating the vehicle interior and a heat exchanger (here, a water refrigerant heat exchanger) 34. The heater core 32 is disposed in a blower duct that connects a blower (not shown) and a vehicle interior outlet, and is configured to warm the air sent from the blower. When the warmed air is blown out from the cabin outlet to the cabin, the cabin is heated. The heat exchanger 34 is connected to a heat generation source (not shown) and configured to transfer the heat generated by the heat generation source to the heat medium circulated in the second circulation path 30 by heat exchange. Here, as a heat generation source, a heat pump, an electric heater or the like is used.

  The second circulation path 30 circulates the heat medium to which the heat is transmitted through the heat exchanger 34 to the heater core 32, and warms the air blown into the vehicle compartment by the heater core 32. More specifically, the second circulation passage 30 is provided on the upstream side of the circulation pipe 36 for circulating, for example, engine cooling water as a heat medium and the heater core 32 of the circulation pipe 36 to forcibly circulate the engine cooling water. And a second circulation pump 38. The upstream end of the circulation pipe 36 is connected to the outlet 32A of the heater core 32 through which the engine cooling water flows out. The downstream end of the circulation pipe 36 is connected to the inlet 32B of the heater core 32 into which the circulatingly returned engine cooling water is introduced. Further, the heat exchanger 34 is disposed in the middle of the circulation pipe 36. The upstream side of the circulation pipe 36 is connected to the inlet 34A of the heat exchanger 34 into which the engine cooling water is introduced, and the downstream side of the circulation pipe 36 is connected to the outlet 34B of the heat exchanger 34 from which the engine cooling water flows out. It is done. The second circulation pump 38 is provided between the heater core 32 and the heat exchanger 34 on the upstream side of the second circulation path 30.

  The second circulation path 30 includes a second detection unit 40 between the outlet 34 B of the heat exchanger 34 and the inlet 32 B of the heater core 32 and in the vicinity of the outlet 34 B. As the second detection unit 40, a water temperature sensor that detects the temperature (second temperature) of the engine coolant that is circulated in the second circulation path 30 immediately after heat exchange is used.

  The second circulation passage 30 is connected in parallel to the first circulation passage 20. Specifically, the upstream side of the second circulation path 30 is connected to the upstream side of the first circulation path 20 via the first switching unit 42. More specifically, the circulation pipe 24 connected to the outlet 22 A of the engine 22 is connected to the first switching unit 42 via the first detection unit 28 and the first circulation pump 26. The first switching unit 42 is connected to the outlet 32A of the heater core 32 via the circulation pipe 36, and connected to the inlet 34A of the heat exchanger 34 via the circulation pipe 36 and the second circulation pump 38. ing.

  On the other hand, the downstream side of the second circulation passage 30 is connected to the downstream side of the first circulation passage 20 via the second switching unit 44. More specifically, the circulation pipe 24 connected to the inlet 22B of the engine 22 is connected to the second switching unit 44. The second switching unit 44 is connected to the inlet 32B of the heater core 32 via the circulation pipe 36 and connected to the outlet 34B of the heat exchanger 34 via the circulation pipe 36 and the second detection unit 40. ing.

  In the present embodiment, for example, a three-way valve is used as each of the first switching unit 42 and the second switching unit 44. The three-way valve is provided across the first circulation passage 20 and the second circulation passage 30. A two-way valve may be used for either or both of the first switching unit 42 and the second switching unit 44. When a two-way valve is used for both, the first switching unit 42 and the second switching unit 44 are provided in the second circulation path 30.

  The vehicle air conditioner 10 according to the present embodiment further includes a controller 46. The controller 46 includes at least a central processing unit (CPU), storage units (ROM, RAM, HD), and an interface (not shown). The controller 46 is connected to the first detection unit 28, the second detection unit 40, the first circulation pump 26, the second circulation pump 38, the first switching unit 42, and the second switching unit 44 via the common bus wiring 48. And are configured to control these operation controls.

  In the present embodiment, engine cooling water is used as a heat medium, and the first circulation path 20 constructs a first water circuit, and the second circulation path 30 constructs a second water circuit. In addition, engine cooling oil etc. can be used as a heat carrier.

(Operation method of vehicle air conditioner)
The operation method of the vehicle air conditioner 10 according to the present embodiment is as shown in FIG. First, in a hybrid vehicle (not shown), the engine 22 shown in FIG. 1 is started, and the switch of the vehicle air conditioner 10 is turned on manually or automatically.

  In the vehicle air conditioner 10, the first circulation path 20 and the second circulation path 30 are two circulation paths (see FIG. 3) in which the first circulation path 20 and the second circulation path 30 are not connected, or one circulation path in which both are connected. It is determined whether it is (see FIG. 4) (S10). The determination is performed by the controller 46 based on the open / close states of the first switching unit 42 and the second switching unit 44 shown in FIG. 1.

  In the two circulation circuits shown in FIG. 3, the valve between the first circulation passage 20 and the second circulation passage 30 is closed in the first switching unit 42 and the second switching unit 44 shown in FIG. . For this reason, the engine coolant in the first circulation passage 20 circulates independently to the engine coolant in the second circulation passage 30. The circulation direction of the engine coolant is indicated by an arrow with a symbol A. When the engine cooling water of the first circulation path 20 is circulated independently, the exhaust heat of the engine 22 can be effectively used, and the engine 22 can be efficiently warmed up. On the other hand, the engine cooling water of the second circulation passage 30 circulates independently to the engine cooling water of the first circulation passage 20. The circulation direction of the engine cooling water is indicated by an arrow with a symbol C. When the engine coolant in the second circulation path 30 is independently circulated, the heat generated by the heat source (not shown) is efficiently transferred to the engine coolant using the heat exchanger 34, and this heat is transmitted to the heater core 32. Because it is transmitted to, it is possible to heat the passenger compartment.

  Further, in the one-system circulation path shown in FIG. 4, the valves between the first circulation path 20 and the second circulation path 30 in the first switching unit 42 and the second switching unit 44 are in the open state. Therefore, the engine cooling water in the first circulation passage 20 also circulates in the second circulation passage 30. The circulation direction from the first circulation path 20 to the second circulation path 30 is indicated by an arrow B with a reference B. When the engine cooling water in the first circulation passage 20 is circulated to the second circulation passage 30, the exhaust heat of the engine 22 is supplied to the heater core 32 to enable effective utilization of the exhaust heat. When exhaust heat is supplied to the heater core 32, the operation of the heat generation source can be stopped or the amount of heat generation can be reduced, so that power consumption can be suppressed.

  If it is determined in step S10 that there are two systems of circulation paths, the water temperature (engine water temperature) of the engine cooling water of the first circulation path 20 is detected, and it is determined whether this engine water temperature is equal to or higher than a threshold value. (S12). The engine water temperature is detected by the first detection unit 28 shown in FIG. Here, the heater intermittent allowance temperature is used as a threshold. In the present embodiment, the heater intermittent permission temperature is circulated to the second circulation passage 30, which is required to reach the target value of the temperature of the air blown out from the vehicle interior outlet based on the vehicle outside air temperature. It is the water temperature (heater water temperature) required for engine cooling water. The determination is performed by the controller 46.

  If it is determined in step S12 that the engine water temperature is equal to or higher than the heater intermittent allowance temperature, it is determined whether the engine water temperature of the first circulation passage 20 is equal to or higher than the heater water temperature of the second circulation passage 30 (S14) ). The heater water temperature is detected by the second detection unit 40 shown in FIG. Also, the determination is performed by the controller 46. If it is determined in step S12 that the engine water temperature does not reach the heater intermittent allowance temperature, switching of the circulation path is not performed.

  If it is determined in step S14 that the engine water temperature is equal to or higher than the heater water temperature, the controller 46 switches the valves of the first switching unit 42 and the second switching unit 44 to the open state. When the valve is opened, the first circulation path 20 and the second circulation path 30 are connected, and the two circulation paths are switched to one circulation path (S16). When switching to one circulation path, the exhaust heat of the engine 22 is utilized in the heater core 32. After step S16, the process returns to step S10, and the processes after step S10 are repeatedly executed. If it is determined in step S14 that the engine water temperature is less than the heater water temperature, the switching of the circulation path is not performed.

  If it is determined in step S10 described above that the circulation path is one system, it is determined whether the engine water temperature is lower than the heater intermittent permission temperature or higher than the heater intermittent permission temperature (S20). When the heater intermittent permission temperature is not satisfied, the controller 46 causes the valves of the first switching unit 42 and the second switching unit 44 to close. When the valve is closed, the first circulation passage 20 and the second circulation passage 30 are disconnected, and one circulation passage is switched to two circulation passages (S22). On the other hand, if it is determined that the temperature is equal to or higher than the heater intermittent allowance temperature, switching of the circulation path is not performed.

(Operation and effect of the present embodiment)
The vehicle air conditioner 10 which concerns on this Embodiment is provided with the 1st circulation path 20 and the 2nd circulation path 30 which circulate through an engine cooling water, as FIG. 1 shows. The first circulation path 20 circulates the exhaust heat of the engine 22 by the engine cooling water. The second circulation passage 30 is connected in parallel to the first circulation passage 20, and circulates the heat of the heater core 32 and the heat generation source for heating the vehicle interior to the heat exchanger 34 and the engine cooling water.

  Here, the vehicle air conditioner 10 includes a first switching unit 42, a second switching unit 44, a first detection unit 28, a second detection unit 40, and a controller 46. In the first detection unit 28, the engine water temperature circulated in the first circulation path 20 is detected. When the engine water temperature does not reach the heater intermittent permission temperature, the controller 46 switches the first switching unit 42 and the second switching unit 44 to the closed state, and makes the first circulation passage 20 and the second circulation passage 30 non-operative. As a connection, it is set as two circulation paths shown by FIG. Therefore, engine cooling water can be circulated independently in each of the first circulation passage 20 and the second circulation passage 30. In the first circulation passage 20, the exhaust heat of the engine 22 is effectively used to warm up the engine 22. In the second circulation path 30, heat is transmitted from the heat generation source to the engine cooling water via the heat exchanger 34 (the heater water temperature is raised), and the engine cooling water is circulated to the heater core 32 to heat the vehicle interior. To be done.

  FIG. 5 shows the relationship between the engine water temperature and the heater water temperature in the vehicle air conditioner 10 according to the present embodiment, the engine speed, and the elapsed time since the start of the engine. The left vertical axis represents water temperature (° C.), the right vertical axis represents engine speed, and the horizontal axis represents elapsed time. For example, the vehicle outside temperature is set to -10 ° C, the cabin temperature is set to 25 ° C in automatic adjustment, and the engine speed is set based on the "International harmonized fuel efficiency and exhaust gas test method (WLTP) of passenger cars etc." In this case, the engine water temperature and the heater water temperature show the rise shown in FIG. The water temperature W1 is a water temperature required to warm up the engine 22. The water temperature W2 is a heater intermittent allowance temperature set to a temperature higher than the water temperature W1. In the two circulation paths, in the first circulation path 20, since the engine 22 immediately after the start is cold, the driving time of the engine 22 is slightly longer, but when the engine water temperature reaches the water temperature W1, it is for warming up. The engine 22 is intermittently driven to an extent that the water temperature W1 is maintained. In the second circulation path 30, for example, the engine coolant water is warmed from the heat pump via the heat exchanger 34, so the heater water temperature rises with the passage of time, and the vehicle interior is heated by the heater core 32.

  Therefore, in the vehicle air conditioner 10, when the engine water temperature does not reach the heater intermittent permission temperature W2, the engine 22 is not driven to heat the engine cooling water circulated in the second circulation path 30, so heating There is no running time of the engine 22 for this.

  On the other hand, the controller 46 switches the first switching unit 42 and the second switching unit 44 to the open state when the engine water temperature is equal to or higher than the heater intermittent allowance temperature W2 and higher than the heater water temperature. 2 Connect the circulation path 30. That is, when the warm-up of the engine 22 is completed, the engine coolant water gradually rises. Therefore, when the above condition is reached, switching from the two circulation paths to the one circulation path is performed. Therefore, the engine cooling water in the first circulation passage 20 flows to the second circulation passage 30, and the engine cooling water to which the exhaust heat of the engine 22 is transmitted is circulated in the heater core 32, whereby the vehicle interior is heated.

  FIG. 6 shows the relationship between the engine water temperature and the heater water temperature, the engine rotational speed, and the elapsed time from the start of the engine in the vehicle air conditioner according to the comparative example. The vertical and horizontal axes correspond to the vertical and horizontal axes shown in FIG. In the vehicle air conditioner according to the comparative example, from the two circulation paths to the one circulation path at a stage where the engine water temperature does not reach the heater intermittent allowance temperature W2 and the heater water temperature (after the time T2 has elapsed from the start of the engine 22). Switching is being performed. As shown in FIG. 6, the heater water temperature drops to the engine water temperature (here, the water temperature W1) immediately after switching to the circulation path of one system. In order to raise the heater water temperature to the heater intermittent allowance temperature W2 using exhaust heat, the engine 22 is driven for a long time.

  In the vehicle air conditioner according to the present embodiment, as compared with the vehicle air conditioner according to the comparative example, the engine water temperature is set to the heater intermittent permission temperature W2 or more and the heater water temperature or more as shown in FIG. There is. Therefore, the heater water temperature does not substantially decrease, and the engine water temperature is already set to be equal to or higher than the heater water temperature after time T1 from the start of the engine 22, so the frequency (intermittent frequency) for stopping the engine 22 can be increased. . That is, the driving time of the engine 22 for heating is shortened.

  Therefore, according to the vehicle air conditioner 10 according to the present embodiment, the exhaust heat is used to warm up the engine 22 while the engine 22 is warming up, and the heating of the heater core 32 is different from the engine 22. A heat source is utilized. Then, after the warm-up of the engine 22 is completed, the exhaust heat of the engine 22 is used to heat the heater core 32. As a result, even if there is a decrease in fuel consumption due to the power consumption of the heat generation source, the drive time of the engine 22 for heating can be shortened overall, and the fuel consumption of the hybrid vehicle can be improved.

  Further, in the vehicle air conditioner 10 according to the present embodiment, since there is almost no sudden drop in the heater water temperature as shown in FIG. 6 as shown in FIG. Cold air is not blown out from the outlet. For example, the passenger of the vehicle does not feel uncomfortable due to the change of the temperature in the passenger compartment.

[Supplementary explanation of the above embodiment]
The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. For example, the present invention is also applicable to a vehicle having a function of stopping the engine when the traveling speed reaches zero and starting the engine when the accelerator is depressed.

Reference Signs List 10 air conditioner for vehicle 20 first circulation path 22 engine 28 first detection unit 30 second circulation path 32 heater core 40 second detection unit 42 first switching unit 44 second switching unit 46 controller

Claims (1)

A first circuit for circulating the exhaust heat of the engine by a heat medium;
Which is connected in parallel with the first circulation path, the heat medium heat pump or electric heater of the heat which is another heat generating source and the heater core and the engine to heat the passenger compartment and a heat exchanger for transferring the heat medium A second circuit that circulates
A switching unit that switches between connection and disconnection between the first circulation path and the second circulation path;
A first detection unit that detects a first temperature of the heat medium circulated in the first circulation path;
A second detection unit that detects a second temperature of the heat medium circulated in the second circulation path;
When the first temperature does not reach the heater intermittent permission temperature set to a temperature higher than the temperature at which the engine is warmed up, the first circuit and the second circuit are disconnected, and the first circuit is not connected. A controller that causes the switching unit to perform switching to connect the first circulation path and the second circulation path when the temperature is equal to or higher than the heater intermittent allowance temperature and equal to or higher than the second temperature;
Equipped with
The heater intermittent allowance temperature is a temperature required for the heat medium circulated in the second circulation path to cause the temperature of air blown into the vehicle compartment via the heater core to reach a target value. , Air conditioning equipment for vehicles.

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