Heat pump system, and its control method and control program

Abstract

Suppresses the noise of mode switching in the heat pump system. [Solution] The heat pump system is configured to be switchable between multiple modes, including a first heating mode that heats the occupant's cabin without utilizing the waste heat of a predetermined cooling target, and a second heating mode that heats the occupant's cabin using the said waste heat. The heat pump system comprises a compressor, a condenser, a first throttle valve, an outdoor unit, a second throttle valve, a chiller, a predetermined on / off valve, and a control device. In the second heating mode, the control device controls the opening of the second throttle valve to be greater than zero, thereby controlling the circulation of the heat transfer medium via the chiller. On the other hand, during the first switching from the second heating mode to the first heating mode, the predetermined on / off valve is fully opened, and the opening of the second throttle valve is gradually reduced to zero, thereby switching the circulation of the heat transfer medium without passing through the chiller.

Description

Technical Field

[0001] The present invention relates to a heat pump system capable of heating the passenger compartment of a moving body such as an electric vehicle.

Background Art

[0002] In recent years, from the viewpoint of reducing carbon dioxide emissions and reducing adverse effects on the global environment, the popularity of electric vehicles such as EVs and HEVs has been increasing. Among these electric vehicles and the like, there are some equipped with a heat pump system that heats the passenger compartment by using the waste heat generated when cooling a battery or the like. According to this heat pump system, by using the waste heat to heat the passenger compartment, the energy consumption can be reduced, and further the adverse effects on the global environment can be reduced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Among such heat pump systems, for example, there is one configured as follows. That is, the heat pump system is configured to be able to circulate a heat medium by a compressor, and includes a condenser, a first throttle valve, and an outdoor unit in order from the upstream side, and also includes a second throttle valve and a chiller at least downstream of the condenser. The chiller is configured to be able to exchange heat between the heat medium of a cooling system that cools a battery or the like and the heat medium of the heat pump system.

[0005] The heat pump system is further equipped with an on / off valve that can change the flow of the heat transfer medium by opening and closing it. Based on the opening and closing of this valve, the system switches between a predetermined first heating mode and a predetermined second heating mode. In the first heating mode, the passenger compartment of the electric vehicle is heated without utilizing waste heat from the battery, etc. On the other hand, in the second heating mode, the passenger compartment is heated using the waste heat. Therefore, in the first heating mode, the heat transfer medium circulates without passing through the chiller, whereas in the second heating mode, the heat transfer medium circulates via the chiller.

[0006] The inventors of this invention have focused on the following problems in such a heat pump system. The on / off valve switches abruptly from one fully open or fully closed position to the other. As a result, when switching from the second heating mode to the first heating mode by opening and closing the on / off valve in this manner, the pressure difference on both sides of the second throttle valve drops sharply, and the flow of the heat transfer medium changes abruptly, generating a switching noise.

[0007] To suppress the switching noise, the following valve switching noise suppression control can be considered. Specifically, in this valve switching noise suppression control, the compressor output is suppressed in advance while the opening of the first throttle valve is increased while the system is in the second heating mode, and then the system is switched to the first heating mode. This suppresses the rapid decrease in the pressure difference on both sides of the second throttle valve that occurs with the switch, and also suppresses the rapid change in the flow of the heat transfer medium, thereby suppressing the generation of switching noise. However, in this case, in addition to requiring such valve switching noise suppression control, energy is wasted for performing such control.

[0008] In the above explanation, the problem was described using the example of an electric vehicle as the moving object and a battery as the object to be cooled. However, similar problems can occur when the moving object is not an electric vehicle, or when the object to be cooled is not a battery.

[0009] This invention has been made in view of the above circumstances, and aims to suppress the noise of mode switching in a heat pump system by a method other than control for preventing valve switching noise. [Means for solving the problem]

[0010] The inventors of the present invention discovered that the switching noise can be suppressed by switching modes not by completely closing the on-off valve, but by gradually reducing the opening of the second throttle valve until it becomes zero, and thus arrived at the present invention. The present invention comprises the following heat pump systems (1) to (12), the control methods (13) and (14), and the control program (15).

[0011] (1) It is mounted on a mobile vehicle, The system is configured to be switchable between multiple modes, including a first heating mode that heats the crew compartment of the mobile unit without utilizing the waste heat of a predetermined cooling target, and a second heating mode that heats the crew compartment using the waste heat. It is a heat pump system, A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to have an adjustable opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, A predetermined on / off valve is configured to be openable and closable, and the flow of the heat transfer medium can be changed by opening and closing it. A control device is provided, The control device is In the second heating mode, the opening of the second throttle valve is controlled to be greater than zero, thereby controlling the circulation of the heat transfer medium through the chiller. During the first switching operation, in which the system should switch from the second heating mode to the first heating mode, the predetermined on-off valve is fully opened, and the opening of the second throttle valve is gradually reduced until it reaches zero, thereby switching the system so that the heat transfer medium circulates without passing through the chiller. Heat pump system.

[0012] According to this configuration, instead of switching from the second heating mode to the first heating mode by opening and closing a predetermined on-off valve, the system switches from the second heating mode to the first heating mode by gradually decreasing the opening of the second throttle valve while the predetermined on-off valve is fully open. As a result, during this switching, the amount of heat transfer fluid flowing to the second throttle valve is gradually reduced, suppressing a sudden drop in the pressure difference on both sides of the second throttle valve, and also suppressing a sudden change in the flow of the heat transfer fluid. Therefore, the noise of mode switching in the heat pump system can be suppressed by methods other than on-off valve switching noise countermeasures.

[0013] (2) The second throttle valve and the chiller are located downstream of the outdoor unit, The aforementioned designated on-off valve is a low-pressure on-off valve located in a path that branches off downstream of the outdoor unit and upstream of the second throttle valve. The control device is In the second heating mode, the low-pressure shut-off valve is completely closed, and the opening of the second throttle valve is controlled to an opening greater than zero. During the first switching operation, the low-pressure on-off valve is fully opened, and then the opening of the second throttle valve is gradually reduced until it reaches zero. The heat pump system described in (1) above.

[0014] This configuration allows for the suppression of mode switching noise in a heat pump system of this type.

[0015] (3) The predetermined on-off valve is a high-pressure on-off valve located in a path that branches off downstream of the condenser and upstream of the first throttle valve, Downstream of the high-pressure on-off valve, the second throttle valve and the chiller are arranged. The control device In the second heating mode, the high-pressure on-off valve is fully opened, and the opening degree of the second throttle valve is controlled to be greater than zero. At the time of the first switching, with the high-pressure on-off valve remaining fully open, the opening degree of the second throttle valve is decreased until it becomes zero. The heat pump system according to (1) above.

[0016] According to this configuration, in a heat pump system having such a configuration, the switching sound of the mode can be suppressed.

[0017] (4) When the control device is to switch from the first heating mode to the second heating mode at the second switching, with the predetermined on-off valve fully open, the opening degree of the second throttle valve is increased from zero. The heat pump system according to any one of (1) to (3) above.

[0018] According to this configuration, instead of switching from the first heating mode to the second heating mode by opening and closing the predetermined on-off valve, the opening degree of the second throttle valve is increased from zero with the predetermined on-off valve fully open, thereby switching from the first heating mode to the second heating mode. Therefore, at the time of such switching, the amount of the heat medium flowing through the second throttle valve is gradually increased to suppress a rapid increase in the pressure difference between both sides sandwiching the second throttle valve and to suppress a rapid change in the flow of the heat medium. Therefore, not only at the first switching but also at the second switching, the switching sound of the mode in the heat pump system can be suppressed.

[0019] (5) The chiller performs heat exchange between the heat medium of the heat pump system and the heat medium of the cooling system for cooling the cooling target. The heat pump system according to any one of (1) to (4) above.

[0020] With this configuration, in the second heating mode, the heat transfer medium of the cooling system is used to heat the heat transfer medium of the heat pump system, allowing the waste heat from the cooling system to be used for heating the crew compartment through a simple mechanism.

[0021] (6) The condenser performs heat exchange between the heat transfer medium of the heat pump system and the heat transfer medium of the heating system that heats the crew compartment. A heat pump system as described in any one of (1) to (5) above.

[0022] With this configuration, in the second heating mode, the heat transfer medium of the heating system is heated by the heat transfer medium of the heat pump system, allowing the waste heat from the cooling system to be used for heating the crew compartment through a simple mechanism.

[0023] (7) In the state of the second heating mode, the control to suppress the output of the compressor and increase the opening of the first throttle valve before switching to the first heating mode is not performed at the time of the first switching. A heat pump system as described in any one of (1) to (6) above.

[0024] This configuration eliminates the energy waste associated with noise reduction control for valve switching by not implementing such control. Therefore, it is possible to improve energy efficiency compared to simply suppressing the implementation of noise reduction control for valve switching, for example.

[0025] (8) The control device is In the second heating mode, before the heat transfer medium overheats in the outdoor unit, switch to the first heating mode. By performing a predetermined sleep-prevention control while in the second heating mode, the period during which sleep does not occur in the second heating mode is extended compared to when the sleep-prevention control is not performed, thereby extending the duration of the second heating mode. The aforementioned sleep prevention control is, A first control is provided as a control to prevent the vehicle from falling over by changing the opening degree of the first throttle valve, By changing the opening degree of the second throttle valve, a second control is provided as a control to prevent the vehicle from falling over, Including at least one of the following: A heat pump system as described in any one of (1) to (7) above.

[0026] The second heating mode is more energy-efficient than the first heating mode because it utilizes waste heat. However, in the second heating mode, depending on the opening of the first and second throttle valves, the pressure reduction range and heat absorption amount in the outdoor unit become smaller, causing the evaporation temperature to rise and making it difficult for the heat transfer medium to evaporate. When the evaporation temperature becomes higher than the outside air temperature, the evaporation of the heat transfer medium in the outdoor unit cannot keep up, resulting in heat transfer medium stagnation. Therefore, the control device needs to switch to the first heating mode before stagnation occurs in the second heating mode.

[0027] In this respect, with this configuration, by performing fall-over prevention control in the second heating mode, the period during which fall-over does not occur in the second heating mode can be extended, thereby extending the duration of the second heating mode. As mentioned above, the second heating mode has higher energy efficiency than the first heating mode. Therefore, the energy efficiency of the entire heat pump system can be improved. Furthermore, because the duration of the second heating mode can be extended in this way, the frequency of switching between the first and second heating modes can be reduced. This ensures the durability and reliability of each valve, and also reduces the frequency of frost formation on the outdoor unit caused by moisture in the outside air freezing.

[0028] (9) It is mounted on a mobile vehicle, The system is configured to be switchable between multiple modes, including a first heating mode that heats the crew compartment of the mobile unit without utilizing the waste heat of a predetermined cooling target, and a second heating mode that heats the crew compartment using the waste heat. It is a heat pump system, A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to have an adjustable opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, A predetermined on / off valve is configured to be openable and closable, and the flow of the heat transfer medium can be changed by opening and closing it. A control device is provided, The control device is In the second heating mode, before the heat transfer medium overheats in the outdoor unit, switch to the first heating mode. In the second heating mode, by performing a predetermined sleep prevention control, the period during which sleep does not occur is extended compared to the case where the sleep prevention control is not performed, thereby extending the duration of the second heating mode. The aforementioned sleep prevention control is, A first control is provided as a control to prevent the vehicle from falling over by changing the opening degree of the first throttle valve, By changing the opening degree of the second throttle valve, a second control is provided as a control to prevent the vehicle from falling over, Including at least one of the following: Heat pump system.

[0029] This configuration also yields the same effects as those described in (8) above.

[0030] (10) The second throttle valve and the chiller are located downstream of the outdoor unit, The aforementioned designated on-off valve is a low-pressure on-off valve located in a path that branches off downstream of the outdoor unit and upstream of the second throttle valve. The control device, in the second heating mode, completely closes the low-pressure shut-off valve and controls the opening of the second throttle valve to an opening greater than zero. The first control is a control that prevents the vehicle from falling over by reducing the opening of the first throttle valve. The second control is a control that prevents the vehicle from falling over by increasing the opening degree of the second throttle valve. The heat pump system described in (8) or (9) above.

[0031] In this configuration, during the second heating mode, the first path including the first throttle valve and the outdoor unit, and the second path including the second throttle valve and the chiller are connected in series with each other. In this configuration, sleep prevention control can be implemented.

[0032] (11) The predetermined on-off valve is a high-pressure on-off valve located in a path that branches off downstream of the condenser and upstream of the first throttle valve, The second throttle valve and the chiller are located downstream of the high-pressure shut-off valve. The control device, in the second heating mode, fully opens the high-pressure shut-off valve and controls the opening of the second throttle valve to an opening greater than zero. The first control is a control that prevents the vehicle from falling over by increasing the opening degree of the first throttle valve. The second control is a control that prevents the vehicle from falling over by reducing the opening of the second throttle valve. The heat pump system described in (8) or (9) above.

[0033] In this configuration, during the second heating mode, the first path including the first throttle valve and the outdoor unit, and the second path including the second throttle valve and the chiller are connected in parallel to each other. In this configuration, sleep prevention control can be implemented.

[0034] (12) The fall asleep prevention control includes both the first control and the second control, A heat pump system as described in any one of (8) to (11) above.

[0035] With this configuration, by performing both the first control and the second control, it is possible to more reliably prevent the heat transfer medium from becoming saturated in the outdoor unit than when only one of them is performed.

[0036] (13) A control method for a heat pump system mounted on a mobile body, configured to be switchable between a plurality of modes, including a first heating mode that heats the occupant compartment of the mobile body without utilizing the waste heat of a predetermined object to be cooled, and a second heating mode that heats the occupant compartment using the waste heat, The aforementioned heat pump system is A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to have an adjustable opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, It comprises a predetermined on / off valve that is configured to be openable and closable, and which can change the flow of the heat transfer medium by opening and closing, In the aforementioned control method, In the second heating mode, the opening of the second throttle valve is controlled to be greater than zero, thereby controlling the circulation of the heat transfer medium through the chiller. During the first switching operation, in which the system should switch from the second heating mode to the first heating mode, the predetermined on-off valve is fully opened, and the opening of the second throttle valve is gradually reduced until it reaches zero, thereby switching the system so that the heat transfer medium circulates without passing through the chiller. A method for controlling a heat pump system.

[0037] This configuration also yields the same effects as the system described in (1) above.

[0038] (14) A control method for a heat pump system mounted on a mobile body, configured to be switchable between a first heating mode that heats the crew compartment of the mobile body without utilizing the waste heat of a predetermined object to be cooled, and a second heating mode that heats the crew compartment using the waste heat, The aforementioned heat pump system is A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to have an adjustable opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, It comprises a predetermined on / off valve that is configured to be openable and closable, and which can change the flow of the heat transfer medium by opening and closing, In the aforementioned control method, In the second heating mode, before the heat transfer medium overheats in the outdoor unit, switch to the first heating mode. In the control method described above, by performing a predetermined sleep prevention control while in the second heating mode, the period during which sleep does not occur in the second heating mode is extended compared to when the sleep prevention control is not performed, thereby extending the duration of the second heating mode. The aforementioned sleep prevention control is, A first control is provided as a control to prevent the vehicle from falling over by changing the opening degree of the first throttle valve, By changing the opening degree of the second throttle valve, a second control is provided as a control to prevent the vehicle from falling over, Including at least one of the following: A method for controlling a heat pump system.

[0039] This configuration also yields the same effects as the system described in (9) above.

[0040] (15) A control program for a computer that functions as a control device for a heat pump system mounted on a mobile body, which is configured to be switchable between a first heating mode that heats the crew compartment of the mobile body without using the waste heat of a predetermined object to be cooled, and a second heating mode that heats the crew compartment using the waste heat, The aforementioned heat pump system is A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to have an adjustable opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, It comprises a predetermined on / off valve that is configured to be openable and closable, and which can change the flow of the heat transfer medium by opening and closing, The aforementioned control program, In the second heating mode, the computer functions as a control device that controls the circulation of the heat transfer medium through the chiller by controlling the opening of the second throttle valve to an opening greater than zero. During the first switching from the second heating mode to the first heating mode, the computer functions as a control device that switches the heat transfer medium to circulate without passing through the chiller by fully opening the predetermined on-off valve and gradually reducing the opening of the second throttle valve until it reaches zero. Control program.

[0041] The program with this configuration also provides the same effects as the system described in (1) and the method described in (13) above. [Effects of the Invention]

[0042] As described above, according to the configurations of (1), (13), and (15), the mode switching noise can be reduced by means other than control for preventing valve switching noise. Furthermore, according to the configurations of (2) to (8) which refer to (1), additional effects can be obtained. In addition, according to the configurations of (8), (9), and (14), the period during which bedtime does not occur even in the second heating mode can be extended, thereby extending the duration of the second heating mode. Furthermore, according to the configurations of (10) to (12) which refer to (8) and (9), the period during which bedtime does not occur even in the second heating mode can be extended, thereby extending the duration of the second heating mode. [Brief explanation of the drawing]

[0043] [Figure 1] This is a configuration diagram showing the heat pump system of the first embodiment. [Figure 2] This is a diagram showing the configuration for the first cooling mode. [Figure 3] This is a configuration diagram showing the first heating mode. [Figure 4] This diagram shows the configuration during the first and second switching phases. [Figure 5] This is a diagram showing the configuration for the second heating mode. [Figure 6] This is a diagram showing the first heating mode of the comparative configuration. [Figure 7] This is a diagram showing the configuration for the second heating mode. [Figure 8] This is a configuration diagram showing a heat pump system according to the second embodiment. [Figure 9] This is a diagram showing the configuration for the first cooling mode. [Figure 10] This is a diagram showing the configuration for the first heating mode. [Figure 11] This is a diagram showing the configuration for the second heating mode. [Modes for carrying out the invention]

[0044] Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited in any way to the following embodiments, and can be implemented with appropriate modifications without departing from the spirit of the invention.

[0045] [First Embodiment] As shown in Figure 1, the vehicle 100 of this embodiment is provided with a passenger compartment Ia and is equipped with a predetermined cooling target 79. The cooling target 79 may be, for example, a battery, an IPU (Intelligent Power Unit) including a battery and its monitoring device, a drivetrain device such as a motor, a control device that controls the drivetrain (a computer including a CPU, ROM, RAM, etc.), an ECU (control unit) of another device, or an engine, etc.

[0046] The vehicle 100 is also equipped with a heat pump system 70, a heating system 80, a cooling system 90, and a control device 75 that controls them. Hereinafter, the heat transfer medium of the heat pump system 70 will be referred to as "heat transfer medium mA", the heat transfer medium of the heating system 80 as "heat transfer medium mB", and the heat transfer medium of the cooling system as "heat transfer medium mC". Each of the heat transfer mediums mA, mB, and mC may be, for example, water or a fluorocarbon refrigerant, or, for example, another substance that can be vaporized and liquefied within the heat pump system 70.

[0047] The heating system 80 is a system for heating the air in the crew compartment Ia and comprises an electric pump 81, a heating element 83, and a heater core 84. The electric pump 81 pumps out the heat transfer medium mB, circulating the heat transfer medium mB in the following order: electric pump 81 → condenser 12 of the heat pump system 70 (described later) → heating element 83 → heater core 84 → and back to the electric pump 81.

[0048] The condenser 12 is configured to exchange heat between the heat transfer medium mA and the heat transfer medium mB. The heating heater 83 is configured to heat the heat transfer medium mB. The heater core 84 is configured to exchange heat between the heat transfer medium mB and the air in the crew compartment Ia.

[0049] The cooling system 90 is a system for cooling the object to be cooled 79 and comprises an electric pump 91, a cooler 94, and a radiator 95. The electric pump 81 pumps out the heat transfer medium mC, circulating the heat transfer medium mC in the following order: electric pump 81 → chiller 24 of the heat pump system 70 (described later) → cooler 94 → radiator 95 → and back to the electric pump 81.

[0050] The chiller 24 is configured to exchange heat between the heat transfer medium mA and the heat transfer medium mC. The cooler 94 is located adjacent to the object to be cooled 79 and is configured to exchange heat between the heat transfer medium mC and the object to be cooled 79. The radiator 95 may be configured to exchange heat between the heat transfer medium mC and radiator water, or to exchange heat between the heat transfer medium mC and air.

[0051] The heat pump system 70 includes a compressor 61 and a first path 10, a second path 20, a third path 30, a fourth path 40, and a fifth path 50. The upstream end of the first path 10 is connected to the discharge port of the compressor 61. The downstream end of the first path 10 is connected to the upstream ends of the second path 20, the third path 30, and the fourth path 40. The downstream ends of the second path 20, the third path 30, and the fourth path 40 are connected to the upstream ends of the fifth path 50. The downstream end of the fifth path 50 is connected to the suction port of the compressor 61. Thus, the second path 20, the third path 30, and the fourth path 40 are arranged in parallel between the first path 10, which is the most upstream, and the fifth path 50, which is the most downstream.

[0052] The compressor 61 circulates the heat transfer medium mA within the heat pump system 70 by compressing and sending out the heat transfer medium mA.

[0053] The first path 10 is provided with, in order from the upstream side, a condenser 12, a first throttle valve 13, and an outdoor unit 14. As described above, the condenser 12 is configured to be able to exchange heat between the heat transfer medium mA and the heat transfer medium mB. The first throttle valve 13 is configured to allow continuous or stepwise adjustment of its opening degree. The outdoor unit 14 is configured to be able to exchange heat between the heat transfer medium mA and the outside air Oa. Note that "outside air Oa" may be read as outside air.

[0054] The second path 20 is provided with a second throttle valve 23 and a chiller 24, in that order from the upstream side. The second throttle valve 23 is configured to allow continuous or stepwise adjustment of its opening degree. As described above, the chiller 24 is configured to allow heat exchange between the heat transfer medium mA and the heat transfer medium mC.

[0055] The third path 30 is provided with a third throttle valve 33 and an evaporator 34, in order from the upstream side. The third throttle valve 33 is configured to allow continuous or stepwise adjustment of its opening. The evaporator 34 is configured to exchange heat between the heat transfer medium mA and the air in the occupant compartment Ia or the outside air that is drawn in.

[0056] A low-pressure on-off valve 43 is provided in the fourth path 40. The low-pressure on-off valve 43 is a solenoid valve or the like, and is configured to be selectively switchable between fully open and fully closed. In this embodiment, "low-pressure on-off valve 43" may be read as "predetermined on-off valve".

[0057] An accumulator 54 is provided in the fifth pathway 50.

[0058] The control device 75 controls the systems 70, 80, and 90 described above. The control device 75 may also be considered as a part of these systems 70, 80, and 90. The control device 75 is primarily composed of a computer and a control program that enables it to function as the control device 75. In other words, the control device 75 is realized through the cooperation of the computer and the control program. The computer includes, for example, a CPU, ROM, RAM, etc. The control program is stored on a recording medium readable by the computer.

[0059] The control device 75 is configured to selectively switch the mode of the heat pump system 70 to one of a plurality of modes. These plurality of modes include at least a predetermined first cooling mode c1, a predetermined first heating mode h1, and a predetermined second heating mode h2. The first cooling mode c1 is a mode for cooling the air in the occupant compartment Ia. The first heating mode h1 is a mode for heating the heat transfer medium mB for warming the air in the occupant compartment Ia without utilizing the waste heat from the cooling target 79. The second heating mode h2 is a mode for heating the heat transfer medium mB using the waste heat from the cooling target 79.

[0060] First, the first cooling mode c1 will be explained with reference to Figure 2. In the first cooling mode c1, the control device 75 completely closes the low-pressure on-off valve 43 and the second throttle valve 23, and controls the opening of the first throttle valve 13 and the third throttle valve 33 to an opening greater than zero. As a result, the heat transfer medium mA circulates in the following order: compressor 61 → first path 10 → third path 30 → fifth path 50 → compressor 61 again. At this time, due to the opening control of the first throttle valve 13 and the third throttle valve 33, the heat transfer medium mA is liquefied in the condenser 12 and outdoor unit 14 upstream of the third throttle valve 33, and vaporized in the evaporator 34 downstream of the third throttle valve 33.

[0061] Therefore, in the outdoor unit 14, heat exchange takes place between the liquefied, high-temperature heat transfer medium mA and the outside air Oa, cooling the heat transfer medium mA. Subsequently, the liquid heat transfer medium mA passes through the third throttle valve 33 and vaporizes in the evaporator 34, becoming cold. Heat exchange takes place between the gaseous heat transfer medium mA and the air in the occupant compartment Ia or the outside air that is drawn in, cooling the air in the occupant compartment Ia. After that, the gaseous heat transfer medium mA returns to the compressor 61 via the accumulator 54.

[0062] Next, the first heating mode h1 will be described with reference to Figure 3. In the first heating mode h1, the control device 75 operates the electric pump 81 to circulate the heat transfer medium mB within the heating system 80.

[0063] Furthermore, the control device 75 completely closes the second throttle valve 23 and the third throttle valve 33 in the heat pump system 70, controls the opening of the first throttle valve 13 to an opening greater than zero, and fully opens the low-pressure shut-off valve 43. As a result, the heat transfer medium mA circulates in the following order: compressor 61 → first path 10 → fourth path 40 → fifth path 50, and back to the compressor 61. At this time, due to the control of the opening of the first throttle valve 13, the heat transfer medium mA is liquefied in the condenser 12 upstream of the first throttle valve 13, while the heat transfer medium mA is vaporized in the outdoor unit 14 downstream of the first throttle valve 13.

[0064] As a result, the heat transfer medium mA that flows from the compressor 61 to the condenser 12 liquefies and becomes hot. Heat exchange takes place between the liquid heat transfer medium mA and the heat transfer medium mB, warming the heat transfer medium mB. The air in the occupant compartment Ia is then warmed by the heat transfer medium mB. The liquid heat transfer medium mA that has passed through the condenser 12 passes through the first throttle valve 13, vaporizes in the outdoor unit 14, and becomes cold. Heat exchange takes place between the gaseous heat transfer medium mA and the air outside the vehicle Oa, warming the heat transfer medium mA. The gaseous heat transfer medium mA then passes through the low-pressure shut-off valve 43 and the accumulator 54 in sequence and returns to the compressor 61.

[0065] Thus, in the first heating mode h1, the heat transfer medium mA is circulated without passing through the chiller 24. This warms the air in the crew compartment Ia without utilizing the waste heat from the cooling target 79.

[0066] Next, the second heating mode h2 will be described with reference to Figure 5. In the second heating mode h2, as in the first heating mode h1, the control device 75 operates the electric pump 81 to circulate the heat transfer medium mB within the heating system 80. Furthermore, the control device 75 operates the electric pump 91 to circulate the heat transfer medium mC within the cooling system 90.

[0067] Furthermore, the control device 75 completely closes the third throttle valve 33 and the low-pressure shut-off valve 43 in the heat pump system 70, and controls the opening of the first throttle valve 13 and the second throttle valve 23 to an opening greater than zero. As a result, the heat transfer medium mA circulates in the order of compressor 61 → first path 10 → second path 20 → fifth path 50 → and back to compressor 61. At this time, due to the control of the opening of the first throttle valve 13 and the second throttle valve 23, the heat transfer medium mA is liquefied in the condenser 12 upstream of the first throttle valve 13, while the heat transfer medium mA is vaporized in the outdoor unit 14 and chiller 24 downstream of the first throttle valve 13.

[0068] Therefore, heat exchange h is performed in the condenser 12 and the outdoor unit 14, as in the first heating mode h1. After that, the gaseous heat transfer medium mA that has passed through the outdoor unit 14 flows through the second throttle valve 23 into the chiller 24. In the chiller 24, heat exchange takes place between the heat transfer medium mA and the heat transfer medium mC, causing the heat transfer medium mC to be cooled and the heat transfer medium mA to be heated. The object to be cooled 79 is then cooled by the heat transfer medium mC. The gaseous heat transfer medium mA that has passed through the chiller 24 returns to the compressor 61 via the accumulator 54.

[0069] The heat transfer medium mA, which has returned to the compressor 61, is sent back to the condenser 12, where heat exchange takes place with the heat transfer medium mB. As a result, the waste heat from the object to be cooled 79 is used to warm the air in the crew compartment Ia. In this way, in the second heating mode h2, the heat transfer medium mA is circulated via the chiller 24. This utilizes the waste heat from the object to be cooled 79 to warm the air in the crew compartment Ia.

[0070] Next, we will describe three problems that need to be solved in this embodiment.

[0071] First, let me explain the first problem. Hereinafter, when the heat transfer medium mA in the outdoor unit 14 cannot evaporate quickly enough and remains in the outdoor unit 14 as a liquid, this will be referred to as "heat transfer medium mA stagnation in the outdoor unit 14" or simply "stagnation." The second heating mode h2 is more energy efficient for heating than the first heating mode h1 because it utilizes the waste heat of the cooling target 79. However, in the second heating mode h2, depending on the opening of the first throttle valve 13 and the second throttle valve 23, the heat transfer medium mA may not evaporate easily in the outdoor unit 14. Specifically, in this embodiment, where the first path 10 and the second path 20 are connected in series in the second heating mode h2, if the opening of the first throttle valve 13 is made too large compared to the opening of the second throttle valve 23, the pressure reduction width and heat absorption amount in the outdoor unit 14 will decrease, causing the evaporation temperature to rise and making it difficult for the heat transfer medium mA to evaporate.

[0072] When the evaporation temperature rises above that of the outside air, the evaporation of the heat transfer medium mA in the outdoor unit 14 cannot keep up, causing the heat transfer medium mA to become stagnant. For this reason, the control device 75 switches to the first heating mode h1 before stagnation occurs in the second heating mode h2. However, it is desirable to maintain the second heating mode h2, which has better energy efficiency for heating, for as long as possible. Also, from the perspective of ensuring the durability and reliability of each valve and suppressing the frequency of frost formation on the outdoor unit 14 due to the freezing of moisture in the outside air, it is desirable to reduce the frequency of switching between the first heating mode h1 and the second heating mode h2.

[0073] Next, the second issue will be explained. Hereinafter, as shown in Figures 6 and 7, the configuration in which an additional on-off valve 22 is provided between the first path 10 and the second path 20 will be referred to as the "comparative configuration." The additional on-off valve 22 is a solenoid valve or the like, and is configured to be selectively switchable between fully open and fully closed.

[0074] Suppose, in the comparative configuration, the system switches from the second heating mode h2 shown in Figure 7 to the first heating mode h1 shown in Figure 6 by fully opening the low-pressure shut-off valve 43 and fully closing the additional shut-off valve 22 while keeping the second throttle valve 23 open to an opening greater than zero. In this case, the following problem occurs. Specifically, with the full closing of the additional shut-off valve 22, the pressure difference on both sides of the second throttle valve 23 decreases rapidly, and the flow of the heat transfer medium mA changes rapidly. This results in the generation of a switching noise.

[0075] As a countermeasure to this second problem, the following valve switching noise suppression control can be considered. In this valve switching noise suppression control, in the second heating mode h2 shown in Figure 7, the rotation speed of the compressor 61 is suppressed in advance to suppress the output, and the opening degree of the first throttle valve 13 is increased. From that state, as described above, the low-pressure on-off valve 43 is fully opened and the additional on-off valve 22 is fully closed to switch to the first heating mode h1 shown in Figure 6. In the above valve switching noise suppression control, by suppressing the output of the compressor 61, the rapid decrease in the pressure difference on both sides of the second throttle valve 23 due to the switching is suppressed, and the rapid change in the flow of the heat transfer medium mA is suppressed, thereby suppressing the generation of switching noise. However, in this case, in addition to the need for such valve switching noise suppression control, energy is wasted for performing such valve switching noise suppression control.

[0076] Next, let's discuss the third issue. Suppose that in the first heating mode h1 of the comparative configuration shown in Figure 6, the additional on-off valve 22 is fully closed and the opening of the second throttle valve 23 is set to a degree greater than zero, and then the additional on-off valve 22 is fully opened and the low-pressure on-off valve 43 is fully closed to switch to the second heating mode h2 shown in Figure 7. In that case, the following problem occurs. Specifically, with the full opening of the additional on-off valve 22, the pressure difference on both sides of the second throttle valve 23 increases rapidly, and the flow of the heat transfer medium mA changes rapidly. This results in a switching noise.

[0077] To solve the above first to third problems, the control device 75 of this embodiment performs the following control. Hereinafter, the time when switching from the second heating mode h2 to the first heating mode h1 will be referred to as "first switching time v1", and the time when switching from the first heating mode h1 to the second heating mode h2 will be referred to as "second switching time v2".

[0078] First, in the second heating mode h2 state shown in Figure 5, a predetermined control is performed to prevent the user from falling asleep. This extends the period during which the user does not fall asleep even in the second heating mode h2, thereby maximizing the duration of the second heating mode h2. Specifically, the timing of switching from the second heating mode h2 to the first heating mode h1 is delayed as much as possible, while the timing of switching from the first heating mode h1 to the second heating mode h2 is accelerated as much as possible.

[0079] The fall-over prevention control includes a first control and a second control. In the first control, fall-over is prevented by reducing the opening of the first throttle valve 13 as necessary. On the other hand, in the second control, fall-over is prevented by increasing the opening of the second throttle valve 23 as necessary. The reduction in the opening of the first throttle valve 13 in the first control and the increase in the opening of the second throttle valve 23 in the second control are performed to the minimum extent possible within the range in which fall-over can be prevented, that is, within the range in which the evaporation temperature of the heat transfer medium mA in the outdoor unit 14 does not exceed the temperature of the outside air. In this way, the opening of the first throttle valve 13 is made as large as possible and the opening of the second throttle valve 23 is made as small as possible within that range. This is because a larger opening of the first throttle valve 13 and a smaller opening of the second throttle valve 23 allows for the utilization of more waste heat from the object to be cooled 79, thereby improving the energy efficiency of heating.

[0080] On the other hand, in the second heating mode h2, the control device 75 switches to the first heating mode h1 in the following cases, for example: Firstly, if it is required to control the opening of the second throttle valve 23 to an opening below a predetermined minimum possible opening in order to prevent overheating, the control device 75 switches to the first heating mode h1. Secondly, if the cooling target 79 is not to be cooled, the control device 75 switches to the first heating mode h1. Thirdly, if the evaporation temperature of the heat transfer medium mA in the outdoor unit 14 based on the heating requirement exceeds a predetermined evaporation temperature threshold, the control device 75 switches to the first heating mode h1. It is preferable that the evaporation temperature threshold be as high as possible within a range lower than the outside air temperature. This predetermined value of the evaporation temperature should be determined considering the accuracy of the evaporation temperature sensor, pressure sensor, etc.

[0081] When switching from the second heating mode h2 to the first heating mode h1, that is, during the first switching v1, the low-pressure on-off valve 43 is first fully opened, as shown in Figure 4. As a result, the heat transfer medium mA flows from the first path 10 to the second path 20 and the fourth path 40, and then merges in the fifth path 50.

[0082] Subsequently, with the low-pressure shut-off valve 43 fully open, the opening of the first throttle valve 13 is gradually increased, while the opening of the second throttle valve 23 is gradually decreased until it reaches zero. When the opening of the second throttle valve 23 reaches zero, as shown in Figure 3, the heat transfer medium mA flows from the first path 10 to only the fourth path 40 of the second path 20 and fourth path 40. In other words, the heat transfer medium mA circulates in the order of compressor 61 → first path 10 → fourth path 40 → fifth path 50 → compressor 61 again, and the system switches to the first heating mode h1.

[0083] Furthermore, for the reasons stated above, in this embodiment, the aforementioned control to counteract the switching noise of the on / off valve is not performed during the first switching v1.

[0084] When switching from the first heating mode h1 to the second heating mode h2, that is, during the second switching v2, first, the opening of the second throttle valve 23 is gradually increased from zero, starting from the state of the first heating mode h1 shown in Figure 3. As a result, as shown in Figure 4, the heat transfer medium mA flows from the first path 10 to the second path 20 and the fourth path 40, and then merges in the fifth path 50. After that, the low-pressure on-off valve 43 is completely closed. As a result, as shown in Figure 5, the heat transfer medium mA flows only from the first path 10 to the second path 20 of the second path 20 and the fourth path 40. That is, the heat transfer medium mA circulates in the order of compressor 61 → first path 10 → second path 20 → fifth path 50 → compressor 61 again, and the system switches to the second heating mode h2.

[0085] The configuration and effects of this embodiment are summarized below.

[0086] The control device 75 needs to switch to the first heating mode h1 before frost buildup occurs in the second heating mode h2. However, the control device 75 performs frost buildup prevention control while in the second heating mode h2. This allows for a longer period of time in the second heating mode h2 without frost buildup compared to when this frost buildup prevention control is not performed, thus extending the duration of the second heating mode h2. Since the second heating mode h2 uses the waste heat from the cooling target 79 for heating, it has higher energy efficiency than the first heating mode h1. As a result, the energy efficiency of heating can be improved throughout the entire heat pump system 70. Furthermore, because the duration of the second heating mode h2 can be extended in this way, the frequency of switching between the first heating mode h1 and the second heating mode h2 can be reduced. This ensures the durability and reliability of each valve and reduces the frequency of frost buildup. In other words, the first problem described above can be solved.

[0087] In this embodiment, the fall prevention control involves both a first control, which prevents fall by reducing the opening of the first throttle valve 13, and a second control, which prevents fall by increasing the opening of the second throttle valve 23. Therefore, fall prevention can be achieved more flexibly and reliably compared to performing only one of the controls. However, if fall prevention can be sufficiently prevented by performing only one of the first or second controls, then only one of them may be performed.

[0088] During the first switching phase v1, the low-pressure shut-off valve 43 is fully opened from the state of the second heating mode h2 shown in Figure 5, and the heat transfer medium mA is allowed to flow through the fourth path 40 in parallel with the second path 20, as shown in Figure 4. Then, with the low-pressure shut-off valve 43 still fully open, the opening of the second throttle valve 23 is gradually reduced to zero. This gradually reduces the flow rate of the heat transfer medium mA flowing through the second path 20, switching to the first heating mode h1 shown in Figure 3. This suppresses a rapid decrease in the pressure difference on both sides of the second throttle valve 23, as well as a rapid change in the flow of the heat transfer medium mA, thereby suppressing the switching noise. In other words, the second problem described above can be solved.

[0089] During the second switching phase v2, starting from the first heating mode h1 shown in Figure 3, the opening of the second throttle valve 23 is gradually increased from zero while the low-pressure shut-off valve 43 remains fully open. This allows the heat transfer medium mA to flow through the second path 20 in parallel with the fourth path 40, as shown in Figure 4. This suppresses a rapid increase in the pressure difference on both sides of the second throttle valve 23, as well as a rapid change in the flow of the heat transfer medium mA, thereby suppressing the switching noise. In other words, the third problem described above can be solved. Subsequently, as mentioned above, the system switches to the second heating mode h2 shown in Figure 5 by fully closing the low-pressure shut-off valve 43.

[0090] As shown in Figure 5, the chiller 24 performs heat exchange between the heat transfer medium mA and the heat transfer medium mC. Therefore, in the second heating mode h2, the waste heat from the cooling target 79 can be utilized with a simple mechanism by heating the heat transfer medium mA with the heat transfer medium mC.

[0091] Furthermore, the condenser 12 performs heat exchange between the heat transfer medium mA and the heat transfer medium mB. Therefore, in the second heating mode h2, the waste heat from the cooling target 79 can be utilized with a simple mechanism by heating the heat transfer medium mB with the heat transfer medium mA.

[0092] During the first switching phase v1, shown in the order of Figure 5 → Figure 4 → Figure 3, the aforementioned valve switching noise reduction control is not implemented. As a result, energy efficiency can be improved compared to simply suppressing the implementation of valve switching noise reduction control, for example.

[0093] [Second Embodiment] Next, the second embodiment will be described with reference to Figures 8 to 11. This embodiment will be described based on the first embodiment, focusing on the differences, and explanations of points that are the same as or similar to the first embodiment will be omitted as appropriate.

[0094] As shown in Figure 8, the heat pump system 70 further includes a check valve 19 and a bypass path 16. The check valve 19 is located between the downstream end of the first path 10 and the upstream ends of the second path 20 and the third path 30. This check valve 19 allows the flow of the heat transfer medium mA from the upstream side to the downstream side, while blocking the flow of the heat transfer medium mA from the downstream side to the upstream side. The upstream end of the fourth path 40 is connected to the downstream end of the first path 10 without going through the check valve 19, as in the first embodiment.

[0095] The bypass route 16 connects the portion of the first route 10 located downstream of the condenser 12 and upstream of the first throttle valve 13 to the portion located downstream of the check valve 19 and upstream of the upstream ends of the second route 20 and the third route 30. A high-pressure on-off valve 17 is provided in the bypass route 16. The high-pressure on-off valve 17 is a solenoid valve or the like, and is configured to be selectively switchable between fully open and fully closed. In this embodiment, "high-pressure on-off valve 17" can be read as "predetermined on-off valve".

[0096] In the first cooling mode c1 shown in Figure 9, the control device 75 performs the same control as in the first embodiment while completely closing the high-pressure on-off valve 17.

[0097] In the first heating mode h1 shown in Figure 10, the control device 75 completely closes the high-pressure shut-off valve 17. Otherwise, the same control is performed as in the first embodiment. That is, the second throttle valve 23 and the third throttle valve 33 are completely closed, the opening of the first throttle valve 13 is controlled to an opening greater than zero, and the low-pressure shut-off valve 43 is fully opened. As a result, the heat transfer medium mA circulates in the order of compressor 61 → first path 10 → fourth path 40 → fifth path 50 → and back to compressor 61.

[0098] In the second heating mode h2 shown in Figure 11, the control device 75 fully opens the high-pressure shut-off valve 17 and the second shut-off valve, while controlling the first throttle valve 13 and the second throttle valve 23 to an opening greater than zero. As a result, the heat transfer medium mA flows in the order of compressor 61 → first path 10 → fourth path 40 → fifth path 50 → back to compressor 61, and also flows through a bypass path 16 that branches off from the first path 10, passes through the second path 20, and then rejoins at the fifth path 50, thus circulating. At this time, due to the opening control of the first throttle valve 13 and the second throttle valve 23, the heat transfer medium mA liquefies in the condenser 12 upstream of the first throttle valve 13 and the second throttle valve 23. On the other hand, the heat transfer medium mA vaporizes in the outdoor unit 14 downstream of the first throttle valve 13 and in the chiller 24 downstream of the second throttle valve 23.

[0099] In this embodiment as well, when the second heating mode h2 is active, the duration of the second heating mode h2 is extended as much as possible by performing sleep prevention control. However, in this embodiment, when the second heating mode h2 is active, the first path 10 and the second path 20 are connected in parallel, not in series. Therefore, the first and second controls in the sleep prevention control of this embodiment are the opposite of those in the first embodiment. That is, in the first control, sleep is prevented by increasing the opening of the first throttle valve 13 as needed. On the other hand, in the second control, sleep is prevented by decreasing the opening of the second throttle valve 23 as needed. These increases in the opening of the first throttle valve 13 in the first control and decreases in the opening of the second throttle valve 23 in the second control are performed to the minimum extent possible within the range where sleep can be prevented, that is, within the range where the evaporation temperature of the heat transfer medium mA in the outdoor unit 14 does not exceed the temperature of the outside air. This allows the opening of the first throttle valve 13 to be kept as small as possible within that range, while the opening of the second throttle valve 23 is kept as large as possible. This is because a smaller opening for the first throttle valve 13 and a larger opening for the second throttle valve 23 allows for greater utilization of the waste heat from the cooling target 79, thereby improving the energy efficiency of the heating system.

[0100] During the first switching phase v1, first, in the state of the second heating mode h2 shown in Figure 11, the opening degree of the first throttle valve 13 is set to an opening degree less than or equal to a predetermined first opening degree, and the opening degree of the second throttle valve 23 is set to an opening degree greater than or equal to a predetermined second opening degree.

[0101] From that state, with the high-pressure on-off valve 17 and the low-pressure on-off valve 43 still fully open, the opening degree of the first throttle valve 13 is gradually increased, while the opening degree of the second throttle valve 23 is gradually decreased until it reaches zero. When the opening degree of the second throttle valve 23 reaches zero, as shown in Figure 10, the heat transfer medium mA no longer flows through the bypass path 16 that branches off from the first path 10, through the second path 20, and then rejoins at the fifth path 50. In other words, the heat transfer medium mA now circulates only in the order of compressor 61 → first path 10 → fourth path 40 → fifth path 50 → compressor 61 again, and the system switches to the first heating mode h1. After that, the high-pressure on-off valve 17 is fully closed.

[0102] During the second switching phase v2, first, the high-pressure shut-off valve 17 is fully opened from the state of the first heating mode h1 shown in Figure 10, and then the opening degree of the second throttle valve 23 is gradually increased from zero. As a result, as shown in Figure 11, the heat transfer medium mA also flows through a path that branches off into a bypass path 16 midway through the first path 10, passes through the second path 20, and then rejoins in the fifth path 50, switching to the second heating mode h2.

[0103] The configuration and effects of this embodiment are summarized below.

[0104] In this embodiment as well, the control device 75 performs sleep prevention control when in the second heating mode h2 state. This extends the duration of the second heating mode h2 compared to when sleep prevention control is not performed. As a result, the energy efficiency of heating can be improved throughout the entire heat pump system 70. Furthermore, the durability and reliability of each valve can be ensured, and the frequency of frost formation can be reduced.

[0105] During the first switching phase v1, the system switches from the second heating mode h2 shown in Figure 11 to the first heating mode h1 shown in Figure 10 by gradually reducing the opening of the second throttle valve 23 to zero while keeping the high-pressure on-off valve 17 and the low-pressure on-off valve 43 fully open. Therefore, compared to switching to the first heating mode h1 from the state of the second heating mode h2 shown in Figure 11 by keeping the opening of the second throttle valve 23 greater than zero and fully closing the high-pressure on-off valve 17, the flow rate of the heat transfer medium mA flowing through the second path 20 can be gradually reduced. As a result, a sudden drop in the pressure difference on both sides of the second throttle valve 23 is suppressed, as is a sudden change in the flow of the heat transfer medium mA, thereby suppressing the switching noise.

[0106] During the second switching phase v2, the system switches from the first heating mode h1 shown in Figure 10 to the second heating mode h2 shown in Figure 11 by fully opening the high-pressure shut-off valve 17 and then gradually increasing the opening of the second throttle valve 23 from zero. Therefore, compared to the case where the system switches from the first heating mode h1 to the second heating mode h2 by fully opening the high-pressure shut-off valve 17 from a state where the opening of the second throttle valve 23 is greater than zero in the first heating mode h1 shown in Figure 10, the flow rate of the heat transfer medium mA flowing through the second path 20 can be gradually increased. As a result, a rapid increase in the pressure difference on both sides of the second throttle valve 23 is suppressed, as is a rapid change in the flow of the heat transfer medium mA, thereby suppressing the switching noise.

[0107] [Other embodiments] The embodiments described above can be modified, for example, as follows: The heat pump system 70, the heating system 80, the cooling system 90, and the control device 75 may be mounted on a mobile body other than a vehicle 100, such as a ship, aircraft, or railway.

[0108] In each of the above embodiments, the control method by the control device 75 corresponds to the "control method for the heat pump system 70". [Explanation of Symbols]

[0109] 12 Condenser 13. First throttle valve 14 Outdoor unit 17. High-pressure shut-off valve (designated shut-off valve) 23. Second throttle valve 24 Chiller 43. Low-pressure shut-off valve (designated shut-off valve) 61 Compressor 70 Heat pump systems 75 Control device 79 Cooling targets 80 Heating Systems 90 Cooling System 100 vehicles (mobile vehicles) h1 First heating mode h2 Second heating mode Ia Crew compartment mA heat pump system heat transfer fluid mB heating system heat transfer fluid Heat transfer medium for mC cooling systems

Claims

1. It is mounted on the mobile vehicle, The system is configured to be switchable between multiple modes, including a first heating mode that heats the occupant compartment of the mobile unit without utilizing the waste heat of a predetermined cooling target, and a second heating mode that heats the occupant compartment using the waste heat. It is a heat pump system, A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to allow adjustment of its opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, A predetermined on / off valve is configured to be openable and closable, and the flow of the heat transfer medium can be changed by opening and closing it. A control device is provided, The control device is In the second heating mode, the opening of the second throttle valve is controlled to be greater than zero, thereby controlling the circulation of the heat transfer medium through the chiller. During the first switching operation, in which the system should switch from the second heating mode to the first heating mode, the predetermined on-off valve is fully opened, and the opening of the second throttle valve is gradually reduced until it reaches zero, thereby switching the system so that the heat transfer medium circulates without passing through the chiller. Heat pump system.

2. The second throttle valve and the chiller are located downstream of the outdoor unit. The aforementioned designated on-off valve is a low-pressure on-off valve located in a path that branches off downstream of the outdoor unit and upstream of the second throttle valve. The control device is In the second heating mode, the low-pressure shut-off valve is completely closed, and the opening of the second throttle valve is controlled to an opening greater than zero. During the first switching operation, the low-pressure on-off valve is fully opened, and then the opening degree of the second throttle valve is gradually reduced until it reaches zero. The heat pump system according to claim 1.

3. The aforementioned predetermined on-off valve is a high-pressure on-off valve located in a path that branches off downstream of the condenser and upstream of the first throttle valve. The second throttle valve and the chiller are located downstream of the high-pressure shut-off valve. The control device is In the second heating mode, the high-pressure shut-off valve is fully opened, and the opening of the second throttle valve is controlled to an opening greater than zero. During the first switching operation, with the high-pressure on-off valve remaining fully open, the opening degree of the second throttle valve is gradually reduced until it reaches zero. The heat pump system according to claim 1.

4. When the control device switches from the first heating mode to the second heating mode, it opens the predetermined on-off valve completely and increases the opening degree of the second throttle valve from zero. A heat pump system according to any one of claims 1 to 3.

5. The chiller performs heat exchange between the heat transfer medium of the heat pump system and the heat transfer medium of the cooling system that cools the object to be cooled. A heat pump system according to any one of claims 1 to 3.

6. The condenser performs heat exchange between the heat transfer medium of the heat pump system and the heat transfer medium of the heating system that heats the crew compartment. A heat pump system according to any one of claims 1 to 3.

7. In the state of the second heating mode, the control to suppress the output of the compressor and increase the opening of the first throttle valve, and then switch to the first heating mode, is not performed during the first switching. A heat pump system according to any one of claims 1 to 3.

8. The control device is In the second heating mode, before the heat transfer medium overheats in the outdoor unit, switch to the first heating mode. By performing a predetermined sleep-prevention control while in the second heating mode, the period during which sleep does not occur in the second heating mode is extended compared to when the sleep-prevention control is not performed, thereby extending the duration of the second heating mode. The aforementioned sleep prevention control is, A first control is provided as a control to prevent the vehicle from falling asleep by changing the opening degree of the first throttle valve, By changing the opening degree of the second throttle valve, a second control is provided as a control to prevent the vehicle from falling asleep, Including at least one of the following: A heat pump system according to any one of claims 1 to 3.

9. It is mounted on the mobile vehicle, The system is configured to be switchable between multiple modes, including a first heating mode that heats the occupant compartment of the mobile unit without utilizing the waste heat of a predetermined cooling target, and a second heating mode that heats the occupant compartment using the waste heat. It is a heat pump system, A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to allow adjustment of its opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, A predetermined on / off valve is configured to be openable and closable, and the flow of the heat transfer medium can be changed by opening and closing it. A control device is provided, The control device is In the second heating mode, before the heat transfer medium overheats in the outdoor unit, switch to the first heating mode. By performing a predetermined sleep-prevention control while in the second heating mode, the period during which sleep does not occur in the second heating mode is extended compared to when the sleep-prevention control is not performed, thereby extending the duration of the second heating mode. The aforementioned sleep prevention control is, A first control is provided as a control to prevent the vehicle from falling asleep by changing the opening degree of the first throttle valve, By changing the opening degree of the second throttle valve, a second control is provided as a control to prevent the vehicle from falling asleep, Including at least one of the following: Heat pump system.

10. The second throttle valve and the chiller are located downstream of the outdoor unit. The aforementioned designated on-off valve is a low-pressure on-off valve located in a path that branches off downstream of the outdoor unit and upstream of the second throttle valve. The control device, in the second heating mode, completely closes the low-pressure shut-off valve and controls the opening of the second throttle valve to an opening greater than zero. The first control is a control that prevents the vehicle from falling over by reducing the opening of the first throttle valve. The second control is a control that prevents the vehicle from falling over by increasing the opening degree of the second throttle valve. The heat pump system according to claim 8.

11. The aforementioned predetermined on-off valve is a high-pressure on-off valve located in a path that branches off downstream of the condenser and upstream of the first throttle valve. The second throttle valve and the chiller are located downstream of the high-pressure shut-off valve. The control device, in the second heating mode, fully opens the high-pressure shut-off valve and controls the opening of the second throttle valve to an opening greater than zero. The first control is a control that prevents the vehicle from falling over by increasing the opening degree of the first throttle valve. The second control is a control that prevents the vehicle from falling over by reducing the opening of the second throttle valve. The heat pump system according to claim 8.

12. The aforementioned fall asleep prevention control includes both the first control and the second control. The heat pump system according to claim 8.

13. A control method for a heat pump system mounted on a mobile body, configured to be switchable between multiple modes, including a first heating mode that heats the occupant compartment of the mobile body without utilizing the waste heat of a predetermined object to be cooled, and a second heating mode that heats the occupant compartment using the waste heat, The aforementioned heat pump system is A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to allow adjustment of its opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, It comprises a predetermined on / off valve that is configured to be openable and closable, and which can change the flow of the heat transfer medium by opening and closing, In the aforementioned control method, In the second heating mode, the opening of the second throttle valve is controlled to be greater than zero, thereby controlling the circulation of the heat transfer medium through the chiller. During the first switching operation, in which the system should switch from the second heating mode to the first heating mode, the predetermined on-off valve is fully opened, and the opening of the second throttle valve is gradually reduced until it reaches zero, thereby switching the system so that the heat transfer medium circulates without passing through the chiller. A method for controlling a heat pump system.

14. A control method for a heat pump system mounted on a mobile body, configured to be switchable between multiple modes, including a first heating mode that heats the occupant compartment of the mobile body without utilizing the waste heat of a predetermined object to be cooled, and a second heating mode that heats the occupant compartment using the waste heat, The aforementioned heat pump system is A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to allow adjustment of its opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, It comprises a predetermined on / off valve that is configured to be openable and closable, and which can change the flow of the heat transfer medium by opening and closing, In the aforementioned control method, In the second heating mode, before the heat transfer medium overheats in the outdoor unit, switch to the first heating mode. By performing a predetermined sleep-prevention control while in the second heating mode, the period during which sleep does not occur in the second heating mode is extended compared to when the sleep-prevention control is not performed, thereby extending the duration of the second heating mode. The aforementioned sleep prevention control is, A first control is provided as a control to prevent the vehicle from falling asleep by changing the opening degree of the first throttle valve, By changing the opening degree of the second throttle valve, a second control is provided as a control to prevent the vehicle from falling asleep, Including at least one of the following: A method for controlling a heat pump system.

15. A control program for a computer that functions as a control device for a heat pump system mounted on a mobile body, which is configured to be switchable between multiple modes, including a first heating mode that heats the passenger compartment of the mobile body without utilizing the waste heat of a predetermined object to be cooled, and a second heating mode that heats the passenger compartment using the waste heat, The aforementioned heat pump system is A compressor that compresses and sends out a heat transfer medium, A condenser located downstream of the compressor, A first throttle valve is located downstream of the condenser and is configured to allow adjustment of its opening, An outdoor unit is located downstream of the first throttle valve and performs heat exchange between the heat transfer medium and the outside air, A second throttle valve, located at least downstream of the condenser and configured to allow adjustment of its opening, A chiller for cooling the object to be cooled, located downstream of the second throttle valve, It comprises a predetermined on / off valve that is configured to be openable and closable, and which can change the flow of the heat transfer medium by opening and closing, The aforementioned control program, In the second heating mode, the computer functions as a control device that controls the opening of the second throttle valve to be greater than zero, thereby controlling the circulation of the heat transfer medium through the chiller. During the first switching from the second heating mode to the first heating mode, the computer functions as a control device that switches the heat transfer medium to circulate without passing through the chiller by fully opening the predetermined on-off valve and gradually reducing the opening of the second throttle valve until it reaches zero. Control program.

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