Heating system of electric vehicle

Abstract

To reduce electrical power required to heating within a cabin of an electric vehicle as much as possible.SOLUTION: A heating system of an electric vehicle 1 contains a cooling medium circulation system which contains a circulation cooling medium path 7 in which a cooling medium circulates and a cooling medium pump 9 which brings cooling medium into communication within circulation cooling medium path, a heat transmission panel 11 which faces to cabin 2 internal face and transmits heat from the cooling medium to the cabin by one part of the circulation cooling medium path abutting, inverter heat exchange means which thermally emits operation waste-heat of an inverter 5 for operating a drive motor to the cooling medium within circulation cooling medium path and circuit heat exchange means for charging which thermally emits the operation waste-heat of a circuit 6 for charging of a battery for driving to the cooling medium within the circulation cooling medium path and heats the cabin via the heat transmission panel by the operation waste-heat of the inverter during travel and by the operation waste-heat of the circuit for charging during charge.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heating system to be equipped in an electric vehicle. [Background technology]

[0002] In motor-driven vehicles such as electric vehicles, the residual heat of the internal combustion engine cannot be utilized at all or only a small amount can be utilized, so the electric power of the on-board battery is utilized to heat the vehicle interior. For example, Patent Document 1 proposes a floor heating device in which a plurality of electric heaters heated by the electric power of the driving battery of the electric vehicle and a pressure detection means are arranged on the floor of the vehicle interior, and only the parts where pressure is detected are energized to the electric heaters. Patent Document 2 discloses a configuration for a vehicle heating device in which planar electric heaters that generate heat by the electric power of the battery are arranged on the left and right walls of the foot area to achieve immediate warmth. Patent Document 3 discloses a configuration in an electric vehicle in which a drive system cooling circuit is used as a hot water circuit for the heating device, a motor and an inverter are used as heaters, and during charging, a discharge circuit for bypassing each cell of the secondary battery is used as a heater, and the heat generated from them is collected by a heat medium, and the heat medium is passed through a radiator having a fan to supply warm air to the vehicle interior. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication 2011-73658 [Patent Document 2] Patent Publication 2010-111250 [Patent Document 3] Patent Publication 2012-183958 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, in the case of an electric vehicle that uses power from an on-board battery to heat the vehicle interior, it is desirable to minimize the power required for heating in order to maximize the driving range and minimize the charging time. In this regard, since the inverter for driving the motor generates heat while the electric vehicle is running, and the charging circuit generates heat while the electric vehicle is charging, if the operating heat of the inverter or the charging circuit can be used for heating, the power required for heating can be reduced. Furthermore, if the operating heat of the above devices can be used to heat the vehicle interior without using a fan to blow in warm air, the power to drive the fan will be unnecessary, and power consumption can be reduced.

[0005] Thus, a primary object of the present invention is to reduce as much as possible the power required to heat the passenger compartment of an electric vehicle. [Means for solving the problem]

[0006] According to the present invention, the above problem is solved by a heating system for an electric vehicle, comprising: a refrigerant circulation system including a refrigerant circulation path through which a refrigerant circulates and a refrigerant pump for circulating the refrigerant through the refrigerant circulation path; a heat transfer panel that faces an interior surface of the electric vehicle and a part of the circulating refrigerant path abuts on the heat transfer panel to transfer heat from the refrigerant to the interior of the vehicle; an inverter heat exchanger for radiating waste heat from an inverter for driving a drive motor of the electric vehicle to the refrigerant in the circulating refrigerant passage; a charging circuit heat exchanger that dissipates heat generated by the operation of a charging circuit of a driving battery of the electric vehicle to the refrigerant in the circulating refrigerant path; This is achieved by a system that heats the vehicle interior via the heat transfer panel using the waste heat from an inverter while the electric vehicle is running, and using the waste heat from an electrical circuit while the electric vehicle is being charged.

[0007] In the above configuration, the "electric vehicle" is basically a battery-powered electric vehicle (BEV), but may be a vehicle equipped with a drive battery and driven by a motor. The "refrigerant" may be a refrigerant normally used in heating systems for automobiles, typically water. The "heat transfer panel" may be a panel-like member that is arranged facing the interior surface of the vehicle, i.e., the floor surface, side wall surface, seat surface, etc., as described above, and is configured to transfer heat from the refrigerant to the vehicle interior mainly by thermal conduction by being wrapped around the panel when a part of the circulating refrigerant path through which the refrigerant flows is in contact with the panel. As the heat transfer panel, a member having high thermal conductivity and strength capable of withstanding the weight of an occupant is preferably used when the heat transfer panel is arranged on the floor surface or seat surface. The "inverter heat exchange means" may be any type of heat exchanger configured to transfer the operating waste heat of the inverter to a refrigerant for cooling the inverter while the vehicle is running or in use, and the "charging circuit heat exchange means" may be any type of heat exchanger configured to transfer the operating waste heat of the inverter to a refrigerant for cooling the charging circuit of the drive battery during charging. Note that in a configuration in which charging of the drive battery is performed via an inverter, the charging circuit of the drive battery may be an inverter.

[0008] According to the above configuration, the exhaust heat generated by the operation of the inverter or the charging circuit is used to heat the passenger compartment, and the heat into the passenger compartment is released from a heat transfer panel arranged on the inside surface of the passenger compartment. Therefore, heating is performed without using a separate heating means such as a heater for heating or a blowing means such as a fan for generating warm air, eliminating the need for electricity to drive these means and reducing the electricity required to heat the passenger compartment, thereby achieving an extension of the driving range or a reduction in charging time.

[0009] In the above-mentioned system of the present invention, when the heating of the vehicle interior is not performed, a bypass passage that bypasses the heat transfer panel may be provided in the circulating refrigerant passage so that the refrigerant is not circulated through the heat transfer panel, and the refrigerant may be circulated through the bypass passage as needed. For this purpose, a switching valve that selectively switches the flow of the refrigerant may be provided in the circulating refrigerant passage at a branch point (upstream and downstream of the flow) between the flow passage communicating with the heat transfer panel and the flow passage communicating with the bypass passage. Note that, when the heating of the vehicle interior is not performed, a radiator may be provided in the circulating refrigerant passage in a normal manner so that the operating waste heat of the inverter or the charging circuit can be released outside the vehicle as needed to adjust the heating temperature. Furthermore, when the heating of the vehicle interior is not performed, the system of the present invention is for cooling the inverter or the charging circuit, so that a configuration for promoting heat dissipation in the bypass passage, for example, a heat dissipation fin, may be provided. Furthermore, a temperature sensor may be provided at an appropriate location in the vehicle interior to manage the temperature in the vehicle interior and to determine whether or not heating is required, and the temperature in the vehicle interior may be monitored in the system.

[0010] In a vehicle, the rear seats have fewer or are farther away from the air conditioning vents than the front seats, so the interior temperature of the vehicle tends to be lower and the vehicle may not heat up quickly, especially in winter. Therefore, in the system of the present invention, a heat transfer panel is placed on the floor or seat surface of the rear seats, and heating can be performed during charging and driving without using additional electricity for heating, without shortening the cruising distance or extending the charging time, and the cold rear seats in winter can be heated precisely. Effect of the Invention

[0011] Thus, according to the system of the present invention, the interior of the vehicle can be heated without using a separate heating means or a blowing means for generating hot air, and the power required for heating the interior of the vehicle can be reduced accordingly, thereby achieving an extension of the driving range or a reduction in the charging time. Note that the system of the present invention may be used in combination with other heating systems as necessary.

[0012] Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the invention. [Brief description of the drawings]

[0013] [Figure 1] 1A and 1B are schematic plan and side views, respectively, of a vehicle incorporating one aspect of the system of the present embodiment, and 1C and 1D are schematic side views of a vehicle incorporating another aspect of the system of the present embodiment. [Diagram 2] FIG. 2 is a flowchart showing the operation of the system of this embodiment. [Explanation of symbols]

[0014] 1...vehicle, 2...vehicle compartment, 3...front seat, 4...rear seat, 5...inverter, 6...charging circuit, 7...refrigerant circulation path, 7a...panel side flow path, 7b...on-panel (or in-panel) flow path, 7c...bypass path, 8...refrigerant reservoir, 9...circulation pump, 10...radiator, 11...heat transfer panel, 12a, b...switching valve, 13...temperature sensor, 20...controller BEST MODE FOR CARRYING OUT THEINVENTION

[0015] The present invention will now be described in detail with reference to some preferred embodiments thereof with reference to the accompanying drawings, in which like reference numerals indicate like parts.

[0016] System Configuration 1(A) and 1(B), the vehicle heating system of this embodiment is configured to heat the interior 2 of a vehicle 1 (an automobile equipped with a driving battery and capable of being driven by a motor) in which a front seat 3 and a rear seat 4 are arranged, by using exhaust heat from an inverter 5 that sends current to a driving motor (not shown) while the vehicle is being driven or traveling, and by using exhaust heat from a charging circuit 6 for a driving battery (not shown) connected to an external charger while the vehicle's driving battery is being charged. Specifically, in one aspect of the system of this embodiment, a part of a refrigerant circulation path 7, which circulates a refrigerant for cooling the inverter 5 and the charging circuit 6, is configured to pass through a heat transfer panel 11 that heats a part of the interior 2. More specifically, the refrigerant circulation path 7 is piped so that the refrigerant, which may be water, is pumped from a refrigerant reservoir (reservoir tank) 8 by a circulation pump 9 as indicated by the dotted arrow in the figure, passes through the inverter 5 and the charging circuit 6, selectively passes through the panel side flow path 7a and the panel upper flow path 7b or the bypass path 7c, and further passes through a radiator 10 before returning to the refrigerant reservoir 8. Here, the inverter 5 and the charging circuit 6 may be provided with a heat exchange mechanism in any form in the refrigerant circulation path 7, configured to transfer the operation exhaust heat from each of them to the refrigerant in a normal manner. In addition, at the upstream and downstream branch points of the panel side flow path 7a and the bypass path 7c, switching valves 12a, b for switching the flow path of the refrigerant are provided, respectively. As shown in the figure, the panel-side flow path 7a reaches the heat transfer panel 11, where the flow path 7b may be configured to extend over the heat transfer panel 11 in any manner so that the refrigerant dissipates heat, or to penetrate the inside of the heat transfer panel 11. The radiator 10 is a radiator for dissipating to the outside the residual heat that has been absorbed by the refrigerant in the inverter 5 or the charging circuit 6 and has not been dissipated at the heat transfer panel 11, and may be configured to air-cool the refrigerant in a normal manner. (In the figure, as an example, the inverter 5, the refrigerant reservoir 8, the circulation pump 9, and the radiator 10 are arranged in the motor room at the front of the vehicle, and the charging circuit 6 is arranged under the trunk at the rear of the vehicle, but this is not limiting.)

[0017] In the above configuration, the heat transfer panel 11 that dissipates heat into the passenger compartment 2 may be made of any material with high thermal conductivity and may be placed at any location on the passenger compartment interior. In general, the rear seats of a passenger car have fewer air conditioning outlets than the front seats, and the vehicle room temperature is likely to be lower than that of the front seats, so the heat transfer panel 11 may be placed, for example, on the floor of the rear seat 4 as shown in the figure. In such a configuration, when the refrigerant flows into the panel-side flow path 7a and dissipates heat from the heat transfer panel 11, it is expected that the temperature difference between the front and rear seat areas will be reduced, and the comfort of the rear seats will be improved, especially in winter. In addition, by heating the floor surface with a material with high thermal conductivity, it is expected that the passengers in the rear seats will be able to enjoy a comfortable feeling of a cold head and warm feet, and a comfortable feeling like a rock bath or foot bath that warms the feet. When the heat transfer panel 11 is placed on the floor surface, it is formed with a strength that can withstand the weight of the passengers. As another example of the location of the heat transfer panel 11, for example, as shown in FIG. 1(C), the heat transfer panel 11 may be incorporated inside the rear seat 4 (or the front seat 3).

[0018] When heating is not required, the refrigerant flows into the bypass path 7c, and heat is not dissipated from the heat transfer panel 11, and heat absorbed by the refrigerant in the inverter 5 or the charging circuit 6 is dissipated to the outside by the radiator 10. In this regard, as shown in FIG. 1(D), a heat dissipation mechanism such as a heat dissipation fin may be provided in the bypass path 7c so that heat is also dissipated in the bypass path 7c (when heating is not being performed, the system functions solely as a cooling system for the inverter 5 or the charging circuit 6). In that case, the radiator 10 can be appropriately made smaller depending on the heat dissipation capacity of the bypass path 7c.

[0019] The operation control of the circulation pump 9 and the switching control of the switching valves 12a, b between the panel side flow path 7a and the bypass path 7c are executed by the controller 20. The controller 20 may be a normal in-vehicle computer device. The controller 20 is configured to operate the circulation pump 9 to circulate the refrigerant through the refrigerant circulation path 7 when the inverter 5 or the charging circuit 6 needs to be cooled during driving and charging of the vehicle, and to switch the switching valves 12a, b so that the refrigerant flows into the panel side flow path 7a when the vehicle interior is heated, and otherwise flows into the bypass path 7c. The switching of the switching valves 12a, b may be performed by appropriately adjusting the ratio of the refrigerant flow rate between the panel side flow path 7a and the bypass path 7c by finely adjusting the resolution of the valve opening adjustment, and in that case, it is expected that a fine and smooth temperature control is also possible. In order to determine whether or not the vehicle interior needs to be heated, the controller 20 may be provided with a detection value of a temperature sensor 13 that detects the vehicle interior temperature.

[0020] System Operation In the operation of the system of the present embodiment, as already mentioned, when the vehicle interior is not heated, the inverter 5 or the charging circuit 6 is cooled exclusively. In this case, the switching valves 12a and 12b control the refrigerant to flow through the bypass passage 7c, and the operation heat of the inverter 5 is absorbed by the refrigerant while the vehicle is running, and the operation heat of the charging circuit 6 is absorbed by the refrigerant while the vehicle is running, and is dissipated by the radiator 10 (or further by the bypass passage 7c). On the other hand, when the vehicle interior is heated, the switching valves 12a and 12b control the refrigerant to flow through the panel-side passage 7a, and the operation heat of the inverter 5 is absorbed by the refrigerant while the vehicle is running, and is dissipated by the heat transfer panel 11 while the charging is running.

[0021] The switching of the refrigerant flow path may be performed, for example, as shown in Fig. 2. Referring to the figure, when a passenger requests heating (by pressing a heating switch, for example) (step 1) and the temperature inside the vehicle compartment detected by the temperature sensor 13 is below a set temperature that may be appropriately set by the passenger (step 2), the refrigerant flow path is switched to the panel-side flow path 7a (step 3), whereby the refrigerant heated by the inverter 5 or the charging circuit 6 flows over (or inside) the heat transfer panel 11, heating the vehicle compartment. On the other hand, when there is no request for heating (step 1) or there is a request for heating but the temperature inside the vehicle compartment is equal to or higher than the set temperature (step 2), heating is not required, so the refrigerant flow path is switched to the bypass path 7c (step 4), whereby the refrigerant heated by the inverter 5 or the charging circuit 6 is dissipated in the radiator 10 (or further in the bypass path 7c).

[0022] Thus, in the configuration of the present embodiment, the waste heat of the inverter 5 or the charging circuit 6 is used as energy for heating, so energy can be saved compared to using separate electrical energy. In addition, heating is possible even during charging, and if the panel 11 is placed on the rear seat, it is possible to heat the area around the rear seat before getting in, which is cold in winter and takes time to warm up even after driving has started. Furthermore, by saving energy required for heating, it is expected that the cruising distance on a single full charge will be extended, or the charging time will be shortened.

[0023] The above description has been given in relation to the embodiment of the present invention, but it will be apparent to those skilled in the art that many modifications and changes can be easily made thereto, and that the present invention is not limited to the embodiment exemplified above, but can be applied to various devices without departing from the concept of the present invention.

Claims

[Claim 1] A heating system for an electric vehicle, comprising: a refrigerant circulation system including a refrigerant circulation path through which a refrigerant circulates and a refrigerant pump for circulating the refrigerant through the refrigerant circulation path; a heat transfer panel that faces an interior surface of the electric vehicle and a part of the circulating refrigerant path abuts on the heat transfer panel to transfer heat from the refrigerant to the interior of the vehicle; an inverter heat exchanger for radiating waste heat from an inverter for driving a drive motor of the electric vehicle to the refrigerant in the circulating refrigerant passage; a charging circuit heat exchanger that dissipates heat generated by the operation of a charging circuit of a driving battery of the electric vehicle to the refrigerant in the circulating refrigerant path; a heat transfer panel for transferring heat to the electric vehicle interior using heat exhausted from an inverter while the electric vehicle is running, and heat transfer panel for transferring heat to the electric vehicle interior using heat exhausted from an electrical circuit while the electric vehicle is being charged.

Images