Cooling system of a vehicle with a thermoelectric module integrated into the cooling circuit of an internal combustion engine

Abstract

Cooling system of a vehicle, comprising: a first refrigerant line (10) configured to circulate a refrigerant between an internal combustion engine (11) and a first radiator (12), and comprising a main line (13) which is a closed circuit to connect the internal combustion engine (11) to the first radiator (12); a second refrigerant line (20) configured to circulate the refrigerant between a thermoelectric module (21) and a second radiator (22) to generate electricity from heat in an exhaust gas released by the combustion engine (11), and configured to circulate the refrigerant passing through the thermoelectric module (21) to a heating element (15) in a cold start mode; a supply line (30) configured to connect an inlet side of the combustion engine (11) in the first refrigerant line (10) and an inlet side of the thermoelectric module (21) in the second refrigerant line (20) to supply the refrigerant in the first refrigerant line (10) to the second refrigerant line (20); and a return line (40) configured to connect an outflow side of the thermoelectric module (21) in the second refrigerant line (20) and an outflow side of the combustion engine (11) in the first refrigerant line (10) to return the refrigerant in the second refrigerant line (20) to the first refrigerant line (10), the cooling system further comprising: a first pump (16) which is provided on an inflow side of a connection point of the main line (13) and the supply line (30), and a second pump (23) which is provided on an inflow side of a connection point of the second refrigerant line (20) and the supply line (30), wherein in the cold start mode, in which the temperature of the refrigerant passing through the combustion engine (11) is less than a first reference temperature (T1), the first pump (16) supplies some refrigerant to the thermoelectric module (21) through the supply line (30) and the second pump (23) is not operated when the temperature of the refrigerant passing through the combustion engine (11) is less than the first reference temperature (T1).

Description

[0001] The invention relates to a cooling system of a vehicle.

[0002] Generally, a vehicle obtains energy by burning fuel in an internal combustion engine. Here, approximately 30% of the fuel's chemical energy is converted into mechanical energy, and the remainder is released as heat. Specifically, the heat generated by the internal combustion engine is transferred via a refrigerant and released through a radiator or dissipated as exhaust gas.

[0003] Exhaust gas typically releases heat at the highest temperature and is generally discharged to the outside via an exhaust pipe. Accordingly, techniques for recovering waste heat from the exhaust gas have been developed to improve the thermal efficiency of the internal combustion engine.

[0004] Among the technologies is a thermoelectric generator (TEG), which is related to thermoelectric power generation and is a system for generating electrical energy using exhaust gas. For thermoelectric power generation, the TEG should be equipped with a device that recovers heat from high-temperature exhaust gas and generates electricity, and should have a separate low-temperature device to create a temperature difference.

[0005] A low-temperature device of a conventional thermoelectric power generation system, as in Fig. As shown in Figure 1, a separate circuit is formed, or a method is used that is connected to a cooling circuit present in the internal combustion engine. In the case of a separate circuit, the amount of electricity generated increases; however, the heat energy recovered from a high-temperature device of a thermoelectric module cannot be used. In the case of connection to the cooling circuit of the internal combustion engine, the temperature difference between the high-temperature and low-temperature devices decreases because the temperature of the refrigerant flowing into the low-temperature device after passing through the internal combustion engine is relatively high, leading to a reduction in electricity generation. Another conventional vehicle cooling system is known from KR 10 2011 132 678 A.

[0006] The invention creates a vehicle cooling system that is suitable for efficiently generating electricity from a thermoelectric module and improving fuel efficiency.

[0007] This problem is solved by a vehicle cooling system according to claim 1. Further developments are the subject of the dependent claims.

[0008] The invention is explained in more detail with reference to the drawing. The drawing shows: Fig. 1 a diagram that conceptually represents a conventional vehicle cooling system; Fig. 2 a diagram that conceptually represents a cooling system of a vehicle according to an embodiment of the invention; Fig. 3. A diagram illustrating refrigerant circulation when the vehicle's cooling system is off Fig. 2 is in a cold start mode; Fig. 4. A diagram illustrating refrigerant circulation when the vehicle's cooling system is off Fig. 2 is in a power generation maximization mode; Fig. 5 A diagram illustrating refrigerant circulation when the vehicle's cooling system is off Fig. 2 is in a system cooling mode; and Fig. 6. A flowchart illustrating the operation of a control unit of the vehicle's cooling system. Fig. 2 represents.

[0009] It is understood that the term "vehicle" or "vehicle-" or any other similar term as used herein includes general motor vehicles, such as passenger cars, including SUVs, buses, trucks, various commercial vehicles, watercraft, including a variety of boats and ships, aircraft, and the like, as well as hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other vehicles using alternative fuels (e.g., fuels derived from raw materials other than petroleum). As referenced herein, a hybrid vehicle is a vehicle that has two or more sources of propulsion, for example, both a gasoline engine and an electric engine.

[0010] The terminology used herein is solely for the purpose of describing particular embodiments and is not intended to limit the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It is further understood that the terms "has" and / or "having" when used in this description describe the presence of the aforementioned features, integers, steps, processes, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, processes, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed elements.Throughout the description, unless explicitly stated otherwise, the word "exhibit" and variations such as "exhibits" or "indicating" are to be understood as implying the inclusion of the mentioned elements, but not the exclusion of any other elements. Furthermore, the terms "unit," "-er," "-or," and "module," as described, refer to units for processing at least one function and operation and can be implemented by hardware components or software components and combinations thereof.

[0011] Furthermore, the control logic according to the present invention can be configured as a non-perishable, computer-readable medium on a computer-readable medium containing executable program instructions that are executed by a processor, a control unit, or the like. Examples of computer-readable media include, but are not limited to, ROM, RAM, CD-ROMs, magnetic tapes, floppy disks, memory sticks, chip cards, and optical data storage devices. The computer-readable storage medium can also be distributed in network-connected computer systems, so that the computer-readable medium is stored and executed in a distributed manner, e.g., via a telematics server or a control area network (CAN).

[0012] Several embodiments of the invention are described in detail below with reference to the exemplary drawings. When adding reference numerals to the components of each drawing, it is noted that the identical or equivalent component is designated by the same number, even if it is shown in other drawings. Furthermore, when describing the embodiment of the invention, a detailed description of well-known features or functions is omitted in order to avoid unnecessarily obscuring the meaning of the invention. <Grundstruktur des Kühlsystems>

[0013] A cooling system according to one embodiment of the invention relates to a vehicle cooling system. As in Fig. As shown in Figure 2, the cooling system of the vehicle according to an embodiment of the invention has a first refrigerant line 10, a second refrigerant line 20, a supply line 30 and a return line 40. Fig. Figure 2 is a diagram that conceptually represents a vehicle cooling system according to an embodiment of the invention. A high-temperature section of a thermoelectric module 21, i.e., a section through which exhaust gas passes, is shown in Fig. 2 omitted.

[0014] The first refrigerant line 10 can be configured to circulate a refrigerant between an internal combustion engine 11 and a first radiator 12. The refrigerant can be an internal combustion engine coolant. The first radiator 12 can cool the refrigerant by exchanging heat between the air flowing on the outside and the refrigerant on the inside. The first radiator 12 can have a pair of water tanks (e.g., reservoirs), pipes whose ends are attached to the water tanks (e.g., reservoirs) to form a refrigerant passage, and connections arranged between the pipes.

[0015] The second refrigerant line 20 can be configured to circulate the refrigerant between the thermoelectric module 21 and a second radiator 22. The thermoelectric module 21 is a device for generating electricity from heat in an exhaust gas emitted by the internal combustion engine 11. The thermoelectric module 21 can utilize a Seebeck effect, in which an electromotive force is generated when a temperature difference is created at the ends of a metal wire. In the thermoelectric module 21, the exhaust gas can be used as a high-temperature device, and a line through which the refrigerant flows can be used as a low-temperature device. Fig. 2 is the high-temperature device through which the exhaust gas flows, omitted.

[0016] The second radiator 22 can perform a heat exchange in the same way as the first radiator 12.

[0017] The supply line 30 connects an inlet side of the combustion engine 11 in the first refrigerant line 10 with an inlet side of the thermoelectric module 21 in the second refrigerant line 20, in order to supply the refrigerant in the first refrigerant line 10 to the second refrigerant line 20. Here, the inlet side refers to the opposite side of the direction in which the refrigerant flows. Fig. 2 corresponds to the inlet side of the combustion engine 11, which is located on the left side of the combustion engine 11. The refrigerant to be introduced into the combustion engine 11 can flow to the thermoelectric module 21 via the supply line 30.

[0018] The return line 40 connects an outflow side of the combustion engine 11 in the first refrigerant line 10 with an outflow side of the thermoelectric module 21 in the second refrigerant line 20, in order to return the refrigerant in the second refrigerant line 20 to the first refrigerant line 10. Here, the outflow side refers to one side of a direction in which the refrigerant flows. Fig. 2 corresponds to the outflow side of the thermoelectric module 21, an outlet side located on the right side of the thermoelectric module 21. The refrigerant supplied by the supply line 30 and having passed through the thermoelectric module 21 can flow through the first refrigerant line 10 via the return line 40. The return line 40 may have a check valve (not shown) that opens and closes the return line 40.

[0019] The low-temperature device of the conventional thermoelectric module, as in Fig. As shown in Figure 1, the thermoelectric module either forms a separate circuit or uses a method connected to a cooling circuit already present in the internal combustion engine. In the case of a separate circuit, the amount of electricity generated increases, but the heat energy recovered from the high-temperature device of the thermoelectric module cannot be used. When connected to the cooling circuit of the internal combustion engine, the temperature difference between the high-temperature and low-temperature devices decreases because the temperature of the refrigerant flowing into the low-temperature device after passing through the internal combustion engine is relatively high, resulting in a reduction in electricity generation.

[0020] According to the invention, the first refrigerant line 10 can be connected to the second refrigerant line 20 to ensure the efficiency of power generation. For example, if cooling of the combustion engine 11 is not necessary or the cooling requirement is reduced, the cooled refrigerant, which is to be introduced into the combustion engine 11 in the first refrigerant line 10, can be introduced into the second refrigerant line 20 to be used as a low-temperature device of the thermoelectric module 21, thereby enabling efficient power generation. First refrigerant line

[0021] The first refrigerant line 10 can have a main line 13 and a bypass line 14. The main line 13 can be formed in a closed circuit connecting the combustion engine 11 to the first radiator 12. The bypass line 14 can be configured to connect the inlet side to the outlet side of the first radiator 12 in the main line 13, diverting the refrigerant in the main line 13 to a heating element (e.g., a heating core) 15. The heating element 15 is a device with a heating component that heats the vehicle. To heat the vehicle interior, the refrigerant can be circulated along the bypass line 14, which connects the combustion engine 11 to the heater 15, and the refrigerant that recovers heat from the low-temperature device of the thermoelectric module 21 can be introduced into the heater 15 to exchange heat with the air supplied to the vehicle interior.

[0022] The return line 40 can be configured to connect the outflow side of the thermoelectric module 21 in the second refrigerant line 20 with the inflow side of the radiator 15 in the bypass line 14. The refrigerant supplied by the supply line 30 and having passed through the thermoelectric module 21 can flow to the radiator 15 via the return line 40. First pump

[0023] The vehicle's cooling system according to one embodiment of the invention can include a first pump (E / M WP) 16. The first pump 16, located in the main line 13, can be configured to pressurize and transfer the refrigerant in the main line 13. The refrigerant can be pressurized by the first pump 16 such that it circulates through the first refrigerant line 10. The first pump 16 can be an electric pump driven by an electric motor using electric current to pressurize and transfer the refrigerant, or it can be a mechanical pump. The first pump 16 can be located on the inlet side of a connection point between the main line 13 and the supply line 30. Second pump, valve and control unit

[0024] The vehicle's cooling system according to one embodiment of the invention can further comprise a second pump (EWP) 23, a valve 31, and a control device 50. The second pump 23, located in the second refrigerant line 20, can be configured to pressurize and transfer the refrigerant in the second refrigerant line 20. The refrigerant can be pressurized by the second pump 23 such that it circulates through the second refrigerant line 20. The second pump 23 can be an electric pump driven by an electric motor using electric current to pressurize and transfer the refrigerant. The second pump 23 can be located on the inlet side of a connection point between the second refrigerant line 20 and the supply line 30.The second pump 23 allows the refrigerant to circulate in the second refrigerant line 20, enabling it to be introduced into the thermoelectric module 21. Various examples of the valve

[0025] Valve 31 can be provided in the supply line 30 such that it controls whether the supply line 30 is open or closed. Valve 31 can be provided in the supply line 30 such that it is a general-purpose valve that controls whether the supply line 30 is open or closed. Alternatively, valve 31 can be a three-way valve such that it is connected to a point where the supply line 30 and the first refrigerant line 10 meet. On the other hand, valve 31 can be a three-way valve such that it is connected to a point where the supply line 30 and the second refrigerant line 20 meet. Since valve 31 controls whether the supply line 30 is open or closed, valve 31 can also be provided such that it controls whether the first and second refrigerant lines 10 and 20 are connected to each other via the supply line 30.This means that when the supply line 30 is open via the valve 31, the refrigerant from the first refrigerant line 10 can flow into the second refrigerant line 20. When the supply line 30 is closed via the valve 31, the refrigerant in the first refrigerant line 10 cannot flow into the second refrigerant line 20. <Ausführliche Beschreibung der Steuereinrichtung>

[0026] The control unit 50 can be configured to control the second pump 23 and the valve 31 based on the temperature of the refrigerant in the first refrigerant line 10. The control unit 50 can include a processor and memory. The processor can be a microprocessor, such as a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or a central processing unit (CPU). The memory can store instructions that serve as a basis for generating an instruction in the processor to determine whether the valve should be opened or closed. The memory can be a data storage medium, such as a hard disk drive (HDD), a solid-state drive (SSD), a volatile medium, or a non-volatile medium. Control of the control unit

[0027] The following describes the control of the vehicle's cooling system according to one embodiment of the invention. Fig. Figure 3 is a diagram that represents refrigerant circulation when the vehicle's cooling system is in cold start mode. Fig. Figure 4 is a diagram that represents refrigerant circulation when the vehicle's cooling system is in a power generation maximization mode. Fig. Figure 5 is a diagram that represents refrigerant circulation when the vehicle's cooling system is in a system cooling mode. Fig. Figure 6 is a flowchart illustrating the operation of the control device. Control in cold start mode

[0028] The following describes the control system in a cold start mode with reference to the Fig. 3 and Fig. 6 described in detail. Cold start mode means that the refrigerant temperature is lower than a first reference temperature T1 when the refrigerant passes through the combustion engine 11 and is then measured. The first reference temperature T1 can be approximately 80 degrees Celsius. The control unit 50 determines whether cold start mode is present (S101, Fig. 6) When the cold start mode is determined in the control unit 50, the control unit 50 can control the valve 31 so that it is opened, and the second pump 23 can be controlled so that it is not operated (S102, Fig. 6). In Fig. Figure 3 shows a section represented by a bold line; a refrigerant circulation is generated when the cold start mode is detected, and a general flow of the refrigerant required to cool the internal combustion engine is omitted. For example, the refrigerant may flow in the main line 13.

[0029] In cold start mode, some refrigerant that would otherwise be introduced into the combustion engine 11 can be introduced into the thermoelectric module 21 by means of the first pump 16, since cooling of the combustion engine 11 is either unnecessary or the cooling requirement is reduced. Therefore, efficient power generation is possible. In this case, the operation of the second pump 23 can be interrupted to minimize power consumption.

[0030] Furthermore, in the case of cold start mode, the refrigerant passing through the thermoelectric module 21 to recover heat can pass through the heater 15 to assist in heating the interior of the vehicle, and the refrigerant passing through the thermoelectric module 21 to recover heat can pass through the combustion engine 11 to assist in warming up the combustion engine 11. Control in power generation maximization mode

[0031] The control system is subsequently configured in a power generation maximization mode with reference to the Fig. 4 and Fig. 6. The power generation maximization mode exists when the temperature of the refrigerant passing through the combustion engine 11 is greater than the first reference temperature T1 and less than a second reference temperature T2, which is higher than the first reference temperature T1. The second reference temperature T2 can be approximately 105 degrees Celsius.

[0032] The control unit 50 determines whether the power generation maximization mode is active (S201, Fig. 6) When the power generation maximization mode is determined in the control unit 50, the control unit 50 can control the valve 31 so that it closes, and the second pump 23 can be operated (S202, Fig. 6). In Fig. Figure 4 shows a section represented by a bold line, a refrigerant circulation that is newly generated when the power generation maximization mode is determined, and a general flow of the refrigerant required to cool the internal combustion engine is omitted. For example, the refrigerant may flow in the main line 13.

[0033] In power generation maximization mode, the refrigerant from the second refrigerant line 20 can circulate to the thermoelectric module 21, while the refrigerant from the first refrigerant line 10 cannot enter the second refrigerant line 20. In power generation maximization mode, if the refrigerant flowing into the low-temperature section of the thermoelectric module 21 mixes with the refrigerant from the first refrigerant line 10, the power generation efficiency may be reduced because the refrigerant temperature of the first refrigerant line 10 is sufficiently high. Therefore, valve 31 can be opened to prevent the refrigerant from the first refrigerant line 10 from flowing into the second refrigerant line 20.

[0034] Furthermore, in the case of power generation maximization mode, the operation of the second pump 23 can be started to maximize power generation. Control in system cooling mode

[0035] The following describes the control in a system cooling mode with reference to the Fig. 5 and Fig. 6 is described in detail. The system cooling mode exists when the temperature of the refrigerant passing through the combustion engine 11 is greater than the second reference temperature T2, or when the temperature of the refrigerant in the second refrigerant line 20 is greater than the second reference temperature T2, and the temperature of the refrigerant in the second refrigerant line 20 is higher than the temperature of the refrigerant in the first refrigerant line 10. That is, compared to the case of the refrigerant circulating through the second refrigerant line 20, the valve 31 can be opened to introduce the refrigerant into the first refrigerant line 10, and therefore the temperature of the refrigerant introduced into the low-temperature device of the thermoelectric module 21 can be reduced, and the flow rate can be increased.

[0036] The control unit 50 determines whether the system cooling mode is active (S301, Fig. 6) Once the system cooling mode has been determined in the control unit 50, the control unit 50 can control the valve 31 to open, and the second pump 23 can be operated or not operated (S302, Fig. 6). In Fig. Figure 5 shows a section represented by a bold line; a refrigerant circulation is generated when the system cooling mode is determined, and a general flow of the refrigerant required to cool the internal combustion engine is omitted. For example, the refrigerant may flow in the main line 13.

[0037] In system cooling mode, valve 31 can be open, and the control unit 50 can control the second pump 23 to operate, allowing refrigerant from the first refrigerant line 10 to be additionally introduced into the second refrigerant line 20. This cools the refrigerant in the second refrigerant line 20, which flows to the low-temperature section of the thermoelectric module 21. Furthermore, it is possible for more refrigerant than before to flow into the low-temperature section of the thermoelectric module 21. The low-temperature refrigerant can be introduced into the low-temperature section of the thermoelectric module 21 at an increased flow rate, which is advantageous for power generation.If the temperature of the refrigerant flowing into the low-temperature section of the thermoelectric module 21 increases more than necessary due to the refrigerant in the second refrigerant line 20, the control device 50 can interrupt the operation of the second pump 23, provided that the net power does not increase. The net power refers to a value that subtracts the amount of power required to drive the second pump 23 from the amount of power generated by the thermoelectric module 21.

[0038] According to the invention, when cooling of the internal combustion engine is not necessary or the need for cooling is reduced, the refrigerant in the first refrigerant line, which is cooled in order to flow into the internal combustion engine, flows into the second refrigerant line to be used as the low-temperature device of the thermoelectric module, thereby efficiently generating electricity.

[0039] Furthermore, according to the invention, the heat recovered by the low-temperature device of the thermoelectric module can be transferred to the radiator to heat the vehicle's interior. The heat recovered by the low-temperature device of the thermoelectric module can also be transferred to the internal combustion engine to enable rapid engine warm-up, thereby improving fuel efficiency. Reference symbol list 10 first refrigerant line 11 Internal combustion engine 12 first radiator 13 Main line 14 Bypass line 15 radiators 16 first pump 20 second refrigerant line 21 thermoelectric module 22 second radiator 23 second pump 30 Supply line 31 Valve 40 Return line 50 Control unit T1 first reference temperature T2 second reference temperature

Claims

Cooling system of a vehicle, comprising: a first refrigerant line (10) configured to circulate a refrigerant between an internal combustion engine (11) and a first radiator (12), and comprising a main line (13) forming a closed circuit to connect the internal combustion engine (11) to the first radiator (12); a second refrigerant line (20) configured to circulate the refrigerant between a thermoelectric module (21) and a second radiator (22) for generating electricity from heat in an exhaust gas released by the internal combustion engine (11), and configured to circulate the refrigerant passing through the thermoelectric module (21) to a heater (15) in a cold start mode; a supply line (30) configuredthat it connects an inlet side of the combustion engine (11) in the first refrigerant line (10) and an inlet side of the thermoelectric module (21) in the second refrigerant line (20) to supply the refrigerant in the first refrigerant line (10) to the second refrigerant line (20); and a return line (40) configured to connect an outlet side of the thermoelectric module (21) in the second refrigerant line (20) and an outlet side of the combustion engine (11) in the first refrigerant line (10) to return the refrigerant in the second refrigerant line (20) to the first refrigerant line (10), the cooling system further comprising: a first pump (16) provided at an inlet side of a connection point of the main line (13) and the supply line (30), and a second pump (23),which is provided on an inflow side of a connection point of the second refrigerant line (20) and the supply line (30), wherein in the cold start mode, in which the temperature of the refrigerant passing through the combustion engine (11) is less than a first reference temperature (T1), the first pump (16) supplies some refrigerant to the thermoelectric module (21) through the supply line (30) and the second pump (23) is not operated when the temperature of the refrigerant passing through the combustion engine (11) is less than the first reference temperature (T1). Cooling system according to claim 1, wherein the first refrigerant line (10) comprises: a bypass line (14) configured to connect the inflow side with the outflow side of the first radiator (12) in the main line (13) to divert a refrigerant in the main line (13) to the heater (15) for heating the vehicle, wherein the return line (40) is configured to connect the outflow side of the thermoelectric module (21) in the second refrigerant line (20) and an inflow side of the heater (15) in the bypass line (14). Cooling system according to claim 2, further comprising: a valve (31) provided in the supply line (30) such that it controls whether the supply line (30) is open or closed; and a control device (50) configured to control the second pump (23) and the valve (31) based on a temperature of the refrigerant in the first refrigerant line (10). Cooling system according to one of claims 1 to 3, further comprising: a valve (31) configured to control whether the first and second refrigerant lines (10, 20) are to be connected to each other via the supply line (30); and a control device (50) configured to control the valve (31) based on the temperature of the refrigerant in the first refrigerant line (10).

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