Electrically driven vehicle with thermal system, and method for operating the vehicle

Abstract

The invention relates to an electrically driven vehicle, comprising at least one radiator (4), a powertrain (5), a battery (21), a cab (16), and a thermal system (1) for heating and / or cooling at least one of the aforementioned components, wherein the thermal system comprises a refrigerant circuit (40), and the heating and / or cooling process is carried out via three coolant circuits. A heating circuit (41), a cooling circuit (41), and a battery circuit (43) are provided by switching two four-way valves (2, 3) and four proportional valves (9, 10, 11, 18).

Description

[0001] Electrically specified vehicle with thermal system and method for operating the vehicle

[0002] The invention relates to an electrically driven vehicle comprising at least one radiator, a drive train, a battery, a cabin and a thermal system for heating and / or cooling at least one of said components, wherein the thermal system comprises a refrigerant circuit.

[0003] The invention also relates to a method for operating an electric vehicle.

[0004] State of the art

[0005] Electric vehicles have three main components: a battery, a powertrain, and a passenger compartment, which must be cooled or heated depending on the power demand and ambient temperatures. Cooling or heating is achieved via a radiator, an air conditioning system, a heat pump system, or a high-voltage PTC (positive temperature coefficient) heater.

[0006] To transport the energy for cooling or heating, the individual components are connected by coolant or refrigerant circuits. There are various system architectures for coolant or refrigerant circuits, which are commonly used in battery-powered electric vehicles. The refrigerant circuit is a central term in the context of heat pump installation and operation. It describes the closed system used in a heat pump to transfer heat from a lower-temperature source to a higher-temperature source. The refrigerant circuit consists of several components, including the evaporator, compressor, condenser, and expansion valve.

[0007] The electrical energy used to cool the battery, powertrain, or passenger compartment of electric vehicles directly impacts the available range. To achieve maximum range, it is important to maximize the efficiency of the cooling system while keeping system costs as low as possible.

[0008] DE 10 2022 123 397 A1 describes a heating, ventilation, and air-conditioning system (HVAC) for a vehicle with a rechargeable energy storage system and a refrigerant circuit through which a refrigerant flow circulates. The refrigerant circuit includes a compressor, an internal condenser, and a radiator heat exchanger of the radiator. A coolant circuit is in fluid communication with the refrigerant circuit and is flowed through by a coolant flow. The coolant circuit includes the radiator, the internal condenser, a heater core, a rechargeable energy storage system, and a three-way coolant valve for selectively directing the coolant flow through the cabin heating / cooling system and / or along a bypass channel to bypass the energy storage system.

[0009] The object of the invention is an electrically powered vehicle with a heating / cooling system that enables the following functions at the lowest possible system cost and with maximum efficiency: waste heat recovery from battery and powertrain waste heat, air heat pump functionality, precise temperature control for the battery, powertrain cooling, cooling, heating, and dehumidification of the passenger compartment, and heat equalization between the passenger compartment, battery, and powertrain. Description of the invention

[0010] The object is achieved with an electrically driven vehicle comprising at least one radiator, a drive train, a battery, a cabin and a thermal system for heating and / or cooling at least one of the said components, wherein the thermal system comprises a refrigerant circuit and the heating and / or cooling takes place via three coolant circuits, wherein a heating circuit, a cooling circuit and a battery circuit are set up via the switching of two four-way valves and four proportional valves.

[0011] This system architecture enables good functionality and efficiency at low system costs.

[0012] By using two cooling circuits for energy transport and one battery cooling circuit, it is possible to recover the maximum amount of waste heat, resulting in good energy efficiency and functionality at the lowest possible system costs. This leads to increased range, CO2 reduction, and lower acquisition costs.

[0013] The refrigerant circuit comprises at least one compressor, an evaporator, a condenser and an expansion valve.

[0014] Advantageously, the refrigerant circuit comprises an accumulator.

[0015] It is advantageous that each of the coolant circuits includes its own pump.

[0016] The cooling circuit includes a first pump, a second four-way valve, the radiator, the drive train, a first four-way valve, the evaporator and a second proportional valve, as well as optionally the cabin heating, ventilation and air conditioning system.

[0017] The heating circuit includes a second pump, the second four-way valve, the first four-way valve, the condenser, a first proportional valve and the cabin heating, ventilation and air conditioning system.

[0018] The battery circuit can be operated separately from the other circuits with a third pump, the battery, the expansion tank and the mixer.

[0019] In combination with the two additional cooling circuits, one for cooling, one for heating, and two four-way valves, it is possible to collect the waste heat from all high-voltage components and also to heat and cool the vehicle.

[0020] Balancing cooling capacity between the battery and the cab results in a cost-effective cooling system with good efficiency and functionality.

[0021] The object is also achieved by a method for operating an electrically powered vehicle, wherein in the battery circuit operating mode the battery conditioning is independent of the two cooling circuits, the heating circuit and the cooling circuit, and in the battery-radiator cooling operating mode the battery is connected to the radiator and the cooling circuit of the drive train and the cooling circuit is switched on when active cooling is required.

[0022] Battery conditioning means heating, cooling or maintaining the actual temperature state of the battery.

[0023] In an advantageous method, the proportional three-way mixing valve is controlled in combination with the pump to control the flow temperature of the coolant and the cooling and heating output by mixing the flow and return of the battery circuit.

[0024] Description of the figures Figure 1 shows a thermal vehicle system,

[0025] Figure 2, Figure 3, Figure 4, Figure 5 and Figure 6 show modifications of the thermal vehicle system.

[0026] Figure 1 shows the concept of a thermal system 1 for an electrically powered vehicle with a heat pump function. The complete thermal system 1 consists of a refrigerant circuit 40 and three connected coolant circuits.

[0027] The refrigerant circuit 40 includes a compressor s, a refrigerant-coolant condenser 6, a first and a second electronic expansion valve 19, 20, a refrigerant-coolant evaporator 7 and a refrigerant-air evaporator 30, which is housed in the heating, ventilation and air conditioning system 17.

[0028] The thermal system 1 has a radiator 4 around which air flows from the outside. The radiator 4 can be designed as a cooling package. The radiator is also equipped with a cooling wheel that can regulate the air flow. The air flow can also be regulated via a so-called shutter system, which is an adjustable louvre flap 34. The radiator circuit is connected to the drive train 5 via a third proportional valve 11. On the inlet side, upstream of the radiator 4, a second four-way valve is installed, while the first four-way valve 2 is installed downstream of the drive train 5 or downstream of the second four-way valve 3. This allows flow through the radiator 4 and the drive train 5 or a bypass of the radiator 4 and the drive train 5.

[0029] The third proportional valve 11 also enables a bypass of the drive train 5. By using the first four-way valve 2 and the second four-way valve 3, the radiator 4 and the drive train 5 can be connected to the heating or cooling circuit 42, 41 and thus used either as a heat source or as a heat sink.

[0030] The coolant circuit of the thermal vehicle system 1 consists of three coolant circuits, a heating circuit 42, a cooling circuit 41 and a battery circuit 43, which have different interactions depending on the valve position.

[0031] The heating circuit 42 includes a second pump 13 that pumps coolant toward the second four-way valve 3. The four-way valve 3 switches the bypass so that the coolant flows to the first four-way valve 2 to enter the condenser 6. Downstream of the condenser 6, a first proportional valve 9 switches the coolant flow to the heating, ventilation, and air conditioning system 17 to heat the cabin 16.

[0032] The cooling circuit 41 comprises a first pump 12, with the second four-way valve 3 switching the cooling flow to the radiator and the drive train. The coolant flow is directed to the evaporator 7 and the second proportional valve 10 via the first four-way valve 2. Depending on requirements, the second proportional valve 10 switches the coolant flow to a mixer 18, from where a battery 21 is supplied with coolant via a third pump 14 or to the heating, ventilation, and air conditioning system 17 to cool the cabin 16. The circuit is closed towards the first pump 2 via an expansion tank 22. The mixer 18 is also a proportional valve, specifically a proportional 3 / 2-way valve.

[0033] The battery circuit 43 can operate almost independently with the third pump 14, the battery 21, the expansion tank 22, and the mixer 18. Depending on the position of the mixer 18, the battery can also be used either as a heat source or as a heat sink. The core of the invention is the use of the proportional three-way valve 18 in combination with the pump 14 to control the coolant flow temperature and the cooling and heating output by mixing the flow (VL) and the return (RL) of the battery circuit 43.

[0034] All components of the powertrain 5 can be either cooled or heated, meaning that waste heat can be utilized for all high-voltage components. This waste heat can be used for cabin or battery heating, resulting in low energy consumption and an increased vehicle range in cold environments. However, heat is generally limited for an electrically powered vehicle, which is why the available heat must be balanced between the battery and the cabin. This is achieved by the mixer 18 in combination with the third pump 14 in the battery circuit 43. This enables precise control of the battery temperature and the heating or cooling output.

[0035] The different operating modes are described below:

[0036] In heat pump mode, the radiator 4 and the drive train 5 are connected to the evaporator 7 via the second four-way valve 3 and the first four-way valve 2 in flow mode, i.e., horizontally continuous in the figure, in order to utilize the energy of the ambient temperature and the waste heat of the drive train 5. The second pump 13 transports the collected heat to the evaporator of the heat pump system of the refrigerant circuit 40. The compressor 8 brings the refrigerant to a higher temperature level. The condenser 6 transfers the heat to the hot cooling circuit 41, and pump 12 transports the heat to the cabin. If necessary, the heat can also be transported to the battery 21. The mixing valve 18 controls the flow temperature and the heating output of the battery coolant by mixing the flow and return flows of the coolant in the battery circuit 43.In cooling mode, the radiator 4 and the drive train 5 are connected to the condenser 6 via the second four-way valve 2 in cross mode.

[0037] Pump 13 ensures a coolant flow through evaporator 7, which heats the coolant. Radiator 4 releases the coolant's heat to the environment and ensures constant coolant inlet temperatures in drive train 5. The coolant from pump 12 flows through evaporator 7 of the refrigerant circuit, and the coolant is cooled. The cold coolant flow can either be completely bypassed by battery 21 or controlled by mixing valve 18 and pump 14. By mixing the supply and return lines of battery 21, the coolant inlet temperature and cooling capacity can be controlled.

[0038] To air condition the passenger compartment, the ambient air is blown through the refrigerant-air evaporator 30 and passed past the cabin heater via air flaps in the heating, ventilation and air conditioning system 17.

[0039] In the battery circuit 43 operating mode, battery conditioning is independent of the two cooling circuits, the heating circuit 42 and the cooling circuit 41. This operating mode can be used for conditions in which the battery 21 needs neither cooling nor heating, but only flushing with coolant. For this purpose, the first proportional valve 9 and the second proportional valve 10 are kept closed while the coolant is circulated by pump 14.

[0040] With battery-radiator cooling, the battery 21 is connected to the radiator 4 and the cooling circuit 41 of the drive train 5. Therefore, the second four-way valve 3 and the first four-way valve 2 are in flow mode, i.e., horizontal in the figure, while the proportional valve 10 is open and pump 12 and pump 14 circulate the coolant. The mixer 18 (proportional 3 / 2-way valve) enables the control of the partial volume flows from the supply line VL and return line RL of the coolant in the battery circuit, to adjust the supply temperature of the coolant via the battery 21. The cooling circuit 40 is switched off. This operating mode can be used for conditions in which battery purging is insufficient, but active cooling by the cooling circuit 40 is not required. In this case, no energy from the high-voltage system is required for battery cooling.

[0041] Figure 2 shows an alternative embodiment. The refrigeration circuit 40 now contains only the compressor 8, the evaporator 7, the condenser 6, and a first electronic expansion valve 19. The cabin with the heating, ventilation, and air conditioning system 17 is connected via the second proportional valve 10 and another valve 28.

[0042] In the cabin, the refrigerant-air cabin heat exchanger is replaced by a cooling air cabin heat exchanger, i.e. by an indirect heat pump system connected to the outlet opening of the second proportional valve 10.

[0043] The cooling air cabin heat exchanger can be bypassed in a bypass 44 via the valve 28.

[0044] Figure 3 shows an embodiment corresponding to Figure 1. However, the two proportional valves 9 and 10 are replaced by shut-off valves, a first shut-off valve 26 and a second shut-off valve 27.

[0045] Figure 4 shows an embodiment corresponding to Figure 2. However, the first and second one-way valves 23 and 24 are replaced by a first shut-off valve 31 and a second shut-off valve 32. As can also be seen, an accumulator 33 is arranged between the refrigerant-coolant evaporator 7 and the compressor s in the refrigerant circuit. The compressor 3 has a low-pressure inlet 8a on the low-pressure side, i.e., the evaporator side, and a high-pressure outlet 8b on the high-pressure side, i.e., the condenser side. Via the valve 29, the high-pressure outlet 8b of the compressor 8 can be recirculated to the accumulator 33 in a hot gas bypass. The air inlet is regulated by a so-called shutter system, which is formed by adjustable louvre flaps 34.

[0046] Figure 5 shows an embodiment that essentially corresponds to Figure 4, but replaces the drive train 5 with the electric motor 5.2 of the electric vehicle's drive train and additionally integrates the inverter 5.1 in a coolant circuit between the radiator 4 and the third proportional valve 11. This allows the flow of cooling water through the electric motor 5.2 through the proportional valve 11, and thus also the cooling, to be reduced.

[0047] Figure 6 shows an embodiment that essentially corresponds to Figure 1, but the first and second one-way valves 23 and 24 are replaced by a first shut-off valve 31 and a second shut-off valve 32. As can also be seen, an accumulator 33 is arranged between the refrigerant-coolant evaporator 7 and the compressor s in the refrigerant circuit. The compressor 8 has a low-pressure inlet 8a on the low-pressure side, i.e., the evaporator side, and a high-pressure outlet 8b on the high-pressure side, i.e., the condenser side. Via the valve 29, the high-pressure outlet 8b of the compressor 8 can be recirculated to the accumulator 33 in a hot gas bypass. The air inlet is regulated by a so-called shutter system, which is formed by adjustable louvre flaps 34.

[0048] A further difference from the embodiment of Figure 1 is that the drive train 5 is replaced by the electric motor 5.2 of the electric vehicle's drive train, and the inverter 5.1 is also integrated into a coolant circuit between the radiator 4 and the third proportional valve 11. This allows the flow of cooling water through the electric motor 5.2 through the proportional valve 11, and thus also the cooling, to be reduced. Reference numeral

[0049] 1 Thermal system

[0050] 2 first four-way valve

[0051] 3 second four-way valve

[0052] 4 Radiators

[0053] 5 Drivetrain

[0054] 5.1 Inverter

[0055] 5.2 Electric motor

[0056] 6 Capacitor

[0057] 7 evaporators

[0058] 8 Compressor

[0059] 9 first proportional valve

[0060] 10 second proportional valve

[0061] 11 third proportional valve

[0062] 12 first pump

[0063] 13 second pump

[0064] 14 third pump

[0065] 15 HVAC Radiator (cold)

[0066] 16 HVAC Radiator (warm)

[0067] 17 Heating, ventilation and air conditioning system

[0068] 18 Mixer / proportional 3 / 2 way valve first electronic expansion valve second electronic expansion valve battery expansion tank first one-way valve second one-way valve air bypass first shut-off valve second shut-off valve valve valve refrigerant-air evaporator first shut-off valve second shut-off valve accumulator shutter system / louvre dampers refrigerant circuit cooling circuit heating circuit battery circuit bypass

Claims

Claims 1 . Electrically powered vehicle comprising at least one radiator (4), a drive train (5), a battery (21), a cabin (16) and a thermal system (1) for heating and / or cooling at least one of said components, wherein the thermal system comprises a refrigerant circuit (40) and the heating and / or cooling takes place via three coolant circuits, wherein a heating circuit (42), a cooling circuit (41) and a battery circuit (43) are set up via the switching of two four-way valves (2, 3) and four proportional valves (9, 10, 11, 18).

2. Electrically driven vehicle according to claim 1, characterized in that the refrigerant circuit (40) comprises at least one compressor (8), one evaporator (7), one condenser (6) and one expansion valve (19) and preferably one accumulator (33).

3. Electrically powered vehicle according to claim 1 or 2, characterized in that each of the coolant circuits comprises its own pump.

4. Electrically driven vehicle according to one of the preceding claims, characterized in that the cooling circuit (41) comprises a first pump (12), a second four-way valve (3), the radiator (4), the drive train (5), a first four-way valve (2), the evaporator (7) and a second proportional valve (10) and optionally the heating, ventilation and air conditioning system (17) of the cabin (16).

5. Electrically driven vehicle according to one of the preceding claims, characterized in that the heating circuit (42) comprises a second pump (13), the second four-way valve (3), the first four-way valve (2), the condenser (6), a first proportional valve (9) and the heating, ventilation and air conditioning system (17) of the cabin (16).

6. Electrically driven vehicle according to one of the preceding claims, characterized in that the battery circuit (43) with a third pump (14), the battery (21), the expansion tank (22) and the mixer (18), preferably a proportional 3 / 2-way valve, can be operated separately from the other circuits, wherein the mixer (18) in combination with the pump (14) is provided for controlling the flow temperature of the coolant of the battery and the cooling and heating power by mixing the flow and the return of the battery circuit (43).

7. Method for operating an electrically driven vehicle according to claims 1 to 6, characterized in that in the battery circuit operating mode the battery conditioning is independent of the two cooling circuits, the heating circuit (42) and the cooling circuit (41) and in the battery-radiator cooling operating mode the battery (21) is connected to the radiator (4) and the cooling circuit (41) of the drive train (5) and when active cooling is required the cooling circuit (40) is switched on.

8. A method for operating an electrically powered vehicle according to claim 7, characterized in that in the operating mode of the battery circuit, the control of the flow temperature of the coolant for conditioning the battery (21) is carried out by regulating and mixing the inlets by the mixer (18), preferably the proportional three-way valve, in combination with the pump (14).

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