Cooling system for at least one electrochemical energy storage device of an electrically powered vehicle

Abstract

Cooling system (100) for at least one electrochemical energy storage device (101) of an electrically powered vehicle (102).

Description

[0001] The invention is based on a cooling system for at least one electrochemical energy storage device of an electrically driven vehicle, a method for operating a cooling system, a device for operating a cooling system and a use of a cooling system according to the preamble of the independent claims. State of the art

[0002] Current cooling concepts for batteries include modules in which the battery cells are mounted on cooling plates, which are water-cooled via a cooling circuit. To improve the cooling effect, the battery cells can be surrounded by cooling hoses.

[0003] After a journey with a heavy load, i.e., a high electrical current, this type of cooling is insufficient for immediate charging, as the battery is too hot. For improved cooling, the entire cooling concept needs to be redesigned; however, the problem of heat dissipation remains, since the cooling systems for batteries, power electronics, and the electric motor are often connected in series.

[0004] Charging can only begin after the battery has cooled down, and this cooling process can take a considerable amount of time. Especially with commercial vehicles, waiting time should be avoided as much as possible, since, for example, a commercial vehicle driver typically has a 45-minute break between driving shifts.

[0005] Furthermore, the batteries are to be fast-charged, meaning with a high electrical current and power, for example, 160 kW up to the MW range, which heats the battery considerably. Therefore, during breaks, the battery is charged as fully as possible using DC fast charging, up to a maximum state of charge (SoC) of 80% to 85%. A state of charge of 100%, especially to achieve maximum capacity and vehicle range, is not possible with a single fast-charging process.

[0006] Therefore, waiting times caused by battery temperature fluctuations at charging stations are fundamentally unacceptable. For commercial vehicles, waiting times, in addition to charging times and traffic-related delays, represent a financial burden, as deadlines must be met, and these are all very tight. Further delays, for example due to cooling processes caused by a necessary charging cycle, are therefore unacceptable. Furthermore, due to the reduced charging time, the battery charge level is insufficient to last until the next break, during which the battery must be recharged.

[0007] According to the state of the art, measures are currently taken such as reducing power a few kilometers before charging stations, which can disrupt traffic flow and prevent pleasant driving, especially when power is reduced and the route includes an uphill gradient.

[0008] Document US 2021 / 384564 A1 discloses a battery pack and a method for externally charging the battery pack. The battery pack may include a charging port configured for charging the battery pack, a cooling circuit configured for cooling the battery pack in a vehicle, and a cooling interface configured for connecting the cooling circuit to an external cooling device outside the vehicle.

[0009] Document US 2015 017 504 A1 discloses a battery module comprising several stacked battery units. Each of the battery units is arranged such that a surface of a heat transfer plate, held by a battery support body formed from an insulating material, faces a main surface of a battery cell.

[0010] The object of the present invention is to further improve the prior art. This object is achieved by the features of the independent claims. Disclosure of the inventionAdvantages of the invention

[0011] In contrast, the inventive method with the characterizing features of the independent claims has the advantage that the cooling system for at least one electrochemical energy storage device of an electrically powered vehicle - a first cooling circuit, which is essentially located within the electrochemical energy storage device; and - a second cooling circuit which is separate from the first cooling circuit and is arranged substantially outside the electrochemical energy store, wherein the second cooling circuit is switched on by an electronic control unit when a charge state of the electrochemical energy store falls below a predetermined target charge state.

[0012] One advantage is that charging can begin immediately after one driving cycle of the electrically powered vehicle, more energy can be charged in a comparable period of time and thus a greater range is available.

[0013] Further advantageous embodiments are the subject of the subclaims.

[0014] According to an advantageous embodiment of the invention, it is provided that the second cooling circuit comprises a coolant tank with coolant, at least one pump for circulating the coolant through hoses of the second cooling circuit, at least one valve, cooling fins and / or cooling plates.

[0015] A further advantage is that the valve includes a multi-way valve, allowing the second cooling circuit to be connected to an external cooling circuit spatially separated from the electrically powered vehicle via at least one connection. This enables heat dissipation during charging, thus allowing the electrochemical energy storage device to be charged with high electrical currents without interruption, for example, due to exceeding temperature limits.

[0016] The first cooling circuit, the second cooling circuit and / or the external cooling circuit are closed cooling circuits.

[0017] Advantageously, the first cooling circuit, the second cooling circuit and / or the external cooling circuit comprise a liquid, for example water with a coolant additive, oil, and / or gaseous coolant, for example carbon dioxide.

[0018] A method according to the invention for operating the cooling system comprises the following steps: a.1) Determining a temperature quantity that represents a temperature of the electrochemical energy storage device; a.2) Comparing the measured temperature with a predetermined target temperature; a.3) Cooling of the electrochemical energy storage device using a first cooling circuit depending on the comparison; b.1) Determining a charge level variable of the electrochemical energy storage device, which represents a charge level of the electrochemical energy storage device; b.2) Comparing the recorded state of charge with a predetermined target state of charge; b.3) Cooling of the electrochemical energy storage device using a second cooling circuit depending on the comparison; c.1) Recording a cooling parameter which represents a connection of the second cooling circuit to an external cooling circuit spatially separated from the electrically powered vehicle for a cooling process; c.2) Comparing the measured cooling capacity with a predetermined target cooling capacity; c.3) Cooling of the electrochemical energy storage device using the second cooling circuit and / or the external cooling circuit depending on the comparison;

[0019] A device according to the invention for operating a cooling system for an electrochemical energy storage device, comprising at least one sensor, at least one switch and at least one means, in particular an electronic battery management control unit, is configured to carry out the steps of the method 6 according to the invention.

[0020] According to an advantageous embodiment of the invention, a computer program is provided comprising commands that cause the device for operating an electrochemical energy storage device to perform the process steps according to the invention.

[0021] Furthermore, a machine-readable storage medium is provided on which the computer program is stored.

[0022] The cooling system according to the invention and / or the method according to the invention for operating the cooling system is used for electrochemical energy storage devices for electric vehicles, fuel cell vehicles, hybrid vehicles, plug-in hybrid vehicles, aircraft, pedelecs or e-bikes. Short description of the characters

[0023] Embodiments of the invention are illustrated in the drawing and explained in more detail in the following description.

[0024] Further advantages and advantageous embodiments of the inventive objects are illustrated by the drawings and explained in the following description. It should be noted that the drawings are for descriptive purposes only and are not intended to limit the invention in any way. Furthermore, the features described below may constitute an object of the invention, individually or in any combination, unless the context explicitly indicates otherwise.

[0025] They show: Fig. 1 a schematic representation of a first embodiment of a cooling system according to the invention; and Fig. 2 a flowchart of an embodiment of a method according to the invention for operating a cooling system. Detailed description of the implementation examples

[0026] The same reference numerals denote the same device components in all figures.

[0027] Fig. 1 shows a schematic representation of a first embodiment of a cooling system 100 according to the invention. An electrochemical energy storage device 101 can be electrically connected by means of electrical connections 105 to a generator and / or consumer spatially separated from the electrochemical energy storage device 101, for example for charging the electrochemical energy storage device 101.

[0028] In the illustrated embodiment, the electrochemical energy storage device 101 is electrically connected to a charging station 118.

[0029] The cooling system 100 for the electrochemical energy storage device 101 of an electrically powered vehicle 102 comprises a first cooling circuit 103, which is essentially located within the electrochemical energy storage device 101. The first cooling circuit 103 includes a coolant tank containing a coolant, a pump for circulating the coolant through hoses of the first cooling circuit 103, which for the sake of clarity are not shown in Fig. 1 are shown.

[0030] The cooling system further comprises a second cooling circuit 104, which is separate from the first cooling circuit 103 and is located essentially outside the electrochemical energy storage device 101, but inside the vehicle 102. The second cooling circuit 104 comprises a coolant tank 107 containing coolant, a pump 108 for circulating the coolant through hoses 110 of the second cooling circuit 104, two valves 109, 116, and cooling fins and plates (not shown) for the efficient dissipation of generated waste heat.

[0031] The electrochemical energy storage device 101 is often located in the same position as the fuel tank in conventionally powered vehicles. The electrochemical energy storage device 101 is enclosed in a housing. Cooling fins can be arranged around this housing to dissipate heat that cannot be carried away by the first cooling circuit 103 and / or the second cooling circuit 104.

[0032] Additionally, cooling hoses 110 can be installed between the cooling fins to enhance heat dissipation. This would also have the advantage that, particularly in summer at high temperatures, the ground temperature is almost twice as high as the specified ambient temperature, and this heat is radiated to the electrochemical energy storage unit 101, allowing for better heat dissipation. If the cooling hoses 110 are located between the cooling fins, they are also better protected against damage, such as from stone chips. In another embodiment, additional cooling plates are installed between individual electrochemical energy storage units 101.

[0033] In the illustrated embodiment, the second cooling circuit 104 is connected by means of the valves 109, 116 via connections 115 to an external cooling circuit 111 spatially separated from the electrically driven vehicle 102. In the illustrated embodiment, the connections 115 are separate from the electrical connections 105. In an alternative embodiment not shown, the electrical connections 105 comprise the connections 115.

[0034] The external cooling circuit 111 comprises a coolant tank 112 with coolant, a pump 113 for circulating the coolant through hoses of the external cooling circuit 111 and a heat exchanger 114 for dissipating heat.

[0035] A control unit 106 is connected to the electrochemical energy storage device 101, the first cooling circuit 103, the second cooling circuit, the first pump 108, the valves 109, 116, the sensor 117, the electrical connections 105 and / or the connections 115 by means of wired, signal lines not shown, and / or wireless connections, in particular to acquire data by means of sensors, for example temperature sensors, and / or to control actuators, for example the pump 108 and / or the valves 109, 116.

[0036] Fig. Figure 2 shows a flowchart of an embodiment of a method according to the invention for operating a cooling system. In step 200, the method is started, for example when the electrically powered vehicle 102 is started.

[0037] In step 201, a temperature variable is detected, for example with the sensor 117, which represents a temperature of the electrochemical energy storage device 101.

[0038] In step 202, the detected temperature value is compared with a predetermined target temperature value, which represents a target temperature of the electrochemical energy storage device 101.

[0039] In step 203, the electrochemical energy storage device 101 is cooled by means of a first cooling circuit 103 if the detected temperature exceeds a predetermined target temperature. Otherwise, the method continues in step 201.

[0040] In step 204, a state of charge variable of the electrochemical energy storage device 101 is detected, which represents a state of charge of the electrochemical energy storage device 101.

[0041] In step 205, the detected state of charge variable is compared with a predetermined target state of charge variable, which, for example, represents a target state of charge of 60% of the electrochemical energy storage device 101.

[0042] The target state of charge is specified for each vehicle and is, for example, 60% of the state of charge of the electrochemical energy storage device. This target state of charge is selected with rapid charging in mind, since these only charge up to approximately 80% of the state of charge of the electrochemical energy storage device 101.

[0043] Values ​​above 60% of the target state of charge only charge the electrochemical energy storage device 101 to a small extent, and a short charging and cooling time is sufficient for this.

[0044] Values ​​below 60% of the target charge level can lead to a delayed start of cooling, as the pause times can change depending on the traffic situation, for example, due to traffic jams or road closures. From this point on, the external cooling circuit 111 supports the first, internal cooling circuit 104 as long as, for example, the ignition is on. With the ignition off, only the first, internal cooling circuit 103 and / or the second cooling circuit 104 continue to run. The external cooling circuit 111 is switched off, as it would place too heavy a load on the electrochemical energy storage device 101.

[0045] In step 206, the electrochemical energy storage device 101 is cooled by means of a second cooling circuit 104 if the detected state of charge value falls below the target state of charge value. Otherwise, the method continues in step 204.

[0046] In step 207, a cooling variable is recorded which represents a connection of the second cooling circuit 104 via connections 115 to an external cooling circuit 111 spatially separated from the electrically driven vehicle 102 for a cooling process.

[0047] In step 208, the detected cooling value is compared with a predefined target cooling value. The target cooling value represents a necessary cooling process of the electrochemical energy storage device 101 by the external cooling circuit 111 in order to be able to charge the electrochemical energy storage device 101, in particular to enable rapid charging.

[0048] In step 209, the electrochemical energy storage device 101 is cooled by means of the second cooling circuit 104 and / or the external cooling circuit 111 if the detected cooling value exceeds the target cooling value. Otherwise, the method continues in steps 201, 204.

[0049] In step 209, the external cooling circuit 111, for example, of a charging station, takes over the cooling of the electrochemical energy storage device 101, whereby a rapid charging process or charging process can advantageously be started immediately. In particular, the spatial arrangement can provide improved heat dissipation.

[0050] Advantageously, mixing of the coolant of the second cooling circuit 104 and the coolant of the external cooling circuit 111 is prevented, since these may be different. If cooling by the external cooling circuit 111 is switched off, for example, by the control unit 106 of the electrically driven vehicle 102 or the charging station, as much of the coolant as possible is removed from the external cooling circuit 111 via a vacuum valve, and the coolant can flow back into the coolant tank 112.

[0051] The method according to the invention can further check, with the external cooling circuit 111 connected, whether a charging process is started in order to avoid having to pump coolant back into the coolant tank 112 even during short breaks without a charging process. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2021 / 384564 A1

[0008] US 2015 017 504 A1

[0009]

Claims

[1] Cooling system (100) for at least one electrochemical energy storage device (101) of an electrically driven vehicle (102), comprising: - a first cooling circuit (103) which is arranged substantially within the electrochemical energy storage device (101); and - a second cooling circuit (104) which is separate from the first cooling circuit (103) and is arranged substantially outside the electrochemical energy store (101), wherein the second cooling circuit (104) is switched on by an electronic control unit (106) when a charge state of the electrochemical energy store (101) falls below a predetermined target charge state. [2] Cooling system (100) according to claim 1, wherein the second cooling circuit (104) comprises a coolant tank (107) with coolant, at least one pump (108) for circulating the coolant through hoses (110) of the second cooling circuit (104), at least one valve (109, 116), cooling fins and / or cooling plates. [3] Cooling system (100) according to one of the preceding claims, wherein the valve (109, 116) comprises a multi-way valve by means of which the second cooling circuit (104) can be connected to an external cooling circuit (111) spatially separated from the electrically driven vehicle (102) via at least one connection (115). [4] Cooling system (100) according to one of the preceding claims, wherein the first cooling circuit (103), the second cooling circuit (104) and / or the external cooling circuit (111) are closed cooling circuits. [5] Cooling system (100) according to one of the preceding claims, wherein the first cooling circuit (103), the second cooling circuit (104) and / or the external cooling circuit (111) comprise a liquid and / or gaseous coolant. [6] Method for operating a cooling system (100) according to one of claims 1 to 5, comprising the following steps: a.1) (201) detecting a temperature variable which represents a temperature of the electrochemical energy storage device (101); a.2) (202) comparing the measured temperature value with a predetermined target temperature value; a.3) (203) cooling the electrochemical energy storage device (101) by means of a first cooling circuit (103) depending on the comparison; b.1) (204) detecting a state of charge variable of the electrochemical energy storage device (101), which represents a state of charge of the electrochemical energy storage device (101); b.2) (205) comparing the detected state of charge variable with a predetermined target state of charge variable; b.3) (206) cooling the electrochemical energy storage device (101) by means of a second cooling circuit (104) depending on the comparison; c.1) (207) detecting a cooling variable which represents a connection of the second cooling circuit (104) to an external cooling circuit (111) spatially separated from the electrically driven vehicle (102) for a cooling process; c.2) (208) comparing the measured cooling quantity with a predetermined target cooling quantity; c.3) (209) cooling the electrochemical energy storage device (101) by means of the second cooling circuit (104) and / or the external cooling circuit (111) depending on the comparison; [7] Device for operating a cooling system (100) for an electrochemical energy storage device (101), comprising at least one sensor (117), at least one switch and at least one means, in particular an electronic battery management control device (106), which are configured to carry out the steps of the method according to claim 6. [8] A computer program comprising instructions causing the apparatus of claim 7 to perform the method steps of claim 6. [9] A machine-readable storage medium on which the computer program according to claim 8 is stored. [10] Use of a cooling system (100) according to one of claims 1 to 5 and / or a method for operating a cooling system (100) according to claim 6 for electrochemical energy storage devices for electric vehicles, fuel cell vehicles, hybrid vehicles, plug-in hybrid vehicles, aircraft, pedelecs or e-bikes.

Images