Temperature control device comprising a pump with a cooling jacket surrounding a motor chamber

Abstract

Device for tempering an object (10), comprising a storage container (12) for a liquid medium, a heat exchanger structure (14) for heat exchange between the medium and the object (10), and a pump (16) driven by an electric motor for circulating the medium between the storage container (12) and the heat exchanger structure (14), characterized in that the pump (16) is arranged in relation to the storage container (12) such that it is immersed in the medium in the storage container with a suction nozzle (32), and that the motor (48) is housed in a motor chamber (50) which is integrated into a housing (30) of the pump and is surrounded by the pumped medium.

Description

[0001] The invention relates to a device for temperature control of an electric vehicle battery, comprising a storage container for a liquid medium that can be filled to a maximum liquid level, a heat exchanger structure for heat exchange between the medium and the battery, and a pump driven by an electric motor for circulating the medium between the storage container and the heat exchanger structure.

[0002] Devices of this type are used, for example, to cool and / or heat lithium-ion cells and the like in electric vehicles.

[0003] Batteries that provide propulsion energy in vehicles generate so much heat at times due to rapid charging and discharging processes that they require active cooling. Conversely, in certain situations, it may also be necessary to heat such batteries to maintain their operating temperature within an optimal range.

[0004] The medium used to regulate the battery temperature can be, for example, a mixture of water and glycol with suitable corrosion inhibitors. However, other types of coolants, such as thermal oil, electrically non-conductive fluids, and the like, can also be used. Depending on the required cooling capacity, the medium can also be brought into thermal contact with a refrigerant from a compressor-based refrigeration unit.

[0005] An example of a known temperature control device of this type is described in DE 20 2019 131 386 A1. The storage tank and the heat exchanger structure are connected by a piping system to form a closed circuit in which the medium is circulated by a pump located outside the storage tank. Typically, seal-free centrifugal pumps are used, for example, magnetically coupled pumps or canned motor pumps.

[0006] From DE 91 01 888 U1 a device for tempering process water for a printing press is known, which has a storage tank for a liquid medium, a heat exchanger structure for heat exchange between the medium and the object, and a pump driven by an electric motor for circulating the medium between the storage tank and the heat exchanger structure, and in which the pump is arranged in relation to the storage tank such that its pump shaft runs vertically and it is immersed in the medium in the storage tank with a suction nozzle.

[0007] Pump systems are known from DE 601 26 061 T2, JP S53 97402 U, JP S50 97 U, CN 206 092 447 U and US 3 748 066 A in which the motor is housed in a motor chamber integrated into a pump casing and surrounded by the pumped medium. In some cases, the motor chamber is located above the maximum fluid level of the medium in the storage tank.

[0008] The object of the invention is to create a temperature control device that is characterized by small space requirements and low weight and is therefore particularly suitable for use in vehicles.

[0009] This problem is solved according to the invention by a device according to claim 1.

[0010] The heat transfer medium is thus used not only to regulate the battery temperature but also to cool the pump's drive motor. This allows for the use of a compact motor that is nevertheless suitable for high pumping capacities. Because the pump's suction port is immersed directly in the medium within the storage tank, leak-prone and space-consuming lines and connections between the storage tank and the pump are eliminated. Furthermore, the installation space is reduced even further, as at least parts of the pump are located within the storage tank. Since the motor chamber is situated in the upper part of the pump housing, above the fluid level, a reliable seal between the motor chamber and the rotor-supporting section of the shaft is significantly simplified.

[0011] In this pump, the pumped medium is guided through the cooling jacket in such a way that it flows circumferentially around the electric motor. From the discharge port, the medium splits into two streams that flow around the motor chamber in opposite directions and rejoin at the discharge port. This design has the advantage that the discharge port can be kept very short, since the medium does not need to be distributed around the circumference of the motor chamber before entering the cooling jacket. No further deflection of the medium is required at the discharge port either, so that (with vertical mounting) the overall height can be considerably reduced. Due to the low profile of the unit consisting of the storage tank and pump, the temperature control device can, for example, be positioned on the roof of a vehicle or even underneath it.

[0012] Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0013] The pressure port enters the lower end of the cooling jacket, while the outlet port is preferably arranged radially at the upper end of the cooling jacket, so that the flow of the medium in the cooling jacket also has an upward component. This prevents the formation of zones with low fluid exchange in the cooling jacket and simultaneously facilitates venting of the pump. An exemplary embodiment is explained in more detail below with reference to the drawing.

[0014] They show: Fig. 1 a schematic diagram of a temperature control device according to the invention; Fig. 2 an axial section through a pump in a storage tank of the temperature control device; and Fig. 3 a section along line III-III in Fig. 2 .

[0015] In Fig. 1 A schematic representation of a temperature control device for a battery (10) of an electric vehicle is shown. The essential components of the temperature control device are a storage container 12 for a liquid, heat-conducting medium (e.g., coolant or thermal oil), a heat exchanger structure 14 for heat exchange between the medium and the battery 10, and a pump 16 with which the medium is circulated in a closed circuit between the storage container 12 and the heat exchanger structure 14.

[0016] In the example shown, the storage container 12 is a hermetically sealed container filled with the liquid medium to such an extent that a gas space 20 remains above the liquid level 18, in which the pressure can be controlled by a pressure relief and venting valve 22. In another embodiment, the container can also be open to the atmosphere.

[0017] In addition, the storage container 12 in this example also has an electric heater 24, which can be used to maintain the temperature of the medium and thus also the temperature of the battery 10 above a certain minimum temperature.

[0018] Optionally, the temperature control device can also have an active cooling function, whereby the cooling energy is generated outside the tank by a heat exchanger (e.g., a free cooler consisting of an air / liquid cooler with a fan or an active refrigeration compressor module) and is transferred to the medium inside the tank via a second heat exchanger in the form of an integrated cooling coil or cooling plates, either inside or outside the tank. If this second heat exchanger is located outside the tank, it is integrated into the hydraulically circulating medium in such a way that the medium circulates through this second heat exchanger, thus achieving energy exchange.

[0019] The pump 16 has a housing 30 which is mounted on or in the storage tank 12 such that a suction nozzle 32 of the pump is immersed in the medium in the storage tank, while a motor chamber 50 integrated into the housing is located above the liquid level 18.

[0020] In Fig. 2 and 3 Pump 16 is shown in more detail.

[0021] The housing 30 forms the suction port 32 at its lower end and a pump chamber 34 further upstream. A shaft 36 is rotatably mounted in the housing 10 and carries at least one impeller 38 within the pump chamber 34. In the example shown, a cascade of three axial impellers is provided, which convey the medium drawn in via the suction port 32 into a pressure line 40 that extends from the upper end of the pump chamber 34 in a position radially offset from the shaft 36.

[0022] The pump 16 is mounted in the storage tank 12 such that the axis of the shaft 36 is vertically oriented and the opening of the suction port 32 is located close to the bottom 44 of the storage tank. The lower part of the pump, which forms the suction port 32, the pump chamber 34, and the lower part of the discharge port 40, is immersed in the medium, while the upper part of the pump is located above the liquid level 18. This upper part of the housing 30 accommodates an electric motor 48, which is thus better protected against the harmful effects of the pumped medium.

[0023] The shaft 36, with its section lying above the liquid level 18, is axially fixedly mounted in the housing 30 by means of rolling bearings 49 and passes through the motor chamber 50, which is closed at its upper end by a cover 52. A rotor 54 of the electric motor is arranged rotationally fixed on the shaft 36 within the motor chamber 50 and is surrounded by a stator 56, which is held stationary in the motor chamber 50 and is in thermal contact with a circumferential wall 58 of the motor chamber via its outer circumferential surface.

[0024] The motor chamber 50 is surrounded over most of its height by a cooling jacket 60, the walls of which are formed in one piece with the circumferential wall 58 of the motor chamber. The cooling jacket 60 has an overall cylindrical shape and forms an annular chamber 62. The pressure line 40 opens at a first circumferential position A, on the right into Fig. 2 , into the lower end of the annular chamber 62. In one of the first circumferential positions A, diametrically opposite circumferential position B, on the left in Fig. 2 , a radially outward outlet nozzle 64 is connected to the upper end of the cooling jacket 60, through which the medium pumped by the pump enters a delivery line leading to the battery 10.

[0025] When the pump is in operation, the fluid is drawn in via the suction port 32 and forced through the pressure port 40 into the annular chamber 62 of the cooling jacket 60. In the first circumferential position A, the flow of the medium splits into two branches that flow around the motor chamber 50 in opposite directions and rejoin in the circumferential position B, as shown in Fig. 3 indicated by arrows.

[0026] The medium flowing through the annular chamber 62 forms a closed fluid body around the pump motor, which is not interrupted by any sound bridges, thus achieving good sound insulation and therefore very quiet operation of the pump.

[0027] In an embodiment not corresponding to the invention, the opening of the pressure line 40 and the transition to the outlet nozzle could also be located close together and separated by a partition.

[0028] The cooling jacket 62 can be dimensioned in height so that the winding packages of the stator 56 are specifically cooled.

[0029] How Fig. 2As shown, the motor chamber 50, which also houses the rolling bearings 49, is sealed against the interior of the storage tank 12 by a shaft seal 66. Optionally, the pump can have a level sensor and an electronic control unit that detects the liquid level 18 and regulates it so that it always remains safely below the position of the shaft seal 66.

[0030] In this example, the circumferential wall of the pump chamber 34 is formed by three stacked and sealed ring modules 68, each accommodating one of the impellers 38. The intake port 32 is formed by a separate housing section connected to the rest of the housing by tie rods 70. This allows the ring modules to be clamped tightly and securely together. After loosening the tie rods 70 and removing the intake port 32, the number of ring modules 68 and impellers 38 can be varied as required or according to the available installation height.

Claims

1. A device for temperature control of a battery (10) of an electric vehicle, comprising a storage tank (12) for a liquid medium that can be filled up to a maximum liquid level, a heat exchanger structure (14) for heat exchange between the medium and the battery (10), and a pump (16) driven by an electric motor (48) for circulating the medium between the storage container (12) and the heat exchanger structure (14), wherein the pump (16) is arranged in relation to the storage tank (12) such that its pump shaft (36) runs vertically and the pump is immersed in the medium in the storage tank with a suction nozzle (32), the motor (48) is housed in a motor chamber (50) which is integrated into a housing (30) of the pump and is surrounded by the pumped medium, the motor chamber (50) is located above a maximum liquid level (18) of the medium in the storage tank (12), characterized in that the pump (16) has a cooling jacket (60) surrounding the motor chamber (50), the cooling jacket has an overall cylindrical shape and forms an annular chamber (62) and is in fluid communication on the one hand with a pump chamber (34) via a pressure connection (40) and on the other hand with an outlet connection (64), and that the pressure connection (40) opens into the cooling jacket (60) in a first circumferential position (A) and the outlet connection (64) is connected to the cooling jacket (60) in a second circumferential position (B) diametrically opposite the first circumferential position.

2. The device according to claim 1, wherein the outlet connection (64) extends radially from the cooling jacket (60).

3. The device according to claim 1 or 2, wherein the outlet connection (64) is arranged at the axial end of the cooling jacket (60) opposite to the pump chamber (34).

4. The device according to one of claims 1 to 3, wherein a peripheral wall of the pump chamber (34) is formed by a plurality of ring modules (68) that can be detached from one another, and a plurality of impellers (38) are detachably held on a shaft (36).

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