Description:TECHNICAL FIELD
[001] Embodiments herein generally relate to thermal management systems in vehicles, and more specifically related to an integrated de-gassing tank assembly for an electric vehicle. Further, embodiments herein relate to a method of operating the integrated de-gassing tank assembly for thermal management of a battery pack in the electric vehicle.

BACKGROUND
[002] A battery thermal management system (BTMS) plays a major role in controlling the thermal behaviour of a battery pack in an electric vehicle. Examples of the BTMS technologies are, but not limited to, an air-cooling system, a liquid-cooling system, a direct-refrigerant cooling system, and a thermo-electric cooling system as well as heating. These systems (i.e., air-cooling system, liquid-cooling system, direct-refrigerant cooling system, and thermo-electric cooling system) are analyzed through a trade-off between performance, weight, size, cost, reliability, safety and energy consumption.
[003] Most electric vehicles that use liquid cooling systems, have two cooling circuits. The first cooling circuit is an electric power train (EPT) cooling circuit, and the second cooling circuit is a battery pack cooling circuit. As part of the battery thermal management system, a battery pack should operate ideally in between 25°C to 35°C. Fig. 1a illustrates a conventional battery thermal management circuit of the electric vehicle in a battery pack heating condition in which hot coolant flows from the EPT cooling circuit to the battery pack cooling circuit by combining both the EPT cooling circuit and the battery pack cooling circuit for heating the battery pack. Fig. 1b illustrates the conventional battery thermal management circuit in a battery pack cooling condition in which the coolant flows in the battery pack cooling circuit for cooling the battery pack. The battery pack cooling condition will be referred to herein as an independent loop circuit and the battery pack heating condition will be referred to herein as a combined loop circuit. In the battery pack cooling condition (i.e., independent loop circuit), both EPT and the battery pack cooling circuits will work independently.
[004] Referring to FIG. 1a and FIG. 1b, the EPT cooling circuit and the battery pack cooling circuit include cooling system components and electronic components, where the cooling system components and the electronic components are configured to drive the electric vehicle (EV). The cooling system components are configured to cool the electronic components to perform a deserved function in the electric vehicle. The EPT cooling circuit includes multiple components like a de-gassing tank (DG tank), a water pump (WP), a low temperature radiator (LTR) and valves which will help to maintain the desired temperature (i.e., 50-60°C) of electronic components in the EPT cooling circuit. The battery pack cooling circuit includes multiple components like a de-gassing tank (DG tank), a water pump (WP), a chiller and valves which will help to maintain the desired temperature (i.e., 25-35°C) of the battery pack in the battery pack cooling circuit.
[005] In the EPT cooling circuit, the de-gassing tank (DG tank) is used for coolant storage and the water pump (WP) is used to circulate the coolant within the EPT cooling circuit. The low temperature radiator (LTR) is used to dissipate the heat from the EPT cooling circuit to an atmosphere. The 3-way direction control valve is used to change the direction of the coolant as per need. A direct current-direct current (DC-DC) converter is used to convert power from a high voltage (HV) bus to a 12V Low Voltage (LV) bus to charge the battery pack and power on-board electronic devices. A traction control unit/motor (TCU) is used to drive the electric vehicle. An on-board charger (OBC) is used to charge the battery pack.
[006] The battery pack cooling circuit includes the cooling system components such as the de-gassing tank (DG tank) and the water pump (WP) which are similar to the EPT cooling circuit. The chiller is used to cool the battery pack. The battery pack includes a plurality of cell modules which store and discharge a low voltage energy to drive the electric vehicle.
[007] The EPT cooling circuit and the battery pack cooling circuit are combined by using flow control valves like 3-way or 4-way electronic valves. The flow control valves are controlled by a controller through various logics. Further, conventional battery thermal management circuit includes individual de-gassing tanks, electronic components, valves and connections for combining the EPT cooling circuit and the battery pack cooling circuit. If the 3-way or 4-way electronic valve requires the logics and the controller operates the 3-way or 4-way electronic valve, the EPT cooling circuit and the battery pack cooling circuit will have more hose connections and T-joints to connect the de-gassing tank and the valves. The current EPT cooling circuit and the battery pack cooling circuit have two coolant valves to combine the EPT cooling circuit and the battery pack cooling circuit. The valves will actuate based on a heating requirement from the battery pack cooling circuit (battery box cooling circuit). The conventional battery thermal management circuit is bulk (large) in size and complex to operate and incurs high cost.

OBJECTS
[008] The principal object of the embodiments herein is to provide an integrated de-gassing tank assembly for a vehicle (e.g., electric vehicle or the like).
[009] Another object of the embodiments herein is to provide a method of operating the integrated de-gassing tank assembly for thermal management of a battery pack in the electric vehicle.
[0010] Another object of the embodiments herein is to provide the integrated de-gassing tank assembly (e.g., electric vehicle or the like) for storage of coolant, and for connecting an electric power train cooling circuit with a battery pack cooling circuit in the vehicle.

BRIEF DESCRIPTION OF FIGURES
[0011] Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0012] FIG. 1a shows a schematic arrangement of a battery thermal management circuit of an electric vehicle in a battery pack heating condition, according to prior art;
[0013] FIG. 1b shows a schematic arrangement of the battery thermal management circuit in a battery pack cooling condition, according to prior art;
[0014] FIG. 2a shows a schematic arrangement of battery thermal management circuit, according to embodiments as disclosed herein;
[0015] FIG. 2b depicts a top view of a de-gassing tank outer shell including mounting members, and ports to connect an electric power train (EPT) cooling circuit and a battery pack cooling circuit, according to embodiments as disclosed herein;
[0016] FIG. 3 depicts an exploded view of an integrated de-gassing tank assembly, according to embodiments as disclosed herein;
[0017] FIG. 4 depicts a sectional view of the integrated de-gassing tank assembly showing a thermostat valve and a non-return valve (NRV) in a battery pack heating condition, according to embodiments as disclosed herein;
[0018] FIG. 5 depicts detail A of fig. 4, where detail A illustrates detailed view of the thermostat valve and the NRV in the battery pack heating condition, according to embodiments as disclosed herein;
[0019] FIG. 6 depicts a sectional view of the integrated de-gassing tank assembly showing thermostat valve and the NRV in a battery pack cooling condition, according to embodiments as disclosed herein;
[0020] FIG. 7 depicts detail B of fig. 6, where detail B illustrates detailed view of the thermostat valve and the NRV in the battery pack cooling condition, according to embodiments as disclosed herein; and
[0021] Fig. 8 depicts a flowchart indicating steps of a method for operating the integrated de-gassing tank assembly for thermal management of a battery pack in an electric vehicle, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0022] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0023] Embodiments herein disclose a single integrated de-gassing tank assembly for both battery pack cooling circuit and electric powertrain (EPT) cooling circuit of an electric vehicle. Referring now to the drawings, and more particularly to FIGS. 2a through 8, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0024] FIG. 2a shows a schematic arrangement of a battery thermal management circuit of the electric vehicle, according to embodiments as disclosed herein. The battery thermal management circuit includes a battery pack cooling circuit (2) and an electric powertrain (EPT) cooling circuit (3). In an embodiment, the battery pack cooling circuit (2) and the EPT cooling circuit (3) are coupled with an integrated de-gassing tank assembly (1). The battery pack cooling circuit (2) is adapted to maintain the desired temperature (25-35°C) of the battery pack (5) in the battery pack cooling circuit (2). The battery pack cooling circuit (2) includes a water pump (WP) (4), a battery pack (5) and a chiller (6), which are connected with hoses and connections (not shown). The EPT cooling circuit (3) assists in maintaining the desired temperature (50-60°C) of the electronic components in the EPT cooling circuit (3). The EPT cooling circuit (3) includes a water pump (WP) (7), a direct current- direct current (DC-DC) converter (8), a traction control unit (TCU) (9), an onboard charger (OBC) (10) and a low temperature radiator (LTR) (11). FIG. 3 depicts an exploded view of the integrated de-gassing tank assembly (1), according to embodiments as disclosed herein. In an embodiment, the integrated de-gassing tank assembly (1) includes a de-gassing tank outer shell (13), a thermostat valve ((20T), as shown in fig. 3), a non-return valve (NRV) ((25V), as shown in fig. 3), a first regulating valve (12A) and a second regulating valve ((12B), as shown in fig. 3, fig. 4 and fig. 6). For the purpose of this description and ease of understanding, the integrated de-gassing tank assembly (1) is explained herein with below reference to thermal management of the battery pack (5) in the electric vehicle. However, it is also within the scope of the invention to use/practice the integrated de-gassing tank assembly (1) for thermal management of power source (engine or battery) in electric hybrid vehicles or any other vehicles or industrial machines, where thermal management of power source (engine or battery) is required, without otherwise deterring the intended function of the integrated de-gassing tank assembly (1) as can be deduced from the description and corresponding drawings.
[0025] The de-gassing tank outer shell (13) is adapted to accommodate or house the thermostat valve (20T) and NRV (25V) therein. Further, the de-gassing tank outer shell (13) is adapted to mount the first regulating valve (12A) and the second regulating valve (12B) thereon. The de-gassing tank outer shell (13) is a split-type de-gassing tank outer shell having a first de-gassing tank outer shell (not shown) and a second de-gassing tank outer shell (not shown) which are secured to each other to form the de-gassing tank outer shell (13). The de-gassing tank outer shell (13) includes a first inlet port ((14), as shown in fig. 3 and fig. 4), a second inlet port ((16), as shown in fig. 3 and fig. 4), a first outlet port ((15), as shown in fig. 3 and fig. 4), a second outlet port ((17), as shown in fig. 3 and fig. 4) and an insulated partition wall ((18), as shown in fig. 3 to fig. 7). The first inlet port (14) of the de-gassing tank outer shell (13) is adapted to be coupled with the battery pack cooling circuit (2). The first inlet port (14) is adapted to facilitate entry of coolant from the chiller (6) of the battery pack cooling circuit (2) to a battery pack coolant chamber ((13A), as shown in fig. 4) defined in the de-gassing tank outer shell (13). The battery pack coolant chamber (13A) is in coolant communication with the battery pack cooling circuit (2) via the first inlet port (14) and the first outlet port (15). The first inlet port (14) is opposite to the second inlet port (16). The first inlet port (14), the NRV valve (25V) and the second inlet port (16) are co-axial to each other. The second inlet port (16) of the de-gassing tank outer shell (13) is adapted to be coupled with the electric powertrain (EPT) cooling circuit (3). The second inlet port (16) is adapted to facilitate entry of hot coolant from the LTR (11) of the EPT cooling circuit (3) to a EPT coolant chamber ((13B), as shown in fig. 4) defined in the de-gassing tank outer shell (13). The EPT coolant chamber (13B) is in coolant communication with the EPT cooling circuit (3) via the second inlet port (16) and the second outlet port (17). The first outlet port (15) of the de-gassing tank outer shell (13) is adapted to be coupled with the battery pack cooling circuit (2). The first outlet port (15) is adapted to facilitate exit of coolant from the battery pack coolant chamber (13A) of the de-gassing tank outer shell (13) to the WP (4) of the battery pack cooling circuit (2). The first outlet port (15) is parallel and spaced apart from the second outlet port (17). The second outlet port (17) of the de-gassing tank outer shell (13) is adapted to be coupled with the EPT cooling circuit (3). The second outlet port (17) is adapted to facilitate exit of coolant from the EPT coolant chamber (13B) of the de-gassing tank outer shell (13) to the WP (7) of the EPT cooling circuit (3). The insulated partition wall (18) is integrated inside the de-gassing tank outer shell (13) to separate the battery pack coolant chamber (13A) and the EPT coolant chamber (13B) in the de-gassing tank outer shell (13) thereby separating the EPT cooling circuit (3) and the battery pack cooling circuit (2) in the integrated de-gassing tank assembly (1). At least one of a non-return valve and a pressure relief valve is integrated in the first inlet port (14), the first outlet port (15), the second inlet port (16) and the second outlet port (17). Further, the de-gassing tank outer shell (13) includes a plurality of mounting members ((13M), as shown in fig. 2b) adapted to facilitate mounting of the integrated de-gassing tank assembly (1) in the vehicle. The thermostat valve (20T) is adapted to be located inside the de-gassing tank outer shell (13). The thermostat valve (20T) is mounted onto the insulated partition wall (18) of the de-gassing tank outer shell (13). The thermostat valve (20T) includes a thermostat housing ((19), as shown in fig. 3 to fig. 7), a thermostat plunger ((20), as shown in fig. 3 to fig. 7), a temperature responsive medium (not shown), a thermostat plunger valve seat ((22), as shown in fig. 3 to fig. 7) and a thermostat plunger spring ((21), as shown in fig. 3, fig. & fig. 7). The thermostat housing (19) is mounted into the insulated partition wall (18) of the de-gassing tank outer shell (13). A first portion ((19A), as shown in fig. 4) of the thermostat housing (19) is disposed in the EPT coolant chamber (13B), and a second portion ((19B), as shown in fig. 4) of the thermostat housing (19) is disposed in the battery pack coolant chamber (13A). Further, the thermostat housing (19) defines a thermostat coolant inlet ((19Y), as shown in fig. 3) and a thermostat coolant outlet ((19Z), as shown in fig. 3). The thermostat housing (19) includes a sheet metal frame, a rubber seal and a jiggle pin, which works as a leak proof mechanism in the thermostat valve (20T) of the integrated de-gassing tank assembly (1). The thermostat plunger (20) is adapted to be movably loaded inside the thermostat housing (19) through the thermostat plunger spring (21). The temperature responsive medium is adapted to be accommodated inside the thermostat plunger (20). The temperature responsive medium is at least wax. At least a portion of the thermostat plunger (20) which accommodates the temperature responsive medium is disposed in the battery pack coolant chamber (13A). The thermostat plunger valve seat (22) is connected to the thermostat plunger (20).
[0026] When the temperature of the battery pack (5) is less than the desired operating temperature of the battery pack (5), the temperature responsive medium which is accommodated in the thermostat plunger (20) is configured to remain in a solid state when a temperature of the coolant in the battery pack coolant chamber (13A) of the battery pack cooling circuit (2) is less than a predefined temperature threshold. The solid state of the temperature responsive medium allows the thermostat plunger (20) to remain in a battery pack heating position (as shown in fig. 4 and fig. 5) in which the thermostat plunger valve seat (22) is dis-engaged from the thermostat coolant inlet (19Y) thereby allowing hot coolant flow from the EPT cooling circuit (3) via the EPT coolant chamber (13B) to the battery pack cooling circuit (2) via the battery pack coolant chamber (13A) for heating the battery pack. The spring force of the thermostat plunger spring (21) retains the thermostat plunger (20) in the battery pack heating position when the temperature responsive medium is in the solid state. Further, the thermostat coolant inlet (19Y) of the thermostat housing (19) is adapted to allow hot coolant flow from the EPT coolant chamber (13B) to the battery pack coolant chamber (13A) via the thermostat coolant outlet (19Z) when the thermostat plunger (20) is in the battery pack heating position. The chiller (6) is in OFF condition while heating the battery pack (5).
[0027] When the temperature of the battery pack (5) is more than the desired operating temperature of the battery pack (5), the temperature responsive medium which is accommodated in the thermostat plunger (20) is configured to undergo a phase change from the solid state to the molten state when the temperature of the coolant in the battery pack coolant chamber (13A) of the battery pack cooling circuit (2) exceeds the predefined temperature threshold. The phase change by the temperature responsive medium from the solid state to the molten state causes the thermostat plunger (20) to move from the battery pack heating position to a battery pack cooling position (as shown in fig. 6 and fig. 7) in which the thermostat plunger valve seat (22) blocks the thermostat coolant inlet (19Y) thereby allowing coolant flow in the battery pack cooling circuit (2) for cooling the battery pack (5). The thermostat plunger (20) is moved to the battery pack cooling position by moving the thermostat plunger (20) in a direction towards the battery pack coolant chamber (13A) against the spring force of the thermostat plunger spring (21) when the temperature responsive medium undergoes phase change from the solid state to the molten state. Further, the plunger valve seat (22) blocks the thermostat coolant inlet (19Y) thereby restricting hot coolant flow from the EPT coolant chamber (13B) to the battery pack coolant chamber (13A) when the thermostat plunger (20) is in the battery pack cooling position. The chiller (6) is in ON condition while cooling the battery pack (5).
[0028] Further, when the temperature of the coolant in the battery pack coolant chamber (13A) of the battery pack cooling circuit (2) falls below the pre-defined temperature threshold, the temperature responsive medium is configured to undergo a phase change from the molten state to the solid state thereby causing the thermostat plunger (20) to move from the battery pack cooling position to the battery pack heating position. The thermostat plunger (20) is moved to the battery pack heating position by moving the thermostat plunger (20) in a direction towards the EPT coolant chamber (13B) due to spring force of the thermostat plunger spring (21) when the temperature responsive medium undergoes phase change from the molten state to the solid state.
[0029] The non-return valve (NRV) (25V) is located inside the de-gassing tank outer shell (13) in vicinity of the thermostat valve (20T), wherein the NRV (25V) is mounted onto the insulated partition wall (18). The NRV (25V) includes a NRV housing (23), a NRV plunger (24), a NRV spring (25) and a NRV plunger valve seat ((26), as shown in fig. 3). The NRV housing (23) is mounted into the insulated partition wall (18) of the de-gassing tank outer shell (13), wherein a first portion ((23A), as shown in fig. 5) of the NRV housing (23) is disposed in the battery pack coolant chamber (13A), and a second portion ((23B), as shown in fig. 5) of the NRV housing (23) is disposed in the EPT coolant chamber (13B). The NRV housing (23) defines a NRV coolant inlet (23Y) and a NRV coolant outlet ((23Z), as shown in fig. 5). The NRV plunger (24) is adapted to be movably loaded inside the NRV housing (23) through the NRV spring (25). The NRV plunger valve seat (26) is connected to the NRV plunger (24). The NRV plunger (24) is adapted to be moved to an open position (as shown in fig. 5) in which the NRV plunger valve seat (26) is disengaged from the NRV coolant inlet (23Y) thereby allowing coolant flow from the battery pack coolant chamber (13A) to the EPT coolant chamber (13B) via the NRV coolant outlet (23Z) when the coolant level reaches a pre-defined coolant level threshold in the battery pack coolant chamber (13A). Further, the NRV plunger (24) is adapted to be moved from the open position to a closed position (as shown in fig. 7) in which the NRV plunger valve seat (26) blocks the NRV coolant inlet (23Y) thereby restricting coolant flow from the battery pack coolant chamber (13A) to the EPT coolant chamber (13B) when the coolant level falls below the pre-defined coolant level threshold in the battery pack coolant chamber (13A).
[0030] The first regulating valve (12A) is adapted to be positioned onto the de-gassing tank outer shell (13) and is in communication with the battery pack coolant chamber (13A). The first regulating valve (12A) is adapted to de-gas the coolant stored in the battery pack coolant chamber (13A) from unwanted gases and vapors. The first regulating valve (12A) includes a first pressure relief valve ((12AV), as shown in fig. 4) and a first threaded cap ((12AC), as shown in fig. 2b to fig. 4). The first threaded cap (12AC) of the first regulating valve (12A) is removably connected to the de-gassing tank outer shell (13). The first regulating valve (12A) is adapted to allow filling of coolant into the battery pack coolant chamber (13A) by removing the first threaded cap (12AC) from the de-gassing tank outer shell (13) during a coolant replenishment condition in the battery pack cooling circuit (2). The second regulating valve (12B) is adapted to be positioned onto the de-gassing tank outer shell (13) and is in communication with the EPT coolant chamber (13B). The second regulating valve (12B) is adapted to de-gas the coolant stored in the EPT coolant chamber (13B) from unwanted gases and vapors. The second regulating valve (12B) includes a second pressure relief valve ((12BV), as shown in fig. 4) and a second threaded cap ((12BC), as shown in fig. 2b to fig. 4). The second regulating valve (12B) is adapted to allow filling of coolant into the EPT coolant chamber (13B) by removing the second threaded cap (12BC) from the de-gassing tank outer shell (13) during coolant replenishment condition in the EPT cooling circuit (3). It is also within the scope of the invention to provide separate threaded cap and separate pressure relief valve for the battery pack coolant chamber (13A) and the EPT coolant chamber (13B) of the de-gassing tank assembly (1). Further, it is also within the scope of the invention to provide a common threaded cap for both the battery pack coolant chamber (13A) and the EPT coolant chamber (13B) of the de-gassing tank assembly (1).
[0031] Fig. 8 depicts a flowchart indicating steps of a method (200) for operating the integrated de-gassing tank assembly (1) for thermal management of the battery pack (5) in the electric vehicle, according to embodiments as disclosed herein. At step (202), the method (200) includes, separating, by an insulated partition wall (18), a battery pack coolant chamber (13A) and an electric powertrain (EPT) coolant chamber (13B) in a de-gassing tank outer shell (13) thereby separating an electric powertrain (EPT) cooling circuit (3) and a battery pack cooling circuit (2) in the integrated de-gassing tank assembly (1). At step (204), the method (200) includes, allowing coolant flow between the battery pack cooling circuit (2) and the battery pack coolant chamber (13A) of the de-gassing tank outer shell (13) via a first inlet port (14) and a first outlet port (15) integrated on the de-gassing tank outer shell (13). At step (206), the method (200) includes, allowing hot coolant flow between the EPT cooling circuit (3) and the EPT coolant chamber (13B) via a second inlet port (16) and a second outlet port (17) integrated on the de-gassing tank outer shell (13). At step (207), the method (200) includes, allowing a temperature responsive medium which is accommodated in a thermostat plunger (20) of a thermostat valve (20T) to remain in a solid state when a temperature of the coolant in the battery pack cooling circuit (2) is less than a predefined temperature threshold. At step (208), the method (200) includes, maintaining the thermostat plunger (20) of the thermostat valve (20T) to remain in a battery pack heating position in which a thermostat plunger valve seat (22) is dis-engaged from a thermostat coolant inlet (19Y) thereby allowing hot coolant flow from the EPT cooling circuit (3) via the EPT coolant chamber (13B) to the battery pack cooling circuit (2) via the battery pack coolant chamber (13A) for heating the battery pack (5) when the temperature responsive medium remains in the solid state. At step (209), the method (200) includes, undergoing, by the temperature responsive medium, a phase change from the solid state to molten state when the temperature of the coolant in the battery pack cooling circuit (2) exceeds the predefined temperature threshold. At step (210), the method (200) includes, moving, by the thermostat plunger (20) of the thermostat valve (20T), from the battery pack heating position to a battery pack cooling position in which the thermostat plunger valve seat (22) blocks the thermostat coolant inlet (19Y) thereby allowing coolant flow in the battery pack cooling circuit (2) for cooling the battery pack (5) when the temperature responsive medium undergoes phase change from the solid state to the molten state.
[0032] Further, the method (200) includes, undergoing, by the temperature responsive medium, a phase change from the molten state to solid state when the temperature of the coolant in the battery pack cooling circuit (2) falls below the predefined temperature threshold. Furthermore, the method (200) includes, moving, by the thermostat plunger (20) of the thermostat valve (20T) from the battery pack cooling position to the battery pack heating position when the temperature responsive medium undergoes the phase change from the molten state to the solid state.
[0033] Further, the method step (208) includes, allowing, hot coolant flow from the EPT cooling circuit (3) to the EPT coolant chamber (13B) of the de-gassing tank outer shell (13) via the second inlet port (16) of the de-gassing tank outer shell (13); allowing hot coolant flow from the EPT coolant chamber (13B) to a thermostat coolant inlet (19Y) defined on a thermostat housing (19); allowing hot coolant flow from the thermostat coolant inlet (19Y) to the battery pack coolant chamber (13A) via a thermostat coolant outlet (19Z) defined on the thermostat housing (19); allowing hot coolant flow from the battery pack coolant chamber (13A) to the battery pack (5) via the first outlet port (15) of the de-gassing tank outer shell (13); allowing hot coolant flow from the battery pack (5) to a chiller (6); and re-circulating coolant flow from the chiller (6) to the battery pack coolant storage chamber (13A) via the first inlet port (14) of the de-gassing tank outer shell (13).
[0034] Further, the method (200) includes, moving, by a non-return valve (NRV) plunger (24) of a NRV (25V) to an open position in which a NRV plunger valve seat (26) is dis-engaged from a NRV coolant inlet (23Y) thereby allowing coolant flow from the battery pack coolant chamber (13A) to the EPT coolant chamber (13B) via the NRV coolant outlet (23Z) when the coolant level reaches a pre-defined coolant level threshold in the battery pack coolant chamber (13A).
[0035] Further, the method step (210) includes, blocking, by the thermostat plunger valve seat (22), the thermostat coolant inlet (19Y) of the thermostat housing (19) thereby restricting hot coolant flow from the EPT coolant chamber (13B) to the battery pack coolant chamber (13A); allowing coolant flow from the chiller (6) to the battery pack coolant chamber (13A) via the first inlet port (14) of the de-gassing tank outer shell (13); allowing coolant flow from the battery pack coolant chamber (13A) to the battery pack (5) via the first outlet port (15) of the de-gassing tank outer shell (13); allowing coolant flow from the battery pack (5) to the chiller (6); and re-circulating coolant flow from the chiller (6) to the battery pack coolant storage chamber (13A) via the first inlet port (14) of the de-gassing tank outer shell (13).
[0036] Furthermore, the method (200) includes, moving, by the NRV plunger (24) from the open position to a closed position in which the NRV plunger valve seat (26) blocks the NRV coolant inlet (23Y) thereby restricting coolant flow from the battery pack coolant chamber (13A) to the EPT coolant chamber (13B) when the coolant level falls below the pre-defined coolant level threshold in the battery pack coolant chamber (13A).
[0037] The method (200) includes, de-gassing, by a first regulating valve (12A), the coolant stored in the battery pack coolant chamber (13A) from unwanted gases and vapors; and allowing, by the first regulating valve (12A), filling of coolant into the battery pack coolant chamber (13A) during a coolant replenishment condition in the battery pack cooling circuit (2).
[0038] Further, the method (200) includes, de-gassing, by a second regulating valve (12B), the coolant stored in the EPT coolant chamber (13B) from unwanted gases and vapors; and allowing, by the second regulating valve (12B), filling of coolant into the EPT coolant chamber (13B) during coolant replenishment condition in the EPT cooling circuit (3).
[0039] The technical advantages of the integrated de-gassing tank assembly (1) are as follows. The integrated de-gassing tank assembly (1) includes single de-gassing tank to combine the EPT cooling circuit with the battery pack cooling circuit using a thermostat valve thereby reducing the number of joints and connections as well as eliminating the usage of electronic flow control valves and electronic controller. The integrated de-gassing tank assembly (1) is easy to manufacture, easy to install and is in-expensive. The integrated de-gassing tank assembly (1) can be easily retrofitted to existing battery thermal management circuit of the electric vehicles. The integrated de-gassing tank assembly (1) maintains ideal temperature for battery box to maintain battery life, performance and avoid thermal runaway. The integrated de-gassing tank assembly (1) can be used in internal combustion (IC) engine vehicles to achieve better cooling performance of the two cooling circuits.
[0040] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.
, Claims:We claim:
1. An integrated de-gassing tank assembly (1) for a vehicle, said integrated de-gassing tank assembly (1) comprising:
a de-gassing tank outer shell (13) having,
a first inlet port (14) adapted to be coupled with a battery pack cooling circuit (2);
a second inlet port (16) adapted to be coupled with an electric powertrain (EPT) cooling circuit (3);
a first outlet port (15) adapted to be coupled with the battery pack cooling circuit (2);
a second outlet port (17) adapted to be coupled with the EPT cooling circuit (3); and
an insulated partition wall (18) integrated inside the de-gassing tank outer shell (13) to separate a battery pack coolant chamber (13A) and an EPT coolant chamber (13B) in the de-gassing tank outer shell (13) thereby separating the EPT cooling circuit (3) and the battery pack cooling circuit (2) in the integrated de-gassing tank assembly (1).

2. The integrated de-gassing tank assembly (1) as claimed in claim 1, wherein the integrated de-gassing tank assembly (1) includes a thermostat valve (20T) adapted to be located inside the de-gassing tank outer shell (13), wherein the thermostat valve (20T) is mounted onto the insulated partition wall (18),
wherein
the battery pack coolant chamber (13A) is in coolant communication with the battery pack cooling circuit (2) via the first inlet port (14) and the first outlet port (15);
the EPT coolant chamber (13B) is in coolant communication with the EPT cooling circuit (3) via the second inlet port (16) and the second outlet port (17); and
the de-gassing tank outer shell (13) includes a plurality of mounting members (13M) adapted to facilitate mounting of the integrated de-gassing tank assembly (1) in the vehicle.

3. The integrated de-gassing tank assembly (1) as claimed in claim 2, wherein the integrated de-gassing tank assembly (1) includes a non-return valve (NRV) (25V) located inside the de-gassing tank outer shell (13) in vicinity of the thermostat valve (20T), wherein the NRV (25V) is mounted onto the insulated partition wall (18).

4. The integrated de-gassing tank assembly (1) as claimed in claim 2, wherein the thermostat valve (20T) includes,
a thermostat housing (19) mounted into the insulated partition wall (18), wherein a first portion (19A) of the thermostat housing (19) is disposed in the EPT coolant chamber (13B), and a second portion (19B) of the thermostat housing (19) is disposed in the battery pack coolant chamber (13A), wherein the thermostat housing (19) defines a thermostat coolant inlet (19Y) and a thermostat coolant outlet (19Z);
a thermostat plunger (20) adapted to be movably loaded inside the thermostat housing (19) through a thermostat plunger spring (21);
a temperature responsive medium adapted to be accommodated inside the thermostat plunger (20), wherein the temperature responsive medium is at least wax, wherein at least a portion of the thermostat plunger (20) which accommodates the temperature responsive medium is disposed in the battery pack coolant chamber (13A); and
a thermostat plunger valve seat (22) connected to said thermostat plunger (20).

5. The integrated de-gassing tank assembly (1) as claimed in claim 3, wherein the NRV (25V) includes,
a NRV housing (23) mounted into the insulated partition wall (18), wherein a first portion (23A) of the NRV housing (23) is disposed in the battery pack coolant chamber (13A), and a second portion (23B) of the NRV housing (23) is disposed in the EPT coolant chamber (13B), wherein the NRV housing (23) defines a NRV coolant inlet (23Y) and a NRV coolant outlet (23Z);
a NRV plunger (24) adapted to be movably loaded inside the NRV housing (23) through a NRV spring (25); and
a NRV plunger valve seat (26) connected to the NRV plunger (24).

6. The integrated de-gassing tank assembly (1) as claimed in claim 4, wherein the temperature responsive medium is configured to remain in a solid state when a temperature of the coolant in the battery pack coolant chamber (13A) of the battery pack cooling circuit (2) is less than a predefined temperature threshold;
the thermostat plunger (20) is configured to remain in a battery pack heating position in which the thermostat plunger valve seat (22) is dis-engaged from the thermostat coolant inlet (19Y) thereby allowing hot coolant flow from the EPT cooling circuit (3) via the EPT coolant chamber (13B) to the battery pack cooling circuit (2) via the battery pack coolant chamber (13A) for heating the battery pack when the temperature responsive medium remains in the solid state; and
the thermostat coolant inlet (19Y) allows hot coolant flow from the EPT coolant chamber (13B) to the battery pack coolant chamber (13A) via the thermostat coolant outlet (19Z) when the thermostat plunger (20) is in the battery pack heating position.

7. The integrated de-gassing tank assembly (1) as claimed in claim 6, wherein the temperature responsive medium is configured to undergo a phase change from the solid state to the molten state when the temperature of the coolant in the battery pack coolant chamber (13A) of the battery pack cooling circuit (2) exceeds the predefined temperature threshold;
the thermostat plunger (20) is adapted to be moved from the battery pack heating position to a battery pack cooling position in which the thermostat plunger valve seat (22) blocks the thermostat coolant inlet (19Y) thereby allowing coolant flow in the battery pack cooling circuit (2) for cooling the battery pack when the temperature responsive medium undergoes the phase change from the solid state to the molten state; and
the plunger valve seat (22) blocks the thermostat coolant inlet (19Y) thereby restricting hot coolant flow from the EPT coolant chamber (13B) to the battery pack coolant chamber (13A) when the thermostat plunger (20) is in the battery pack cooling position.

8. The de-gassing tank assembly (1) as claimed in claim 5, wherein the NRV plunger (24) is adapted to be moved to an open position in which the NRV plunger valve seat (26) is dis-engaged from the NRV coolant inlet (23Y) thereby allowing coolant flow from the battery pack coolant chamber (13A) to the EPT coolant chamber (13B) via the NRV coolant outlet (23Z) when the coolant level reaches a pre-defined coolant level threshold in the battery pack coolant chamber (13A); and
the NRV plunger (24) is adapted to be moved from the open position to a closed position in which the NRV plunger valve seat (26) blocks the NRV coolant inlet (23Y) thereby restricting coolant flow from the battery pack coolant chamber (13A) to the EPT coolant chamber (13B) when the coolant level falls below the pre-defined coolant level threshold in the battery pack coolant chamber (13A),
wherein
the de-gassing tank outer shell (13) is a split-type de-gassing tank outer shell having a first de-gassing tank outer shell and a second de-gassing tank outer shell which are secured to each other to form the de-gassing tank outer shell (13);
the first inlet port (14) is opposite to the second inlet port (16);
the first outlet port (15) is parallel and spaced apart from the second outlet port (17);
the first inlet port (14), the NRV valve (25V) and the second inlet port (16) are co-axial to each other; and
at least one of a non-return valve and a pressure relief valve is integrated in the first inlet port (14), the first outlet port (15), the second inlet port (16) and the second outlet port (17).

9. The de-gassing tank assembly (1) as claimed in claim 1, wherein the integrated de-gassing tank assembly (1) includes,
a first regulating valve (12A) adapted to be positioned onto the de-gassing tank outer shell (13) and is in communication with the battery pack coolant chamber (13A), wherein the first regulating valve (12A) is adapted to de-gas the coolant stored in the battery pack coolant chamber (13A) from unwanted gases and vapors, wherein the first regulating valve (12A) is adapted to facilitate filling of coolant into the battery pack coolant chamber (13A) during a coolant replenishment condition in the battery pack cooling circuit (2); and
a second regulating valve (12B) adapted to be positioned onto the de-gassing tank outer shell (13) and is in communication with the EPT coolant chamber (13B), wherein the second regulating valve (12B) is adapted to de-gas the coolant stored in the EPT coolant chamber (13B) from unwanted gases and vapors, wherein the second regulating valve (12B) is adapted to facilitate filling of coolant into the EPT coolant chamber (13B) during coolant replenishment condition in the EPT cooling circuit (3).

10. A method (200) of operating an integrated de-gassing tank assembly (1) for thermal management of a battery pack (5) in an electric vehicle, said method (200) comprising:
separating, by an insulated partition wall (18), a battery pack coolant chamber (13A) and an electric powertrain (EPT) coolant chamber (13B) in a de-gassing tank outer shell (13) thereby separating an electric powertrain (EPT) cooling circuit (3) and a battery pack cooling circuit (2) in the integrated de-gassing tank assembly (1);
allowing coolant flow between the battery pack cooling circuit (2) and the battery pack coolant chamber (13A) of the de-gassing tank outer shell (13) via a first inlet port (14) and a first outlet port (15) integrated on the de-gassing tank outer shell (13);
allowing hot coolant flow between the EPT cooling circuit (3) and the EPT coolant chamber (13B) via a second inlet port (16) and a second outlet port (17) integrated on the de-gassing tank outer shell (13);
allowing a temperature responsive medium which is accommodated in a thermostat plunger (20) of a thermostat valve (20T) to remain in a solid state when a temperature of the coolant in the battery pack cooling circuit (2) is less than a predefined temperature threshold;
maintaining the thermostat plunger (20) of the thermostat valve (20T) to remain in a battery pack heating position in which a thermostat plunger valve seat (22) is dis-engaged from a thermostat coolant inlet (19Y) thereby allowing hot coolant flow from the EPT cooling circuit (3) via the EPT coolant chamber (13B) to the battery pack cooling circuit (2) via the battery pack coolant chamber (13A) for heating the battery pack (5) when the temperature responsive medium remains in the solid state;
undergoing, by the temperature responsive medium, a phase change from the solid state to the molten state when the temperature of the coolant in the battery pack cooling circuit (2) exceeds the predefined temperature threshold; and
moving, by the thermostat plunger (20) of the thermostat valve (20T), from the battery pack heating position to a battery pack cooling position in which the thermostat plunger valve seat (22) blocks the thermostat coolant inlet (19Y) thereby allowing coolant flow in the battery pack cooling circuit (2) for cooling the battery pack (5) when the temperature responsive medium undergoes phase change from the solid state to the molten state,
wherein
the insulated partition wall (18) is integrated inside the de-gassing tank outer shell (13); and
the thermostat valve (20T) is located inside the de-gassing tank outer shell (13) and is mounted onto the insulated partition wall (18).

11. The method (200) as claimed in claim 10, wherein the method step of said maintaining the thermostat plunger (20) of the thermostat valve (20T) to remain in the battery pack heating position in which the thermostat plunger valve seat (22) is dis-engaged from the thermostat coolant inlet (19Y) thereby allowing hot coolant flow from the EPT cooling circuit (3) via the EPT coolant chamber (13B) to the battery pack cooling circuit (2) via the battery pack coolant chamber (13A) for heating the battery pack (5) when the temperature responsive medium remains in the solid state, includes,
allowing, hot coolant flow from the EPT cooling circuit (3) to the EPT coolant chamber (13B) of the de-gassing tank outer shell (13) via the second inlet port (16) of the de-gassing tank outer shell (13);
allowing hot coolant flow from the EPT coolant chamber (13B) to thermostat coolant inlet (19Y) defined on a thermostat housing (19);
allowing hot coolant flow from the thermostat coolant inlet (19Y) to the battery pack coolant chamber (13A) via a thermostat coolant outlet (19Z) defined on the thermostat housing (19);
allowing hot coolant flow from the battery pack coolant chamber (13A) to the battery pack (5) via the first outlet port (15) of the de-gassing tank outer shell (13);
allowing hot coolant flow from the battery pack (5) to a chiller (6); and
re-circulating coolant flow from the chiller (6) to the battery pack coolant storage chamber (13A) via the first inlet port (14) of the de-gassing tank outer shell (13).

12. The method (200) as claimed in claim 11, wherein the method step of said moving, by the thermostat plunger (20) of the thermostat valve (20T), from the battery pack heating position to the battery pack cooling position in which the thermostat plunger valve seat (22) blocks the thermostat coolant inlet (19Y) thereby allowing coolant flow in the battery pack cooling circuit (2) for cooling the battery pack (5) when the temperature responsive medium undergoes phase change from the solid state to the molten state, includes,
blocking, by the thermostat plunger valve seat (22), the thermostat coolant inlet (19Y) of the thermostat housing (19) thereby restricting hot coolant flow from the EPT coolant chamber (13B) to the battery pack coolant chamber (13A);
allowing coolant flow from the chiller (6) to the battery pack coolant chamber (13A) via the first inlet port (14) of the de-gassing tank outer shell (13);
allowing coolant flow from the battery pack coolant chamber (13A) to the battery pack (5) via the first outlet port (15) of the de-gassing tank outer shell (13);
allowing coolant flow from the battery pack (5) to the chiller (6); and
re-circulating coolant flow from the chiller (6) to the battery pack coolant storage chamber (13A) via the first inlet port (14) of the de-gassing tank outer shell (13).

13. The method (200) as claimed in claim 12, wherein the method (200) comprises,
moving, by a non-return valve (NRV) plunger (24) of a NRV (25V) to an open position in which a NRV plunger valve seat (26) is dis-engaged from a NRV coolant inlet (23Y) thereby allowing coolant flow from the battery pack coolant chamber (13A) to the EPT coolant chamber (13B) via the NRV coolant outlet (23Z) when the coolant level reaches a pre-defined coolant level threshold in the battery pack coolant chamber (13A); and
moving, by the NRV plunger (24) from the open position to a closed position in which the NRV plunger valve seat (26) blocks the NRV coolant inlet (23Y) thereby restricting coolant flow from the battery pack coolant chamber (13A) to the EPT coolant chamber (13B) when the coolant level falls below the pre-defined coolant level threshold in the battery pack coolant chamber (13A),
wherein
the NRV (25V) is located inside the de-gassing tank outer shell (13) and is mounted onto the insulated partition wall (18) in vicinity of the thermostat valve (20T).

14. The method (200) as claimed in claim 10, wherein the method (200) includes,
de-gassing, by a first regulating valve (12A), the coolant stored in the battery pack coolant chamber (13A) from unwanted gases and vapors;
allowing, by the first regulating valve (12A), filling of coolant into the battery pack coolant chamber (13A) during a coolant replenishment condition in the battery pack cooling circuit (2);
de-gassing, by a second regulating valve (12B), the coolant stored in the EPT coolant chamber (13B) from unwanted gases and vapors; and
allowing, by the second regulating valve (12B), filling of coolant into the EPT coolant chamber (13B) during coolant replenishment condition in the EPT cooling circuit (3),
wherein
the first regulating valve (12A) is adapted to be positioned onto the de-gassing tank outer shell (13) and is in communication with the battery pack coolant chamber (13A); and
the second regulating valve (12B) is adapted to be positioned onto the de-gassing tank outer shell (13) and is in communication with the EPT coolant chamber (13B).