Patent Publication Number: US-2022223942-A1

Title: Battery module cooling structure

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 USC § 119(a) of Korean Patent Application No. 10-2021-0002891, filed on Jan. 8, 2021 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a battery module cooling structure, and more specifically, to a battery module cooling structure which uniformly cools heat generated in a battery module. 
     2. Discussion of Related Art 
     Recently, as interest in environmental protection increases, instead of development of internal combustion engine vehicles using conventional combustion engines, development of other types of vehicles that are environmentally friendly and fuel-efficient, that is, hybrid vehicles and electric vehicles, is being actively conducted. 
     Since a hybrid vehicle is driven using two power sources in which a conventional engine and a motor, which is driven using electrical energy, are linked, the hybrid vehicle is positioned as an alternative next-generation vehicle which has been spotlighted recently in the United States, Japan, and Europe due to effects of reducing environmental pollution caused by exhaust gas and improving fuel efficiency. 
     Generally, in a hybrid vehicle, an engine driven by gasoline and diesel and used as a main power source and a motor used as auxiliary power source are used, and the hybrid vehicle travels using the engine as a power source at a predetermined speed or more and travels using the motor as a power source when traveling at a lower speed. 
     In addition, in an electric vehicle, a motor is mainly used as a main power source. 
     A battery management system (BMS) is used as a power source required for driving the motor, and the BMS acts as an important factor related to a lifetime of a hybrid vehicle and an electric vehicle. 
     The BMS is configured to supply power while repeating charging and discharging when a vehicle is traveling. 
     Generally, the BMS includes a plurality of battery modules. 
     In addition, each of the plurality of battery modules includes a plurality of pouch type battery cells and a cartridge supporting the plurality of pouch type battery cells. 
     When the conventional battery module is used for a long time, heat is generated, and particularly, in the case of a high-capacity battery, since an amount of current increases when the battery is charged or discharged, more heat is generated. 
     In this case, when the generated heat is not cooled sufficiently, the performance of the battery is degraded, or furthermore, the battery may also catch fire or explode. 
     Accordingly, the battery should be essentially cooled in order to maintain and improve the performance of the battery, and a battery cooling system is used in an eco-friendly vehicle in order to ensure a lifetime and the performance of a battery installed in the eco-friendly vehicles. 
     Such a battery cooling system is divided into an air cooling type battery cooling system using air, a water cooling type battery cooling system using cooling water, or a coolant cooling type battery cooling system using a coolant. 
     In addition, factors affecting the heat dissipation performance may be divided into external factors, such as air, cooling water, and a coolant as described above, and internal factors related to a heat dissipation structure of a battery cooling apparatus. 
     Meanwhile, the plurality of battery modules are positioned sequentially. 
     In addition, cooling water, which cools the battery modules, flows in a cooling module in contact with the battery modules from one side to the other side of the cooling module. 
     Accordingly, the battery modules are cooled in the order in which the cooling water passes. 
     Accordingly, when the cooling water flows into the cooling module, cooling efficiency of a battery module coming into contact with the cooling water at an initial stage is high. 
     However, the cooling water, of which a temperature is increased by exchanging heat with the battery module coming into contact with the cooling water at the initial stage, cools a battery module which will come into contact therewith relatively later. 
     Accordingly, there is a problem in that cooling efficiency of the battery module, which comes into contact with the cooling water at a later stage, is lower than that of the battery module, which comes into contact with the cooling water at the initial stage. 
     That is, a flow rate of the cooling water should be increased in order to control the battery module coming into contact with the cooling water at the later stage to have an optimum temperature. 
     Accordingly, there is a problem in that the battery module coming into contact with the cooling water at the initial stage is over cooled to decrease overall cooling efficiency of the BMS. 
     SUMMARY 
     The present disclosure is directed to providing a battery module cooling structure capable of cooling heat generated in a specific battery module to increase cooling efficiency of a battery management system (BMS). 
     The above-described objective, the other objectives, advantages, and features of the present disclosure and methods of achieving the same will be clear with reference to the following embodiments and the accompanying drawings. 
     According to an aspect of the present disclosure, there is provided a battery module cooling structure including a plurality of battery modules fixed to a vehicle body, a cooling block in which cooling water flows and which is in contact with the battery module to cool the battery module, and a plurality of valve members which are coupled to the cooling block and which control the cooling water to selectively flow in the cooling block, wherein the cooling block includes a first cooling module disposed at any one portion of upper or lower portions of the battery module, and a second cooling module positioned at the other portion of upper or lower portions of the battery module. 
     The second cooling module selectively may cool any one or all of the plurality of battery modules at the same time. 
     The first cooling module may include a first cooling plate which constitutes a body and in which the cooling water flows, an inlet pipe which is coupled to the first cooling plate and allows the cooling water to flow into the first cooling plate from the outside, an outlet pipe which is coupled to the first cooling plate at a position spaced apart from the inlet pipe and allows the cooling water to be discharged from the first cooling plate to the outside, a first connecting pipe having one end coupled to the first cooling plate and the other end coupled to the second cooling module, and a second connecting pipe disposed at a position spaced apart from the first connecting pipe and having one end coupled to the first cooling plate and the other end coupled to the second cooling module. 
     The first connecting pipe may communicate with the inlet pipe, and the second connecting pipe may communicate with the outlet pipe. 
     In the first connecting pipe, the cooling water may flow from the first cooling plate to the second cooling module, and in the second connecting pipe, the cooling water may flow from the second cooling module to the first cooling plate. 
     The second cooling module may include a plurality of second cooling plates of which the number corresponds to the plurality of the battery modules and in which the cooling water flows, a circulation path in which cooling water introduced into the second cooling plate flows, a discharge path in which the cooling water discharged from the second cooling plate flows, and a connection path which communicates with the circulation path and the discharge path and is connected to the first connecting pipe and the second connecting pipe. 
     The second cooling plate may include a body part in which an accommodation space is formed, an inlet part which allows the body part and the circulation path to communicate with each other, a discharge part which allows the body part and the discharge path to communicate with each other, and a cooling path which is positioned in the accommodation space of the body part and has one end coupled to the inlet part and the other end coupled to the discharge part. 
     The connection path may allow the cooling water introduced from the first connecting pipe to flow to the circulation path and the cooling water introduced from the discharge path to flow to the first cooling module through the second connecting pipe. 
     A partition wall may be positioned between the first connecting pipe and the discharge path in the connection path. 
     Each of the valve members may include an inlet valve which is coupled to the circulation path and controls the cooling water flowing in the circulation path and a discharge valve which is coupled to the discharge path and controls the cooling water flowing in the discharge path. 
     The inlet valve may communicate with the circulation path in one and the other directions and communicate with the inlet part in a direction in which the second cooling plate is positioned between the one and the other directions, and the discharge valve may communicate with the discharge path in one and the other directions and communicate with the discharge part in a direction in which the second cooling plate is positioned between the one and the other directions. 
     The inlet valve positioned at a position corresponding to the battery module to be cooled may open the circulation path in a direction in which the cooling water is introduced, close the circulation path in a direction in which the cooling water is discharged, and open the inlet part so that the cooling water flows into the cooling path. 
     The inlet valve positioned between the connection path and the battery module cooled by the second cooling plate may open the circulation path coupled to the inlet valve in the one and the other directions. 
     When the cooling water is discharged from the cooling path, the discharge valve may open the discharge part, close the discharge path in a direction in which the cooling water is introduced, and open the discharge path in a direction in which the cooling water is discharged so that the cooling water is discharged in a direction in which the connection path is positioned. 
     The discharge valve positioned between the connection path and the discharge valve of the battery module cooled by the second cooling plate may open the discharge path coupled to the discharge valve in the one and the other directions. 
     According to another aspect of the present disclosure, there is provided a battery module cooling structure including a plurality of battery modules fixed to a vehicle body, a cooling block which includes a first cooling module positioned at any one portion of upper or lower portions of the battery module and a second cooling module positioned at the other portion of upper or lower portions of the battery module and is in contact with the battery module to cool the battery module, a plurality of valve members which are coupled to the cooling block and control cooling water to selectively flow in the cooling block, and a plurality of support fixtures each having one end coupled to the first cooling module and the other end coupled to the second cooling module so that the second cooling module is supported by the first cooling module. 
     The first cooling module and the second cooling module may be connected to allow the cooling water to flow therebetween. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present disclosure will become more apparent to those of ordinary skill in the art by describing exemplary embodiments thereof in detail with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view illustrating a battery module cooling structure according to one embodiment of the present disclosure; 
         FIG. 2  is an exploded perspective view illustrating the battery module cooling structure according to one embodiment of the present disclosure; 
         FIG. 3  is a plan view illustrating the battery module cooling structure according to one embodiment of the present disclosure; and 
         FIGS. 4 and 5  are perspective views illustrating a flow of cooling water flowing in the battery module cooling structure according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Embodiments of the present disclosure are provided to more completely describe the present disclosure to those skilled in the art, the embodiments described below will be changed into various different forms, and the scope of the present disclosure is not limited to the following embodiments. Further, the embodiments are provided to make the present disclosure more complete and true and to convey the spirit of the present disclosure to those skilled in the art. In addition, in the accompanying drawings, components are exaggerated for convenience and clarity of description, and components that are the same are referred to by the same reference numerals. As used in the present specification, the term “and/or” includes any and all combinations of the associated listed items. 
     The terms used herein are used only to describe the specific embodiments and are not to limit the present disclosure. 
     Unless the context clearly indicates otherwise, the singular forms described in the specification include the plural forms. In addition, the terms “comprise” and “comprising,” when used herein, specify some stated shapes, numbers, steps, operations, members, elements, and/or presence of groups thereof but do not preclude one or more other shapes, numbers, operations, members, elements, and/or presence or addition of groups thereof. 
     Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a perspective view illustrating a battery module cooling structure according to one embodiment of the present disclosure,  FIG. 2  is an exploded perspective view illustrating the battery module cooling structure according to one embodiment of the present disclosure,  FIG. 3  is a plan view illustrating the battery module cooling structure according to one embodiment of the present disclosure, and  FIGS. 4 and 5  are perspective views illustrating a flow of cooling water flowing in the battery module cooling structure according to one embodiment of the present disclosure. 
     Referring to  FIGS. 1 to 5 , the battery module cooling structure according to one embodiment of the present disclosure includes a battery module  100 , a cooling block  200 , valve members  300 , and support fixtures  400 . 
     The battery module  100  is provided as a plurality of battery modules  100 , includes a plurality of battery cells and a cover member, in which the battery cells are accommodated, and is fixed to a vehicle body. 
     The battery module  100  stores power to be supplied to a high voltage battery system. 
     The plurality of battery modules  100  are arranged in a horizontal direction. 
     Preferably, the battery modules  100  may be arranged in the form of two columns and four rows according to a use environment when viewed from above as illustrated in  FIG. 1 . 
     Hereinafter, in the present disclosure, the battery modules  100  arranged in the form of two columns and four rows will be described for the sake of convenience in the description. 
     The plurality of battery modules  100  are described to be arranged in the form of two columns and four rows, but are not limited thereto, and may be various arranged according to a use environment. 
     Meanwhile, the battery cell of the present disclosure may be manufactured as one of various types and may be manufactured as a pouch type preferably. 
     In the pouch type battery cell, since a flexible aluminum laminate sheet is used as an exterior member, the pouch type battery cell is formed in a form which is easily bent. 
     Since a shape of the pouch type battery cell may be relatively freely formed, and the pouch type battery cell is lightweight, the pouch type battery cell is mainly used in the battery module  100  for a vehicle in which a plurality of battery cells should be provided. 
     The cooling block  200  is in contact with the battery modules  100 , and cooling water flows in the cooling block  200  to cool heat of the battery modules  100 . 
     To this end, the cooling water for cooling the battery modules  100  flows into the cooling block  200 . 
     The cooling water flows in the cooling block  200 , and the cooling block  200  absorbs heat generated in the battery modules  100  when the battery modules  100  are charged or discharged. 
     The cooling block  200  include a first cooling module  210 , a second cooling module  220 , and the valve members  300 . 
     The first cooling module  210  is positioned at any one portion of upper or lower portions of the battery modules  100 . 
     In the present disclosure, the first cooling module  210  is positioned at the lower portion of the plurality of battery modules  100  preferably as illustrated in the drawings. 
     In addition, in the first cooling module  210 , the cooling water flows to cool the plurality of battery modules  100  at the same time. 
     The first cooling module  210  includes a first cooling plate  211 , an inlet pipe  212 , an outlet pipe  213 , a first connecting pipe  214 , and a second connecting pipe  215 . 
     The first cooling plate  211  may be formed in a quadrangular shape and constitutes a body of the first cooling module  210 , and the cooling water flows in the first cooling plate  211 . 
     The inlet pipe  212  is formed in the form of a hollow pipe and coupled to an upper portion of the first cooling plate  211 . 
     In addition, the inlet pipe  212  allows the cooling water to flow into the first cooling plate  211  from the outside. 
     The outlet pipe  213  is formed in the form of a hollow pipe and coupled to the upper portion of the first cooling plate  211  at a position spaced apart from the inlet pipe  212 . 
     In addition, the outlet pipe  213  allows the cooling water to flow from the inlet pipe  212 , flow in the first cooling plate  211 , cool the plurality of battery modules  100 , and then be discharged. 
     Meanwhile, the first cooling module  210  and the second cooling module  220  are connected so that the cooling water flows therebetween. 
     To this end, the first connecting pipe  214  and the second connecting pipe  215  are positioned between the first cooling module  210  and the second cooling module  220 . 
     One end of the first connecting pipe  214  is coupled to the first cooling plate  211 , and the other end thereof is coupled to the second cooling module  220 . 
     In addition, one end of the second connecting pipe  215  is coupled to the first cooling plate  211 , and the other end thereof is coupled to the second cooling module  220  at a position spaced apart from the first connecting pipe  214 . 
     In the first connecting pipe  214 , the cooling water flows from the first cooling plate  211  to the second cooling module  220 , and in the second connecting pipe  215 , the cooling water flows from the second cooling module  220  to the first cooling plate  211 . 
     That is, the cooling water easily flows between the first cooling module  210  and the second cooling module  220  due to the first connecting pipe  214  and the second connecting pipe  215 . 
     Specifically, one end of the first connecting pipe  214  is connected to the inlet pipe  212  in second cooling plates  221 , and one end of the second connecting pipe  215  is connected to the outlet pipe  213  in the second cooling plates  221 . 
     That is, the cooling water introduced through the inlet pipe  212  may flow to the first connecting pipe  214 , and the cooling water discharged through the second connecting pipe  215  may flow to the outlet pipe  213 . 
     Accordingly, when the cooling water introduced through the inlet pipe  212  flows to the first connecting pipe  214 , the cooling water introduced through the inlet pipe  212  may be effectively blocked from flowing to the second connecting pipe  215 . 
     In addition, when the cooling water discharged through the second connecting pipe  215  flows to the outlet pipe  213 , the cooling water discharged through the second connecting pipe  215  may be effectively blocked from flowing to the inlet pipe  212 . 
     The second cooling module  220  is positioned at the other portion of upper or lower portions of the battery module  100 . 
     In the present disclosure, the second cooling module  220  is positioned at the upper portion of the plurality of battery modules  100  preferably as illustrated in the drawings. 
     The second cooling module  220  receives the cooling water from the first cooling module  210  through the first connecting pipe  214 . 
     In addition, the second cooling module  220  may selectively cool only any one of the plurality of battery modules  100 . 
     Specifically, the second cooling module  220  selectively cools the battery module  100  of which cooling efficiency is low because the cooling water, which is already heated to a high temperature due to heat exchange, comes into contact with the battery module  100  disposed close to the inlet pipe  212  among the plurality of battery modules  100  sequentially disposed when the plurality of battery modules  100  are cooled by the first cooling module  210 . 
     Accordingly, since the second cooling module  220  may uniformly cool each of the plurality of battery modules  100  to an optimum temperature, cooling efficiency of the plurality of battery modules  100  can be improved significantly. 
     Particularly, by increasing a flow rate of the cooling water in the cooling block  200  to cool the battery module  100  coming into contact with the cooling water already heated to a high temperature, the battery module  100  disposed close to the inlet pipe  212  may be prevented from being excessively cooled, and cooling efficiency thereof is prevented from being decreased. 
     Meanwhile, although it has been described that the second cooling module  220  selectively cools only one of the plurality of battery modules  100 , the second cooling module  220  may also cool the plurality of battery modules  100  at the same time. 
     Accordingly, since the second cooling module  220  may cool the plurality of battery modules  100  at the same time, the second cooling module  220  may more effectively cool the plurality of battery modules  100  along with the first cooling module  210 . 
     The second cooling module  220  includes the second cooling plates  221 , a circulation path  226 , a discharge path  227 , and a connection path  228 . 
     The number of the second cooling plates  221  corresponds to the plurality of battery modules  100 , and the cooling water flows in the second cooling plates  221 . 
     The second cooling plates  221  include body parts  222 , inlet parts  223 , discharge parts  224 , and cooling paths  225 . 
     The body part  222  is a body part  222  of the second cooling plate  221 , an accommodation space, in which the cooling path  225  is positioned, is formed in the body part  222 , and the body part  222  is formed in a quadrangular shape. 
     The number of body parts  222  corresponds to the plurality of battery modules  100 , and each of the body parts  222  is positioned at the upper portion of one of the plurality of battery modules  100 . 
     The inlet part  223  is formed in a pipe shape, receives the cooling water from the circulation path  226 , and allows the cooling water to flow to the body part  222 . 
     That is, one end of the inlet part  223  communicates with the body part  222 , and the other end thereof communicates with the circulation path  226  so that the body part  222  communicates with the circulation path  226 . 
     The discharge part  224  is formed in a pipe shape, receives the cooling water from body part  222 , and allows the cooling water to flow to the discharge path  227 . 
     That is, one end of the discharge part  224  communicates with the discharge path  227 , and the other end thereof communicates with the body part  222  in a direction opposite to a direction in which the inlet part  223  is positioned so that the body part  222  communicates with the discharge path  227 . 
     The cooling path  225  is formed in a pipe shape and positioned in the accommodation space of the body part  222 . 
     In addition, when the cooling water flows into the cooling path  225  from the outside, the cooling path  225  cools the battery module  100  disposed under the body part  222 . 
     To this end, one end of the cooling path  225  is connected to the inlet part  223 , and the other end thereof is connected to the discharge part  224 . 
     Accordingly, the cooling path  225  receives the cooling water from the inlet part  223 , and the cooling water flows in the cooling path  225  to cool the battery module  100  disposed under the body part  222  and is discharged through the discharge part  224 . 
     The circulation path  226  receives the cooling water from the first cooling module  210  through the first connecting pipe  214  and allows the cooling water to flow to the battery module  100  which needs to be cooled. 
     In addition, the inlet parts  223  are disposed between and coupled to an outer circumferential surface of the circulation path  226  and the body parts  222  of the plurality of second cooling plates  221 . 
     That is, when the cooling water introduced from the first connecting pipe  214  reaches the battery module  100 , which needs to be cooled, among the plurality of battery modules  100 , the circulation path  226  allows the cooling water to flow into the body part  222  of the second cooling plate  221  through the inlet disposed between the circulation path  226  and the body part  222  of the second cooling plate  221 . 
     The circulation path  226  is positioned around outer circumferential surfaces of the plurality of second cooling plates  221  to surround all of the plurality of second cooling plates  221 . 
     The discharge path  227  is positioned between the plurality of battery modules  100  arranged in the form of two columns. 
     In addition, the discharge parts  224  are disposed between and coupled to an outer circumferential surface of the discharge path  227  and the body parts  222  of the plurality of second cooling plates  221 . 
     The discharge path  227  receives the cooling water which cools the battery module  100 , which needs to be cooled, from the body part  222  of the second cooling plate  221  through the discharge part  224  and discharges the cooling water to the connection path  228 . 
     The discharge path  227  allows the cooling water discharged from the body part  222  of the second cooling plate  221  through the discharge part  224  to be discharged to the first cooling module  210 . 
     An outer circumferential surface of the connection path  228  is coupled to the first connecting pipe  214  and the second connecting pipe  215 , and the connection path  228  communicates with the inlet pipe  212  and the outlet pipe  213  through the first connecting pipe  214  and the second connecting pipe  215 . 
     That is, the connection path  228  allows the cooling water introduced from the first connecting pipe  214  to flow to the circulation path  226  and allows the cooling water introduced from the discharge path  227  to flow to the first cooling module  210  through the second connecting pipe  215 . 
     Specifically, the connection path  228  receives the cooling water from the inlet pipe  212  through the first connecting pipe  214 , allows the cooling water to flow to the circulation path  226 , and discharges the cooling water to the outlet of the first cooling module  210  through the second connecting pipe  215 . 
     Meanwhile, a partition wall  229  is formed between the first connecting pipe  214  and the discharge path  227  in the connecting pipe. 
     The partition wall  229  prevents the cooling water introduced from the first connecting pipe  214  from being mixed with the cooling water discharged from the discharge path  227  and discharged to the second connecting pipe  215 . 
     That is, the partition wall  229  allows the cooling water introduced from the first connecting pipe  214  to flow to the circulation path  226 . 
     Meanwhile, the valve members  300  are positioned between the circulation path and the inlet and between the discharge path  227  and the discharge part  224 . 
     The number of valve members  300  corresponds to the plurality of battery modules  100 , and the valve members  300  are connected to the second cooling module  220  to allow the cooling water to selectively flow to the second cooling module  220 . 
     That is, the valve member  300  may be formed in a 3-way structure, and the cooling water introduced from the inlet pipe  212  may flow into the second cooling module  220  according to whether the valve member  300  is opened. 
     The valve members  300  include inlet valves  310  and discharge valves  320 . 
     The number of the inlet valves  310  corresponds to the plurality of battery modules  100 , and the inlet valves  310  are coupled to the circulation path  226  and control the cooling water flowing in the circulation path  226 . 
     Specifically, the inlet valve  310  communicates with the circulation path  226  in one and the other directions and communicates with the inlet part  223  in a direction in which the body part  222  of the second cooling plate  221  is positioned between the one and the other direction. 
     In addition, when any one of the plurality of battery modules  100  should be cooled, as illustrated in  FIGS. 4 and 5 , the inlet valve  310 , which is positioned at a position corresponding to the battery module  100  to be cooled, among the plurality of inlet valves  310  opens the circulation path  226 _ 1  in a direction in which the cooling water flows. 
     At the same time, the circulation path  226 _ 2  is closed in a direction in which the cooling water is discharged, and the inlet part  223  is opened. 
     That is, the inlet valve  310  opens the circulation path  226 _ 1  in the direction in which the cooling water is introduced and closes the circulation path  226 _ 2  in the direction in which the cooling water is discharged. 
     Accordingly, the cooling water introduced into the circulation path  226 _ 1  may flow into the cooling path  225  of the second cooling plate  221  through the open inlet part  223 . 
     In this case, the inlet valve  310  positioned between the connection path  228  and the battery module  100  cooled by the second cooling plate  221  opens the circulation path  226  coupled to the inlet valve  310  in the one and the other directions. 
     Accordingly, the cooling water flows through the inlet valve  310 , which is opened in the one and the other directions, to the inlet valve  310  corresponding to the battery module  100  to be cooled. 
     Accordingly, the inlet valve  310  may selectively cool only the battery module  100  to be cooled among the plurality of battery modules  100 . 
     Meanwhile, the meaning of selectively cooling only any one of the plurality of battery modules  100  is that the second cooling module  220  cools only one battery module  100 , which is particularly and excessively heated, among the plurality of battery modules  100  and does not cool the plurality of battery modules  100  at the same time. 
     The discharge valves  320  are coupled to the discharge path  227  and control the cooling water flowing in the discharge path  227 . 
     Specifically, the discharge valve  320  communicates with the discharge path  227  in one and the other directions and communicates with the discharge part  224  in a direction in which the second cooling plate  221  is positioned between the one and the other directions. 
     In addition, as illustrated in  FIGS. 4 and 5 , the discharge valve  320  opens the discharge part  224  to allow the cooling water, which cools the battery module  100 , to be discharged through the discharge part  224 . 
     At the same time, in the discharge path  227 _ 2  connected to one end and the other end of the discharge valve  320 , the discharge path  227 _ 1  is opened in a direction in which the connection path  228  is positioned, and the discharge path  227 _ 2 , which is connected to the other end of the discharge valve  320 , is closed in a direction opposite to the direction in which the connection path  228  is positioned. 
     That is, when the cooling water is discharged from the cooling path  225 , the discharge part  224  may be opened, the discharge path  227 _ 2  may be closed in a direction in which the cooling water is introduced, the discharge path  227 _ 1  may be opened in a direction in which the cooling water is discharged, and thus the discharge path  227 _ 1  may discharge the cooling water in the direction in which the connection path  228  is positioned. 
     In this case, the discharge valve  320  positioned between the connection path  228  and the battery module  100  cooled by the second cooling plate  221  opens the discharge path  227  coupled to the discharge valve  320  in the one and the other directions. 
     Accordingly, the discharge valve  320  may easily discharge the cooling water which cools the battery module  100 , which needs to be cooled, among the plurality of battery modules  100  to the connection path  228 . 
     One end of the support fixture  400  is coupled to the first cooling module  210 , and the other end thereof is coupled to the second cooling module  220  so that the second cooling module  220  is supported by the first cooling module  210 . 
     Accordingly, the support fixture  400  may firmly support the second cooling module  220  which is shaken due to the flow of the cooling water when the cooling water flows in the second cooling module  220 . 
     According to the present disclosure, since a second cooling module can uniformly cool each of a plurality of battery modules to an appropriate temperature, cooling efficiency of the plurality of battery modules can be increased significantly. 
     In addition, since any one of the plurality of battery modules is selectively cooled, it is prevented that the battery module disposed close to an inlet pipe is excessively cooled by increasing a flow rate of the cooling water in the cooling module in order to cool a battery module coming into contact with cooling water already heated to a high temperature. 
     In addition, since the second cooling module can cool the plurality of battery modules at the same time, the second cooling module can cool the plurality of battery modules more effectively along with a first cooling module. 
     As described above, the embodiment disclosed in the present specification should be considered in a descriptive sense only and not for purposes of limitation, the scope of the present disclosure is defined not by the above description but by the appended claims, and it should be interpreted that the scope of the present disclosure encompasses all differences falling within equivalents of the appended claims.