JP2020155379A - Battery cooling system for vehicle - Google Patents

Abstract

To provide uniform cooling performance to a heat-exchange member provided in a battery cooling system for a vehicle.SOLUTION: A cooling system includes a main heat medium supply line (10), a main heat medium recovery line (20), a plurality of connection lines (301 to 30N) which are provided in parallel between the above lines (10, 20) and each of which connects the above lines, a plurality of heat-exchange members (401 to 40N) which are provided to the connection lines respectively and each of which has a heat medium inflow portion and a heat medium outflow portion, heat exchange being performed between a heat medium flowing inside each heat-exchange member and a battery, and the plurality of heat-exchange members having substantially the same shape, and a plurality of fixed throttles (501 to 50N-1) for equalizing the pressure difference between the heat medium inflow portion and the heat medium outflow portion of each heat-exchange member. The fixed throttles are provided at least to the remaining connection lines (301 to 30N-1) excluding a connection line (30N) which has the smallest pressure difference described above assuming that it is not present.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cooling system that cools a battery for a vehicle such as an electric vehicle by using a heat medium.

The battery heats up when charging. In particular, when a battery for a vehicle such as an electric vehicle is quickly charged, the heat generated by the battery is large. If charging is continued while the battery is hot, the deterioration of the battery is accelerated, the charging capacity is reduced, and the mileage of the electric vehicle is shortened. In order to solve this problem, the battery is cooled by using a heat medium (refrigerant, coolant, etc.). (See, for example, Patent Document 1)

It is desired that an electric vehicle can travel a long distance with one charge and can complete a quick charge in a short time. In order to satisfy such a requirement, a battery consisting of a large number of battery modules is installed in the vehicle. It is desirable that the performance difference between a large number of battery modules (including the difference in the degree of deterioration due to heat generation) is small, and a design device is desired so that the temperature difference between the battery modules is as small as possible. It is desirable that such a design device can be realized at low cost and is easy to manufacture or assemble.

Japanese Unexamined Patent Publication No. 2012-190675

The present invention provides a technique capable of equalizing the cooling performance of a plurality of heat exchange members provided in a vehicle battery cooling system.

According to one embodiment of the present invention, it is a battery cooling system for a vehicle.
The main heat medium supply line, the main heat medium recovery line, and the main heat medium supply line and the main heat medium recovery line are provided in parallel, and each connects the main heat medium supply line and the main heat medium recovery line. A plurality of connection lines and a plurality of heat exchange members provided in each of the plurality of connection lines, each of which has a heat medium inflow portion and a heat medium outflow portion, and flows inside each heat exchange member. The pressure difference between a plurality of heat exchange members having substantially the same shape as each other that exchange heat between the heat medium and the battery, and the heat medium inflow part and the heat medium outflow part of each heat exchange member. It comprises a plurality of fixed throttles for equalization, and the plurality of fixed throttles are provided at least in the remaining connection lines except the connection line having the smallest pressure difference assuming that there are no multiple fixed throttles. A cooling system is provided.

According to the above embodiment, it is possible to make the cooling performance of a plurality of heat exchange members provided in the cooling system of the battery for the vehicle uniform.

It is a piping system diagram of the cooling system of the vehicle battery which concerns on one Embodiment. It is a piping system diagram of the cooling system of the vehicle battery which concerns on another embodiment. It is an exploded perspective view which shows an example of the structure of the heat exchange member. It is an axial sectional view of the quick connector with a built-in fixed diaphragm. It is a figure explaining the assembly of a fixed diaphragm and a quick connector.

As shown in FIG. 1, the vehicle battery cooling system is configured as part of a heat medium circulation path (not shown) and includes a main heat medium supply line 10 and a main heat medium recovery line 20. The circulation path has a pump that sends out a heat medium and a cooling unit that cools the heat medium (neither is shown). Further, when the heat medium is a refrigerant, an expansion device is provided between the downstream side of the cooling unit and the battery cooling system. N (N is a natural number of 2 or more) connection lines 30 are provided in parallel between the main heat medium supply line 10 and the main heat medium recovery line 20. In the embodiment of FIG. 1, seven connection lines 30 are provided. In the present specification, in order to distinguish the N connection lines 30 from each other, the "connection line 30" may be referred to as "connection line 30 ₁ to 30 _N ".

Each connection line 30 connects the main heat medium supply line 10 and the main heat medium recovery line 20. A heat exchange member 40 is interposed in each of the plurality of connection lines 30. In the present specification, in order to distinguish the N heat exchange members 40 from each other, the "heat exchange member 40" may be referred to as "heat exchange member 40 ₁ to 40 _N ".

Each heat exchange member 40 has a heat medium inflow portion and a heat medium outflow portion. The heat exchange member 40 is configured such that heat exchange is performed between the heat medium flowing inside the heat exchange member 40 and the battery or the battery module (not shown) through the outer wall thereof.

The plurality of heat exchange members 40 have the same shape and dimensions. That is, when the same pressure difference is applied between the heat medium inflow part and the heat medium outflow part, each heat exchange member 40 heat medium between the heat medium inflow part and the heat medium outflow part at the same flow rate. Is configured to flow. By making the plurality of heat exchange members 40 having the same shape and size, it is possible to keep the manufacturing cost of the cooling system including the plurality of heat exchange members 40 low.

The main heat medium supply line 10 is provided with the same number (N) of connection points 12 as the number of connection lines 30 at intervals along the flow direction of the heat medium. The main heat medium recovery line is provided with the same number (N) of connection points 22 as the number of connection lines 30 at intervals along the flow direction of the heat medium. In order to distinguish N connection points 12 (22) from each other, "connection point 12 (22)" may be referred to as "connection point 12 _{1 to} 12 _N (22 _{1 to} 22 _N )".

Each connection line 30 is the i-th connection point 12 _i from the upstream side (i is a natural number of 1 or more and N or less) with respect to the flow direction of the heat medium in the main heat medium supply line 10, and the main heat medium recovery line 20. and it connects the i-th connection point 22 _i from the downstream side with respect to the flow direction of the heat medium. i-th connection lines which connects the connection point 12 _i and the i-th connection point 22 _i is also referred to as the i-th connection lines 30 _i.

A fixed diaphragm 50 is provided for each of the remaining connection lines 30 ₁ to 30 _N-1 except for the _Nth connection line 30 _N. In order to distinguish N-1 fixed diaphragms 50 from each other, "fixed diaphragm 50" is also referred to as "fixed diaphragm 50 ₁ to 50 _N-1 ". The N-1 fixed throttle ₅₀ 1 _{to 50 N-1} specifications are different from each other as different pressure losses together the heat medium passing through the fixed aperture ₅₀ 1 _{to 50 N-1,} thereby the N The pressure difference between the heat medium inflow part and the heat medium outflow part in the heat exchange members 40 ₁ to 40 _N is the same.

When the connection relationship between the main heat medium supply line 10, the main heat medium recovery line 20 and the connection line 30 shown in FIG. 1 is adopted, if there is no fixed throttle 50, pressure loss due to piping resistance will occur, and i defined above. The smaller the value of the connection line 30 _i , the larger the pressure difference between the corresponding connection points 12 _i and 22 _i . Further, the pressure difference between the connection points 12 _i and 22 _i is larger. The pressure difference between the heat medium inflow portion and the heat medium outflow portion of the heat exchange member 40 provided in the connection line 30 _i is also larger.

Therefore, the smaller the i value of the connection line 30 _i , the larger the pressure loss when passing through the fixed throttle 50 (50 _i ) provided there, thereby increasing the pressure loss of the N connection lines 30 ₁ to 30. The flow rate of the heat medium can be made uniform between _N.

When the heat medium is a coolant that does not change phase in the process of circulating in the circulation path, the fixed throttle 50 is preferably provided on the upstream side of the heat exchange member 40 of each connection line 30 as shown in FIG. By arranging the heat exchange member 40 on the downstream side of the fixed throttle 50, that is, in the path where the pressure of the heat medium is reduced by the fixed throttle 50, the heat exchange member 40 having low pressure resistance can be adopted.

When the heat medium is a refrigerant that changes phase in the process of circulating in the circulation path, it is preferable to provide the fixed throttle 50 on the downstream side of the heat exchange member 40 of each connection line 30, as shown in FIG. According to this arrangement, since the upstream side of the fixed throttle 50 has more liquid phase of the refrigerant than the downstream side, the liquid phase tends to remain in the refrigerant even after the heat is absorbed from the battery module, and the temperature does not change. Can be demonstrated.

A fixed throttle 50 is provided on the upstream side of the heat exchange member 40 in some of the connection lines 30 among the plurality of connection lines 30, and the fixed throttle 50 is provided on the downstream side of the heat exchange member 40 in the remaining connection lines 30. You may. However, in order to facilitate manufacturing control, it is preferable to unify to either the upstream side or the downstream side.

An example of the configuration of the heat exchange member 40 will be described with reference to FIG. The heat exchange member 40 includes a top plate 41, a base plate 42, a gasket 43, a composite phase changing material 44, and connector pipes 46 and 47. The base plate 42 is formed with a recess 45 for accommodating the composite phase changing material 44. With the gasket 43, the composite phase changing material 44, and the connector pipes 46, 47 arranged between the top plate 41 and the base plate 42, the top plate 41 and the base plate 42 are joined by using a joining technique such as brazing. Therefore, the heat exchange member 40 can be formed. Inside the heat exchange member 40, a meandering heat medium passage for fluid communication between one of the connector pipes 46 and 47 and the other is formed. One of the connector pipes 46 and 47 serves as the heat medium inflow portion of the heat exchange member 40, and the other serves as the heat medium outflow portion. The configuration shown in FIG. 3 is a known configuration disclosed in Japanese Patent Application Laid-Open No. 2016-040770, which relates to a prior application of Valeo System Termic, which is an affiliated company of the Applicant. Please refer to the relevant gazette.

The configuration of the heat exchange member 40 is not limited to that shown in FIG. For example, the heat exchange member 40 may be composed of the top plate 41, the base plate 42, and the connector pipes 46, 47 without using the gasket 43 and the composite phase changing material 44. As a result, the heat medium passage of the heat exchange member 40 can be configured with the minimum necessary parts.

In one embodiment, a vehicle battery is configured by a plurality of battery modules. Each battery module has substantially the same planar shape (for example, a rectangle) as the top plate 41 of the heat exchange member 40, and is placed on the top plate 41 while being thermally coupled.

According to the embodiments shown in FIGS. 1 and 2, the flow rate of the heat medium flowing through each heat exchange member 40 can be made uniform, so that the cooling performance of each heat exchange member 40 can be made uniform. Further, as a result, the flow velocity of the heat medium flowing through each heat exchange member 40 can be made uniform. As a result, the temperatures of the plurality of battery modules constituting the vehicle battery can be made uniform, and the lifespan of the plurality of battery modules can be made uniform.

In another embodiment, the battery module may be placed on the top plate 41 of the heat exchange member 40 so as to straddle a plurality of adjacent heat exchange members 40, for example. In this case, the battery module extends in the left-right direction of FIGS. 1 and 2. In this case, it is possible to reduce the temperature variation for each part of one battery module.

Next, an embodiment of the installation of the fixed diaphragm 50 will be described with reference to FIGS. 4 and 5. The fixed throttle 50 is provided on the quick connector 60 that connects the connection line 30 and the heat exchange member 40.

The quick connector 60 has a first engaging element 61 and a second engaging element 62. The first engaging element 61 is connected, for example, to a pipeline (which forms part of the connecting line 30) branching from the main heat medium supply line 10 or the main heat medium recovery line 20.

The second engaging element 62 is composed of, for example, the connector pipe 46 (or 47) of the heat exchange member 40. A groove 46r (or 47r) is formed in the connector pipe 46. The first engaging element 61 comprises a retainer consisting of a claw 65 that engages (by snap fit) the groove 46r. The first engaging element 61 can accommodate at least a tip-side portion of the second engaging element 62.

The pipe constituting the second engaging element 62 may be provided with a bead (a ring-shaped overhang portion formed on the outer peripheral surface of the pipe), in which case the retainer of the first engaging element 61 also conforms to the bead. It is configured to do.

A fixed diaphragm 50 (orifice) is attached to the tip of the second engaging element 62. A through hole is provided in the central portion of the fixed diaphragm 50, and this through hole serves as a heat medium flow path. The through hole has a diameter D and a length (axial length) L. The fixed diaphragm 50 preferably has an elastic force. Further, the fixed diaphragm 50 is formed by using a material that does not chemically react with or has little reaction with the heat medium or the additive of the heat medium in the operating temperature range of the heat medium.

When the heat medium is coolant, for example, silicon rubber, ethylene propylene rubber, or the like is used as the material of the fixed drawing 50.

When the heat medium is a refrigerant, a compressor is used to circulate the refrigerant, and lubricating oil is used to protect the wear of the internal components of the compressor. In this case, for example, silicon rubber, nitrile rubber, hydrogenated nitrile rubber, or the like is used as the material of the fixed drawing 50. By using such a material, the function of the fixed drawing can be exhibited for a long period of time without the chemical reaction proceeding with the lubricating oil circulating in the piping path together with the refrigerant.

An annular sealing member 63 (O-ring) is held in a circumferential groove formed on the inner peripheral surface of the first engaging element 61. As shown in FIG. 4, when the second engaging element 62 is housed in the first engaging element 61, the sealing member 63 is the outer peripheral surface of the second engaging element 62 (connector pipes 46, 47). To seal between the first engaging element 61 and the second engaging element 62.

Before engaging the first engaging element 61 and the second engaging element 62, first, the small diameter portion of the fixed diaphragm 50 is inserted into the tip portion of the second engaging element 62 (see arrow I in FIG. 5). ). Next, the second engaging element 62 is moved so that the second engaging element 62 is inserted into the first engaging element 61 (see arrow II in FIG. 5). By doing so, the claw 65 is engaged (snap-fitted) with the groove 46r (47r), whereby the first engaging element 61 and the second engaging element 62 are engaged so as not to be easily separated. To do.

At this time, the end face of the fixed diaphragm 50 comes into contact with the annular stopper 64 formed inside the first engaging element 61, or approaches with a small gap. This makes it possible to prevent the fixed diaphragm 50 from coming out of the second engaging element 62. That is, the fixed diaphragm 50 engages the first engaging element 61 and the second engaging element 62 in a state of being mounted on the second engaging element 62 of the quick connector 60, whereby the first engaging element 61 Will be held between and the second engaging element 62.

By changing at least one of the diameter D and the length L of the through hole of the fixed diaphragm 50, the degree of pressure drop of the heat medium passing through the fixed diaphragm 50 can be changed. The diameter D can be freely changed within a range smaller than the inner diameter of the second engaging element 62 (for example, the connector pipes 46 and 47). Further, the length L can be freely changed within a range in which the fixed diaphragm 50 can be inserted into the second engaging element 62.

According to the embodiments shown in FIGS. 4 and 5, by changing only the shape of the fixed throttle 50, the quick connector 60 does not change the shapes of the first engaging element 61 and the second engaging element 62. The pressure loss inside can be adjusted, whereby the pressure difference between the heat medium inflow portion and the heat medium outflow portion of each heat exchange member 40 can be equalized.

According to the embodiments shown in FIGS. 4 and 5, it is possible to make all the quick connectors 60 included in one cooling system have the same specifications. Therefore, in standardizing the parts of the battery cooling system. It is beneficial. Since the fixed diaphragm 50 may have a simple shape that is rotationally symmetric, it is possible to keep the cost increase of the cooling system low by preparing a plurality of types of fixed diaphragms 50.

In the above embodiment, the fixed throttle 50 is not provided in the connection line 30 _N having the maximum i value (i = N), that is, the connection line 30 _N having the minimum pressure difference at both ends, but it may be provided. .. In that case, a fixed throttle 50 (50 _N ) configured to minimize the pressure loss is provided on the connection line 30 _N. Specifically, for example, it is assumed that it is essential to provide the fixed throttle 50 for reasons such as the internal structure of the quick connector 60 (for example, to fill a gap or to secure stable engagement). In this case, the fixed diaphragm 50 may also be provided on the connection line 30 _N having the maximum i value (i = N).

The heat medium may be a coolant or a refrigerant. The term "coolant" as used herein means a liquid that cools an object to be cooled by removing heat from the object to be cooled without accompanying an essential phase change. Specifically, as the coolant, water containing an antifreeze component (a component that lowers the freezing point) such as that used in automobile engine cooling water is exemplified. Further, the term "refrigerant" is a heat medium used in a refrigeration cycle, and cools an object to be cooled by removing heat corresponding to heat of vaporization at the time of phase change from a liquid phase to a gas phase from the object to be cooled. It means the fluid to be cooled. Specifically, as the refrigerant, a refrigerant for an air conditioner for vehicles, for example, HFC-134a widely used conventionally, HFO-1234yf corresponding to recent EU regulations, and the like can be used.

10 Main heat medium supply line 20 Main heat medium recovery line 30 (30 ₁ to 30 _N ) Connection line 40 (40 ₁ to 40 _N ) Heat exchange member 50 (50 ₁ to 50 _N-1 ) Fixed throttle 60 Quick connector 61 No. 1 Engagement element 62 Second engagement element D Flow path diameter of fixed throttle L Flow path length of fixed throttle

Claims (7)

A battery cooling system for vehicles
Main heat medium supply line (10) and
Main heat medium recovery line (20) and
The main heat medium supply line (10) and the main heat medium recovery line (20) are provided in parallel, and each of the main heat medium supply line (10) and the main heat medium recovery line (20) Multiple connection lines (30 ₁ to 30 _N ) to connect
A plurality of the plurality of heat exchanging member provided in each of the connecting lines _{(30) (40 1 ~40 N} ), each having a heat medium inlet and a heat medium outlet portion, wherein each heat exchanger A plurality of heat exchange members (40 ₁ to 40 _N ) having substantially the same shape as each other, which exchange heat between the heat medium flowing inside the members (40 ₁ to 40 _N ) and the battery.
A plurality of fixed throttles (50 ₁ to 50 _N-1 ) for equalizing the pressure difference between the heat medium inflow portion and the heat medium outflow portion of each heat exchange member, and
With
The plurality of fixed diaphragms (50 ₁ to 50 _N-1 ) are connected lines (30 _N ) having the smallest pressure difference when it is assumed that the plurality of fixed diaphragms (50 ₁ to 50 _N-1 ) are not present. except the remaining are at least provided in the connecting line _{(30 1 ~30 N-1)} , a cooling system. The cooling system according to claim 1, wherein the connection line (30 _N ) having the smallest pressure difference is not provided with the fixed throttle. The cooling system according to claim 1 or 2, wherein at least one of the flow path diameter (D) and the flow path length (L) of the plurality of fixed throttles (50 ₁ to 50 _N-1 ) is different from each other. A plurality of quick connectors (60) for connecting the plurality of heat exchange members (40 ₁ to 40 _N ) and the plurality of connection lines (30 ₁ to 30 _N ) are further provided, and each of the quick connectors (60) is provided. Each fixed throttle (50 ₁ to 50 _N-1 ) has a first engaging element (61) and a second engaging element (62) that engage with each other, and each of the fixed throttles (50 ₁ to 50 _N-1 ) is the said of the quick connector (60). By engaging the first engaging element (61) with the second engaging element (62) while being mounted on the second engaging element (62), the first engaging element (61) The cooling system according to any one of claims 1 to 3, which is configured to be held between the second engaging element (62) and the second engaging element (62). N (N is a natural number of 2 or more) connection points (12 _{1 to} 12 _N ) are spaced apart from each other along the flow direction of the heat medium in the main heat medium supply line (10). Provided on the supply line (10)
The main heat medium collecting line (20) spaced apart from each other along the flow direction of the heat medium in the N connection points (22 1 _{through 22 N)} is provided in the main heat medium collecting line (20),
There are N of the plurality of connection lines (30 ₁ to 30 _N ), and the plurality of connection lines (30 ₁ to 30 _N ) are from the upstream side with respect to the flow direction of the heat medium in the main heat medium supply line (10). The i-th (i is a natural number of 1 or more and N or less) connection point (12 _{1 to} 12 _N ) and the i-th connection point from the downstream side with respect to the flow direction of the heat medium in the main heat medium recovery line (20). The connection line (30) connecting (22 _{1 to} 22 _N ) and the i-th connection point (12 _i ) and the i-th connection point (22 _i ) is connected to the i-th connection line (22 _i ). When it is called 30 _i ) and the fixed diaphragm (50) provided therein is called the i-th fixed diaphragm (50 _i ), the flow path diameter (D) of the fixed diaphragm having a smaller i value is larger. The cooling system according to claim 3, wherein the flow path length (L) of the fixed diaphragm is smaller or the i value is smaller, and the flow path length (L) is longer. The cooling system according to any one of claims 1 to 5, wherein the heat medium is cooling water or coolant. The cooling system according to any one of claims 1 to 5, wherein the heat medium is a refrigerant.

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