CN215771274U

CN215771274U - Snakelike passageway radiator of cylindrical lithium cell of electric automobile

Info

Publication number: CN215771274U
Application number: CN202121823858.XU
Authority: CN
Inventors: 夏国栋; 许朋; 马丹丹
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2022-02-08
Anticipated expiration: 2031-08-05

Abstract

The utility model belongs to the technical field of enhanced heat transfer, and particularly relates to a serpentine channel radiator of a cylindrical lithium battery of an electric automobile. The device comprises: a distribution header, a fluid inlet, a serpentine conduit, a battery, a collection header, a porous media, a fluid outlet. The device can meet the heat dissipation of the battery during discharging, and effectively solves the problem of overlarge temperature rise of the battery.

Description

Snakelike passageway radiator of cylindrical lithium cell of electric automobile

Technical Field

The utility model belongs to the technical field of enhanced heat transfer, and particularly relates to a cooling device applied to the field of electric automobile lithium battery thermal management.

Background

With the increasing shortage of energy problems, the living environment is gradually worsened, the pollution is high, and the development of the traditional automobile with high energy consumption is limited. The new energy automobile has the advantages of low energy consumption, low pollution and the like, and is widely concerned by the students, and the development of the new energy automobile is greatly supported by the nation. The lithium ion battery is used as a power source spring of a new energy automobile, and the heat accumulation is generated due to the polarization reaction in the energy supply process, so that the service life and the performance of the battery are influenced, and even the safety problems such as battery combustion are caused, so that how to dissipate the heat of the lithium ion battery becomes a problem which needs to be solved urgently.

At present, the cooling mode of the lithium battery is mainly air cooling, liquid cooling, phase change cooling and heat pipe cooling. The air cooling controls the temperature by changing the air flow direction and the inlet and outlet flow, the phase change cooling covers the phase change material on the wall surface of the battery, the phase change material absorbs heat to reduce the temperature of the battery, and the heat pipe cooling takes away the heat of the battery by using the vaporization of a working medium; liquid cooling utilizes the high specific heat capacity of cooling liquid, takes away the battery surface heat through the method of pump drive, because its outstanding heat-sinking capability can guarantee that the battery is in ideal state for a long time, etc. has become the object of study of scholars.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a radiator which can effectively control the temperature rise and the temperature difference of a 26650-type battery on the basis of single-phase convective heat transfer and is used for solving the problems of local high temperature and overlarge temperature difference of a lithium battery.

The utility model designs a serpentine channel radiator of a cylindrical lithium battery of an electric automobile, which is characterized by comprising an inlet (1), a distribution header (2), a serpentine channel (4), a porous medium (6), an outlet (8), a collection header (5) and a cylindrical battery (3) as shown in figure 1; the distribution header (2) is of a hollow plate-shaped structure, the upper part of one surface of the distribution header (2) is provided with a fluid inlet (1) connected with an external pipeline, and the other opposite side of the distribution header is communicated with one end of a snake-shaped channel (4);

the collecting header (5) is of a hollow plate-shaped structure, the upper part of one side of the collecting header (5) is provided with an outlet (8), and the other opposite side of the collecting header is communicated with the other end of the snake-shaped channel (4); the snake-shaped channel (4) is of a snake-shaped hollow-cavity plate-shaped structure, namely a hollow-cavity corrugated plate structure; the distribution header (2) is parallel to the collection header (5), the serpentine channels (4) are positioned between the distribution header (2) and the collection header (5), one end of each serpentine channel (4) in the length direction of each corrugation is connected and communicated with the distribution header (2), the other end of each serpentine channel is connected and communicated with the collection header (5), a plurality of serpentine channels (4) are arranged between the distribution header (2) and the collection header (5), peaks and troughs between every two adjacent serpentine channels (4) are relatively encircled to form a similar cylindrical cavity, and the troughs and the peaks are relatively connected to form a peak; a cylindrical battery (3) is arranged in each column-like cavity, a plurality of cylindrical batteries (3) are counted, the serpentine channel (4) and the cylindrical batteries (3) in each column-like cavity are in opposite arc-shaped surrounding contact, a gap is also formed between the serpentine channel (4) and the cylindrical batteries (3), and porous media (6) are filled in the gap; the cylindrical batteries (3) are arranged in an array and are parallel to the collecting header (5), and the axial height direction of the cylindrical batteries (3) is the height direction of the radiator.

Four parallel curved fins (7) are arranged in the height direction of the radiator, namely the height direction of each serpentine channel (4), each serpentine channel (4) is divided into 5 independent fluid channels along the height direction by the four parallel curved fins (7), and the bending of each curved fin (7) is changed along with the bending of each serpentine channel (4); the specific positions are shown in fig. 5 and 6, and the function is to increase the heat exchange area;

porous medium (6) are hollow rod-shaped structure heat-transfer device, and the direction of height of its axial is parallel and equal height with the battery axial, and the space of serpentine channel (4) and cylindrical battery (3) in the class column cavity is filled up to closely arranging of a plurality of parallel hollow rod-shaped structures for serpentine channel (4), porous medium (6), cylindrical battery (3) in proper order in close contact with, the effect is increase heat transfer area, reduces heat accumulation, improves battery module homogeneity.

Each cylindrical battery (3) is wrapped and clamped by two snake-shaped channels (4) at two sides of the cylindrical battery; along the trend of the liquid working medium, namely the corrugated length direction, each serpentine pipeline is distributed in a sine shape, and wave crests and wave troughs corresponding to two adjacent serpentine channels (4) are in an arc-shaped structure and are parallelly, annularly, closely and fixedly connected with the surface of the battery (3).

6 snake-shaped channels (4) are arranged between the distribution header (2) and the collection header (5); each serpentine channel (4) is provided with 5 complete wave crests or wave troughs.

The serpentine channel radiator is a radiator composed of a plurality of arrayed serpentine channels and is processed by 3D printing technology, and in order to clarify the structure of the radiator, 3D views, a top view, a side view, a front view and a side view of a single serpentine channel and 3D views of specific positions and shapes of curved fins (7) are respectively given in figures 1, 2, 3, 4, 5 and 6.

As shown in fig. 2, in the serpentine channel heat exchanger, the working medium flows through the fluid inlet (1), the distribution header (2), the serpentine channel (4), the fluid outlet (8) and the collection header (5) in sequence. After flowing through the distribution header (2), the heat exchange working medium uniformly disperses into the serpentine channel (4), takes heat away from the surface of the cylindrical battery (3) through single-phase convection heat exchange, and then is collected into the collection header.

The utility model adopts the following technical scheme:

the main part of the heat exchanger adopts a serpentine channel (4). The serpentine channel consists of curved fins and a 0.5mm thick channel. The heat exchange coefficient is effectively enhanced. The pipeline has carried out the extension design, has avoided the too high problem of battery module afterbody temperature, and the area of contact and the lithium cell number of passageway and lithium cell can be according to the size and the in service behavior design optimization of actual battery, and wherein bent shape fin (7) have increased fluid disturbance and area of contact. The serpentine channel extension channel design increases the heat exchange area of the tail part of the battery, reduces the heat exchange area of the tail part and enhances the heat exchange coefficient; curved fins (7) are added to increase turbulence to enhance heat exchange;

and the surface of the battery at the tail part of the battery module is provided with a porous medium (6) which is tightly attached to the surface of the battery (3) and the serpentine channel (4). The design of the heat-conducting medium can reduce the heat accumulation of the battery at the tail part and improve the uniformity of the battery module; the design of the holes may reduce the weight of the battery module. The position of the porous medium (6) and the diameter and the number of the holes can be changed according to the requirements of practical application.

In consideration of the practical application problem of the heat exchanger, the inlet and the outlet (8) of the serpentine pipeline are designed on the module level, and the flowing direction of the fluid in the channel is the same. Compared with the inlet and the outlet in the vertical direction of the fluid, the serpentine channel of the inlet and the outlet in the horizontal direction of the fluid can effectively reduce the occupied volume, so that the battery packs are more compact and easy to package. The flow of each serpentine channel can be controlled according to different battery discharge rates, so that the temperature of the batteries in the module is uniform.

The heat exchange working medium is cooling liquid mixed by 50% of ethylene glycol and water, so that the freezing in winter is prevented. According to the working medium and the optimal working temperature range of the cylindrical lithium battery (3), single-phase convective heat transfer is formed on the surface of the battery to realize the cooling technical requirement.

The utility model has the following advantages and effects:

1. compare traditional serpentine channel heat exchanger, novel serpentine channel has increased path length, has strengthened the heat transfer characteristic, has obviously reduced battery module highest temperature.

2. Compare traditional serpentine channel heat exchanger, add curved shape fin in the novel serpentine channel, strengthened fluid disturbance and heat transfer area, improved battery module's temperature homogeneity.

3. The battery modules adopt a symmetrical structure, and can be connected in parallel or in series according to actual use conditions, so that the structure is more compact, and the space is saved.

4. The porous medium is added at the tail part of the battery module, and the position and the size of the porous medium can be set according to actual conditions, so that the heat exchange characteristic is enhanced, and the temperature uniformity of the battery module is improved.

Drawings

FIG. 1: front view of serpentine pipeline heat exchanger

FIG. 2: top view of serpentine tube heat exchanger of the present invention

FIG. 3: side view of serpentine tube heat exchanger of the present invention

FIG. 4: top view of single serpentine channel of the utility model

FIG. 5: single serpentine channel side view of the present invention

FIG. 6: 3D drawing of curved fins in serpentine channel of the utility model

Reference numbers in the figures: 1-fluid inlet, 2-distribution header, 3-cylindrical battery, 4-serpentine channel, 5-collection header, 6-porous medium, 7-curved fin, 8-fluid outlet.

Detailed Description

The utility model provides a serpentine channel heat exchanger for single-phase convective heat exchange, and is further described with reference to the accompanying drawings and detailed description.

Example 1

The structure is shown in the attached drawings. The serpentine channel heat exchanger consists of a serpentine channel and 26550 size batteries. The serpentine pipeline is made of metal aluminum, and the curved fins and the porous medium are made of aluminum so as to reduce weight. The battery is an 26550 type battery, and the working medium is cooling liquid mixed by 50% of ethylene glycol and water. Because the central temperature of the battery is difficult to measure in practice, the performance of the serpentine channel heat exchanger is tested by adopting a numerical simulation method.

This embodiment has tested two kinds of different microchannel heat exchangers altogether, its battery type is 26650 batteries, the battery quantity is 23, battery discharge rate is 1C, 2C and 3C, battery and serpentine channel contact angle is 56.5 °, import and export flow is 3744ml/min, import and export hydraulic radius is the same, serpentine channel height is 65mm, curved shape fin diameter is 1mm, porous medium closely laminates battery surface and serpentine channel, length is 65mm and battery height, place in battery module afterbody battery surface, the laminating diameter of its porous medium and serpentine channel is 32mm, the laminating diameter with the battery is 26mm, the laminating angle with the battery is 67 °, the laminating angle with serpentine channel is 56.5 °. Traditional serpentine channel length is 211.15mm, and novel serpentine channel length is 241.87mm, and the width is 90mm, and the entrance temperature sets up to 20 ℃, and the diameter in porous medium hole is 2mm, and the number is 3, sets up in battery module afterbody intermediate position. Whole simulation process working medium gets into by distribution header (2) upside entry (1), and every snakelike passageway (4) is evenly distributed to working medium, takes away the heat from battery (3) surface through heat convection in snakelike passageway (4), then collects and collects header (5), flows out (8) by the fluid outlet at last.

The simulation results of the traditional serpentine channel heat exchanger and the novel serpentine channel heat exchanger are compared. When the cross sections of the heat exchanger channels are the same, the battery discharge power is 1C, 2C and 3C respectively, and the inlet flow is 3744ml/min, the highest temperature of the battery module of the traditional serpentine channel heat exchanger is 295.29K, 299.75K and 306.64K respectively, and the maximum temperature difference is 1.94K, 5.97K and 12.21K. The reason is that the tail part of the battery is not contacted with a serpentine channel, the heat exchange area is small, the tail lithium battery cannot be sufficiently cooled, the temperature of the tail battery is high, the highest temperature and the maximum temperature difference of the battery module are high, and the temperature uniformity of the battery module is poor. The highest temperature of the battery module of the novel serpentine channel heat exchanger is 294.01K, 295.75K and 298.45K respectively, the maximum temperature difference is 0.76K, 2.3K and 4.68K, the highest temperature is reduced by 1.26K, 3.86K and 7.91K respectively compared with the traditional serpentine channel heat exchanger, the maximum temperature difference is reduced by 1.18K, 3.67K and 7.53K, the problem that the temperature of a battery at the tail part of the battery is too high due to insufficient heat dissipation is solved by increasing curved fins (7), increasing the lengths of a porous medium (6) and a serpentine channel and increasing the contact area of the fluid disturbance and the tail part of the battery module, the temperature uniformity of the battery module is improved, the phenomenon that the local temperature at the tail part of the battery is too high is reduced, the heat dissipation of the battery under the high discharge rate is realized, the temperature of the lithium battery can be maintained in the optimal working range, the service life is prolonged, and the potential safety hazard in the driving process is reduced.

Claims

1. A snakelike channel radiator of a cylindrical lithium battery of an electric automobile is characterized by comprising an inlet (1), a distribution header (2), a snakelike channel (4), a porous medium (6), an outlet (8), a collection header (5) and a cylindrical battery (3); the distribution header (2) is of a hollow plate-shaped structure, the upper part of one surface of the distribution header (2) is provided with a fluid inlet (1) connected with an external pipeline, and the other opposite side of the distribution header is communicated with one end of a snake-shaped channel (4); the collecting header (5) is of a hollow plate-shaped structure, the upper part of one side of the collecting header (5) is provided with an outlet (8), and the other opposite side of the collecting header is communicated with the other end of the snake-shaped channel (4); the snake-shaped channel (4) is of a snake-shaped hollow-cavity plate-shaped structure, namely a hollow-cavity corrugated plate structure; the distribution header (2) is parallel to the collection header (5), the serpentine channels (4) are positioned between the distribution header (2) and the collection header (5), one end of each serpentine channel (4) in the length direction of each corrugation is connected and communicated with the distribution header (2), the other end of each serpentine channel is connected and communicated with the collection header (5), a plurality of serpentine channels (4) are arranged between the distribution header (2) and the collection header (5), peaks and troughs between every two adjacent serpentine channels (4) are relatively encircled to form a similar cylindrical cavity, and the troughs and the peaks are relatively connected to form a peak; a cylindrical battery (3) is arranged in each column-like cavity, a plurality of cylindrical batteries (3) are counted, the serpentine channel (4) and the cylindrical batteries (3) in each column-like cavity are in opposite arc-shaped surrounding contact, a gap is also formed between the serpentine channel (4) and the cylindrical batteries (3), and porous media (6) are filled in the gap; the cylindrical batteries (3) are arranged in an array and are parallel to the collecting header (5), and the axial height direction of the cylindrical batteries (3) is the height direction of the radiator.

2. The serpentine channel heat sink for the cylindrical lithium battery of the electric vehicle as recited in claim 1, wherein four parallel curved ribs (7) are disposed in a height direction of the heat sink, i.e., in a height direction of each serpentine channel (4), the four parallel curved ribs (7) divide each serpentine channel (4) into 5 independent fluid channels in the height direction, and the curvature of the curved ribs (7) varies with the curvature of the serpentine channel (4).

3. The serpentine channel radiator for the cylindrical lithium battery of the electric automobile as claimed in claim 1, wherein the porous medium (6) is a hollow rod-shaped structure heat conducting device, the axial height direction of the porous medium is parallel to the axial direction of the battery and is equal to the axial height of the battery, and a plurality of parallel hollow rod-shaped structures are closely arranged to fill the gap between the serpentine channel (4) and the cylindrical battery (3) in the quasi-cylindrical cavity, so that the serpentine channel (4), the porous medium (6) and the cylindrical battery (3) are in close contact in sequence, and the serpentine channel radiator has the effects of increasing the heat exchange area, reducing the heat accumulation and improving the uniformity of the battery module.

4. The serpentine channel heat sink for cylindrical lithium batteries of electric vehicles as claimed in claim 1, wherein each cylindrical battery (3) is surrounded and held by two serpentine channels (4) on both sides thereof; along the trend of the liquid working medium, namely the corrugated length direction, each serpentine pipeline is distributed in a sine shape, and wave crests and wave troughs corresponding to two adjacent serpentine channels (4) are in an arc-shaped structure and are parallelly, annularly, closely and fixedly connected with the surface of the battery (3).

5. The serpentine channel radiator for the cylindrical lithium battery of the electric vehicle as claimed in claim 1, wherein 6 serpentine channels (4) are provided between the distribution header (2) and the collection header (5); each serpentine channel (4) is provided with 5 complete wave crests or wave troughs.

6. The serpentine channel radiator for the cylindrical lithium battery of the electric vehicle as claimed in claim 1, wherein in the serpentine channel heat exchanger, the working medium flows through the fluid inlet (1), the distribution header (2), the serpentine channel (4), the fluid outlet (8) and the collection header (5) in sequence. After flowing through the distribution header (2), the heat exchange working medium uniformly disperses into the serpentine channel (4), takes heat away from the surface of the cylindrical battery (3) through single-phase convection heat exchange, and then is collected into the collection header.