CN113745697B - Manufacturing method of parallel flow water cooling disc assembly of lithium battery - Google Patents

Abstract

The invention discloses a method for manufacturing a parallel flow water cooling plate assembly of a lithium battery. The steps are: (1) prepare N aluminum flat tubes; (2) prepare two headers: each header includes a Composite aluminum pipe, the composite aluminum pipe includes an inner layer plate and an outer layer plate compounded on the outer wall of the inner layer plate, and the melting point of the outer layer plate is lower than the melting point of the inner layer plate; (3) Pre-assembly: N The two ends of an aluminum flat tube are inserted into the mounting holes on a header respectively, and a brazing material piece is sandwiched between two adjacent aluminum flat tubes to form a component assembly; (4) Brazing : Put the component assembly into the brazing furnace, complete the brazing, and make the parallel flow water cooling plate assembly. The parallel flow water cooling plate assembly produced by this application has a flat outer surface, which can increase the contact area with the lithium battery and improve the heat exchange efficiency. The wall thickness of the aluminum flat tube is thin, which is conducive to heat transfer. The heat exchange efficiency of the parallel flow water cooling plate assembly is about 3 times higher than that of the plate water cooling plate assembly.

Description

A method of manufacturing a parallel flow water cooling plate assembly for lithium batteries

Technical field

The invention relates to a method for manufacturing a parallel flow water cooling plate assembly of a lithium battery.

Background technique

At present, the water-cooled base for water-cooled lithium battery cooling uses plate-type water-cooled plate assemblies. Please refer to Figure 1 and Figure 2. This type of plate water-cooled plate assembly places an aluminum plate in a mold and blows it with high-pressure air so that the aluminum plate follows the shape of the mold to form a water-cooled plate 101 with curved grooves. Two water-cooled plates 101 are stacked together and brazed to form a flow channel 103 between the opposite grooves, and then a liquid inlet pipe 110 and a liquid outlet pipe 120 are installed at both ends of the flow channel, thus forming a Plate water-cooling plate assembly 100 for lithium batteries.

This plate-type water-cooled plate assembly has significant defects. 1. The thickness of the aluminum plate needs to be at least 1mm, which requires high manufacturing costs. The thicker aluminum plate also leads to a longer heat transfer distance, so the heat exchange efficiency is low. 2. Since the upper surface of the plate water-cooling plate assembly is uneven, the contact surface between the upper surface and the lithium battery is small (generally only about 80%), which also reduces its heat exchange efficiency. 3. Due to the long length of the flow channel, a high-power water pump is needed to drive the cooling water. In order to avoid excessive temperature rise in the area close to the liquid outlet pipe, the cooling water needs a higher flow rate, which further increases the The power of the water pump. 4. The inner surface area of the plate water-cooling plate assembly can generally only reach 1.5 times the area of the water-cooling base, and the heat exchange efficiency is too low.

Contents of the invention

In order to solve the above problems, the present invention proposes a manufacturing method of a parallel flow water cooling plate assembly for lithium batteries, which includes the following steps:

(1) Prepare N aluminum flat tubes. Each aluminum flat tube has several straight and parallel through holes. N is an integer ≥ 1;

(2) Prepare two headers:

Each header pipe includes a composite aluminum pipe. Both ends of the composite aluminum pipe are blocked with plugs, and a mounting hole is opened on each composite aluminum pipe. The mounting hole is along the length of the composite aluminum pipe. Elongated holes extending in the direction;

The composite aluminum pipe includes an inner layer plate and an outer layer plate composited on the outer wall of the inner layer plate, and the melting point of the outer layer plate is lower than the melting point of the inner layer plate;

(3) Pre-assembly:

Insert the two ends of N aluminum flat tubes into the mounting holes on a header respectively. The N aluminum flat tubes are laid along the same plane and parallel to each other. When N ≥ 2, the two adjacent aluminum flat tubes are A solder sheet is sandwiched between the tubes, and a pipe joint is installed on each header to form a component assembly; the melting point of the solder sheet is lower than the melting point of the inner plate;

(4) Brazing:

Put the component assembly into the brazing furnace, raise the furnace temperature to the set temperature, melt the outer plate and the solder sheet, complete the brazing, and make the parallel flow water cooling plate assembly. Specifically, N=1-10. The height of the aluminum flat tube is 8.0-8.2mm.

In this application, only one installation hole is opened on each composite aluminum tube. After all the aluminum flat tubes are arranged in a row along the same plane, the same ends of all the aluminum flat tubes are inserted into the installation of one composite aluminum tube. In the hole, instead of opening one installation hole for each aluminum flat tube, only one installation hole is opened on each composite aluminum tube, which can reduce the difficulty of opening the installation hole and enable adjacent aluminum flat tubes to fit together. , to increase the inner surface area of the parallel flow water cooling plate assembly.

In this application, aluminum flat tubes are used to make the parallel flow water cooling plate assembly. Since the aluminum flat tubes have a flat outer surface, they can increase the contact area with the lithium battery and improve the heat exchange efficiency. Moreover, the wall thickness of the aluminum flat tubes is thin, and there are Conducive to heat transfer. The water-cooling flow channel is formed by the inner hole of the aluminum flat tube. Since the water-cooling flow channel is linear and parallel to each other, curved flow channels are no longer used. The cooling water enters a header, then enters each water-cooling flow channel, and finally passes through Another header pipe collects and discharges the cooling water. The linear water-cooling flow channel is used to shorten the flow distance of the cooling water and expand the total flow cross-section. This can reduce the energy consumption of the cooling water drive pump and reduce cooling costs. Moreover, the inner surface area of this parallel flow water cooling plate assembly is 3.5-4 times the area of the chassis, which is more than twice larger than the plate water cooling plate assembly. Based on the above parameters, the heat exchange efficiency of the parallel flow water cooling plate assembly is about 3 times higher than that of the same large plate water cooling plate assembly.

Specifically, each aluminum flat tube includes a top plate, a bottom plate and two side plates, wherein the top plate and the bottom plate are spaced apart along the height direction and parallel to each other, and each side plate closes the same side of the top plate and the bottom plate in the width direction, The thickness of both the top plate and the bottom plate is 0.5±0.1mm. Aluminum flat tubes are now mature products and can be purchased directly from the market or customized. In order to ensure heat transfer efficiency, the thickness of the top and bottom plates of the aluminum flat tubes in this application is 0.5±0.1mm.

Specifically, the material of the inner plate of the composite aluminum pipe is aluminum alloy grade 3003, and the material of the outer plate is aluminum alloy grade 4045; during the brazing process, the set temperature of the furnace temperature is 610-620°C. The solder sheet is made of 4045 grade aluminum alloy material with a melting point of 605 degrees Celsius.

Using the above-mentioned solder sheet and brazing temperature, the outer layer plate and the solder sheet can be melted smoothly. The metal liquid produced after melting flows into the gaps of each joint part, sealing the gaps of all parts, and sealing the gaps. Each component is brazed into a whole.

Furthermore, in order to ensure that the plugs can be stably maintained on the composite aluminum pipe, each plug is stamped from a single composite aluminum plate. The plug includes a main body and a sealing portion arranged around the main body. The main body is Forming a step shape with the sealing part, the main part is tightly inserted into the composite aluminum pipe, and the sealing part is pressed against the end surface of the composite aluminum pipe; the composite aluminum plate includes a base plate and a brazing layer compounded on the base plate, The brazing layer is located on the side of the base plate facing the composite aluminum tube. The material of the substrate of the composite aluminum plate can be aluminum alloy grade 3003, and the material of the brazing layer can be aluminum alloy grade 4045.

This design can effectively expand the contact area between the plug and the composite aluminum tube, and improve the stability of the plug. During brazing, the brazing layer melts into a metal liquid and forms a metal layer with the outer plate of the composite aluminum tube. The liquid together brazes the plug on the composite aluminum pipe, ensuring the sealing and stability of the plug.

Further, the height of the mounting hole is the same as the height of the aluminum flat tube, and the width of the mounting hole is the same as the total width of the N aluminum flat tubes. During manufacturing, arrange the aluminum flat tubes and insert them into the mounting holes toward the same end. Since the aluminum flat tubes have a certain elasticity, this elasticity is used to clamp the solder sheet between the two aluminum flat tubes. , during the brazing process, the solder sheet melts, the aluminum flat tube returns to its original shape, and is brazed together by the molten solder produced after melting. This design can minimize the gaps between the aluminum flat tubes and increase the flow channel area of the parallel flow water cooling plate assembly.

Description of the drawings

Figure 1 is a schematic diagram of a lithium battery water-cooling plate assembly in the prior art.

Figure 2 is a view along the A-A direction in Figure 1 .

Figure 3 is a schematic structural diagram of a parallel flow water cooling plate assembly prepared by the present invention.

FIG. 4 is a top view of FIG. 3 .

Figure 5 is a view along B-B direction in Figure 4 .

FIG. 6 is an enlarged view of part C in FIG. 5 .

Figure 7 is a cross-sectional view of the header.

Figure 8 is a schematic structural diagram of an aluminum flat tube.

Figure 9 is a schematic structural diagram of the plug.

FIG. 10 is a top view of FIG. 9 .

Figure 11 is a view along D-D direction in Figure 10 .

Detailed ways

The structure of the parallel flow water cooling plate assembly of the lithium battery is first described below. Please refer to Figures 3 to 7. The parallel flow water cooling plate assembly includes four aluminum flat tubes 20 arranged along the same plane and parallel to each other. The aluminum flat tubes are brazed together to form a cooling row pipe. A header pipe 30 is installed and sealed at both ends of the length direction of the cooling row pipe, and a pipe joint is installed on the two header pipes. One of the pipes is The joint is used as the refrigerant inlet pipe 36, and the other pipe joint is used as the refrigerant outlet pipe 37.

The manufacturing method of the parallel flow water cooling plate assembly is described below. The size of the parallel flow water cooling plate assembly manufactured in this embodiment is 1000mm*800mm. The manufacturing method includes the following steps:

(1) Prepare four aluminum flat tubes 20, that is, N=4.

Please refer to Figure 8. Each aluminum flat tube 20 includes a top plate 21, a bottom plate 22 and two side plates 23. The top plate 21 and the bottom plate 22 are spaced apart along the height direction and parallel to each other. Each side plate 23 connects the top plate and the bottom plate 23. The same side of the bottom plate in the width direction is closed, and the thickness V of the top plate and the bottom plate is both 0.5±0.1mm. There are also 29 intermediate partitions 24 provided between the top plate and the bottom plate, so that the aluminum flat tube is formed with 30 linear and mutually parallel through holes, and each through hole is formed into a water cooling channel 26. The width S of each aluminum flat tube 20 is 200mm, and the height H is 8.0-8.2mm.

(2) Prepare two header pipes 30:

Each header 30 includes a composite aluminum tube 31, which is in the shape of a straight tube. Both ends of the composite aluminum tube 31 are blocked with plugs 40 , and a mounting hole 32 is opened along the length direction of each composite aluminum tube 31 .

The composite aluminum pipe 31 includes an inner layer plate 311 and an outer layer plate 312 compounded on the outer wall of the inner layer plate 311, and the melting point of the outer layer plate is lower than the melting point of the inner layer plate.

In this embodiment, the height of the mounting hole is the same as the height of the aluminum flat tube, and the width of the mounting hole is the same as the total width of the four aluminum flat tubes, that is, the width of the mounting hole is 800 mm.

(3) Pre-assembly:

Insert one end of the four aluminum flat tubes 20 into the mounting hole 32 on one header 30 at the same time, and insert the other ends of the four aluminum flat tubes 20 into the mounting hole 32 on the other header 30 at the same time. , four aluminum flat tubes are laid along the same plane and parallel to each other, a solder sheet 50 is sandwiched between two adjacent aluminum flat tubes 20, and a pipe joint is installed on each header to form a component assembly. into; the melting point of the solder sheet is lower than the melting point of the inner layer plate.

Please refer to Figures 9 to 11. Each plug 40 is stamped from a single piece of aluminum plate. The plug 40 includes a main body 41 and a sealing portion 42 arranged around the main body. There is a gap between the main body and the sealing portion. Forming a step shape, the main body part is tightly inserted into the composite aluminum pipe, and the sealing part is pressed against the end surface of the composite aluminum pipe.

The composite aluminum plate includes a base plate 43 and a brazing layer 44 compounded on the base plate 43. The brazing layer is located on the side of the base plate facing the composite aluminum tube.

(4) Brazing:

Put the component assembly into the brazing furnace, raise the furnace temperature to the set temperature, melt the outer plate and the solder sheet, complete the brazing, and make the parallel flow water cooling plate assembly.

The material of the inner plate of the composite aluminum pipe is aluminum alloy grade 3003, and the material of the outer plate is aluminum alloy grade 4045. The aluminum alloy of grade 3003 is an aluminum-manganese alloy with a melting point of 660°C. The aluminum alloy of grade 4045 is an aluminum-silicon alloy with a melting point of 605°C. During the brazing process, the furnace temperature is set to 610-620°C. , to ensure that the outer panel can be completely melted and the inner panel can remain in its original state. The melted outer board flows into the gaps between the joints, where it is bonded and sealed.

In this embodiment, each parallel flow water cooling plate assembly is made of four aluminum flat tubes. It can be understood that according to the number of holes and width of different aluminum flat tubes, other numbers of aluminum flat tubes can also be used. For example, Made of three 40-hole aluminum flat tubes. In addition, according to the different widths and cooling requirements of the parallel flow water cooling plate assembly, 5, 8 or 10 aluminum flat tubes can also be used.

The performance comparison of this embodiment and the plate water-cooling plate assembly corresponding to this embodiment is listed in the following table.

The parallel flow water cooling plate assembly and plate water cooling plate assembly in the above table are both used to cool the same model of lithium batteries. It can be seen from the above table that the parallel flow water cooling plate assembly in this application has higher heat exchange efficiency and can reduce the power consumption of the cooling water drive pump.

Claims (7)

1. A method for manufacturing a parallel flow water cooling plate assembly for lithium batteries, which is characterized in that it includes the following steps: (1) Prepare N aluminum flat tubes. Each aluminum flat tube has several straight and parallel through holes. N is an integer ≥ 1; (2) Prepare two headers: Each header pipe includes a composite aluminum pipe. Both ends of the composite aluminum pipe are blocked with plugs, and a mounting hole is opened on each composite aluminum pipe. The mounting hole is along the length of the composite aluminum pipe. Elongated holes extending in the direction; The composite aluminum pipe includes an inner layer plate and an outer layer plate composited on the outer wall of the inner layer plate, and the melting point of the outer layer plate is lower than the melting point of the inner layer plate; (3) Pre-assembly: Insert the two ends of N aluminum flat tubes into the mounting holes on a header respectively. The N aluminum flat tubes are laid along the same plane and parallel to each other. When N ≥ 2, the two adjacent aluminum flat tubes are A solder sheet is sandwiched between the tubes, and a pipe joint is installed on each header to form a component assembly; the melting point of the solder sheet is lower than the melting point of the inner plate; (4) Brazing: Put the component assembly into the brazing furnace, raise the furnace temperature to the set temperature, melt the outer plate and the solder sheet, complete the brazing, and make the parallel flow water cooling plate assembly. 2. The manufacturing method according to claim 1, characterized in that, N=1-10. 3. The manufacturing method according to claim 1, characterized in that each aluminum flat tube includes a top plate, a bottom plate and two side plates, wherein the top plate and the bottom plate are spaced apart along the height direction and parallel to each other, and each side plate The plate closes the same side of the top plate and the bottom plate in the width direction, and the thickness of the top plate and the bottom plate is 0.5±0.1mm. 4. The manufacturing method according to claim 1, characterized in that the material of the inner layer plate of the composite aluminum pipe is an aluminum alloy of grade 3003, and the material of the outer layer plate is an aluminum alloy of grade 4045; during the brazing process, the furnace The set temperature is 610-620℃. 5. The manufacturing method according to claim 1, characterized in that the height of the aluminum flat tube is 8.0-8.2mm. 6. The manufacturing method according to claim 1, characterized in that each plug is stamped from a whole piece of composite aluminum plate, and the plug includes a main body and a sealing part arranged around the main body, and the main body is Forming a step shape with the sealing part, the main body part is tightly inserted into the composite aluminum pipe, and the sealing part is pressed against the end surface of the composite aluminum pipe; The composite aluminum plate includes a base plate and a brazing layer composited on the base plate. The brazing layer is located on the side of the base plate facing the composite aluminum pipe. 7. The manufacturing method according to claim 1, characterized in that the height of the mounting hole is the same as the height of the aluminum flat tube, and the width of the mounting hole is the same as the total width of the N aluminum flat tubes.