CN111707115A - A Diffusion Welded Compact Heat Exchanger With Combined Heat Exchange Plates - Google Patents

Abstract

The invention relates to a diffusion-welded compact heat exchanger with combined heat exchange plates. The core part of the heat exchanger is composed of etched plates and ribbed plates. The etched plates are chemically etched to prepare micro flow channels, which are suitable for cleaning High-quality working fluid, the ribbed plates are machined to prepare larger flow channels, which are suitable for working fluids with low cleanliness. The combined use of the two flow channels reduces the requirement for the cleanliness of the working fluid; the two plates are alternately stacked And the heat exchange core body is formed by diffusion welding, which ensures the high temperature and high pressure resistance performance of the heat exchanger; the heat exchange core body does not need baffles to ensure the compactness of the heat exchanger; the ribbed plates can be processed into sufficient Rib width to meet diffusion welding requirements.

Description

A Diffusion Welded Compact Heat Exchanger With Combined Heat Exchange Plates

technical field

The invention relates to the technical field of heat exchange equipment, in particular to a diffusion-welded compact heat exchanger with combined heat exchange plates.

Background technique

Heat exchangers are general equipment for heat exchange and are widely used. Conventional shell-and-tube heat exchangers have problems such as low heat exchange efficiency and large volume and weight. Traditional plate heat exchangers and plate-fin heat exchangers have problems such as low temperature and pressure resistance, which are difficult to adapt to compact heat exchangers. It can be used in environments with high requirements for high temperature and high pressure resistance.

Printed circuit board heat exchanger (PCHE) is a new type of compact and high-efficiency heat exchanger. The heat exchanger uses chemical etching to prepare micro flow channels on the heat exchange plates. The heat exchange plates with different flow channels are superimposed on each other. The heat exchanger core is constructed by diffusion welding. The heat exchanger has the advantages of high heat transfer efficiency, strong high temperature resistance and high pressure resistance, small size and light weight, and the application effect is good. This type of heat exchanger has been introduced in detail in the prior art, especially in the form of the heat exchanger, the arrangement of the channels, the combination of the channels, and the enhanced heat exchange structure in the channels. However, limited by the chemical etching process, the size of the flow channel of the heat exchanger is small, and the cleanliness of the working fluid is very high. For the working fluid with low cleanliness such as seawater and flue gas, it is easy to cause large particles to block the flow It affects heat exchange and brings safety hazards, which limits the application scope of printed circuit board heat exchangers.

Chinese patent documents CN107782181A and CN106403688A disclose a heat exchange core structure of etched plates + formed plates + partitions. In this structure, the cross-sections of the formed plates are continuously arranged in a plurality of "ji" shapes, and the size of the flow channel is relatively large. It can pass the working fluid with low cleanliness. However, this technology still has the following shortcomings: 1) the thickness of the formed plate used is relatively thin, the pressure resistance is low, and the pressure of the working medium on the formed plate side cannot be too high; 2) when the entire core is prepared by diffusion welding , the rigidity of the "ji"-shaped structure of the formed plate is poor, and the fins in the vertical direction are easily collapsed. Therefore, the pressure of the indenter cannot be set too large during diffusion welding, which will affect the diffusion connection effect on the etched plate side, which in turn affects the The pressure resistance of the etched plate side; 3) This technology increases the complexity of the heat exchanger core, improves the manufacturing difficulty, and needs to set up more partitions to separate the etched plate and the forming plate, which increases the equipment weight, reduced compactness.

SUMMARY OF THE INVENTION

Aiming at the defects of the prior art, the purpose of the present invention is to provide a diffusion welded compact heat exchanger with combined heat exchange plates. The core part of the heat exchanger is composed of etched plates and ribbed plates. The etched plates The micro flow channel prepared by etching is suitable for the working fluid with high cleanliness. The ribbed plate is machined to form a larger size flow channel, which is suitable for the working fluid with low cleanliness. The combination of the two flow channels reduces the cleanliness of the working fluid. The etched plate and the ribbed plate are connected by diffusion welding to ensure the high temperature and high pressure resistance of the heat exchanger.

In order to achieve the above purpose, the technical scheme adopted in the present invention is: a compact heat exchanger with diffusion welding with combined heat exchange plates, comprising a heat exchange core body, a cold side head, a cold side pipe, and a hot side head The heat exchanger core is composed of etched plates and ribbed plates. The etched plates are chemically etched to prepare fluid channels, and the ribbed plates are machined on a flat plate. The fluid channel is prepared by removing material, two kinds of plates are alternately stacked, and the heat exchange core body is formed by a diffusion welding method.

Specifically, the etched plate is a single-sided etching fluid channel, the ribbed plate is single-sided to process the fluid channel, and the etched plate and the ribbed plate are alternately stacked in the form of a plane covering the opening surface of the flow channel, and the middle No partition required.

The fluid channels on the etched plate form hot-side or cold-side fluid channels, the fluid channels on the ribbed plate form cold-side or hot-side fluid channels, and the hot fluid and the cold fluid exchange heat in countercurrent.

The inlet and outlet of the fluid channel on the etched plate and the inlet and outlet of the fluid channel on the ribbed plate are staggered with each other, the inlet and outlet of the hot side fluid channel are respectively connected to the hot side head and the hot side nozzle, and the inlet and outlet of the cold side fluid channel are respectively connected. Connect the cold side head and the cold side nozzle respectively.

The inlet and outlet sections of the fluid channels on the etched plate are both perpendicular to the inlet and outlet sections of the fluid channels on the ribbed plate, and the middle section of the fluid channels on the etched plate is perpendicular to the ribbed plate. The middle segments of the fluid channels on the sheet are parallel.

The flow channel shapes of the etched plates and the ribbed plates are periodic S-shape, Z-shape or linear shape, or any combination of these shapes.

The cross-sectional shape of the fluid channel etched on the etched plate is semicircular, and the centerlines of the fluid channels are parallel to each other.

The cross-sectional shape of the fluid channel processed on the ribbed plate is rectangular, the centerlines of the fluid channels are parallel to each other, and rounded corners are arranged at the lower corners of the rectangular fluid channel.

A plurality of the heat exchange cores can be spliced into a larger core body by welding, and then together with the hot side head, the cold side head, the hot side pipe and the cold side pipe, form a larger heat exchanger.

beneficial effect

The heat exchange core of the present invention is formed by alternately stacking etched plates and ribbed plates through diffusion welding, and has the following advantages: (1) The etched plates are chemically etched to form micro flow channels, which are suitable for high cleanliness. Working fluid, the size of the semicircular flow passage is small, but the flow passages are dense, the heat exchange area is large, and the heat exchange effect is good; Large particles of impurities avoid blockage of the flow channel and reduce the requirements for the cleanliness of the working medium; the combination of etched plates and ribbed plates can realize the heat exchange between the high-cleanness working fluid and the low-cleanness working fluid , which expands the application range of compact heat exchangers; (2) The ribbed plate is prepared by machining from a flat plate, and the ribs can be processed into a sufficient width to meet the requirements of diffusion welding and ensure that the ribbed plate has a relatively high thickness. High pressure resistance; at the same time, it avoids that the rigidity is poor and the vertical fins are easily collapsed when the "ji" character is used to form the plate in the prior art, so that the pressure of the diffusion welding indenter should not be too large and thus affect the etching plate The problem of diffusion welding effect and pressure bearing capacity of the layer; (3) The rectangular fluid channel on the ribbed plate, and the lower corner is set to be rounded, which can reduce the flow dead zone and reduce the scaling; (4) Etch the plate and The ribbed plates can be arranged into various periodic flow channel structures, which can not only increase the heat exchange area, but also disturb the fluid, destroy the heat transfer boundary layer, enhance the heat exchange efficiency, and thus improve the compactness of the heat exchanger; (5) ) The present invention adopts the technical scheme of etched plate + ribbed plate to form a heat exchange core, compared with the method of using etched plate + formed plate + partition in the prior art, the setting of the partition is cancelled, and the It is difficult to manufacture, and further reduces the weight of the heat exchanger and improves the compactness of the heat exchanger; (6) Multiple heat exchange cores can be spliced into larger cores by welding, which can make up for the heat exchange effect of diffusion welding equipment. The height and size of the core are limited to meet the needs of heat exchangers with larger heat loads.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the heat exchanger of the present invention;

Figure 2 is a schematic diagram of the composition of the heat exchange core in the present invention;

3 is a schematic cross-sectional view of the middle section of the heat exchange core in the present invention;

4 is a schematic diagram of the structure of the hot side inlet of the heat exchange core in the present invention;

Fig. 5 is a schematic diagram of the structure of the cold side inlet of the heat exchange core in the present invention;

FIG. 6 is a schematic diagram of the flow process shape of the etched plate flow channel in the present invention;

Figure 7 is a schematic diagram of the flow process shape of a ribbed sheet flow channel in the present invention;

FIG. 8 is a schematic structural diagram of a heat exchanger formed by splicing a plurality of heat exchange cores in the present invention.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figures 1-2, a diffusion welded compact heat exchanger with combined heat exchange plates of the present invention includes a heat exchange core 1, a cold side head 2, a cold side pipe 3, and a hot side head 4 and the hot side connection 5; wherein, the heat exchange core 1 is composed of etched plates 101 and ribbed plates 102 stacked alternately; microfluidic channels are prepared on the etched plates 101 by chemical etching, and the The ribbed plate 102 is machined to prepare larger-sized fluid channels on a flat plate, two kinds of plates are alternately stacked, and the heat exchange core 1 is formed by diffusion welding. The flow channel processed by the chemical etching method is a micro flow channel, which has a smaller size and is suitable for the working fluid with high cleanliness. The flow channel obtained by the machining method has a larger size and is suitable for the working fluid with low cleanliness. The combined use of the flow channels reduces the requirements for the cleanliness of the working fluid and broadens the application scope of the heat exchange core.

Both the etched plate 101 and the ribbed plate 102 are processed with flow channels on one side, and the other side is flat. When the two are alternately stacked, as shown in Figure 2-3, the ribbed plate 102 is processed with a flow channel on one side and etched on the other side. The plane of the plate 101 is connected, the flow channel surface of the etched plate 101 is connected to the plane of another ribbed plate 102, and the flow channel surface of the other ribbed plate 102 is connected to the plane of the other etched plate 101, By analogy, a closed flow channel can be formed without a partition in the middle, the structure is compact, and the weight of the heat exchanger can be effectively reduced.

The fluid channel on the etched plate 101 constitutes a hot-side (or cold-side) fluid channel, the fluid channel on the ribbed plate 102 constitutes a cold-side (or hot-side) fluid channel, and the hot fluid and the cold fluid are in countercurrent flow For heat exchange, the inlet and outlet of the hot-side fluid channel and the cold-side fluid channel are staggered. The inlet and outlet of the hot-side fluid channel are respectively connected to the hot-side head 4 and the hot-side nozzle 5, and the inlet and outlet of the cold-side fluid channel are respectively connected to the cold-side seal. The head 2 and the cold side connecting pipe 3 , the hot side sealing head 4 and the cold side sealing head 2 are distributed on different sides of the heat exchange core 1 .

The inlet section and outlet section of the flow channel of the etched plate 101 are both perpendicular to the inlet section and the outlet section of the flow channel of the ribbed plate 102, and the middle section of the flow channel of the etched plate 101 is perpendicular to the ribbed plate. The middle segments of the sheets 102 are parallel.

The ribbed sheet 102 is formed by machining grooves on the flat plate by removing material, that is, fluid channels. Compared with the prior art, the ribbed sheet obtained by processing solid materials is formed by bending a thin sheet. The heat exchange plate has higher strength. During processing, the ribs between adjacent flow channels can be processed to have a sufficient width to ensure that the ribbed plate 102 has sufficient strength, is not easily deformed, and can adapt to diffusion welding.

The fluid channel prepared by chemical etching on the etched plate 101 has a semicircular cross-sectional shape, and the centers of the flow channels are parallel to each other. a), (b), and (c) respectively show the linear, periodic Z-shaped and periodic S-shaped flow channel flow shapes on the etched plate 101. Of course, the above are only examples, but not limited to this. The cross-sectional shape of the flow channel and the shape of the flow channel of the plate 101 may also be other shapes obtained by those skilled in the art through routine transformation.

The cross section of the fluid channel on the ribbed plate 102 is rectangular, and the corners on the lower side of the channel are provided with rounded corners to reduce the flow dead zone and prevent scale accumulation. The center lines of the fluid channels are parallel to each other, and the flow shape is linear or periodic Z , S-shape, etc. Figure 7(a), (b), (c) respectively show the linear, periodic Z-shape and periodic S-shape flow channel flow shapes on the ribbed plate 102. Of course, the above only As an example, but not limited thereto, the cross-sectional shape of the flow channel and the flow shape of the flow channel of the ribbed plate sheet 102 may also be other shapes obtained by those skilled in the art through conventional transformation.

The etched plate 101 and the ribbed plate 102 can use the same flow shape, or different flow shapes can be used in combination to meet different requirements for enhancing heat exchange or reducing flow resistance.

FIG. 4 is a partial schematic view of the hot side inlet of the heat exchanger core 1 shown in FIG. 1 . At the hot side inlet, the hot side fluid enters the semicircular fluid channel uniformly, and FIG. 5 is the heat exchanger core 1 shown in FIG. 1 . Partial schematic diagram of the cold side inlet, where the cold side fluid enters the rectangular fluid channel uniformly.

As shown in FIG. 8 , a plurality of the heat exchange cores 1 can be spliced into a larger core body by welding, and then formed with a hot-side head, a cold-side head, a hot-side connecting pipe and a cold-side connecting pipe Larger heat exchangers to meet the demands of larger heat loads.

The working process of the heat exchanger is as follows: the cold and hot side fluids enter the channels of the cold side and the hot side of the heat exchange core from the cold and hot side inlet pipes respectively, and the fluids on both sides fully exchange heat, and then flow out through the outlet pipe for heat exchange. device.

The technical solutions and embodiments listed in the present invention are not intended to be limiting, and solutions that are equivalent or have the same effect as the technical solutions and embodiments listed in the present invention are all within the scope of protection of the present invention.

Claims (9)

1. A diffusion welding compact heat exchanger with combined heat exchange plates comprises a heat exchange core body, a cold side end socket, a cold side connecting pipe, a hot side end socket and a hot side connecting pipe, and is characterized in that the heat exchange core body is composed of etching plates and ribbed plates, the etching plates are used for preparing fluid channels by adopting a chemical etching method, the ribbed plates are used for preparing the fluid channels on a flat plate by adopting a machining method in a material removing mode, the two plates are alternately stacked, and the heat exchange core body is formed by a diffusion welding method.

2. The diffusion-welded compact heat exchanger with assembled heat exchange plates according to claim 1, wherein the etched plates are etched on one side to form fluid channels, the ribbed plates are machined on one side to form fluid channels, and the etched plates and the ribbed plates are alternately stacked in a manner that the planes cover the open surfaces of the flow channels without a partition plate in between.

3. A diffusion-welded compact heat exchanger with assembled heat exchanger plates according to claim 1, characterized in that the fluid channels of the etched plates form hot-side or cold-side fluid channels, the fluid channels of the ribbed plates form cold-side or hot-side fluid channels, and hot and cold fluids exchange heat in countercurrent.

4. The diffusion-welded compact heat exchanger with the combined heat exchange plates as recited in claim 1, wherein the inlet and outlet of the fluid channel on the etched plate and the inlet and outlet of the fluid channel on the ribbed plate are staggered, the inlet and outlet of the hot-side fluid channel are respectively connected with the hot-side end socket and the hot-side connecting pipe, and the inlet and outlet of the cold-side fluid channel are respectively connected with the cold-side end socket and the cold-side connecting pipe.

5. A diffusion-welded compact heat exchanger with assembled heat exchanger plates according to claim 1, characterized in that the inlet and outlet sections of the fluid channels on the etched plates are perpendicular to the inlet and outlet sections of the fluid channels on the ribbed plates, and the middle sections of the fluid channels on the etched plates are parallel to the middle sections of the fluid channels on the ribbed plates.

6. The diffusion-welded compact heat exchanger with combined heat exchange plates as recited in claim 1 in which the flow path shapes of the etched and ribbed plates are periodic S-shaped, Z-shaped, or linear, or any combination thereof.

7. The diffusion-welded compact heat exchanger with assembled heat exchange plates as recited in claim 1 in which the etched plates have etched flow channels with semi-circular cross-sectional shapes and the flow channels have their centerlines parallel to each other.

8. The diffusion-welded compact heat exchanger with combined heat exchange plates as recited in claim 1 in which the cross-sectional shape of the fluid channel formed on the ribbed plates is rectangular, the center lines of the fluid channels are parallel to each other, and the corners of the lower side of the rectangular fluid channel are provided with rounded corners.

9. The diffusion-welded compact heat exchanger with combined heat exchange plates as recited in claim 1 in which a plurality of said heat exchange cores can be spliced into a larger core by welding, and then the larger core, the hot side end socket, the cold side end socket, the hot side connecting pipe and the cold side connecting pipe form a larger heat exchanger.

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