Compact printed circuit board heat exchanger for underwater vehicles

Abstract

This invention discloses a compact printed circuit board type heat exchanger for an underwater vehicle, comprising a heat exchanger core and a shell sleeved around it. Pressure plates are respectively provided at both ends of the heat exchanger core. The heat exchanger core includes multiple alternately sealed and stacked cold fluid plates and hot fluid plates, with fluid channels provided on the cold and hot fluid plates. The hot and cold working fluids flow counter-currently in the fluid channels to form heat exchange. The heat exchanger core adopts a ring-column structure and is fixedly sleeved on the underwater vehicle, which indirectly increases the thickness of the underwater vehicle shell, thus reducing the design thickness of the underwater vehicle shell. Secondly, a vacuum insulation cavity is formed between the shell and the heat exchanger core, reducing coupled heat transfer and ensuring efficient operation of the heat exchanger. When the core expands at high temperatures, a margin is provided for thermal expansion during the heat exchange process, reducing the influence of seawater outside the shell on heat exchange and improving the safety of the heat exchanger.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology, specifically to a compact printed circuit board heat exchanger for an underwater transport vehicle. Background Technology

[0002] Heat exchangers are essential general-purpose industrial equipment, playing a crucial role in fields such as chemical engineering, energy, and agriculture. For underwater vehicles, heat exchangers are a vital component of their propulsion systems, and their heat exchange capacity determines the vehicle's speed and range. However, traditional heat exchangers in underwater platforms are bulky and heavy, and their heat exchange performance is significantly affected by underwater swaying conditions, limiting the vehicle's operational performance. Therefore, improving the compactness of heat exchangers, enhancing operational stability, and ensuring heat exchange capacity while reducing weight and size are of paramount importance.

[0003] Printed circuit board heat exchangers (PCHEs) are plate heat exchangers that utilize all-solid-state welding. Channel structures are formed on the plates using chemical etching technology, and the heat exchanger core is formed by vacuum diffusion welding. No additional solder is required, resulting in high-quality welding between the plates and a core strength exceeding 95% of the base material. These heat exchangers offer advantages such as high heat transfer efficiency, compact size, high temperature and pressure resistance, and low leakage, meeting the requirements for heat exchangers in underwater vehicles. However, their typically rectangular shape necessitates an additional mounting platform when used in underwater vehicles. Furthermore, when facing high heat transfer power demands, PCHEs need to be designed to be very long, but this is constrained by the length of the diffusion welding furnace and the welding quality. Although multiple baffle designs are often employed in the process, pressure losses are significant at the baffle bends, and axial heat conduction is also a serious problem. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a compact printed circuit board heat exchanger for underwater vehicles, used in underwater vehicle heat exchange systems. This compact printed circuit board heat exchanger has a compact structure and improves heat exchange efficiency.

[0005] This invention is achieved through the following technical solution:

[0006] A compact printed circuit board type heat exchanger for an underwater vehicle includes a heat exchanger core, which is covered by a shell. A vacuum insulation cavity is provided between the heat exchanger core and the shell. A clamping plate is provided at both ends of the heat exchanger core. The heat exchanger core includes a plurality of alternating sealed and stacked cold fluid plates and hot fluid plates.

[0007] One side of each hot fluid plate is provided with an annular hot-side flow channel, and the two ends of the hot-side flow channel are respectively connected to a hot fluid inlet and a hot fluid outlet, which are used to connect the outlet and inlet of the heat source of the underwater vehicle. The hot fluid inlet and hot fluid outlet of each hot fluid plate are coaxially arranged and connected. One side of each cold fluid plate is provided with an annular cold-side flow channel, and the two ends of the cold-side flow channel are respectively connected to a cold fluid inlet and a cold fluid outlet, which are used to connect the outlet and inlet of the cold source of the underwater vehicle. The cold fluid inlet and cold fluid outlet of each cold fluid plate are coaxially arranged and connected.

[0008] Preferably, both the hot-side flow channel and the cold-side flow channel are provided with multiple concentric support rings, dividing the hot-side flow channel and the cold-side flow channel into multiple channels from the inside out, and the support rings of each plate are coaxially arranged.

[0009] Preferably, the width of the plurality of flow channels decreases sequentially from the inside to the outside.

[0010] Preferably, the flow channel is a linear flow channel, a Z-shaped flow channel, or an S-shaped flow channel.

[0011] Preferably, the housing includes multiple annular shell plates, which are respectively fitted over the cold fluid plate and the hot fluid plate. The shell plates are connected to the fluid plates by support strips. When the cold fluid plate or the hot fluid plate is stacked alternately, the multiple annular shell plates form the housing.

[0012] Preferably, a vacuum groove is provided between the shell plate and the fluid plate.

[0013] Preferably, the working fluid in the hot-side flow channel and the cold-side flow channel flows in opposite directions.

[0014] Preferably, the heat exchanger core is provided with an axially arranged hot flow main inlet channel, cold flow main inlet channel and cold flow main outlet channel;

[0015] The total hot flow inflow channel is connected to the inlet of the hot side flow channel of the hot fluid plate, the total cold flow inflow channel is connected to the inlet of the cold side flow channel of each cold fluid plate, and the total cold flow outflow channel is connected to the outlet of the cold side flow channel of each cold fluid plate.

[0016] Preferably, a vacuum insulation cavity is provided between the total heat flow channel and the total cold flow channel.

[0017] Preferably, the outlet of the hot-side flow channel is located on the inner annular wall of the hot fluid plate.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] This invention provides a compact printed circuit board heat exchanger for an underwater vehicle, comprising a heat exchanger core formed by alternating stacks of multiple cold fluid plates and hot fluid plates. Fluid channels are provided on the cold and hot fluid plates, and the hot and cold working fluids flow counter-currently in the fluid channels to form heat exchange. The heat exchanger core adopts a ring-cylinder structure and is fixedly sleeved on the underwater vehicle, which indirectly increases the thickness of the underwater vehicle shell, thereby reducing the design thickness of the underwater vehicle shell and eliminating the need for an additional heat exchanger fixing platform. At the same time, other shell sections of the underwater vehicle can be used to bear the pressure on the upper and lower sides of the cylindrical heat exchanger, thus eliminating the need for a thick clamping plate, reducing space occupation and overall weight. Secondly, a shell is provided outside the heat exchanger core, and a vacuum insulation cavity is formed between the shell and the heat exchanger core to reduce coupled heat transfer and ensure efficient operation of the heat exchanger. When the core expands at high temperature, a margin is provided for thermal expansion during the heat exchange process, reducing the impact of seawater outside the shell on heat exchange and improving the safety of the heat exchanger. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the printed circuit board heat exchanger of the present invention;

[0021] Figure 2 This is a schematic diagram of the heat fluid plate of the present invention;

[0022] Figure 3 This is a schematic diagram of the cold fluid plate of the present invention.

[0023] In the diagram: 1-Upper clamping plate, 2-Cold fluid plate, 3-Hot fluid plate, 4-Lower clamping plate, 5-Hot side axial total inlet, 6-Cold side axial total inlet, 7-Cold side axial total outlet, 8-Hot side radial total outlet, 9-Hot side flow channel, 10-Hot side inlet guide area, 11-Hot fluid inlet, 12-Cold fluid outlet, 13-Inlet and outlet vacuum insulation groove, 14-Shell flow channel vacuum insulation groove, 15-Cold fluid inlet, 16-Hot fluid outlet, 17-Hot fluid plate support bar, 18-Shell, 19-Cold fluid plate support bar, 20-Cold side flow channel, 21-Cold side outlet guide area. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings. These descriptions are intended to explain the invention and not to limit it.

[0025] See Figure 1-3 A compact printed circuit board type heat exchanger for an underwater vehicle includes a heat exchanger core and pressure plates pressed at both ends thereon. The heat exchanger core includes a plurality of alternatingly sealed stacked cold fluid plates 2 and hot fluid plates 3.

[0026] One side of the hot fluid plate 3 is provided with an annular hot-side channel 9, and the two ends of the hot-side channel are respectively connected to the hot fluid inlet 11 and the hot fluid outlet 16. The hot fluid inlet 11 and the hot fluid outlet 16 of each hot fluid plate 3 are coaxially arranged and connected. The hot fluid inlet 11 and the hot fluid outlet 16 form a hot circulation path with the heat source of the underwater vehicle. One side of the cold fluid plate 2 is provided with an annular cold-side channel 20, and the two ends of the cold-side channel 20 are respectively connected to the cold fluid inlet 15 and the cold fluid outlet 12. The cold fluid inlet 15 and the cold fluid outlet 12 of each cold fluid plate 2 are coaxially arranged and connected. The cold fluid inlet 15 and the cold fluid outlet 12 form a cold circulation path with the cold source of the underwater vehicle.

[0027] See Figure 2 The hot fluid plate 3 has a ring structure. The hot side channel 9 is processed on one end face of the hot fluid plate 3 using the PCHE method. Multiple concentric support rings are set in the hot side channel 9, which divides the hot side channel 9 into multiple heat exchange channels from the inside to the outside. At the same time, the support rings provide pressure support for two adjacent hot fluid plates 3 and cold fluid plates 2. The support rings of each hot fluid plate 3 are coaxially arranged, which provides rigid support for the entire heat exchanger core. This saves space for arranging a fixed platform for the entire heat exchanger, while also increasing the thickness of the submersible hull and improving the pressure resistance of the submersible.

[0028] The width of the multiple heat exchange channels decreases sequentially from the inside to the outside. Since the heat exchange channels are in the form of a ring, the inner channel is relatively short. Therefore, the inner channel is widened to balance the heat exchange between the inner and outer sides, so that the heat exchange capacity of each heat exchange channel is the same. The heat exchange channels are linear, Z-shaped, or S-shaped, which increases the optimization space for heat exchange and flow resistance and can meet the design requirements of multiple heat exchange conditions.

[0029] The hot fluid inlet 11 is a rectangular hole opened in the hot fluid plate 3. The hot fluid inlet 11 is connected to multiple heat exchange channels through the hot side inlet guide area. The hot fluid outlet 16 is opened on the inner ring wall of the hot fluid plate 3. The hot fluid outlet 16 is arranged at a right angle to the hot side channel 9. The connection between the hot fluid outlet 16 and the hot side channel 9 adopts an arc transition to reduce the flow resistance of the heat working fluid. The hot fluid plate 3 also has a cold fluid outlet 12 and a cold fluid inlet 15. The cold fluid outlet 12 is located inside the hot fluid inlet 11, and the cold fluid inlet 15 is located on the ring side of the cold fluid outlet 12. An inlet and outlet vacuum insulation groove 13 is provided between the cold fluid inlet 15 and the cold fluid outlet 12.

[0030] An annular shell 18 is coaxially arranged on the outer side of the heat fluid plate 3. An annular shell-flow channel vacuum insulation groove 14 is provided between the inner wall of the shell 18 and the outer wall of the heat fluid plate 3. The inner wall of the shell 18 and the outer wall of the heat fluid plate 3 are connected by multiple heat fluid plate support strips 17, which are evenly distributed in an annular shape.

[0031] See Figure 3 The cold fluid plate 2 has a ring structure. The cold side channel 20 is formed on one side end face of the cold fluid plate 2 by photochemical etching or mechanical processing. Multiple concentric support rings are provided in the cold side channel 20, dividing the cold side channel 20 into multiple cold channels from the inside to the outside. The arrangement of the support rings is the same as that of the hot fluid plate 3, and the support rings of the cold fluid plate 2 and the support rings of the hot fluid plate 3 have the same diameter and are arranged coaxially.

[0032] The cold fluid outlet 12 and the cold fluid inlet 15 are two rectangular holes opened on the cold fluid plate 2. A vacuum groove is provided between the cold fluid outlet 12 and the cold fluid inlet 15. The cold fluid outlet 12 is connected to the end of the cold side flow channel through the cold side outlet guide area. A hot fluid inlet 11 is also opened on the cold fluid plate 2.

[0033] An annular shell 18 is coaxially arranged on the outer side of the cold fluid plate 2. An annular shell-channel vacuum insulation groove 14 is provided between the inner wall of the shell 18 and the outer wall of the cold fluid plate 2. The inner wall of the shell 18 and the outer wall of the hot fluid plate 3 are connected by multiple cold fluid plate support strips 19. The multiple cold fluid plate support strips 19 are evenly distributed in an annular shape and are arranged in a staggered circumferential arrangement with the hot fluid plate support strips 17 to reduce the coupling heat transfer between the cold fluid plate and the hot fluid plate.

[0034] See again Figure 1 The heat exchanger core is composed of several cold fluid plates 2 and hot fluid plates 3 stacked alternately. The hot fluid inlet 11, hot fluid outlet 16, cold fluid inlet 15 and cold fluid outlet 12 on each cold fluid plate 2 and hot fluid plate 3 are arranged coaxially. Therefore, the heat exchanger core forms an axially arranged total hot flow inlet channel, total cold flow inlet channel and total cold flow outlet channel. The total hot flow inlet channel is connected to the hot fluid inlet 11 of each hot fluid plate 3, the total cold flow inlet channel is connected to the cold fluid inlet 15 of each cold fluid plate 2, and the total cold flow outlet channel is connected to the hot fluid inlet 11 of each cold fluid plate 2.

[0035] The clamping plate includes an annular upper clamping plate 1 and a lower clamping plate 4, which are press-fitted onto both ends of the heat exchanger core. The lower clamping plate 4 seals the ends of the total hot flow inlet channel, the total cold flow inlet channel, and the total cold flow outlet channel. The upper clamping plate 1 is provided with a hot-side axial total inlet 5, a cold-side axial total inlet 6, and a cold-side axial total outlet 7. The hot-side axial total inlet 5 is connected to the total hot flow inlet channel, the cold-side axial total inlet 6 is connected to the total cold flow inlet channel, and the cold-side axial total outlet 7 is connected to the total cold flow outlet channel. A hot-side radial total outlet 8 is formed on the annular inner wall of the heat exchanger core. The cold-side axial total inlet 6 is connected to the cold source outlet of the underwater vehicle, the cold-side axial total outlet 7 is connected to the cold source inlet of the underwater vehicle, the hot-side axial total inlet 5 is connected to the heat source outlet of the underwater vehicle, and the hot-side radial total outlet 8 is connected to the heat source inlet of the underwater vehicle.

[0036] The cold fluid plate and its connected housing, as well as the hot fluid plate and its connected housing, are all integrally formed. The material is stainless steel, aluminum alloy, titanium alloy, or copper alloy. The processing method is photochemical etching or mechanical processing. The width of the support strip of the flow channel is 1-4mm, the thickness of the cold fluid plate and the hot fluid plate is 1-4mm, and the depth of the flow channel is 0.5-3mm.

[0037] The hot and cold side channels have rectangular, semi-circular, and elliptical cross sections. They can be processed by photochemical etching or mechanical machining. Their hydraulic diameter is 1-3 mm. The inner heat exchange channel is wider than the outer one, which is intended to make the heat exchange between the inner and outer channels more uniform.

[0038] This printed circuit board heat exchanger uses vacuum diffusion welding to bond adjacent cold fluid plates and hot fluid plates together to form an annular cylindrical heat exchanger. A vacuum insulation cavity is formed between the heat exchanger core and the shell. The cavity is filled with insulating material and then sealed after being evacuated to reduce coupled heat transfer and ensure efficient operation of the heat exchanger. When the core expands at high temperatures, a margin is provided for thermal expansion during the heat exchange process, reducing the impact of seawater outside the shell on heat exchange and improving the safety of the heat exchanger. Secondly, this printed circuit board heat exchanger is processed into an integrated pressure-bearing device with the submersible shell, which can reduce the design thickness of the shell and increase the thickness of the underwater vehicle shell, thereby improving its pressure-bearing capacity. It also eliminates the need for an additional heat exchanger fixing platform, and other shell sections can be used to bear the pressure on the upper and lower sides of the cylindrical heat exchanger. Therefore, a thicker clamping plate is not required, reducing space occupation and overall weight. In addition, the heat exchanger is made of stainless steel, aluminum alloy, copper alloy, or titanium alloy with high welding quality and can withstand seawater and carbon dioxide environments.

[0039] The working principle of the printed circuit board heat exchanger provided by the present invention will be explained below.

[0040] The hot fluid flows in from the axial total inlet 5 on the hot side, enters the hot fluid inlet 11 corresponding to the hot fluid plate 3, enters the hot side flow channel 9 through the hot side inlet guide zone 10, and after heat exchange is completed in the counterclockwise direction, it flows out from the hot fluid outlet 16 and enters the heat source inlet of the underwater carrier.

[0041] The cold fluid flows in from the cold-side axial main inlet 6, enters the cold fluid inlet 15 corresponding to the cold fluid plate 2, and then flows into the cold-side flow channel 20. It flows counter-currently to the hot fluid in a clockwise direction. After heat exchange, it flows out from the cold fluid outlet 12 through the cold-side outlet guide zone 21 and converges at the cold-side axial main outlet 7 before flowing out to the cold source inlet of the underwater transport vehicle. The hot fluid outlet 16, the hot-side axial main inlet 5, the cold-side axial main inlet 6, and the cold-side axial main outlet 7 all feature rounded corner designs to prevent dead zones during the working fluid flow. All the aforementioned main inlet and outlet guide forms can be converted according to actual operating conditions and space constraints.

[0042] This printed circuit board heat exchanger utilizes vacuum diffusion welding technology to solid-state weld the upper pressure plate, several hot fluid plates, cold fluid plates, and the lower pressure plate. The inlet and outlet areas of each heat exchange plate form the inlet and outlet of the entire heat exchanger fluid. Vacuum diffusion welding is used to solid-state connect and form a ring-column heat exchanger core structure, resulting in high flow channel precision, high processing efficiency, minimal plate deformation, high core strength, and low leakage. Due to the ring-column structure, which conforms to the shell shape, vacuum diffusion welding can simultaneously fabricate a pressure-bearing device, effectively increasing the shell thickness and providing stability for the heat exchanger. The annular flow channel significantly extends the heat exchange channel length of traditional cuboid PCHEs while exhibiting lower flow resistance than PCHEs using multi-stage baffled flow channels.

[0043] The heat exchange plates have axial corner hole and radial flow guiding forms for fluid inlet and outlet. Hot fluid flows in from the axial inlet of the annular columnar heat exchanger core, is split once through several hot fluid plates, and then flows into each heat exchange channel in the plates. It flows to the outlet area and flows out from the radial inner side of the columnar core through the radial flow guiding channel. Cold fluid flows in from the axial inlet of the annular columnar heat exchanger core, is split once through several cold fluid plates, and then flows into each heat exchange channel in the plates. It flows in the opposite direction to the hot fluid in a spatial parallel space and flows out from the axial outlet of the columnar core. The hot-side axial total inlet 5, cold-side axial total inlet 6, and cold-side axial total outlet 7 of this invention adopt a corner hole type flow guiding method. The fluid flows into the heat exchange plates along the axial direction of the column and flows into and out of the heat exchange channels along the radial direction of the column. The hot-side radial total outlet 8 adopts a baffle flow guiding method so that the fluid can flow out radially.

[0044] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A compact printed circuit board heat exchanger for an underwater transport vehicle, characterized in that, It includes a heat exchanger core, which is fitted with a shell. A vacuum insulation cavity is provided between the heat exchanger core and the shell. A clamping plate is provided at both ends of the heat exchanger core. The heat exchanger core includes multiple alternating sealed stacked cold fluid plates (2) and hot fluid plates (3). One side of the hot fluid plate (3) is provided with an annular hot side channel (9), and the two ends of the hot side channel are respectively connected to the hot fluid inlet (11) and the hot fluid outlet (16), which are used to connect the outlet and inlet of the heat source of the underwater vehicle. The hot fluid inlet (11) and the hot fluid outlet (16) of each hot fluid plate (3) are coaxially arranged and connected. One side of the cold fluid plate (2) is provided with an annular cold side channel (20), and the two ends of the cold side channel (20) are respectively connected to the cold fluid inlet (15) and the cold fluid outlet (12), which are used to connect the outlet and inlet of the cold source of the underwater vehicle. The cold fluid inlet (15) and the cold fluid outlet (12) of each cold fluid plate (2) are coaxially arranged and connected.

2. The compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 1, characterized in that, Both the hot-side flow channel (9) and the cold-side flow channel (20) are provided with multiple concentric support rings, which divide the hot-side flow channel (9) and the cold-side flow channel (20) into multiple flow channels from the inside to the outside, and the support rings of each plate are coaxially arranged.

3. A compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 2, characterized in that, The widths of the multiple flow channels decrease sequentially from the inside out.

4. A compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 2, characterized in that, The flow channel can be a linear flow channel, a Z-shaped flow channel, or an S-shaped flow channel.

5. A compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 1, characterized in that, The shell includes multiple annular shell plates, which are respectively fitted outside the cold fluid plate (2) and the hot fluid plate (3). The shell plates are connected to the fluid plates by support strips. When the cold fluid plate (2) or the hot fluid plate (3) are stacked alternately, the multiple annular shell plates form a shell.

6. A compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 5, characterized in that, A vacuum groove is provided between the shell plate and the fluid plate.

7. A compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 1, characterized in that, The working fluid flows in opposite directions in the hot side channel (9) and the cold side channel (20).

8. A compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 1, characterized in that, The heat exchanger core is provided with an axially arranged hot flow inflow channel, cold flow inflow channel and cold flow outflow channel; The total hot flow inflow channel is connected to the inlet of the hot side flow channel (9) of the hot fluid plate, the total cold flow inflow channel is connected to the inlet of the cold side flow channel (20) of each cold fluid plate (2), and the total cold flow outflow channel is connected to the outlet of the cold side flow channel (20) of each cold fluid plate (2).

9. A compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 8, characterized in that, A vacuum insulation cavity is provided between the main heat flow channel and the main cold flow channel.

10. A compact printed circuit board heat exchanger for an underwater transport vehicle according to claim 8, characterized in that, The outlet of the hot side flow channel (9) is located on the inner ring wall of the hot fluid plate.

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