CN116182600A - Brayton cycle integrated heat exchanger and heat exchange method of a submarine vehicle - Google Patents

Abstract

The invention discloses a Brayton cycle integrated heat exchanger and heat exchange method for a submarine, comprising a heat recovery module and a pre-cooling module; the heat recovery module includes several alternately stacked heat flow plates and cold flow plates, The pre-cooling module is sleeved on the outside of the heat recovery module, and there is a vacuum insulation cavity between the pre-cooling module and the heat recovery module; the heat exchanger is integrally processed with the shell of the submarine, and the heat exchanger is used as a heat exchanger part of the submersible, which increases the thickness of the submersible’s shell and improves its pressure resistance. At the same time, it can reduce the thickness of the submersible’s shell and reduce its own weight. A vacuum chamber is set between the reheating module and the pre-cooling module. After the first heat exchange between the fluid and the cold fluid in the regenerator, it enters the pre-cooler for secondary heat exchange with the seawater outside, which improves the heat exchange efficiency, reduces the coupling through the vacuum insulation chamber, and provides the regenerator Thermal expansion reserves deformation space to improve the operating safety of the submersible.

Description

Brayton cycle integrated heat exchanger and heat exchange method of a submarine vehicle

technical field

The invention relates to the technical field of submarine vehicle heat exchange, in particular to a Brayton cycle integrated heat exchanger and a heat exchange method for a submarine vehicle.

Background technique

The ocean is an important strategic location for high-quality development, involving resources, military and other important fields. With the development of submarines such as YL and heavy-duty UUV, our country is moving towards building a marine power. Small submersibles mainly use electric power, while large submersibles basically use thermal power. The thermal power system includes steam Rankine cycle system and Brayton cycle system.

Conventional thermal power is mainly the steam Rankine cycle, but the power system has a large volume and mass, and the thermal efficiency is not high. The supercritical carbon dioxide Brayton cycle has low compression power consumption, high efficiency, and more compact structure, which is the development trend of future underwater thermal power systems. The heat exchange equipment of the Brayton cycle system mainly includes a regenerator and a precooler, and its heat exchange capacity restricts the system efficiency. At the same time, when it is applied to a submarine, it faces difficulties such as limited space, high temperature and high pressure of the working medium. Therefore, it is very important to design and develop a high-efficiency and high-safety supercritical carbon dioxide Brayton cycle heat exchanger for submersibles.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a Brayton cycle integrated heat exchanger of a submersible. The heat exchanger has a compact structure, has the characteristics of high temperature and high pressure resistance, and improves the underwater operation safety of the submersible.

The present invention is realized through the following technical solutions:

A Brayton cycle integrated heat exchanger of a submersible, including a heat recovery module and a precooling module;

The heat recovery module is a hollow columnar structure, which includes several alternately stacked hot flow plates and cold flow plates, the end faces of the hot flow plates are formed with hot side flow channels, and the end faces of the cold flow plates are formed with cold side flow channels;

The pre-cooling module is sleeved on the outside of the heat recovery module, and there is a vacuum insulation chamber between the pre-cooling module and the heat recovery module. The pre-cooling module includes several shell plates, and one side of the shell plate is provided with a pre-cooling flow channel ;

The outlets of the hot-side runners are respectively connected to the pre-cooling runners of the concentric shells and the inlets of the pre-cooling runners of the lower shell. After the hot fluid in the hot-side runners exchanges heat with the cold fluid in the cold-side runners, respectively The pre-cooling passages entering the two adjacent shell plates exchange heat with the external environment of the submersible and then flow out.

Preferably, both the hot-side runner and the cold-side runner are provided with a plurality of concentric splitter rings, which divide the hot runner into a plurality of splitters, and the widths of the plurality of splitters gradually decrease from inside to outside.

Preferably, the splitter rings of the cold flow plate and the hot flow plate are arranged with the same diameter.

Preferably, a vacuum heat insulation groove is provided between the hot flow plate and the cold flow plate and the same-plane shell plate, and a plurality of ribs are arranged in the vacuum heat insulation layer and are uniformly distributed on the circumference, and are used to connect the same plane shell plate And hot flow plate or or cold flow plate.

Preferably, the outlet of the hot-side flow channel communicates with the pre-cooling flow channel of the same plane shell plate through the flow channel, and the flow channel is provided with a split hole, and the split hole communicates with the inlet of the pre-cooling flow channel of the lower shell plate.

Preferably, the pre-cooling flow channel includes two semi-circular flow channels, and the hot fluid flows in opposite directions in the two flow channels.

Preferably, the inlet of the pre-cooling channel is provided with a divider plate, and the outlet of the pre-cooling channel is provided with a partition.

Preferably, the working fluids in the hot-side flow channel and the cold-side flow channel flow in opposite directions.

Preferably, flow turbulence structures are arranged in the hot-side flow channel and the cold-side flow channel.

A heat exchange method for a Brayton cycle integrated heat exchanger of a submersible, comprising the following processes:

The hot fluid of the Brayton cycle system flows into the hot side flow channel of each hot flow plate, and the cold fluid of the Brayton cycle flows into the cold side flow channel of each cold flow plate. The hot fluid and the cold fluid flow in reverse for heat exchange, and the heated cold fluid Entering the Brayton cycle system, the cooled thermal fluid enters the pre-cooling flow channel corresponding to the hot flow plate and the lower cold flow plate after splitting, and the thermal fluid enters the Brayton cycle system after secondary heat exchange with seawater in the pre-cooling flow channel.

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

The invention provides a brayton cycle integrated heat exchanger of a submarine, the heat exchanger is integrally processed with the shell of the submarine, and the heat exchanger is used as a part of the shell to increase the thickness of the shell of the submarine and improve the Its pressure resistance can reduce the weight of the submersible. A vacuum chamber is set between the heat recovery module and the pre-cooling module. The secondary heat exchange improves the heat exchange efficiency. Compared with the traditional rectangular printed circuit board heat exchanger, the annular flow channel can process longer flow channels, and the flow resistance is smaller than that of the multi-stage baffle flow channel; because The length of the inner flow channel of the circumference is shorter, so the width of the inner side of the plate heat exchange flow channel is wider than that of the outer side, so that the heat exchange of the inner and outer flow channels is more uniform; secondly, the coupling heat transfer is reduced through the vacuum insulation cavity, and for The thermal expansion of the regenerator reserves space for deformation to improve the operating safety of the submersible. The entire heat exchanger is used as a pressure-bearing part of the submersible, which saves the space required for arranging a fixed platform for the heat exchanger.

Description of drawings

Fig. 1 is a schematic diagram of the explosion of the core body of the heat exchanger of the present invention.

Fig. 2 is a schematic diagram of the thermal fluid plate of the present invention.

Fig. 3 is a schematic diagram of the cold fluid plate of the present invention.

In the figure: In the figure: 1-upper compression plate, 2-hot flow plate, 3-cold flow plate, 4-lower compression plate, 5-separation partition, 6-pre-cooling runner, 7-vacuum insulation tank , 8-cold side runner, 9-cold side axial outlet, 10-hot side axial inlet, 11-shell piece 11, 12-cold side axial inlet, 13-split hole, 14-hot side runner, 15-Pre-cooling outlet.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings, which are explanations rather than limitations of the present invention.

Referring to Figure 1, a Brayton cycle integrated heat exchanger of a submarine includes a heat recovery module and a precooling module.

The heat recovery module is a hollow columnar structure, which includes several alternately stacked hot flow plates 2 and cold flow plates 3. The end faces of the hot flow plates 2 are formed with hot side channels 14, and the end faces of the cold flow plates 3 are formed with cold side channels. Runner 8; the pre-cooling module includes several pre-cooling runners, which are arranged on the hot runner plate 2 and the cold runner plate 3 respectively, and the pre-cooling runners are sleeved outside the hot-side runner 14 and the cold-side runner 8 .

Along its axial direction, the heat recovery module is provided with a hot flow axial flow channel, a precooling module axial flow outlet, a cold flow axial flow channel and a cold flow axial flow channel, and each hot side flow channel 14 The inlet is connected with the heat flow axially entering the flow channel, and the outlets of each hot side flow channel 14 are respectively connected with the inlet of the pre-cooling flow channel on the same heat flow plate and the inlet of the pre-cooling flow channel on the lower cold flow plate 3. The outlet and the inlet of the channel communicate with the cold flow axial inlet channel and the cold flow axial outlet channel respectively.

Referring to Fig. 2, the heat flow plate is an annular plate, and its inner diameter is the same as the outer diameter of the submersible. The side axial inlet 10 and the split hole 13, the inlet of the hot side flow channel 14 communicates with the hot side axial inlet 10, the outlet of the hot side flow channel 14 communicates with the split hole 13, and the split hole 13 is respectively connected with the pre-cooling flow of the hot flow plate. channel and the pre-cooling flow channel of the cold flow plate 3, that is, the hot fluid enters the hot side flow channel 14 through the hot side axial inlet 10, and then flows to the split hole 13, and the split hole divides the hot fluid into two paths, respectively entering In the pre-cooling flow channel 6 of the heat flow plate and the pre-cooling flow channel of the lower cold flow plate, the hot fluid in the two pre-cooling flow channels enters the Brayton cycle system from the outlet of the pre-cooling flow channel into the axial flow outlet of the pre-cooling module.

The hot-side runner 14 is provided with a plurality of concentric shunt rings, and the plurality of shunt rings are arranged at intervals from inside to outside, so as to divide the hot runner into a plurality of shunts, and the widths of the multiple shunts gradually decrease from the inside to the outside. , because the length of the runners in the circumference is shorter, the width of the inner runners is greater than the width of the outer runners, so that the heat transfer of each runner is more uniform.

The heat flow plate is provided with a hot-side axial inlet 10 and a diversion hole 13, the hot-side axial inlet 10 communicates with the inlet of each split channel through the diversion area, and the outlet of the hot-side runner 14 is a baffle flow channel and a split flow channel. The holes are connected, and the baffle flow channel is set along the radial direction of the heat flow plate and extends toward the outer ring wall of the heat flow plate.

The heat flow plate is also provided with a cold-side axial inlet 12 and a cold-side axial outlet, which serve as via holes for the cold flow axially entering the flow channel and the cold flow axially flowing out of the flow channel. 12 is used to communicate with the inlets of the cold side flow channels 8 of two adjacent cold flow plates, and the cold side axial outlet is used to communicate with the outlets of the cold side flow channels 8 of two adjacent cold flow plates.

The pre-cooling flow channel 6 on the heat flow plate is an annular flow channel, the inlet of the pre-cooling flow channel 6 faces the split hole 13, and the pre-cooling outlet 15 of the pre-cooling flow channel is symmetrically arranged along the center of the heat flow plate and the entrance, and the pre-cooling flow channel The inlet and outlet of 6 are provided with a divider baffle 5, which is used to divide the hot fluid into two paths in the pre-cooling flow channel. A partition is set in the middle of the outlet to avoid the hedging phenomenon when the two hot fluids are converging.

The outer concentric sleeve of the heat flow plate is provided with a shell piece 11, and an annular vacuum heat insulation groove 7 is arranged between the shell piece 11 and the heat flow plate. A plurality of ribs are arranged in the vacuum heat insulation groove 7, and the circumference of the plurality of ribs is Evenly distributed, the connection strength between the shell and the heat flow plate 2 is improved through the rib plate.

Referring to Fig. 3, the cold flow plate 3 is an annular plate, and its inner diameter is the same as the outer diameter of the submersible. The cold flow plate 3 is used to be sleeved on the shell of the submersible. The plate 3 is provided with a cold-side axial outlet 9 and a cold-side axial inlet 12, the inlet of the cold-side flow channel 8 communicates with the cold-side axial inlet 12, and the outlet of the cold-side flow channel 8 communicates with the cold-side axial outlet 9 .

The cold side flow channel 8 is provided with a plurality of concentric shunt rings, and the plurality of shunt rings are arranged at intervals from inside to outside, so as to divide the cold side flow channel 8 into a plurality of shunt channels, and the width of the multiple shunt channels is from the inside to the outside. Since the length of the runners in the circumference is shorter, the width of the inner runners is greater than that of the outer runners, so that the heat transfer of each runner is more uniform, and the outlets of multiple runners pass through the diversion area and the cold side. The axial outlet 9 is connected, and the cold fluid enters the cold side flow channel 8 through the cold side axial inlet 12, and then flows to the cold side axial outlet 9, enters the cold flow axial flow channel and then enters the Brayton cycle system.

The pre-cooling flow channel 6 on the cold flow plate is an annular flow channel, the inlet of the pre-cooling flow channel 6 communicates with the split hole 13 of the hot flow plate, and the pre-cooling outlet 15 of the pre-cooling flow channel is connected to the side pre-cooling outlet 15 of the hot flow plate. The position and structure are the same, the inlet and outlet of the pre-cooling channel 6 on the side of the cold flow plate are provided with a splitter 5, which is used to divide the hot fluid into two channels in the pre-cooling channel, and the two channels of human fluid flow in opposite directions. The outlet flows out from the axial flow outlet of the pre-cooling module, and the middle part of the outlet of the pre-cooling flow channel is provided with a partition to avoid the hedging phenomenon when the two hot fluids converge.

The outer concentric sleeve of the cold flow plate is provided with a shell piece 11, and an annular vacuum heat insulation groove 7 is arranged between the shell piece 11 and the cold flow plate, and a plurality of ribs are arranged in the vacuum heat insulation groove 7, and a plurality of ribs The plates are evenly distributed around the circumference, and the connection strength between the shell and the cold flow plate is improved through the rib plate. The cold flow plate is also provided with a hot side axial inlet, which is used to communicate with the inlets of the hot side flow channels 8 of two adjacent heat flow plates.

The hot-side flow channels, cold-side flow channels and pre-cooling flow channels on the hot flow plate and cold flow plate are all processed by mechanical processing or photochemical etching, and the flow channel cross-sections of the hot-side flow channels and the cold-side flow channels can be Rectangular, semicircular or elliptical, with a hydraulic diameter of 1 to 3mm, and a spoiler structure is set in each branch channel of the hot side channel and the cold side channel, and the branch channel is a straight channel, a Z-shaped channel or an S-shaped flow channel The fluids in the hot-side flow channel and the cold-side flow channel flow in opposite directions, and the thickness of the hot flow plate and the cold flow plate in this embodiment is 1-4mm. The hot flow plate and cold flow plate are made of stainless steel, aluminum alloy, copper alloy or titanium alloy, with high welding quality and can withstand seawater and carbon dioxide environment.

Both ends of the heat recovery module are provided with an upper compression plate 1 and a lower compression plate 4, and the upper compression plate 1 is provided with a hot fluid inlet and an outlet, and a cold fluid inlet and an outlet, which are respectively connected to the heat flow axially. The flow channel, the axial flow outlet of the pre-cooling module, the cold flow axial inlet flow channel and the cold flow axial outlet flow channel are connected, and the two adjacent hot flow plates and cold flow plates are welded by vacuum diffusion welding in solid phase, and the heat flow plate The inner ring wall of the cold flow plate is welded to the shell of the submersible. After all the hot flow plates and cold flow plates are alternately stacked and welded, the hot side axial 10 inlets of all the hot flow plates and cold flow plates form a hot flow axial confluence flow. The outlets of the pre-cooling runners of all hot runner plates and cold runner plates form the axial flow outlet of the pre-cooling module, and the cold-side axial inlets 12 of all hot runner plates and cold runner plates form cold flow axial inlet runners, and all hot runner plates and the cold side axial outlet 9 of the cold flow plate to form a cold flow axial outlet flow channel.

Referring to Fig. 1 again, the heat exchange method of the Brayton cycle integrated heat exchanger of the submersible of the present invention is described in detail below, including the following steps:

Step 1. Use vacuum diffusion welding technology to perform solid-phase welding on the upper compression plate, several hot fluid plates, cold fluid plates, and lower compression plates to form a heat exchanger;

The shells on the heat flow plate and the cold flow plate form a shell, and the vacuum heat insulation grooves on the heat flow plate and the cold flow plate form a vacuum heat insulation cavity, which is evacuated to a vacuum and sealed, leaving a safety margin for thermal expansion. The entire heat exchanger body and the submarine shell are processed at the same time to form an integrated pressure-bearing device.

The diameters of the distribution rings in the hot-side flow channel 14 and the cold-side flow channel 8 are the same, forming rigid supports for two adjacent hot flow plates and cold flow plates, and improving the rigidity of the entire heat exchanger.

Step 2. The heat flow of the heat exchanger axially merges into the flow channel and connects to the outlet of the turbine in the Brayton cycle system. The hot fluid of the turbine flows from the heat flow axially into the flow channel and enters the hot side flow channel of each heat flow plate. The axial flow outlet of the cold module is connected to the precooler inlet of the Brayton cycle system;

The cold flow axially flows into the flow channel to connect with the compressor outlet of the Brayton cycle system, and the cold flow axially flows out of the flow channel to connect to the regenerator cold side inlet of the Brayton cycle system.

Step 3. After the hot fluid enters the hot flow axially merged into the flow channel, it is split. After the split, the hot fluid enters the hot side flow channel 14 of each hot flow plate through the hot side axial inlet 10; the cold fluid enters the cold flow axially merged into the flow channel. After splitting, the hot fluid enters the cold side flow channel 8 of each cold flow plate through the cold side axial inlet 12;

The hot fluid and the cold fluid exchange heat, and the cold fluid heated up by the heat exchange enters the cold flow axial confluence flow channel through the outlet of the cold side flow channel 8, and then enters the Brayton cycle system.

The hot fluid after heat exchange and cooling passes through the split hole and enters the pre-cooling flow channel 6 of the hot flow plate and the lower cold flow plate respectively, and is divided into two paths in the pre-cooling flow channel and flows opposite to each other, and is separated from the seawater outside the shell. After the first heat exchange, the cooled hot fluid enters the axial flow outlet of the pre-cooling module and enters the Brayton cycle system.

In this embodiment, the thermal fluid is SCO ₂ .

The Brayton cycle integrated heat exchanger of the submarine provided by the present invention has the following beneficial effects:

1. The printed circuit board heat exchanger and the submersible shell are processed at the same time to form an integrated pressure-bearing device. The heat exchanger does not need to be equipped with an additional fixed platform. At the same time, other shell sections can be used to bear pressure on the upper and lower sides of the cylindrical heat exchanger. Therefore, there is no need for a thick compression plate, which reduces the space occupation and the weight of the whole machine; the regenerator, precooler, and shell are integrated into one body, without the need for pipe boxes and connecting pipelines, and the space utilization rate is high.

2. In the heat exchanger, there is a vacuum or vacuum filler insulation layer in the middle of the heat recovery and pre-cooling modules, which reduces coupling heat transfer and ensures efficient operation of the heat exchanger. When the heat recovery module expands at high temperature, the vacuum heat insulation layer provides The space margin improves the safety of the heat exchanger, and at the same time reduces the influence of coupling heat transfer between modules.

3. The reheating and pre-cooling module of the heat exchanger divides the core body into several cold and hot fluid plate pairs through the diversion hole and the diversion partition plate, and at the same time forms 4 pre-cooling channels with the same length in each group of plate pairs, improving cooling efficiency.

4. The hot side and cold side flow channels of the heat exchanger are the entire circumference. In a diffusion welding furnace of the same volume, compared with the traditional rectangular printed circuit board heat exchanger, the processable flow channels are longer, and at the same time, it is more The flow resistance of the stage baffle channel is smaller.

5. In the present invention, due to the shorter length of the inner flow channel of the circumference, the width of the inner side of the heat exchange flow channel of the plate is wider than that of the outer side, so that the heat transfer amount of the inner and outer flow channels is more uniform, and the form of the flow channel can be Z-shaped S-shape, etc., improve the optimization space of heat transfer and flow resistance, and can meet the design requirements of multiple heat transfer conditions.

The above content is only to illustrate the technical ideas of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solutions according to the technical ideas proposed in the present invention shall fall within the scope of the claims of the present invention. within the scope of protection.

Claims (10)

1. A Brayton cycle integrated heat exchanger of a submersible, characterized in that it comprises a heat recovery module and a precooling module; The heat recovery module is a hollow columnar structure, which includes several alternately stacked heat flow plates (2) and cold flow plates (3). The end surface of the heat flow plate (2) is formed with a hot side flow channel (14), and the cold flow The end surface of the plate (3) is formed with a cold side flow channel (8); The pre-cooling module is sleeved on the outside of the heat recovery module, and there is a vacuum insulation chamber between the pre-cooling module and the heat recovery module. The pre-cooling module includes several shell plates, and one side of the shell plate is provided with a pre-cooling flow channel (6); The outlets of the hot-side runners (14) are respectively connected to the pre-cooling runners of the concentric shells and the inlets of the pre-cooling runners of the lower shell, and the hot fluid in the hot-side runners (14) is connected to the hot fluid in the cold-side runners. After exchanging heat, the cold fluid enters the pre-cooling passages of two adjacent shell plates to exchange heat with the external environment of the submersible and then flows out. 2. The Brayton cycle integrated heat exchanger of a submersible according to claim 1, wherein a plurality of concentric shunt rings are all arranged in the hot side flow channel (14) and the cold side flow channel , divide the hot runner into multiple sub-runners, and the width of the multiple sub-runners decreases sequentially from the inside to the outside. 3. The Brayton cycle integrated heat exchanger of a submarine according to claim 2, wherein the splitter rings of the cold flow plate and the hot flow plate are arranged with the same diameter. 4. the Brayton cycle integrated heat exchanger of a kind of submersible according to claim 1, is characterized in that, between said heat flow plate and cold flow plate respectively and the same plane shell plate, vacuum insulation groove ( 7), the vacuum heat insulation layer is provided with a plurality of ribs uniformly distributed on the circumference, which are used to connect the shell plate and the heat flow plate or the cold flow plate on the same plane. 5. The Brayton cycle integrated heat exchanger of a submersible according to claim 1, wherein the outlet of the hot side flow channel communicates with the pre-cooling flow channel of the same plane shell plate through the flow channel, A split hole is arranged on the flow channel, and the split hole communicates with the inlet of the pre-cooling flow channel of the lower shell plate. 6. The Brayton cycle integrated heat exchanger of a submersible according to claim 1, wherein the pre-cooling flow path comprises two half-ring flow paths, and the hot fluid is reversed in the two flow paths. to the flow. 7 . The Brayton cycle integrated heat exchanger of a submersible according to claim 6 , wherein a diverter plate is provided at the inlet of the pre-cooling channel, and a partition is provided at the outlet of the pre-cooling channel. 7 . 8 . The Brayton cycle integrated heat exchanger of a submersible according to claim 1 , wherein the working medium in the hot-side flow channel and the cold-side flow channel flow in reverse directions. 9 . The Brayton cycle integrated heat exchanger of a submarine vehicle according to claim 1 , wherein a spoiler structure is arranged in the hot-side flow channel and the cold-side flow channel. 10 . 10. The heat exchange method of the Brayton cycle integrated heat exchanger of a kind of submarine vehicle described in any one of claims 1-9, it is characterized in that, comprising the following process: The hot fluid of the Brayton cycle system flows into the hot side flow channel of each hot flow plate, and the cold fluid of the Brayton cycle flows into the cold side flow channel of each cold flow plate. The hot fluid and the cold fluid flow in reverse for heat exchange, and the heated cold fluid Entering the Brayton cycle system, the cooled thermal fluid enters the pre-cooling flow channel corresponding to the hot flow plate and the lower cold flow plate after splitting, and the thermal fluid enters the Brayton cycle system after secondary heat exchange with seawater in the pre-cooling flow channel.

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