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

Abstract

The invention discloses a brayton cycle integrated heat exchanger of a submarine and a heat exchange method, wherein the brayton cycle integrated heat exchanger comprises a backheating module and a precooling module; the heat regeneration module comprises a plurality of alternately stacked hot flow plates and cold flow plates, the precooling module is sleeved outside the heat regeneration module, and a vacuum heat insulation cavity is arranged between the precooling module and the heat regeneration module; the heat exchanger and the shell of the submarine craft are integrally processed, the heat exchanger is used as a part of the heat exchanger, the thickness of the shell of the submarine craft is increased, the compression resistance of the submarine craft is improved, meanwhile, the thickness of the shell of the submarine craft is reduced, the self weight of the submarine craft is reduced, a vacuum cavity is arranged between the heat regeneration module and the precooling module, after the heat exchange is carried out on hot fluid and cold fluid in the heat regenerator for one time, the hot fluid and the cold fluid enter the precooler to carry out secondary heat exchange with external seawater, the heat exchange efficiency is improved, the coupling is reduced through the vacuum heat insulation cavity, a deformation space is reserved for the thermal expansion of the heat regenerator, and the operation safety of the submarine craft is improved.

Description

Brayton cycle integrated heat exchanger of submarine aircraft and heat exchange method

Technical Field

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

Background

Ocean is a strategic place for high quality development, and relates to important fields such as resources, military and the like. With the development of YL, heavy UUV and other submarines, our country is continuously advancing towards the construction of ocean countries. The small-sized submersible vehicle is mainly powered by electricity, while the large-sized submersible vehicle basically adopts thermal power, and a thermal power system comprises a steam Rankine cycle system and a Brayton cycle system.

The conventional thermal power is mainly steam Rankine cycle, but the power system has large volume and mass and low thermal efficiency. The supercritical carbon dioxide Brayton cycle has low compression power consumption, high efficiency and more compact structure, and is a development trend of future underwater thermodynamic systems. The heat exchange equipment of the Brayton cycle system mainly comprises a heat regenerator and a precooler, the heat exchange capacity of the heat regenerator restricts the system efficiency, and the heat exchange equipment is applied to a submarine, and faces the difficulties of limited space, high temperature and high pressure of working media and the like. Therefore, it is very important to develop a supercritical carbon dioxide brayton cycle heat exchanger which meets the limited space and has high efficiency and high safety for the design of the submarine.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the brayton cycle integrated heat exchanger of the submarine, which has the characteristics of compact structure, high temperature resistance and high pressure resistance and improves the underwater operation safety of the submarine.

The invention is realized by the following technical scheme:

a Brayton cycle integrated heat exchanger of a submarine comprises a backheating module and a precooling module;

the heat regeneration module is of a hollow columnar structure and comprises a plurality of alternately stacked heat flow plates and cold flow plates, wherein a hot side flow channel is formed on the end face of each heat flow plate, and a cold side flow channel is formed on the end face of each cold flow plate;

the precooling module is sleeved outside the backheating module, a vacuum heat insulation cavity is arranged between the precooling module and the backheating module, the precooling module comprises a plurality of shell plates, and one side of each shell plate is provided with a precooling runner;

the outlets of the hot side flow channels are respectively connected with the precooling flow channels of the concentric shell plates and the precooling flow channel inlets of the lower shell plates, and after the hot fluid in the hot side flow channels exchanges heat with the cold fluid in the cold side flow channels, the hot fluid enters the precooling flow channels of the two adjacent shell plates respectively and flows out after exchanging heat with the external environment of the submarine.

Preferably, a plurality of concentric flow dividing rings are arranged in the hot side flow passage and the cold side flow passage, the hot flow passage is divided into a plurality of flow dividing passages, and the widths of the flow dividing passages are gradually decreased from inside to outside.

Preferably, the flow dividing rings of the cold flow plate and the hot flow plate are arranged in the same diameter.

Preferably, a vacuum heat insulation groove is arranged between the hot flow plate and the cold flow plate and the coplanar shell plate respectively, and a plurality of rib plates are arranged in the vacuum heat insulation layer and are circumferentially and uniformly distributed and used for connecting the coplanar shell plate and the hot flow plate or the cold flow plate.

Preferably, the outlet of the hot side runner is communicated with the precooling runner of the same plane shell plate through a runner, a diversion hole is arranged on the runner, and the diversion hole is communicated with the inlet of the precooling runner of the lower shell plate.

Preferably, the pre-cooling flow channel comprises two half-ring flow channels, and the hot fluid reversely flows in the two flow channels.

Preferably, the inlet of the pre-cooling flow channel is provided with a flow dividing plate, and the outlet of the pre-cooling flow channel is provided with a baffle plate.

Preferably, the working media in the hot side flow channel and the cold side flow channel flow reversely.

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

A heat exchange method of a Brayton cycle integrated heat exchanger of a submarine comprises the following steps:

the hot fluid of the Brayton cycle system flows into the hot side flow channels of all the hot flow plates, the cold fluid of the Brayton cycle flows into the cold side flow channels of all the cold flow plates, the hot fluid and the cold fluid reversely flow to exchange heat, the cold fluid after temperature rise enters the Brayton cycle system, the cooled hot fluid is shunted and then enters the pre-cooling flow channels corresponding to the hot flow plates and the lower cold flow plates, and the hot fluid enters the Brayton cycle system after secondary heat exchange with seawater in the pre-cooling flow channels.

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

the brayton cycle integrated heat exchanger of the submarine, provided by the invention, is integrally processed with the shell of the submarine, the heat exchanger is used as a part of the shell, the thickness of the shell of the submarine is increased, the compression resistance of the submarine is improved, the self weight of the submarine is reduced, a vacuum cavity is arranged between a heat recovery module and a precooling module, hot fluid and cold fluid exchange heat once in the heat recovery device and then enter the precooler to exchange heat with external seawater for the second time, the heat exchange efficiency is improved, compared with the traditional cuboid printed circuit board type heat exchanger, the annular flow channel is longer than the processable flow channel, and meanwhile, the flow resistance of the annular flow channel is smaller than that of the annular flow channel; the length of the inner side flow channel of the circumference is shorter, so that the inner side width of the plate heat exchange flow channel is wider than the outer side, and the heat exchange quantity of the inner side flow channel and the outer side flow channel is more uniform; and secondly, coupling heat transfer is reduced through the vacuum heat insulation cavity, a deformation space is reserved for thermal expansion of the heat regenerator, the operation safety of the submarine is improved, the whole heat exchanger is used as a pressure-bearing member of the submarine, and the space required for arranging a fixed platform is saved for the heat exchanger.

Drawings

Fig. 1 is an exploded schematic view of a heat exchanger core of the present invention.

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

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

In the figure: in the figure: 1-upper layer compression plate, 2-heat flow plate, 3-cold flow plate, 4-lower layer compression plate, 5-diversion baffle, 6-pre-cooling flow channel, 7-vacuum heat insulation groove, 8-cold side flow channel, 9-cold side axial outlet, 10-hot side axial inlet, 11-shell piece 11, 12-cold side axial inlet, 13-diversion hole, 14-hot side flow channel and 15-pre-cooling outlet.

Detailed Description

The invention will now be described in further detail with reference to the accompanying drawings, which illustrate but do not limit the invention.

Referring to fig. 1, a brayton cycle integrated heat exchanger of a submarine comprises a backheating module and a precooling module.

The heat regeneration module is of a hollow columnar structure and comprises a plurality of alternately stacked heat flow plates 2 and cold flow plates 3, wherein a hot side flow channel 14 is formed on the end face of the heat flow plates 2, and a cold side flow channel 8 is formed on the end face of the cold flow plates 3; the precooling module comprises a plurality of precooling flow channels which are respectively arranged on the hot flow plate 2 and the cold flow plate 3, and the precooling flow channels are sleeved outside the hot side flow channel 14 and the cold side flow channel 8.

The heat regeneration module is axially provided with a heat flow axial converging flow passage, a precooling module axial flow outlet, a cold flow axial converging flow passage and a cold flow axial converging flow passage, the inlet of each hot side flow passage 14 is communicated with the heat flow axial converging flow passage, the outlet of each hot side flow passage 14 is respectively communicated with the precooling flow passage inlet on the same heat flow plate and the precooling flow passage inlet of the lower layer cold flow plate 3, and the outlet and the inlet of each precooling flow passage are respectively communicated with the cold flow axial converging flow passage and the cold flow axial converging flow passage.

Referring to fig. 2, the heat flow plate is an annular plate, the inner diameter of the heat flow plate is the same as the outer diameter of the casing of the submarine, the heat flow plate is sleeved on the casing of the submarine, the hot side flow channel 14 is an annular groove, the hot side axial inlet 10 and the diversion hole 13 are arranged on the heat flow plate, the inlet of the hot side flow channel 14 is communicated with the hot side axial inlet 10, the outlet of the hot side flow channel 14 is communicated with the diversion hole 13, the diversion hole 13 is respectively communicated with the pre-cooling flow channel of the heat flow plate and the pre-cooling flow channel of the cold flow plate 3, namely, hot fluid enters the hot side flow channel 14 through the hot side axial inlet 10 and then flows into the diversion hole 13, the diversion hole divides the hot fluid into two paths, and enters the pre-cooling flow channel 6 of the heat flow plate and the pre-cooling flow channel of the lower cold flow plate respectively, and the hot fluid in the two pre-cooling flow channels enter the brayton circulation system after entering the pre-cooling module axial flow outlet from the outlets of the pre-cooling flow channels.

The hot side runner 14 is provided with a plurality of concentric split rings, the split rings are arranged at intervals from inside to outside to divide the hot runner into a plurality of split runners, the widths of the split runners decrease from inside to outside in sequence, and the widths of the inner split runners are larger than those of the outer split runners due to the shorter lengths of the split runners in the circumference, so that the heat exchange quantity of each split runner is more uniform.

The hot-side axial inlet 10 and the diversion holes 13 are arranged on the hot-flow plate, the hot-side axial inlet 10 is communicated with the inlets of all the diversion channels through the diversion area, the outlets of the hot-side flow channels 14 are baffle flow channels and are connected with the diversion holes, the baffle flow channels are arranged along the radial direction of the hot-flow plate and extend towards the outer annular wall direction of the hot-flow plate, and the diversion holes are respectively communicated with the pre-cooling flow channels of the hot-flow plate and the pre-cooling flow channels of the lower cold-flow plate.

The hot flow plate is further provided with a cold side axial inlet 12 and a cold side axial outlet, the cold side axial inlet 12 is used for communicating inlets of the cold side flow channels 8 of two adjacent cold flow plates, and the cold side axial outlet is used for communicating 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 is opposite to the split flow hole 13, the pre-cooling outlet 15 of the pre-cooling flow channel is symmetrically arranged along the center of the heat flow plate and the inlet, the inlet of the pre-cooling flow channel 6 is provided with the split flow partition plate 5 for dividing the heat fluid into two paths in the pre-cooling flow channel, the two paths of human fluids flow in opposite directions, flow out of the pre-cooling module axial flow outlet through the outlet after converging, and the partition plate is arranged in the middle of the outlet of the pre-cooling flow channel to avoid the phenomenon that the two paths of heat fluids send opposite flows when converging.

The outside concentric cover of heat flow board is equipped with shell piece 11, is provided with annular vacuum heat insulation groove 7 between shell piece 11 and the heat flow board, is provided with a plurality of gusset in the vacuum heat insulation groove 7, and a plurality of gusset circumference equipartitions improve the joint strength of shell piece and heat flow board 2 through the gusset.

Referring to fig. 3, the cold flow plate 3 is an annular plate, the inner diameter of the cold flow plate 3 is the same as the outer diameter of a shell of the submarine, the cold flow plate 3 is used for being sleeved on the shell of the submarine, the cold side flow channel 8 is an annular groove, the cold side axial outlet 9 and the cold side axial inlet 12 are arranged on the cold flow plate 3, the inlet of the cold side flow channel 8 is communicated with the cold side axial inlet 12, and the outlet of the cold side flow channel 8 is communicated with the cold side axial outlet 9.

The cold side runner 8 is internally provided with a plurality of concentric split rings, the split rings are arranged at intervals from inside to outside, the cold side runner 8 is divided into a plurality of split runners, the widths of the split runners decrease from inside to outside in sequence, and as the lengths of the split runners in the circumference are shorter, the widths of the split runners in the inner side are larger than those of the split runners in the outer side, the heat exchange capacity of each split runner is more uniform, the outlets of the split runners are communicated with the cold side axial outlet 9 through a flow guiding area, and cold fluid enters the cold side runner 8 through the cold side axial inlet 12 and then flows to the cold side axial outlet 9, enters the brayton cycle system after entering the cold side axial outlet runner.

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 is communicated with the flow dividing hole 13 of the hot flow plate, the pre-cooling outlet 15 of the pre-cooling flow channel is identical to the pre-cooling outlet 15 on the hot flow plate side in position and structure, the flow dividing partition plate 5 is arranged at the inlet of the pre-cooling flow channel 6 on the cold flow plate side and is used for dividing hot fluid into two paths in the pre-cooling flow channel, the two paths of human fluids flow in opposite directions, flow out of the pre-cooling module axial flow outlet through the outlet after converging, and the partition plate is arranged in the middle of the outlet of the pre-cooling flow channel, so that the phenomenon of opposite flushing of the two paths of hot fluids during converging is avoided.

The outside concentric cover of cold flow board is equipped with shell piece 11, is provided with annular vacuum heat insulation groove 7 between shell piece 11 and the cold flow board, is provided with a plurality of gusset in the vacuum heat insulation groove 7, and a plurality of gusset circumference equipartitions improve shell piece and cold flow board's joint strength through the gusset. And the cold flow plates are further provided with hot side axial inlets which are used for communicating inlets of hot side flow channels 8 of two adjacent hot flow plates.

The hot side runner, the cold side runner and the precooling runner on the hot side runner and the cold side runner are processed in a mechanical processing or photochemical etching mode, the cross sections of the hot side runner and the cold side runner can be rectangular, semicircular or elliptic, the hydraulic diameter is 1-3 mm, turbulence structures are arranged in each sub-runner of the hot side runner and the cold side runner, the sub-runners are straight runners, Z-shaped runners or S-shaped runners, fluid in the hot side runner and the cold side runner reversely flows, and the thickness of the hot side runner and the cold side runner is 1-4mm in the embodiment. The hot flow plate and the cold flow plate are processed by stainless steel, aluminum alloy, copper alloy or titanium alloy, and have high welding quality and can bear seawater and carbon dioxide environments.

The two ends of the backheating module are provided with an upper-layer compression plate 1 and a lower-layer compression plate 4, the upper-layer compression plate 1 is provided with a hot fluid inlet and a hot fluid outlet, the cold fluid inlet and the cold fluid outlet are respectively communicated with a hot fluid axial converging flow passage, a precooling module axial flow outlet, a cold fluid axial converging flow passage and a cold fluid axial converging flow passage, two adjacent hot fluid plates and cold fluid plates are welded by adopting a vacuum diffusion welding solid phase, inner annular walls of the hot fluid plates and the cold fluid plates are welded with a shell of the submarine, after all the hot fluid plates and the cold fluid plates are alternately overlapped and welded, hot side axial 10 inlets of all the hot fluid plates and the cold fluid plates form a hot fluid axial converging flow passage, precooling flow passage outlets of all the hot fluid plates and the cold fluid plates form a precooling module axial flow inlet, and cold side axial inlets 12 of all the hot fluid plates and cold side axial outlets 9 of the cold fluid plates form a cold flow converging flow passage.

Referring again to fig. 1, the following describes in detail the heat exchange method of the brayton cycle integrated heat exchanger of the submarine according to the invention, comprising the following steps:

step 1, performing solid-phase welding on an upper compression plate, a plurality of hot fluid plates, a cold fluid plate and a lower compression plate by adopting a vacuum diffusion welding technology to form a heat exchanger;

the shell piece on the hot flow plate and the cold flow plate form a shell, the vacuum heat insulation grooves on the hot flow plate and the cold flow plate form a vacuum heat insulation cavity, the cavity is vacuumized and sealed, and a safety margin of thermal expansion is reserved. The whole heat exchanger body and the submarine shell are processed simultaneously to form an integrated pressure-bearing device.

The diameter of each diverter ring in the hot side runner 14 and the cold side runner 8 is the same, and the adjacent two hot flow plates and cold flow plates are rigidly supported, so that the rigidity of the whole heat exchanger is improved.

Step 2, a heat flow axial inflow channel of the heat exchanger is connected with a turbine outlet of the Brayton cycle system, and a heat flow which is subjected to work by the turbine flows into a hot side channel of each heat flow plate of the flow channel from the heat flow axial inflow channel, and an axial flow outlet of the precooling module is connected with a precooler inlet of the Brayton cycle system;

the cold flow axial converging flow passage is connected with a compressor outlet of the Brayton cycle system, and the cold flow axial converging flow passage is connected with a cold side inlet of a regenerator of the Brayton cycle system.

Step 3, the hot fluid enters the hot fluid axial inflow channels and is split, and the split hot fluid enters the hot side flow channels 14 of each hot fluid plate through the hot side axial inlets 10; the cold fluid enters the cold fluid axial inflow channel and is split, and the split hot fluid enters the cold side channels 8 of each cold flow plate through the cold side axial inlets 12;

the hot fluid and the cold fluid exchange heat, and the cold fluid with heat exchange and temperature rise enters the cold fluid axial converging flow passage through the outlet of the cold side flow passage 8 and then enters the Brayton cycle system.

The heat exchange and cooling hot fluid is respectively carried out in the pre-cooling flow channels 6 of the hot flow plate and the lower cold flow plate through the flow dividing holes, is divided into two paths in the pre-cooling flow channels and flows in opposite directions, carries out secondary heat exchange with seawater outside the shell, and enters the pre-cooling module axial flow outlet to enter the Brayton cycle system after being cooled again.

In the present embodiment, the thermal fluid is SCO ₂ 。

The brayton cycle integrated heat exchanger of the submarine aircraft has the following beneficial effects:

1. the printed circuit board type heat exchanger and the submarine shell are processed simultaneously to form an integrated pressure-bearing device, the heat exchanger does not need to be provided with an additional fixed platform, and the upper side and the lower side of the cylinder heat exchanger can be subjected to pressure bearing by utilizing other shell sections, so that thicker compacting plates are not needed, and the space occupation and the weight of the whole machine are reduced; the heat regenerator, the precooler and the shell are integrated into a whole, a pipe box and a connecting pipeline are not needed, and the space utilization rate is high.

2. The heat-returning and pre-cooling module in the heat exchanger is provided with the vacuum or vacuum filler heat-insulating layer in the middle, so that coupling heat transfer is reduced, efficient operation of the heat exchanger is guaranteed, when the heat-returning module expands at high temperature, the vacuum heat-insulating layer provides space allowance, the safety of the heat exchanger is improved, and meanwhile, the coupling heat transfer influence among the modules is reduced.

3. The heat exchanger backheating and precooling module divides the core body into a plurality of cold and hot fluid plate pairs through the diversion holes and the diversion partition plates, and meanwhile 4 precooling flow passages with the same length are formed in each group of plate pairs, so that the cooling efficiency is improved.

4. The hot side flow channel and the cold side flow channel of the heat exchanger are the whole circumferences, and in the diffusion welding furnace with the same volume, compared with the traditional cuboid printed circuit board type heat exchanger, the heat exchanger can process the flow channel longer, and meanwhile, the flow resistance is smaller than that of the heat exchanger adopting a multi-stage baffling flow channel.

5. In the invention, the length of the circumferential inner side runner is shorter, so that the inner side width of the plate heat exchange runner is wider than the outer side, the heat exchange quantity of the inner side runner and the outer side runner is more uniform, and meanwhile, the runner forms can be Z-shaped, S-shaped and the like, thereby improving the optimization space of heat exchange and flow resistance and meeting the design requirement of multiple heat exchange working conditions.

The above is only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited by this, and any modification made on the basis of the technical scheme according to the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims (10)

1. The brayton cycle integrated heat exchanger of the submarine is characterized by comprising a backheating module and a precooling module;

the heat regeneration module is of a hollow columnar structure and comprises a plurality of alternately stacked heat flow plates (2) and cold flow plates (3), wherein a hot side flow channel (14) is formed on the end face of each heat flow plate (2), and a cold side flow channel (8) is formed on the end face of each cold flow plate (3);

the precooling module is sleeved outside the backheating module, a vacuum heat insulation cavity is arranged between the precooling module and the backheating module, the precooling module comprises a plurality of shell plates, and one side of each shell plate is provided with a precooling runner (6);

the outlets of the hot side flow channels (14) are respectively connected with the precooling flow channels of the concentric shells and the precooling flow channel inlets of the lower shells, and after the hot fluid in the hot side flow channels (14) exchanges heat with the cold fluid in the cold side flow channels, the hot fluid enters the precooling flow channels of the two adjacent shells respectively to exchange heat with the external environment of the submarine and then flows out.

2. The integrated brayton cycle heat exchanger of a submarine according to claim 1, wherein a plurality of concentric split rings are arranged in the hot side runner (14) and the cold side runner, the hot runner is divided into a plurality of split runners, and the widths of the split runners are gradually decreased from inside to outside.

3. The integrated brayton cycle heat exchanger of a submarine according to claim 2, wherein said cold flow plate and said hot flow plate are arranged in the same diameter.

4. The brayton cycle integrated heat exchanger of a submarine according to claim 1, wherein a vacuum heat insulation groove (7) is arranged between the hot flow plate and the cold flow plate and the coplanar shell plates respectively, and a plurality of rib plates are arranged in the vacuum heat insulation layer and are circumferentially and uniformly distributed and used for connecting the coplanar shell plates and the hot flow plate or the cold flow plate.

5. The brayton cycle integrated heat exchanger of a submarine according to claim 1, wherein the outlet of the hot-side runner is communicated with the pre-cooling runner of the same plane shell plate through a runner, and a diversion hole is arranged on the runner and is communicated with the inlet of the pre-cooling runner of the lower shell plate.

6. The integrated brayton cycle heat exchanger of claim 1, wherein the pre-cooling flow path comprises two half-loop flow paths in which the hot fluid flows in opposite directions.

7. The integrated brayton cycle heat exchanger of a submarine according to claim 6, wherein a flow dividing plate is provided at an inlet of the pre-cooling flow channel, and a baffle is provided at an outlet of the pre-cooling flow channel.

8. The integrated brayton cycle heat exchanger of a submarine according to claim 1, wherein working fluid in said hot side runner and said cold side runner flow in reverse.

9. The integrated brayton cycle heat exchanger of a submarine according to claim 1, wherein turbulence structures are provided in said hot side runner and said cold side runner.

10. A method of exchanging heat in a brayton cycle integrated heat exchanger of a submarine according to any of claims 1-9, comprising the steps of:

the hot fluid of the Brayton cycle system flows into the hot side flow channels of all the hot flow plates, the cold fluid of the Brayton cycle flows into the cold side flow channels of all the cold flow plates, the hot fluid and the cold fluid reversely flow to exchange heat, the cold fluid after temperature rise enters the Brayton cycle system, the cooled hot fluid is shunted and then enters the pre-cooling flow channels corresponding to the hot flow plates and the lower cold flow plates, and the hot fluid enters the Brayton cycle system after secondary heat exchange with seawater in the pre-cooling flow channels.

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