An efficient heat pipe heat exchanger with a microchannel structure

Abstract

The present invention discloses an efficient heat pipe heat exchanger with a microchannel structure, which relates to the technical field of heat exchange devices. It includes a heat exchange core body, in which a plurality of heat pipe holes are axially machined. A plurality of small hole channels are arranged around the heat pipe holes. Both the small hole channels and the heat pipe holes penetrate through the heat exchange core body. Heat pipes are inserted into the heat pipe holes, and pressure-bearing gaps are arranged between adjacent small hole channels and between the small hole channels and the heat pipe holes; a heat transfer medium flows in the small hole channels, and the heat pipes are the heat sources of the heat pipe heat exchanger, and heat exchange occurs between the heat transfer medium and the heat pipes. In the present invention, the entire length of the heat pipe has no direct contact with the heat transfer medium, so the heat pipe does not need to bear the pressure of the heat transfer medium. At the same time, the heat transfer medium does not directly flow across the heat pipe bundle, and the heat pipe bundle will not have the flow-induced vibration problem of a heat exchanger with a traditional structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchange devices, and particularly relates to a high-efficiency heat pipe heat exchanger with a microchannel structure. Background Art

[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.

[0003] A heat pipe reactor is a unique small reactor system. Compared with traditional reactors, the heat pipe reactor is significantly reduced in terms of power, size, weight, etc., and has characteristics such as factory prefabrication, device transportability, and self-regulation during operation. The heat pipe reactor is generally greatly simplified in system design, with significantly improved safety and flexibility, and can achieve rapid installation, deployment, and application in different environmental scenarios. Especially for space, ocean, and remote onshore areas, the heat pipe reactor has advantages such as high energy density, stable power output, low supporting supply requirements, long operation life, and small floor area compared with other energy forms. Therefore, it has great application potential in aspects such as energy guarantee of major equipment and facilities.

[0004] A heat pipe heat exchanger is an important device of a heat pipe reactor. The heat pipe transfers the heat of the reactor core from the evaporation section to the condensation section. The heat pipe heat exchanger uses the heat pipe as a heat source to heat the working medium to the temperature required by the thermoelectric conversion system. The heat transfer efficiency of the heat pipe heat exchanger is crucial for improving the electric power level of the heat pipe reactor.

[0005] CN114914004A discloses a heat exchanger for a heat pipe reactor. The heat pipe heat exchanger uses baffles on the shell side, and the heat transfer medium flows laterally between the heat pipe bundles. In this scheme, the heat pipe is in contact with the heat transfer medium, which is a direct pressure-bearing boundary. To improve the heat transfer efficiency, integral fins are arranged outside the heat pipe bundles.

[0006] CN115662663A discloses another integral heat exchanger for a movable land-based heat pipe reactor. This scheme uses a shell-and-tube heat exchanger, that is, a sleeve is installed outside the heat pipe, and the heat transfer medium flows longitudinally in the gap between the heat pipe and the sleeve for heat transfer. In this scheme, the heat pipe is in contact with the heat transfer medium, which is a direct pressure-bearing boundary.

[0007] For the two types of heat pipe heat exchangers proposed above, the heat transfer medium flows laterally or longitudinally with the heat pipe bundles, but the heat pipes are all pressure-bearing boundaries, and the heat pipe walls need to have a sufficient thickness to withstand the external pressure of high-temperature and high-pressure media. Summary of the Invention

[0008] The present invention provides a heat pipe heat exchanger with a microchannel structure, which can be connected to a plurality of heat pipes extending from the reactor core to achieve heat transfer between the heat pipes and the medium. At the same time, through a special microchannel structure design, the heat exchanger has extremely high heat transfer efficiency, which plays an important role in improving the electric power level of the heat pipe reactor.

[0009] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0010] The present invention is an efficient heat pipe heat exchanger with a microchannel structure, including a heat exchange core body. A plurality of heat pipe holes are axially machined in the heat exchange core body. Heat pipes are inserted into the heat pipe holes. A plurality of small hole channels are arranged around the heat pipe holes along the axial or radial direction of the heat pipe holes. Both the small hole channels and the heat pipe holes penetrate the heat exchange core body. A pressure-bearing gap is provided between adjacent small hole channels and between the small hole channels and the heat pipe holes; a heat transfer medium flows through the small hole channels, and heat exchange is carried out between the heat transfer medium and the heat pipes.

[0011] Optionally, the heat exchange core body is a solid formed structure formed by diffusion welding of multiple axially stacked plate parts. The heat pipe holes are formed by deep hole drilling after diffusion welding of the heat exchange core body. The small hole channels are formed by drilling holes in each plate part and then performing diffusion welding.

[0012] Optionally, the heat pipes extend from the core of a heat pipe micro-reactor. The positions of the heat pipe holes correspond to the positions of the heat pipes in the core of the heat pipe micro-reactor. A heat-conducting medium is filled in the gap between the heat pipes and the heat pipe holes.

[0013] Optionally, the small hole channels are arranged along the axial direction of the heat pipe holes and are parallel to the heat pipe holes; a plurality of small hole channels are evenly distributed along the circumferential side of the heat pipe holes, and the heat transfer medium flows axially along the small hole channels.

[0014] Optionally, an inlet header and an outlet header are respectively arranged on both sides of the heat exchange core body. The inlet header is arranged on one side of the heat exchange core body close to the tail of the heat pipe, and the outlet header is arranged on one side of the heat exchange core body far from the tail of the heat pipe.

[0015] Optionally, a plurality of small hole channels are evenly distributed inside the heat exchange core body along the axial direction of the heat pipe holes. The small hole channels are arranged along the radial direction of the heat pipe holes and are perpendicular to the heat pipe holes.

[0016] Optionally, a single small hole channel penetrates between multiple heat pipe holes and is arranged in an S shape; the heat transfer medium flows radially along the small hole channel.

[0017] Optionally, an inlet header and an outlet header are arranged at the middle position of the heat exchange core body. The directions of the inlet header and the outlet header are both perpendicular to the axial direction of the heat pipe holes.

[0018] Optionally, an inlet nozzle is arranged on the inlet header, and the inlet nozzle is used to introduce the heat transfer medium. An outlet nozzle is arranged on the outlet header, and the outlet nozzle is used to export the heat transfer medium; the inlet header and the inlet nozzle, and the outlet header and the outlet nozzle are both connected by welding.

[0019] Optionally, a plurality of sleeves are provided in both the inlet header and the outlet header. The sleeves are arranged through the entire length of the inlet header or the outlet header, and the sleeves are sleeved outside the heat pipes.

[0020] The present invention has the following beneficial effects:

[0021] 1. The present invention provides an efficient heat pipe heat exchanger with a microchannel structure. Heat transfer occurs between the heat pipes in the heat pipe holes and the heat transfer medium in the small hole channels. The small hole channels are arranged near the heat pipe holes, including two arrangement methods: along the axial direction of the heat pipe holes and along the radial direction of the heat pipe holes. Compared with traditional heat exchangers, the heat transfer efficiency of this structure is significantly improved.

[0022] 2. The heat pipes of the present invention are installed in the heat pipe holes of the heat exchange core. The heat transfer medium exchanges heat with the heat pipes through the small hole channels. At the same time, sleeves are provided in the inlet header and the outlet header, and the heat pipes at the inlet header and the outlet header are installed in the sleeves. Through the structural design, the heat pipes have no direct contact with the heat transfer medium along the entire axial length, so the heat pipes do not need to bear the medium pressure. The selection of the heat pipe wall thickness is not restricted by pressure, and there is no need to consider the corrosion effect of the heat transfer medium on the heat pipes, so their service life is longer.

[0023] 3. In the present invention, the heat transfer medium flows through the small hole channels and does not directly flow across the heat pipe bundle horizontally, so the heat pipe bundle will not have the flow-induced vibration problem of traditional heat exchangers, and the heat exchange process is more stable.

[0024] 4. The small hole channels serve as the pressure-bearing boundary of the heat transfer medium. Due to their small scale, they can be applied to high-temperature and high-pressure working conditions of different heat transfer media.

[0025] 5. Different from the horizontal flow of the heat transfer medium and the tube bundle in traditional heat exchangers, the heat transfer medium in the small hole channels flows axially, reducing the pressure drop when the heat transfer medium flows. The reduction of the pressure drop is crucial for improving the thermoelectric conversion efficiency of the thermoelectric conversion system.

[0026] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for describing the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0029] Figure 2Schematic diagram of the heat exchange core structure in the first embodiment of the present invention;

[0030] Figure 3 Schematic diagram of the inlet header structure in the first embodiment of the present invention;

[0031] Figure 4 Schematic diagram of the outlet header structure in the first embodiment of the present invention;

[0032] Figure 5 Schematic diagram of the internal structure in the second embodiment of the present invention.

[0033] In the drawings, the list of components represented by each reference numeral is as follows:

[0034] 1. Inlet header; 2. Heat exchange core; 21. Heat pipe holes; 22. Small hole channels; 3. Outlet header; 4. Heat pipes; 5. Sleeves; 6. Inlet nozzles; 7. Outlet nozzles. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0036] Please refer to Figures 1-4 As shown, the present invention is a high-efficiency heat pipe heat exchanger with a microchannel structure, including a heat exchange core 2. A plurality of heat pipe holes 21 are axially machined in the heat exchange core 2. A plurality of small hole channels 22 are arranged around the heat pipe holes 21. Both the small hole channels 22 and the heat pipe holes 21 penetrate through the heat exchange core 2. Heat pipes 4 are inserted into the heat pipe holes 21. A pressure-bearing gap is provided between adjacent small hole channels 22 and between the small hole channels 22 and the heat pipe holes 21; A heat transfer medium flows in the small hole channels 22. The heat pipes 4 are the heat sources of the heat pipe heat exchanger, and heat exchange occurs between the heat transfer medium and the heat pipes 4.

[0037] In this embodiment, the small hole channels 22 are arranged axially along the heat pipe holes 21 and are parallel to the heat pipe holes 21; A plurality of small hole channels 22 are evenly distributed along the circumferential side of the heat pipe holes 21, and the heat transfer medium flows axially along the small hole channels 22.

[0038] The heat pipe heat exchanger with the microchannel structure in this embodiment is applicable to heat transfer media including but not limited to gases such as air, He-Xe, and S-CO2. It mainly includes structures such as an inlet header 1, a heat exchange core 2, an outlet header 3, heat pipes 4, sleeves 5, inlet nozzles 6, and outlet nozzles 7:

[0039] Such as Figure 1As shown, the heat pipe 4 is the core heat transfer component in the heat pipe micro-reactor, responsible for exporting the heat from the reactor core and transferring it to the heat transfer medium. The heat pipe 4 installed in the heat pipe heat exchanger is its condensation section.

[0040] The heat pipe 4 is axially installed in the heat pipe hole 21 of the heat exchange core 2 to receive and transfer the heat of the heat pipe 4. A plurality of small hole channels 22 are arranged outside the heat pipe hole 21, and the heat transfer medium flows longitudinally in the small hole channels 22 to conduct efficient heat transfer with the heat pipe 4.

[0041] The heat exchange core 2 is a solid formed structure, which is manufactured by diffusion welding of multi-layer plates stacked axially or radially. In addition, it can also be considered to be formed by processing technologies such as machining, additive manufacturing, laser cutting, chemical etching, electrical discharge machining, electrochemical machining or stamping. The processing technology should be selected in combination with the size of the heat exchange core 2 and the processing ability of the small hole channels 22.

[0042] The heat pipe hole 21 on the heat exchange core 2 is axially processed to install the heat pipe 4 and receive and transfer the heat of the heat pipe 4. Small hole channels 22 are processed near the heat pipe hole 21 for the flow of the heat transfer medium. The positioning of the heat pipe hole 21 corresponds to the arrangement of the heat pipe 4 in the heat pipe 4 micro-reactor core layout. The cooperation between the heat pipe 4 and the heat pipe hole 21 should comprehensively consider the influence of assembly requirements, processing ability and heat transfer resistance. A heat conduction medium can also be filled in the gap between the heat pipe 4 and the heat pipe hole 21 to reduce the heat transfer resistance. The processing of the heat pipe hole 21 is a mature process. To control the gap between the heat pipe 4 and the heat pipe hole 21, preferably, the heat pipe hole 21 should be processed after the diffusion welding of the heat exchange core 2.

[0043] The small hole channels 22 on the heat exchange core 2 are used for the flow of the heat transfer medium to transfer the heat transferred by the heat pipe 4 in the heat pipe hole 21 to the heat transfer medium. The small hole channels 22 should be configured in combination with factors such as pressure bearing capacity, processing ability, heat exchange ability and pressure drop. Preferably, the small hole channels 22 should be arranged around the heat pipe hole 21 to reduce the heat resistance between the heat pipe 4 and the heat transfer medium. Preferably, the shape of the small hole channels 22 is circular. Considering the heat exchange ability, pressure drop and processing difficulty of the heat exchanger, other shapes of small hole channels 22 can also be considered.

[0044] The size of the small hole channels 22 is small and cannot adopt the same deep hole drilling processing technology after diffusion welding as the heat pipe hole 21. In this embodiment, it is manufactured by the process of drilling holes in each plate and then performing diffusion welding. The hole bridges between the small hole channels 22 and the hole bridges between the small hole channels 22 and the heat pipe hole 21 should have sufficient width to withstand the operating pressure of the heat transfer medium.

[0045] The inlet header 1 and the inlet nozzle 6 are connected by welding. The function of the inlet header 1 is to make the heat transfer medium enter the heat pipe heat exchanger concentratedly. To achieve countercurrent heat exchange between the heat transfer medium and the heat pipe 4, the inlet header 1 is usually arranged at the end of the condensation section of the heat pipe 4; the outlet header 3 and the outlet nozzle 7 are connected by welding. The function of the outlet header 3 is to make the heat transfer medium flow out of the heat pipe heat exchanger concentratedly. To achieve countercurrent heat exchange between the heat transfer medium and the heat pipe 4, the outlet header 3 is usually arranged at the starting position of the condensation section of the heat pipe 4. A sleeve 5 is arranged along the entire axial length of the inlet header 1 and the outlet header 3 as the pressure-bearing boundary of the heat transfer medium, so as to achieve the purpose of avoiding the heat pipe 4 from bearing pressure. Since the entire length of the heat pipe 4 has no direct contact with the heat transfer medium, it does not need to bear the medium pressure.

[0046] Furthermore, the pressure-bearing boundary of the inlet header 1 should have sufficient size to bear the operating pressure of the heat transfer medium. To ensure that the heat pipe 4 does not bear the heat transfer medium pressure at the tail of the condensation section, preferably, a plugging structure is arranged at the end of the heat exchange core 2. It can also be considered to arrange a sleeve 5 along the entire axial length of the inlet header 1 as the pressure-bearing boundary of the heat transfer medium, so as to achieve the purpose of avoiding the heat pipe 4 from bearing pressure.

[0047] Furthermore, the outlet header 3 is not located at the end of the heat pipe 4. A sleeve 5 is arranged along the entire axial length of the outlet header 3 as the pressure-bearing boundary of the heat transfer medium, so as to achieve the purpose of avoiding the heat pipe 4 from bearing pressure.

[0048] The sleeve 5 in the outlet header 3 should have sufficient size to bear the operating pressure of the heat transfer medium. Sufficient clearance should be set between the sleeve 5 and the heat pipe 4 to meet the assembly requirements of the heat pipe 4. Both sides of the sleeve 5 are respectively connected to the tube sheet and the heat exchange core 2. The connection between the sleeve 5 and the tube sheet can refer to the connection method of the heat transfer tube 4 and the tube sheet in a conventional heat exchanger, and the process of expanding and welding is used. The connection between the sleeve 5 and the heat exchange core 2 is limited by space. Preferably, it is considered to weld from the inside of the sleeve 5 by the internal hole welding process. It can also be considered to weld from the outside of the sleeve 5 by other welding processes.

[0049] In this embodiment, the heat pipe heat exchanger is horizontally arranged. Different from the transverse flow between the heat transfer medium and the tube bundle in a traditional heat exchanger, the heat transfer medium in the small hole flow channel 22 flows axially, reducing the pressure drop when the heat transfer medium flows. The reduction of the pressure drop is crucial for improving the thermoelectric conversion efficiency of the thermoelectric conversion system. Therefore, the thermoelectric conversion efficiency of the present invention is higher.

[0050] Embodiment 2:

[0051] The difference between this embodiment and Embodiment 1 is that in this embodiment:

[0052] Such as Figure 5As shown, a plurality of small hole channels 22 are uniformly distributed along the axial direction of the heat pipe holes 21 inside the heat exchange core 2. The small hole channels 22 are arranged radially with respect to the heat pipe holes 21 and are perpendicular to the heat pipe holes 21.

[0053] A single small hole channel 22 is arranged in a S shape and penetrates between multiple heat pipe holes 21; the heat transfer medium flows radially through the small hole channel 22.

[0054] An inlet header 1 and an outlet header 3 are arranged at the middle position of the heat exchange core 2, and the directions of the inlet header 1 and the outlet header 3 are both perpendicular to the axial direction of the heat pipe holes 21.

[0055] An inlet header 11 and an outlet header 33 are respectively arranged on the front and rear sides of the heat exchange core 22, and the setting directions of the inlet header 11 and the outlet header 33 are both perpendicular to the direction of the heat pipe 4.

[0056] The small hole channels 22 are arranged radially in the gaps between the heat pipe 4 bundles. The inlet header 1 and the outlet header 3 are arranged on both sides of the heat exchange core 2 in the radial direction. The heat transfer medium in the small hole channels 22 flows transversely to exchange heat with the heat pipe 4.

[0057] By processing the radial small hole channels 22, an inlet header 1 and an outlet header 3 are formed on both sides of the heat exchange core 2. The heat transfer part still adopts the longitudinal flow mode to realize the heat transfer of the microchannel structure. This scheme has the structural advantages that the entire length of the heat pipe 4 is not under pressure and there is no need to set up a protective sleeve 5, etc.

[0058] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0059] The above - disclosed preferred embodiments of the present invention are only used to help explain the present invention. The preferred embodiments do not elaborate all the details, nor do they limit the invention to the specific embodiments described. Obviously, according to the content of this specification, many modifications and changes can be made. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the relevant technical fields can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. An efficient heat pipe heat exchanger with a microchannel structure, characterized in that It includes a heat exchange core body. A plurality of heat pipe holes are axially machined in the heat exchange core body. Heat pipes are inserted into the heat pipe holes. A plurality of small hole channels are arranged radially around the heat pipe holes along the radial direction of the heat pipe holes. Both the small hole channels and the heat pipe holes penetrate through the heat exchange core body. Pressure-bearing gaps are arranged between adjacent small hole channels and between the small hole channels and the heat pipe holes. A heat transfer medium flows through the small hole channels, and heat exchange is carried out between the heat transfer medium and the heat pipes. A plurality of small hole channels are uniformly distributed along the axial direction of the heat pipe holes inside the heat exchange core body. The small hole channels are arranged radially along the heat pipe holes and are perpendicular to the heat pipe holes. A single small hole channel is inserted between multiple heat pipe holes and is arranged in an S shape. The heat transfer medium flows radially along the small hole channels.

2. The high-efficiency heat pipe heat exchanger with a microchannel structure according to claim 1, wherein, The heat exchange core body is a solid formed structure welded by diffusion of multiple axially stacked plate parts. The heat pipe holes are formed by deep hole drilling after diffusion welding of the heat exchange core body. The small hole channels are formed by punching each plate part and then carrying out diffusion welding.

3. The high-efficiency heat pipe heat exchanger with a microchannel structure according to claim 1, characterized in that, The heat pipes extend from the core of a heat pipe micro-reactor. The positions of the heat pipe holes correspond to the positions of the heat pipes in the core of the heat pipe micro-reactor. A heat-conducting medium is filled in the gap between the heat pipes and the heat pipe holes.

4. The high-efficiency heat pipe heat exchanger with a microchannel structure according to claim 1, characterized in that, An inlet header and an outlet header are arranged at the middle position of the heat exchange core body. The directions of both the inlet header and the outlet header are perpendicular to the axial direction of the heat pipe holes.

5. The high-efficiency heat pipe heat exchanger with a microchannel structure according to claim 4, characterized in that An inlet nozzle is arranged on the inlet header. The inlet nozzle is used for introducing the heat transfer medium. An outlet nozzle is arranged on the outlet header. The outlet nozzle is used for discharging the heat transfer medium. The inlet header and the inlet nozzle, and the outlet header and the outlet nozzle are all connected by welding.

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