Compact type high-pressure-resistant wide-channel heat exchanger structure

Abstract

The invention discloses a compact high-pressure-resistant wide-channel heat exchanger structure which is suitable for direct heat exchange between high-pressure cleaning fluid and low-pressure fluid easy to block. The heat exchanger comprises a plurality of high-pressure side flowing units and low-pressure side flowing channels, each high-pressure side flowing unit is composed of a first plate and a second plate, the high-pressure side surface of each first plate is machined to form a micro-channel array of a fin structure, and each second plate is a smooth surface or a matched structural surface. The two are welded to form a closed high-pressure fluid channel, and the mechanical strength of the high-pressure fluid channel is close to that of base metal. A low-pressure side flow channel is formed between every two adjacent high-pressure side units, and disturbance micro-channels are formed in the surfaces of the channels. The structure further comprises a flange type low-pressure seal head and an all-welded high-pressure seal head, has high efficiency, reliability and maintainability, and is suitable for compact heat exchange application scenes of ocean energy power, nuclear energy and high-end heat energy systems.

Description

Technical Field

[0001] The present invention belongs to the field of heat exchanger structural design and enhanced heat transfer technology, and relates to compact heat exchanger structural optimization technology under high-parameter working conditions. Specifically, it relates to a high-efficiency, high-pressure-resistant wide-channel heat exchanger structure that can achieve efficient, stable and easy-to-maintain heat exchange under high-pressure, high-temperature and easily blocked working conditions. Background Art

[0002] Heat exchangers, devices that exchange heat between cold and hot fluids, are widely used in energy, power, chemicals, petroleum, food, and other fields. In industrial processes, heat exchangers not only undertake the important task of heat energy conversion and recovery, but are also key components for achieving energy-saving and efficient operation of the system. With the increasing complexity and high performance of process systems, heat exchangers face increasing challenges in design and application. This is especially true when heating or cooling fluids containing impurities, dirt, and viscosity. Heat exchangers must not only be highly efficient, but also anti-clogging, compact, and reliable. This is especially true under high-parameter conditions and in situations where there are strict requirements on volume and weight. The design challenges of heat exchangers are even more prominent.

[0003] At present, traditional heat exchangers mainly include shell and tube heat exchangers, plate heat exchangers and printed circuit board heat exchangers (PCHE). Among them, the tube heat exchanger has a simple structure and can withstand higher pressures and temperatures, but the heat exchanger is relatively large in size and weight, occupies a large space, and the problem of heat exchange tube vibration damage needs to be considered. As compact heat exchangers, plate heat exchangers and printed circuit board heat exchangers play an important role in the industrial field due to their high efficiency. However, due to the limitations of sealing, the working pressure and temperature of plate heat exchangers generally do not exceed 2.5MPa and 250℃. Even if a full welding process is used, the working pressure and temperature usually do not exceed 4MPa and 350℃.

[0004] Printed circuit board heat exchangers (PCBHEs) use chemical etching to create flow channels on the plates, which are then connected using diffusion welding. The core's structural strength approaches that of the parent material, resulting in high reliability in high-pressure and high-temperature environments. They are often used in high-parameter applications such as supercritical CO2 (S-CO2) power generation cycles, aerospace, and nuclear power systems. While PCHEs offer excellent resistance to high pressures and temperatures, the diameter of etched flow channels in traditional PCBHEs is generally limited to 5mm. These narrow and tortuous channels require a high degree of fluid cleanliness, making them difficult to clean and maintain once clogged. Furthermore, due to their highly integrated structure, PCHEs are difficult to clean, disassemble, and maintain on-site, limiting their applicability to fluids containing impurities or harsh operating conditions.

[0005] On the other hand, with the rapid development of offshore platforms, ship propulsion systems, and high-efficiency power generation technologies, an increasing number of engineering scenarios require efficient heat exchange between high-pressure, high-temperature fluids and easily clogged fluids (such as seawater) within confined spaces and harsh environments. For example, in offshore gas turbine waste heat utilization and S-CO2 power generation systems, the high-pressure S-CO2 must be cooled to a specific temperature to maintain system circulation efficiency. Although seawater is an inexhaustible cooling medium and does not require additional transportation, it contains algae, microorganisms, and suspended particles, placing higher demands on the heat exchanger's anti-clogging, cleanability, and maintainability.

[0006] In short, traditional compact heat exchanger designs, such as tubular, plate, and printed circuit board heat exchangers, struggle to simultaneously meet the requirements for high efficiency, compactness, and reliability, and are also struggling to adapt to stable operation in harsh environments prone to clogging. Therefore, designing a heat exchanger structure that combines high pressure resistance, excellent anti-clogging performance, a compact structure, and the ability to operate stably under harsh conditions is a pressing technical challenge in the fields of heat exchanger structural design and thermal engineering applications. Summary of the Invention

[0007] (1) Purpose of the invention

[0008] In order to solve the above technical problems, the present invention aims to provide a compact high-pressure resistant wide-channel heat exchanger structure. By adopting a microchannel configuration combining chemical etching and diffusion welding on the high-pressure side, the flow channel structure strength is ensured to be close to that of the base material, thereby improving the pressure resistance and structural reliability of the heat exchanger. A wide channel design is introduced on the low-pressure side, and combined with etched transverse grooves, a spoiler column array and a multi-flow distribution structure, efficient heat exchange and anti-clogging operation of fluids containing impurities are achieved, while having good disassembly and convenience for cleaning and maintenance. This structure takes into account compactness, high efficiency, high pressure resistance and anti-pollution capabilities, and is particularly suitable for direct heat exchange processes between scaling fluids such as seawater and sewage and high-pressure working fluids (such as S-CO2). It can effectively improve the thermal energy utilization efficiency and engineering adaptability of the overall system, and meet the comprehensive demand for high-performance heat exchange equipment under space and weight-constrained working conditions.

[0009] (2) Technical solution

[0010] In order to achieve the purpose of the invention and solve the technical problems, the present invention adopts the following technical solutions:

[0011] A compact high-pressure resistant wide-channel heat exchanger structure for achieving direct heat exchange between a high-pressure fluid and a low-pressure, easily clogged fluid, comprising a plurality of high-pressure side flow units and low-pressure side flow channels, wherein:

[0012] Each high-pressure side flow unit includes at least a first plate and a second plate, and the two surfaces of each plate are respectively formed into a high-pressure side surface and a low-pressure side surface, wherein: the main part of the high-pressure side surface of the first plate is processed to form a fin structure microchannel extending along a first direction and distributed in an array in a second direction orthogonal to the first direction, so as to enhance the heat exchange area and fluid disturbance, and improve the heat exchange efficiency of the high-pressure clean fluid under high heat flux density conditions; the high-pressure side surface of the second plate is set to a smooth surface or processed to form a structural surface complementary to the high-pressure side surface of the first plate, the high-pressure side surfaces of the first plate and the second plate are arranged opposite to each other and are connected by welding after being fitted to each other to form a closed high-pressure fluid channel, and the high-pressure channel has a mechanical strength close to that of the base material to ensure structural safety and sealing performance under high-pressure and high-temperature working conditions;

[0013] The multiple high-pressure side flow units are arranged at discrete intervals along the height direction, and their overall structure is firmly connected in the height direction through at least two pressure-bearing plates arranged at both ends of the first direction. The pressure-bearing plates are used to limit the height dimension of the overall structure of the heat exchanger and withstand the external force caused by the flow of the low-pressure side fluid; the space between each two adjacent high-pressure side flow units forms a low-pressure side flow channel, which is used to guide the low-pressure fluid to flow along the second direction, so that a cross-flow heat exchange structure is formed between the low-pressure fluid and the high-pressure fluid; each low-pressure side flow channel is spatially defined by two relatively arranged low-pressure side surfaces, namely the low-pressure side surface of the first plate of a high-pressure side flow unit, and the low-pressure side surface of the second plate of another adjacent high-pressure side flow unit, wherein at least one of the low-pressure side surfaces is processed with a disturbance function micro-groove structure extending along the second direction, which is used to increase the contact area between the fluid and the wall, improve the disturbance intensity and inhibit the deposition of pollutants.

[0014] (3) Technical effects

[0015] Compared with the existing technology, the compact high-pressure resistant wide-channel heat exchanger structure of the present invention has the following beneficial and significant technical effects: the high-pressure side of the heat exchanger forms a fluid flow channel through etching and diffusion welding, and the strength of the channel is close to that of the base material, which not only improves the pressure resistance of the heat exchanger but also has a higher compactness; the low-pressure side fluid side that is prone to clogging adopts a wide flow channel design and adopts a composite enhanced heat transfer technology, which not only solves the problem of easy clogging, but also solves the problem of low laminar flow heat transfer coefficient, thereby improving the efficiency of the heat exchanger; the diversion and confluence structure of the low-pressure side fluid that is prone to clogging is designed as a flange connection structure, which is easy to clean and maintain during actual use, thereby improving the practicality of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of indirect heat exchange between S-CO2 and seawater;

[0017] Figure 2 This is a schematic diagram of the surface structure of the high-pressure side (S-CO2) plate;

[0018] Figure 3 Schematic diagram of the plate surface structure on the low-pressure side (seawater side);

[0019] Figure 4 Schematic diagram of the connection between the high-pressure side (S-CO2) flow unit and the low-pressure side (seawater side) plates.

[0020] Description of reference numerals:

[0021] 1-Seawater treatment system, 2-Seawater circulation pump, 3-Plate heat exchanger, 4-Water pump, 5-Printed circuit board heat exchanger, 6-First plate, 7-Second plate, 8-High-pressure side surface of first plate (S-CO2 side), 9-High-pressure side surface of second plate (S-CO2 side), 10-Low-pressure side surface of first plate (seawater side), 11-Partition channel, 12-Circular groove, 13-Low-pressure side surface of second plate (seawater side), 14-Partition, 15-Spoiler column, 16-Pressure plate. DETAILED DESCRIPTION

[0022] The present invention aims to provide a compact, high-pressure, wide-channel heat exchanger structure for direct heat exchange between a high-pressure, clean fluid and a low-pressure, easily clogged fluid. To further clarify the objectives, technical solutions, and advantages of the present invention, the technical solutions in the embodiments of the present invention are described in more detail below, in conjunction with the accompanying drawings. The described embodiments are only a portion of the embodiments of the present invention, not all of them. These embodiments are illustrative and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] During operation, gas turbines on offshore platforms release approximately 70% of the heat released by fuel combustion into the atmosphere along with the turbine flue gas. Due to space limitations on offshore platforms, effectively utilizing this medium- to high-temperature waste heat (200-600°C) is difficult. Supercritical carbon dioxide (S-CO2) Brayton cycle power generation technology, due to its outstanding compactness, is expected to be the optimal solution for recovering waste heat from gas turbine flue gas on offshore platforms. The precooler is a key component of the S-CO2 Brayton cycle power generation system. Its primary function is to cool the S-CO2 to a specific temperature before it enters the compressor. Seawater is undoubtedly the optimal cooling medium. However, seawater contains a large amount of algae, arthropods, and microorganisms, which pose a risk of clogging the heat exchanger. To ensure stable system operation, it is necessary to consider the issues of precooler anti-clogging, cleaning, and maintenance.

[0024] The precooler of the offshore gas turbine waste heat S-CO2 power generation system is designed to cool the S-CO2 with an inlet pressure of 9.35 MPa from an inlet temperature of 80°C to 38°C with a flow rate of 220 kg / s. The seawater temperature is 33°C. Figure 1 As shown in the figure, currently, there is no heat exchanger suitable for direct heat exchange between S-CO2 circulating medium and seawater, because the pressure on the S-CO2 side (high pressure side) is higher and the seawater side (low pressure side) must consider issues such as corrosion prevention, clogging, cleaning and maintenance. Figure 1 As shown in Table 1, a mature optional solution is indirect heat exchange between the S-CO2 circulating medium and seawater. After the seawater is treated by the seawater treatment system 1, it is transported to the plate heat exchanger 3 through the seawater circulation pump 2. The closed circulating water is transported to the plate heat exchanger 3 through the water pump 4. After the two exchange heat, the closed circulating water enters the printed circuit board type heat exchanger 5 to cool the S-CO2 circulating medium. If the inlet pressure and inlet temperature of the closed circulating water are 0.5MPa and 35℃ respectively, a water flow rate of 868.1kg / s is required, and the outlet temperature is 45℃. The plate heat exchanger and printed circuit board type heat exchanger are designed respectively. As shown in Table 1, the total volume of the two heat exchangers in the indirect heat exchange solution between the S-CO2 circulating medium and seawater is 49.7m 3 , with a total weight of 32.4t.

[0025] Table 1 Design results of heat exchanger for indirect heat exchange between S-CO2 and seawater

[0026] parameter result Plate heat exchanger 3 dimensions, m 6.0×1.66×4.408 Plate heat exchanger 3 materials titanium PCB heat exchanger 5 dimensions, m 1.690×3.834×0.91 PCB Heat Exchanger 5 Materials Stainless steel <![CDATA[Total volume, m 3 > 49.8 Total weight, t 32.4

[0027] This embodiment discloses a compact high-pressure wide-channel heat exchanger that can be used for direct heat exchange between high-pressure S-CO2 circulating medium and low-pressure seawater. The heat exchanger includes multiple high-pressure side flow units and low-pressure side flow channels. Figure 2As shown, the S-CO2 flow channel (i.e., the high-pressure side flow unit) of the heat exchanger is formed by diffusion welding two plates, a first plate 6 and a second plate 7. The two surfaces of each plate are respectively formed into a high-pressure side (S-CO2 side) surface and a low-pressure side (seawater side) surface. Specifically, the main portion of the high-pressure side (S-CO2 side) surface 8 of the first plate 6 is chemically etched with a fin-structured microchannel array structure. The microchannel array extends as a whole along a first direction and is distributed in an array in a second direction orthogonal to the first direction. This is used to enhance the heat exchange area and fluid disturbance, thereby improving the heat exchange efficiency of the high-pressure clean fluid under high heat flux conditions. The high-pressure side (S-CO2 side) surface 9 of the second plate 7 has a smooth surface structure or is machined to form a structural surface that complements the high-pressure side surface of the first plate. The S-CO2 high-pressure side surface 8 of the first plate 6 and the S-CO2 high-pressure side surface 9 of the second plate 7 are arranged opposite to each other and are connected by diffusion welding after being bonded to each other to form a closed high-pressure fluid channel, thereby constituting a complete high-pressure side flow unit of S-CO2. The high-pressure fluid channel has a mechanical strength close to that of the base material to ensure structural safety and sealing performance under high-pressure and high-temperature working conditions.

[0028] Preferably, the number of high-pressure side flow units is designed according to the required heat exchange capacity and structural size requirements of the heat exchanger. In the fin structure microchannel array formed by processing the high-pressure side surfaces 8 and 9 of the first plate 6 and / or the second plate 7, the cross-sectional shape of the microchannel is rectangular, circular, semicircular, triangular or trapezoidal, and the arrangement of the microchannel array is linear, staggered or honeycomb, so as to maximize the microchannel density and optimize the uniformity of fluid distribution, ensure that the flow distribution of high-pressure fluid in each microchannel is uniform, and avoid local hot spots and flow dead zones; and the microchannel structure is designed through numerical optimization and formed by etching or precision milling, with good dimensional consistency and structural stability, which can effectively improve the turbulence degree and heat transfer coefficient of high-pressure clean fluid in the channel, significantly enhance the heat exchange capacity under high heat flux density, and ensure the structural integrity under high-pressure working conditions and consistent matching with the welding sealing area.

[0029] Preferably, the first and second plates 6 and 7 are made of one of the following materials: stainless steel, titanium alloy, nickel-based alloy, aluminum alloy, or copper alloy. The material selection is based on a comprehensive consideration of the operating environment, fluid characteristics, temperature, and / or pressure. When processing corrosive fluids, corrosion-resistant materials or an anti-corrosion coating are used on the plate surfaces. When operating at temperatures exceeding 350°C, high-temperature resistant alloys are used. The plate thickness ranges from 1 to 10 mm, determined based on the operating pressure and structural requirements, to ensure long-term, reliable operation of the heat exchanger under high-pressure and high-temperature conditions. Furthermore, the high-pressure side surfaces 8 and 9 of the first and second plates 6 and 7 are connected by diffusion welding, with the weld zone confined to the closed edge of the high-pressure side fluid boundary. The diffusion welding is performed under pressure in a controlled atmosphere furnace or vacuum hot press furnace to ensure a continuous grain transition in the weld joint. The mechanical strength of the weld zone is no less than 90% of the parent material strength, effectively preventing leakage and fatigue failure. This allows the high-pressure fluid channel to withstand operating pressures exceeding 9 MPa, and the plate thickness can be reduced to 2 to 5 mm.

[0030] In the embodiment of the present invention, the plurality of high-pressure side flow units of the heat exchanger are arranged at discrete intervals in the height direction, and the two pressure-bearing plates 16 provided at both ends in the first direction are used to realize a stable connection of the overall structure in the height direction. The pressure-bearing plates 16 are used to limit the height dimension of the overall structure of the heat exchanger and withstand the external force caused by the flow of the low-pressure side fluid, such as Figure 4 As shown. The space between each two adjacent high-pressure side flow units forms a low-pressure side flow channel (i.e., a seawater side flow channel) for guiding the low-pressure fluid to flow in the second direction, so that a cross-flow heat exchange structure is formed between the low-pressure fluid and the high-pressure fluid. Each low-pressure side flow channel is spatially defined by two relatively arranged low-pressure side surfaces, namely, the low-pressure side (seawater side) surface 10 of the first plate 6 of a high-pressure side flow unit, and the low-pressure side (seawater side) surface 13 of the second plate 7 of another adjacent high-pressure side flow unit. At least one of the low-pressure side surfaces is machined to have a disturbance function micro-groove structure extending along the second direction, which is used to increase the contact area between the fluid and the wall, increase the disturbance intensity and inhibit the deposition of pollutants, as shown. Figure 3 shown.

[0031] Preferably, a plurality of high-pressure side flow units are precisely positioned between the two pressure plates 16 arranged at both ends of the first direction by setting a registration structure. The registration structure includes a positioning hole, a positioning boss or a tooth groove structure to ensure the geometric symmetry and spacing consistency of the high-pressure side channel and the low-pressure side channel, avoid uneven channels or abnormal local flow resistance caused by assembly errors, and improve the overall assembly accuracy and operational stability. In addition, the material of the pressure plate 16 is the same as or has a similar thermal expansion coefficient to the first plate 6 and the second plate 7 to avoid thermal stress problems caused by temperature changes, and is connected to the plurality of high-pressure side flow units by diffusion welding; and the outer sides of the two pressure plates 16 are respectively provided with diversion and confluence channels for high-pressure fluid and low-pressure fluid, and the diversion and confluence channels of the high-pressure fluid are connected to the pressure plate by a full welding method to ensure sealing under high-pressure working conditions, and the diversion and confluence channels of the low-pressure fluid are connected to the pressure plate by a flange connection method, and a sealing gasket is provided at the flange connection for easy disassembly, cleaning and maintenance.

[0032] Preferably, the low-pressure side flow channel of the heat exchanger is set to a wide channel with a height of 5-50 mm, and is adjusted according to the characteristics of low-pressure fluids that are prone to clogging. When processing fluids containing larger particles or impurities, the channel height can be set to a larger value to reduce the risk of clogging; when processing fluids containing smaller particles or slight contamination, the channel height can be set to a smaller value to improve the compactness of the structure; the height of the high-pressure fluid channel can be set to 0.5-3 mm as needed to process clean high-pressure fluids and maximize the heat exchange area in a limited space.

[0033] Preferably, the disturbance function micro-groove structure formed on the low-pressure side surface of the first plate 6 and / or the second plate 7 includes at least one of the following: uniformly distributed transverse grooves, corrugated grooves, serrated grooves, triangular fins, square fins, circular fins or fishbone fin structures, the micro-groove structure is formed by chemical etching, laser or mechanical processing methods, and the size of the groove or fin is optimized according to the Reynolds number of the low-pressure fluid and the particle size of the pollutants to enhance fluid disturbance, break the boundary layer and reduce the risk of particle deposition, thereby improving heat transfer efficiency and anti-clogging performance without significantly increasing the pressure drop.

[0034] like Figure 4 As shown, a number of partitions 14 extending along the second direction are arranged between the two relative low-pressure side surfaces of each low-pressure side flow channel, which are used to divide the low-pressure side flow channel into multiple parallel sub-channels, and the height of the partition 14 is set according to the height of the low-pressure side flow channel, which is used to limit the effective flow space of the low-pressure fluid in the channel, shorten the local flow path, and extend the boundary layer development zone to enhance heat exchange and improve cleaning and maintenance performance.

[0035] More specifically, Figure 3As shown, each seawater-side flow channel (low-pressure flow channel) consists of two different S-CO2 flow units (high-pressure flow units) spaced adjacent to each other in the height direction. The flow on the low-pressure (seawater-side) surface 10 of the first plate 6 is divided into three flow zones. Multiple baffle channels 11, spaced along the first direction, are provided between the different flow zones to provide isolation. The flow zones are chemically etched with transverse grooves to increase the wall roughness, thereby increasing the heat exchange area and fluid disturbance. This not only enhances heat exchange but also improves anti-clogging capabilities.

[0036] The low-pressure side (seawater side) surface 10 of the first plate 6 on the seawater side has evenly arranged circular grooves 12, and each circular groove 12 is distributed in an array along the first direction and the second direction, and the circular grooves arranged opposite to each other on the two low-pressure side surfaces correspond to each other. The low-pressure side (seawater side) surface 13 of the second plate 7 is also provided with the same partition grooves and circular grooves as the low-pressure side (seawater side) surface 10 of the first plate 6. The low-pressure side (seawater side) surface 10 of the first plate 6 and the low-pressure side (seawater side) surface 13 of the second plate 7 are connected to each other through the partition 14 and the spoiler column 15, as shown in FIG. Figure 4 As shown, the baffle 14 and the circular column 15 are respectively placed in the corresponding baffle groove 11 and the circular groove 12 by diffusion welding or mechanical pressing, forming a multi-flow flow channel on the seawater side, wherein the circular groove plays a positioning and fixing role, and the spoiler column can not only further increase the lateral disturbance of the low-pressure fluid and improve the turbulence of the flow field, but also play a supporting role, thereby improving the overall rigidity and anti-deformation ability of the heat exchanger on the low-pressure side.

[0037] Preferably, the number of multiple parallel subchannels is determined based on the flow rate and flow characteristics of the low-pressure fluid; the inlet and outlet of each subchannel are connected to the low-pressure side diversion and confluence structure; the subchannels can be set to equal or unequal length structures in the flow direction. When set to unequal length structures, the subchannel path near the center of the heat exchanger is longer, and the subchannel path near the edge of the heat exchanger is shorter. By rationally designing the flow resistance of each subchannel, the flow distribution of the low-pressure fluid in each subchannel is ensured to be uniform, thereby improving heat exchange efficiency and system reliability. Since the flow path of the fluid in a single flow channel is shortened compared to a single flow path, the laminar boundary layer development section is lengthened, which plays a role in enhancing heat exchange. In addition, the flow of the short flow path is easier to clean and maintain. The seawater sides of different S-CO2 flow units are welded together by a pressure plate 16 to ensure sufficient strength. The height of the pressure plate 16 is the height of the seawater flowing between the plates and is selected according to the actual situation of the seawater.

[0038] Furthermore, the flow distribution and convergence on the seawater side (low-pressure side) is achieved through a flanged semicircular head structure, which is detachably connected to the two pressure plates at both ends of the second direction via flanges and bolts. This facilitates the disassembly of the low-pressure side channel for cleaning and maintenance during system operation. The flange structure has both mechanical positioning and sealing functions, ensuring the stability and maintainability of the system during long-term operation. The flow distribution and convergence on the S-CO2 side adopts a fully welded semicircular or conical head structure, which is connected to the two pressure plates 16 at both ends of the first direction by full welding, ensuring pressure bearing capacity, ensuring the sealing reliability and structural strength of high-pressure fluids under high-pressure conditions (e.g., above 9 MPa), while avoiding stress concentration and leakage risks caused by bolted connections.

[0039] As shown in Table 2, the direct heat exchange solution between S-CO2 and seawater adopts a compact high-pressure wide-channel heat exchanger disclosed in the invention. The total volume of the heat exchanger is 23.3m 3 , total weight ~9.3t.

[0040] Table 2 Design results of a compact high-pressure wide-channel heat exchanger disclosed in the present invention

[0041] parameter result Dimensions of high pressure wide channel heat exchanger, m 2.45×7.96×1.21 High-pressure wide-channel heat exchanger materials titanium <![CDATA[Total volume, m 3 > ～23.6 Total weight, t ～9.3

[0042] Comparing the design results of the two-stage heat exchanger used in the indirect heat exchange solution between S-CO2 and seawater with the design results of the compact, high-pressure, wide-channel heat exchanger structure proposed in this invention, the latter significantly reduces both overall structural size and equipment weight. Specifically, the integrated high- and low-pressure channel layout and enhanced heat exchange microchannel design adopted in this invention not only effectively reduce the number of heat exchange units required in the system, but also significantly compress the equipment's geometric size and weight, reducing the complexity of structural installation and maintenance, providing a more advantageous heat exchange solution for practical engineering applications.

[0043] The above embodiments fully and effectively achieve the objectives of the present invention. Those skilled in the art will appreciate that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the above specific embodiments. Although the present invention has been described with reference to the embodiments currently considered to be the most practical and preferred, it should be understood that the present invention is not limited to the disclosed embodiments, and any modifications that do not deviate from the functional and structural principles of the present invention are intended to be included within the scope of the claims.

Claims

1. A compact high-pressure wide-channel heat exchanger structure for achieving direct heat exchange between high-pressure clean fluid and low-pressure easily clogged fluid, characterized in that: It comprises at least a plurality of high-pressure side flow units and low-pressure side flow channels, wherein: Each high-pressure side flow unit includes at least a first plate and a second plate, and the two surfaces of each plate are respectively formed into a high-pressure side surface and a low-pressure side surface, wherein: the high-pressure side surface of the first plate is processed to form a fin structure microchannel extending along a first direction and distributed in an array in a second direction orthogonal to the first direction; the high-pressure side surface of the second plate is set as a smooth surface or processed to form a structural surface that complements the high-pressure side surface of the first plate, and the high-pressure side surfaces of the first plate and the second plate are arranged opposite each other and welded after being affixed to each other to form a closed high-pressure fluid channel; The plurality of high-pressure side flow units are arranged at discrete intervals along the height direction, and the overall structure is stably connected in the height direction by two pressure-bearing plates arranged at both ends in the first direction; a low-pressure side flow channel is formed between each two adjacent high-pressure side flow units to guide the low-pressure fluid to flow along the second direction, so that a cross-flow heat exchange structure is formed between the low-pressure fluid and the high-pressure fluid; Each low-pressure side flow channel is spatially defined by two relatively arranged low-pressure side surfaces, namely the low-pressure side surface of the first plate of a high-pressure side flow unit and the low-pressure side surface of the second plate of another adjacent high-pressure side flow unit, and at least one of the low-pressure side surfaces is machined with a disturbance function micro-groove structure.

2. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1 is characterized in that: In each high-pressure side flow unit, the first plate and the second plate are made of one of the following materials: stainless steel, titanium alloy, nickel-based alloy, aluminum alloy or copper alloy. The selection of materials is based on a comprehensive consideration of the working environment, fluid properties, temperature and / or pressure factors; when processing corrosive fluids, corrosion-resistant materials are selected or an anti-corrosion coating is applied to the plate surface; when the working temperature exceeds 350°C, high-temperature resistant alloy materials are selected; the plate thickness is 1-10mm and is determined according to the working pressure and structural requirements.

3. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1 or 2, characterized in that: In each high-pressure side flow unit, the high-pressure side surfaces of the first plate and the second plate are connected by diffusion welding, and the welding area is limited to the closed edge of the high-pressure side fluid boundary. The diffusion welding is pressurized and sintered in a controlled atmosphere furnace or a vacuum hot pressing furnace to ensure that the weld joint achieves continuous grain transition in the microstructure, and the mechanical strength of the weld zone is not less than 90% of the strength of the parent material.

4. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1 is characterized in that: The multiple high-pressure side flow units are precisely positioned with the two pressure-bearing plates at both ends of the first direction by setting a registration structure, and the registration structure includes a positioning hole, a positioning boss or a tooth groove structure.

5. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1 or 4, characterized in that: The material of the pressure plate is the same as or has a similar thermal expansion coefficient to that of the first plate and the second plate, and is connected to multiple high-pressure side flow units by diffusion welding; and the outer sides of the two pressure plates are respectively provided with diversion and convergence channels for high-pressure fluid and low-pressure fluid, the diversion and convergence channels of the high-pressure fluid are connected to the pressure plate by full welding, and the diversion and convergence channels of the low-pressure fluid are connected to the pressure plate by flange connection, and a sealing gasket is provided at the flange connection.

6. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1 or 4, characterized in that: The diversion and confluence channels of the high-pressure fluid adopt a hemispherical or conical head form, which is connected to the two pressure plates at both ends of the first direction by full welding, and the head has a material and pressure resistance grade consistent with the base material of the pressure plate; the diversion and confluence channels of the low-pressure fluid adopt a semicircular head structure, which is detachably connected to the two ends of the second direction of the two pressure plates by flanges and bolts.

7. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1 is characterized in that: The number of high-pressure side flow units is designed according to the required heat exchange capacity and structural size requirements of the heat exchanger; in the fin structure microchannel array formed by processing the high-pressure side surface of the first plate and / or the second plate, the cross-sectional shape of the microchannel is rectangular, circular, semicircular, triangular or trapezoidal, and the arrangement of the microchannel array is linear, staggered or honeycomb; and the microchannel structure is designed through numerical optimization and formed by etching or precision milling.

8. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1 is characterized in that: The disturbance function micro-groove structure formed on the low-pressure side surface of the first plate and / or the second plate includes at least one of the following: uniformly distributed transverse grooves, corrugated grooves, serrated grooves, triangular fins, square fins, circular fins or fishbone fin structures. The micro-groove structure is formed by etching or milling, and the size of the grooves or fins is optimized according to the Reynolds number of the low-pressure fluid and the particle size of the pollutants.

9. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1, characterized in that: A plurality of circular grooves are distributed on the two opposite low-pressure side surfaces of each low-pressure side flow channel, and the circular grooves are distributed in an array along the first direction and the second direction, and the circular grooves arranged oppositely on the two low-pressure side surfaces correspond to each other one by one; a cylindrical spoiler column is provided between the two opposite circular grooves, and the two ends of the spoiler column are respectively embedded in the corresponding circular grooves, and are fixedly connected to the plate by diffusion welding or mechanical pressing.

10. The compact high-pressure resistant wide-channel heat exchanger structure according to claim 1, characterized in that: A plurality of baffle grooves extending in a second direction are provided on two opposing low-pressure side surfaces of each low-pressure side flow channel at intervals along a first direction, and the baffle grooves arranged opposite each other on the two low-pressure side surfaces correspond to each other one by one; a baffle is provided between the two opposing baffle grooves, and the two ends of the baffle are respectively embedded in the corresponding baffle grooves and fixedly connected to the plate by diffusion welding or mechanical pressing, so as to divide the low-pressure side flow channel into a plurality of parallel sub-channels; The height of the partition is set according to the height of the low-pressure side flow channel.

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