A porous flow channel heat exchanger and its processing method

Abstract

The present invention provides a porous flow channel heat exchanger and a processing method. In the processing method, the upper wall flow channel is mechanically processed on the heat exchanger plate; the porous medium particles are made into a viscous mixed particle powder; the mixed particle powder is filled into the entire upper wall flow channel to form a porous particle bonding layer within the upper wall flow channel; and a single heat exchanger plate is hot-pressed and sintered to form a metallurgical bond between the porous medium particles in the mixed particle powder and between the porous medium particles and the inner wall of the upper wall flow channel, thereby producing a single-layer porous flow channel heat exchanger. The present invention also provides a method for preparing a multi-layer porous flow channel heat exchanger. The processing method provided by the present invention can simultaneously complete the hot-pressing sintering of the porous medium particles and the heat exchanger plates, thereby solving the problem that the existing technology increases the specific surface area and heat exchange efficiency by designing a small single flow channel size, which increases the processing difficulty and even makes it difficult to achieve.

Description

Technical Field

[0001] The present invention belongs to the field of printed circuit board type heat exchangers, relates to the processing direction of heat exchangers, and specifically relates to a multi-porous flow channel heat exchanger and a processing method thereof. Background Art

[0002] Heat exchange is an important link in energy transfer and conversion, and exists in many industrial production processes. The development of efficient and compact heat exchangers can help improve heat exchange performance, reduce the size of heat exchange equipment, optimize the space occupied and investment cost of the heat exchange system, and at the same time play a role in energy conservation and emission reduction.

[0003] Microchannel heat exchangers, represented by printed circuit board heat exchangers (PCHE), have compact structure, large specific surface area, and high heat transfer efficiency. They are considered the first choice for efficient heat exchange in confined spaces or under high temperature and high pressure conditions.

[0004] However, PCHE mainly increases the specific surface area by reducing the flow channel size. The specific surface area of PCHE with millimeter-level flow channel can reach 5000m 2 / m 3 The connection between PCHE plates is mainly achieved through diffusion welding. Diffusion welding is to press the weldment into a vacuum or reducing gas atmosphere, apply a certain temperature and pressure, and maintain it for a certain time to complete the connection between the plates. The welding temperature is generally 0.5-0.8T 熔 (T 熔 melting point), the applied pressure is small.

[0005] However, the single flow channel size of PCHE is so small that further reducing the flow channel size or changing the flow channel type will bring difficulties to processing, and there may also be problems of partial flow channel blockage, making it difficult to further increase the specific surface area of PCHE. Summary of the Invention

[0006] The present invention provides a porous flow channel heat exchanger and a processing method thereof, so as to solve the problem that the prior art scheme of increasing the specific surface area and heat exchange efficiency by designing a small single flow channel size increases the processing difficulty and even makes it difficult to realize.

[0007] In a first aspect of the present invention, a method for processing a single-layer porous channel heat exchanger is provided, comprising:

[0008] The upper wall flow channel is machined on the heat exchanger plate;

[0009] The porous medium particles are made into a viscous mixed particle powder;

[0010] Filling the entire upper wall flow channel with the mixed particle powder to form a porous particle bonding layer in the upper wall flow channel;

[0011] A single heat exchanger plate is hot-pressed and sintered to achieve metallurgical bonding between the porous medium particles in the mixed particle powder and between the porous medium particles and the inner wall of the upper wall flow channel, thereby forming a porous sintered layer of particles tightly bonded to the upper wall flow channel to produce a single-layer porous flow channel heat exchanger.

[0012] In a second aspect of the present invention, a method for manufacturing a multi-layer porous channel heat exchanger is provided, comprising:

[0013] At least one upper wall flow channel is machined on each heat exchanger plate;

[0014] The porous medium particles are made into a viscous mixed particle powder;

[0015] Filling each of the upper wall flow channels with the mixed particle powder to form a porous particle bonding layer within the upper wall flow channels;

[0016] Multiple heat exchanger plates are stacked together in a completely opposite order with the upper wall flow channels facing the same direction, the stability of the stacking is maintained and longitudinal pressure is applied to make the adjacent heat exchanger plates closely contact each other, and hot pressing and sintering are performed while maintaining a stable and close contact state, so that metallurgical bonding is generated between the porous medium particles in the mixed particle powder, and between the porous medium particles and the inner wall of the upper wall flow channel and the lower wall of the adjacent heat exchanger plate, respectively, to form a porous sintered layer of particles that is closely bonded to the upper wall flow channel and the lower wall of the adjacent heat exchanger plate, so as to produce a multi-layer porous flow channel heat exchanger.

[0017] Furthermore, the porous medium particles and the heat exchanger plates have similar melting points, so that metallurgical bonding is formed by mutual diffusion of atoms between the interfaces of the porous medium particles and the heat exchanger plates during hot pressing and sintering.

[0018] Furthermore, the method further comprises: installing a cover plate made of the same material as the heat exchanger plates on the uppermost layer of the stacked heat exchanger plates.

[0019] Furthermore, lower wall fins directly opposite to the upper wall flow channel are processed on the lower wall surface of at least part of the heat exchanger plate, and the lower wall fins are used to apply pressure to the porous bonding layer of particles in the upper wall flow channel after overlapping.

[0020] Furthermore, the step of preparing the porous medium particles into a viscous mixed particle powder comprises:

[0021] Adding three additives, namely, a plasticizer, a binder, and a lubricant, to the porous medium particles, weighing them in a mass ratio of 80%-90% of the porous medium particles and 20%-10% of the additives, and uniformly mixing and stirring to obtain a mixed particle powder;

[0022] Wherein, the plasticizer can be selected from any one or more of paraffin wax and yellow wax;

[0023] The binder can be any one or more of resin and polyvinyl alcohol;

[0024] The lubricant may be any one or more of glycerin, stearic acid and graphite.

[0025] Furthermore, the method further includes the step of removing air from the porous bonding layer of particles before hot pressing and sintering:

[0026] The wall surface of the heat exchanger plate is heated to dry the porous bonding layer of particles, volatilize the organic solvent in the mixed particle powder, and discharge the air in the mixed particle powder so that the mixed particle powder is initially bonded to the upper wall flow channel.

[0027] In a third aspect of the present invention, there is provided a porous flow channel heat exchanger prepared based on the processing method of the above-mentioned single-layer porous flow channel heat exchanger, comprising:

[0028] Heat exchanger plates;

[0029] A heat exchange channel is formed on a wall surface of the heat exchanger plate;

[0030] A fluid inlet is formed on the heat exchange channel, and the fluid inlet is used to introduce a cold fluid or a hot fluid;

[0031] A granular porous sintered layer is formed by hot-pressing and sintering porous medium particles in the heat exchange channel, and the granular porous sintered layer is metallurgically bonded to the inner wall of the heat exchange channel;

[0032] Wherein, any exposed surface of the porous sintered granular layer in the heat exchange channel is a fluid outlet.

[0033] In a fourth aspect of the present invention, a porous flow channel heat exchanger prepared based on the above-mentioned processing method of a multi-layer porous flow channel heat exchanger is provided, comprising:

[0034] At least two heat exchanger plates stacked opposite each other;

[0035] A heat exchange channel is formed on the wall surface of the same side of each heat exchanger plate, and the heat exchange channel is used to pass a fluid working medium;

[0036] The granular porous sintered layer is formed by hot-pressing and sintering porous medium particles in the heat exchange flow channel, and the granular porous sintered layer is metallurgically bonded to the inner wall of the heat exchange flow channel and the wall surface of the adjacent heat exchanger plate;

[0037] A cover plate is provided on the outermost heat exchanger plate exposed by the granular porous sintered layer, and a wall surface of the cover plate is metallurgically bonded to the granular porous sintered layer;

[0038] wherein, the heat exchanger plates of the odd-numbered layers and the even-numbered layers in sequence are respectively fed with cold and hot fluids;

[0039] The heat exchanger plates of the odd-numbered layers and the even-numbered layers are each provided with a set of fluid inlets and fluid outlets connected with all heat exchange flow channels into which the same fluid working medium flows.

[0040] Furthermore, ribs facing the heat exchange channel are provided on all the heat exchanger plates except the outermost heat exchanger plate and the cover plate, and the ribs are used to compress the porous sintered layer of particles in the heat exchange channel;

[0041] The fins are an integral structure matching the heat exchange channel, or a plurality of fins are intermittently arranged along the direction of the heat exchange channel.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The processing method of the porous flow channel heat exchanger (single-layer or multi-layer) provided by the present invention mainly involves mechanically processing the flow channel on the heat exchanger plate, applying porous medium particles in the flow channel, and using a hot pressing and sintering process to form a metallurgical bond by atomic mutual diffusion between the porous medium particles and the interface of the heat exchanger plate, thereby improving the specific surface area and heat transfer efficiency of a single flow channel and the entire heat exchanger plate, without increasing the processing difficulty by excessively reducing the flow channel size.

[0044] The porous flow channel heat exchanger (single layer or multilayer) disclosed in the present invention utilizes the metallurgical bonding characteristics of the material structure between the heat exchanger plate and the granular porous sintered layer, thereby improving the specific surface area and heat exchange efficiency of a single flow channel and the entire heat exchanger plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0046] Figure 1 This is an example diagram of a porous channel heat exchanger in Example 2 of the present invention;

[0047] Figure 2 In Example 2 of the present invention Figure 1 AA cross-section diagram;

[0048] Figure 3 In Example 2 of the present invention Figure 1 BB cross-section diagram;

[0049] Numbers in the figure:

[0050] 1 and 3 are fluid inlets, 2 and 4 are fluid outlets, 5 is a cover plate, 6 is a heat exchange channel, 7 is a heat exchanger plate, and 8 is a fin. DETAILED DESCRIPTION

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0052] The present invention provides a porous flow channel heat exchanger and a processing method thereof, which mainly processes flow channels on heat exchanger plates, and combines the characteristics of porous medium particles to sinter the porous medium particles into the flow channels, and utilizes the material properties of the porous medium particles and the wall surface of the heat exchanger plates to metallurgically bond them under hot pressing and sintering.

[0053] The porous medium can form interconnected pores within the flow channel, and heat exchange between two heat exchange media can be achieved by filling the flow channel with porous medium particles. The fluid working medium has good fluidity in the porous medium, and the porous medium has a large specific surface area and good thermal conductivity, which can effectively enhance heat exchange. The multi-porous heat exchanger and its processing method provided by the present invention improve the specific surface area and heat exchange efficiency of a single flow channel and the entire heat exchanger plate; and at the same time, it solves the defects of increasing the specific surface area and heat exchange efficiency by reducing the flow channel size (excessive reduction makes processing difficult and easily causes problems such as blockage).

[0054] Based on the above-mentioned basic scheme of porous channel heat exchanger and processing method, several embodiments are provided below:

[0055] Example 1

[0056] This embodiment provides a method for directly processing a multi-hole channel heat exchanger from a single-layer heat exchanger plate, specifically as follows:

[0057] The upper wall flow channel is machined on the heat exchanger plate;

[0058] The porous medium particles are made into a viscous mixed particle powder;

[0059] Filling the entire upper wall flow channel with the mixed particle powder to form a porous particle bonding layer in the upper wall flow channel;

[0060] A single heat exchanger plate is hot-pressed and sintered to achieve metallurgical bonding between the porous medium particles in the mixed particle powder and between the porous medium particles and the inner wall of the upper wall flow channel, thereby forming a porous sintered layer of particles tightly bonded to the upper wall flow channel to produce a single-layer porous flow channel heat exchanger.

[0061] During the preparation of the upper wall flow channel, the size of the upper wall flow channel is first determined based on the actual heat exchange requirements. The flow channel structure and size of the cold and hot side heat exchanger plates can be the same or different. The flow channel size varies with the viscosity of the fluid. When the viscosity of the fluid is large, the size of the upper wall flow channel can be appropriately increased to reduce the resistance generated during the flow of the fluid.

[0062] There is no specific restriction on the form of the flow channel. The flow channel can have any cross-sectional shape, and the flow channel can be straight or curved. It can be a combination of multiple flow channels or a tree-like branch structure. The relationship between adjacent flow channels can be parallel or any other relationship. For ease of processing, it is generally preferred that the cross-sectional shape of the flow channel can be rectangular, trapezoidal, triangular or semicircular, the flow channel is straight or regularly curved, and the same heat exchanger plate is designed to be parallel, regularly or symmetrically distributed.

[0063] Generally, the width of the upper wall flow channel is preferably 1mm-1m, the depth is preferably 1mm-100mm, and the rib width between adjacent flow channels is preferably 1-100mm, which is determined according to actual heat exchange requirements.

[0064] After the size of the upper wall flow channel is determined, the flow channel is preferably processed by etching or mechanical processing methods (milling, wire cutting). The processed heat exchanger plates are immersed in a cleaning agent or organic solvent for ultrasonic cleaning (5 minutes), and then dried with cold air to remove oil stains, burn marks and impurities on the inner wall of the upper wall flow channel, completing the preparation process of the upper wall flow channel.

[0065] In the process of preparing the porous bonding layer of particles, the particle size, shape and material type of the porous medium particles are selected according to the size of the upper wall flow channel and the required porosity.

[0066] Porous media particles are generally spherical, elliptical, or other shapes, with a particle size ranging from 1 μm to 5 mm. To maintain a complete pore structure, ensure close bonding between particles, and minimize the proportion of closed pores, porous media particles with smooth surfaces and uniform particle size are generally preferred.

[0067] The porous medium particles and the heat exchanger plates can be made of the same metal material or different metal materials with similar melting points. The particles can also be made of non-metallic materials.

[0068] When the heat exchanger plates and particles are made of different materials, the melting points of the two materials must be close, between 0.7-0.8T 熔 There is an intersection within the temperature range, and the pressure is determined according to the material. This ensures that the porous medium particles and the heat exchanger plates, whether they are made of the same metal or different materials, are metallurgically bonded by the mutual diffusion of atoms between the interfaces of the porous medium particles and the heat exchanger plates during hot pressing and sintering.

[0069] Among them, common materials for heat exchanger plates and particles include copper, aluminum, iron, nickel, stainless steel, other alloys, inorganic non-metals, etc. The melting point of copper is 1083°C, the melting point of aluminum is 660°C, the melting point of iron is 1583°C, the melting point of nickel is 1453°C, and the melting point of 304 stainless steel is 1398-1454°C. Actual processing includes but is not limited to the above materials.

[0070] The method for preparing porous medium particles into a viscous mixed particle powder is as follows:

[0071] First, particles of appropriate size were selected using a sieve, and then ultrasonically cleaned in anhydrous ethanol for 30 minutes. The cleaned particles were placed in an oven and dried at 60°C for 10 minutes.

[0072] The particles are then treated in an acidic aqueous solution and left to dry. Appropriate amounts of additives, including plasticizers, binders, and lubricants, are added to the particles, weighing 80%-90% of the particles and 20%-10% of the additives. The mixture is then evenly mixed and stirred to form a viscous mixed particle powder.

[0073] Among them, the plasticizer can be paraffin, yellow wax, etc., the binder can be resin, polyvinyl alcohol, etc., and the lubricant can be glycerin, stearic acid, graphite, etc.

[0074] When the mixed granular powder is filled in the upper wall flow channel to form a porous bonding layer of particles, its surface is generally difficult to keep flat due to operational problems. Therefore, in a preferred embodiment, a clamp can be used to rub back and forth along the upper wall surface of the heat exchanger plate to keep the outer surface of the porous bonding layer of particles in the upper wall flow channel flat and compressed.

[0075] In a preferred embodiment, air in the porous bonding layer of particles is removed before hot pressing and sintering, specifically by heating the wall surface of the heat exchanger plate to dry the porous bonding layer of particles.

[0076] Specifically, a hot air spray gun is generally used to heat the lower wall surface (the side wall surface can also be selected) of the plate to a temperature of about 120°C to accelerate the drying of the mixed particle powder, accelerate the volatilization of the organic solvent in the mixed particle powder, and discharge the air in the powder, so that the mixed particle powder in the porous bonding layer of the particles is more tightly bonded to the flow channel on the upper wall.

[0077] In this embodiment, a single heat exchanger plate can be fixed in a high-temperature and high-pressure adjustable environment for hot pressing and sintering, or a single heat exchanger plate can be assembled in a high-temperature resistant fixture and placed in a high-temperature and high-pressure adjustable environment for hot pressing and sintering (but in this case, the granular porous adhesive layer on the wall of the single heat exchanger plate is generally set not to contact the fixture).

[0078] Among them, the melting point and chemical properties of the material of the high-temperature resistant fixture and the heat exchanger plates and porous medium particles should be quite different to avoid diffusion between atoms, which may cause welding between the high-temperature resistant fixture and the heat exchanger plates and porous medium particles.

[0079] The specific method of hot pressing and sintering a single heat exchanger plate is as follows:

[0080] The individual heat exchanger plates are assembled in a high temperature resistant fixture and then placed in a hot pressing furnace to maintain a vacuum atmosphere (vacuum degree 5×10 -2 Pa or less) or reducing gas atmosphere (nitrogen-hydrogen mixed gas), the heating rate in the furnace is 10°C / min, and pressure is applied by a pressure-applying component.

[0081] 0.4-0.45T 熔 Keep warm within the temperature range for 10-15 minutes; heat up to 0.6-0.65T 熔 , keep warm for 10 minutes, then raise the temperature to 0.7-0.75T 熔 , keep warm and pressurize for 20-25 minutes, then slowly cool to below 100℃-150℃, take out the fixture, at this time, metallurgical bonding occurs between the porous medium particles and between the porous medium particles and the inner wall of the upper wall flow channel, and a single-layer porous flow channel heat exchanger is obtained.

[0082] The porous channel heat exchanger that has been processed will have some burrs and impurities on the surface of the porous structure, which will fall off under the impact of the flow of the working fluid for a long time, posing the risk of contaminating the working fluid and clogging the flow channel, and surface treatment is required.

[0083] Porous materials have complex internal structures, so electrochemical etching can be used as a surface treatment method for these materials. A metal with more active chemical properties than the heat exchanger material is used as the cathode, and the porous channel heat exchanger being treated is used as the anode. The electrolyte is an acidic solution, and a small amount of water can be added to the electrolyte to increase the solution's conductivity. By controlling the solution concentration and etching time, the treatment effect on burrs and impurities is guaranteed while avoiding damage to the basic structure of the porous material.

[0084] In this embodiment, during the processing of the porous flow channel heat exchanger, hot pressing and sintering are performed as an integrated part. The prepared porous flow channel heat exchanger changes the form and processing method of the heat exchanger in the prior art. While improving the heat transfer specific surface area, there is no need to excessively reduce the flow channel size. When the heat exchanger plates and the porous medium are made of different materials, the advantages of different materials can be utilized at the same time. Furthermore, it can be completed only by mechanical processing of the flow channel and hot pressing and sintering technology, and the processing difficulty is relatively low.

[0085] Example 2

[0086] This embodiment provides a porous flow channel heat exchanger (single layer) manufactured based on the processing method provided in Example 1, and its example is shown in FIG. Figure 1 As shown, the structural diagram of the heat exchanger plate can be referred to Figure 2 and Figure 3 (Refer to the single-layer heat exchanger plate structure in the figure. There is no fin structure in Example 2). The structure includes:

[0087] Heat exchanger plates 7;

[0088] The heat exchange channel 6 is formed on a wall surface of the heat exchanger plate 7;

[0089] The fluid inlet 1 or 3 is formed on the heat exchange channel 6, and the fluid inlet 1 or 3 is used to introduce a cold fluid or a hot fluid;

[0090] A granular porous sintered layer is formed by hot-pressing and sintering porous medium particles in the heat exchange channel 6, and the granular porous sintered layer is metallurgically bonded to the inner wall of the heat exchange channel 6;

[0091] Wherein, any exposed surface of the porous sintered granular layer in the heat exchange channel is the fluid outlet 2 or 4 .

[0092] In the aforementioned heat exchange flow channel, the flow direction shape of the flow channel is not limited and can be straight or zigzag along the flow direction. The cross-sectional shape of the flow channel is not limited and can be rectangular, trapezoidal, triangular, or semicircular. The specific flow direction shape and cross-sectional shape can be selected according to the heat exchange requirements. Different flow directions and cross-sectional shapes do not affect the smooth flow of the fluid in the flow channel.

[0093] The single-layer heat exchanger provided in this embodiment is equivalent to using the exposed porous sintered granular layer as the fluid outlet and heat exchange interface, which can also improve the heat exchange efficiency.

[0094] Example 3

[0095] This embodiment provides a method for processing a porous channel heat exchanger (multi-layer), which differs from the first embodiment in that it includes:

[0096] At least one upper wall flow channel is machined on each heat exchanger plate;

[0097] The porous medium particles are made into a viscous mixed particle powder;

[0098] Filling each of the upper wall flow channels with the mixed particle powder to form a porous particle bonding layer within the upper wall flow channels;

[0099] Multiple heat exchanger plates are stacked together in a completely opposite order with the upper wall flow channels facing the same direction, the stability of the stacking is maintained and longitudinal pressure is applied to make the adjacent heat exchanger plates closely contact each other, and hot pressing and sintering are performed while maintaining a stable and close contact state, so that metallurgical bonding is generated between the porous medium particles in the mixed particle powder, and between the porous medium particles and the inner wall of the upper wall flow channel and the lower wall of the adjacent heat exchanger plate, respectively, to form a porous sintered layer of particles that is closely bonded to the upper wall flow channel and the lower wall of the adjacent heat exchanger plate, so as to produce a multi-layer porous flow channel heat exchanger.

[0100] Furthermore, a cover plate made of the same material as the heat exchanger plates is installed on the topmost layer of the stacked heat exchanger plates to form a metallurgical bond with the heat exchanger plates on the top layer.

[0101] In order to make the connection between the mixed particle powder and the flow channel and the lower wall of the adjacent heat exchanger plate tighter, lower wall ribs that are opposite to the upper wall flow channel are processed on the lower wall surface of at least part of the heat exchanger plate. The lower wall ribs are used to apply pressure to the porous bonding layer of particles in the upper wall flow channel after overlapping.

[0102] This manufacturing method is equivalent to using the lower wall fins as a part of the outward protrusion of the heat exchanger plate as an integral part. In this way, the mixed particle powder can be compressed when stacked, and the connection tightness between adjacent heat exchanger plates can be increased.

[0103] The specific hot pressing sintering method of the multilayer heat exchanger is as follows:

[0104] Assemble the laminated heat exchanger plates in a high temperature fixture, and then place them in a hot pressing furnace, ensuring that the high temperature fixture is placed between the upper and lower pressure components, and maintain a vacuum atmosphere (vacuum degree 5×10 -2 Pa or less) or reducing gas atmosphere (nitrogen-hydrogen mixed gas), the heating rate in the furnace is 10°C / min, and pressure is applied by a pressure-applying component.

[0105] Apply 1.5-2MPa pre-pressure to the structure in the furnace, 熔 Keep warm within the temperature range for 10-15 minutes; adjust the pressure to 8-10MPa and raise the temperature to 0.6-0.65T 熔, keep warm for 10 minutes, then raise the temperature to 0.7-0.75T 熔 , keep warm and hold pressure for 20-25 minutes, release the pressure after the end of the heat preservation and pressure holding, slowly cool to below 100℃-150℃, take out the mold, and obtain the welded part. At this time, metallurgical bonding is generated between the porous medium particles and between the porous medium particles and the inner wall of the upper wall flow channel to obtain a multi-layer porous flow channel heat exchanger.

[0106] After the upper wall flow channel is machined on the heat exchanger plate, the surface to be welded is polished with sandpaper to control the roughness of the surface to be welded within the precision range required for diffusion welding (0.8-1.6μm). The processed heat exchanger plate is soaked in a detergent or organic solvent for ultrasonic cleaning (5 minutes), and then dried with cold air to remove oil stains, burn marks, and impurities on the surface of the flow channel and the surface to be welded.

[0107] A mixed particle powder is then prepared according to the steps in Example 1. After the upper wall flow channels of the prepared heat exchanger plates are filled with the mixed particle powder and bonded to form a porous bonded layer of particles, the multiple heat exchanger plates are stacked together in a sequence with the upper wall flow channels facing the same direction, and hot-pressed and sintered to produce a multi-layered, porous channel heat exchanger. The hot-pressing and sintering process and post-sintering treatment steps in this example are identical to the hot-pressing and sintering process and surface treatment of the porous channel heat exchanger in Example 1 and are not further described.

[0108] In addition, in this embodiment 3, before or after hot pressing and sintering, a cover plate made of the same material as the heat exchanger plates is installed on the topmost stacked heat exchanger plates to ensure that the outer surface of the heat exchanger is in a horizontal sealed state for easy use.

[0109] Although there are similarities between Example 3 and Example 1, Example 3 is not obtained by simply transforming Example 1. The single-layer heat exchanger proposed in Example 1 has no direct technical inspiration to be obtained based on Example 3. It is a new technical solution.

[0110] Example 4

[0111] This embodiment provides a porous flow channel heat exchanger (multi-layer) manufactured based on the processing method provided in Example 3, and its example is shown in FIG. Figure 1 As shown, the structural diagram of the heat exchanger plate can be referred to Figure 2 and Figure 3 (There is no rib 8 structure in this embodiment 4), the structure includes:

[0112] At least two heat exchanger plates 7 stacked opposite to each other;

[0113] The heat exchange channel 6 (equivalent to the upper wall channel) is formed on the wall surface on the same side of each heat exchanger plate 7, and the heat exchange channel 6 is used to pass the fluid working medium;

[0114] The granular porous sintered layer is formed by hot-pressing and sintering porous medium particles in the heat exchange channel 6. The granular porous sintered layer is metallurgically bonded to the inner wall of the heat exchange channel 6 and the wall surface of the adjacent heat exchanger plate 7;

[0115] The cover plate 5 is provided on the outermost heat exchanger plate 7 exposed by the granular porous sintered layer, and the wall surface of the cover plate 5 is metallurgically bonded to the granular porous sintered layer;

[0116] The heat exchanger plates 7 of the odd-numbered and even-numbered layers are respectively fed with different hot and cold fluids;

[0117] The heat exchanger plates of the odd-numbered layers and the even-numbered layers are each provided with a set of fluid inlets 1 or 3 and fluid outlets 2 or 4 connected with all heat exchange flow channels into which the same fluid working medium flows.

[0118] Single-layer heat exchangers are primarily used for cooling heat transfer structures. When the working medium passes through the porous medium, it cools the heat structure through sweating cooling, film cooling, etc. Multi-layer heat exchangers are primarily used for efficient heat exchange between two media, transferring heat from the high-temperature medium to the low-temperature medium.

[0119] Furthermore, ribs 8 facing the heat exchange channel are provided on all the heat exchanger plates 7 except the outermost heat exchanger plate 7 and the cover plate 5 , and the ribs 8 are used to compress the porous sintered layer of particles in the heat exchange channel 6 .

[0120] The fins 8 are an integral structure matching the heat exchange channel 6, or a plurality of fins are intermittently arranged along the direction of the heat exchange channel.

[0121] The discontinuous setting is the preferred option, mainly because the porous sintered layer of particles in the heat exchange channel (upper wall channel) is a viscous structure before formation and has a certain fluidity. It is difficult to ensure that it is completely flat during processing and filling. If it is a completely matched overall structure, it may be difficult to flatten it.

[0122] The above embodiments are merely exemplary embodiments of the present application and are not intended to limit the scope of the present application. The scope of protection of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and scope of protection of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present application.

Claims

1. A method for processing a porous channel heat exchanger, characterized in that: include: The upper wall flow channel is machined on the heat exchanger plate; The porous medium particles are made into a viscous mixed particle powder; Filling the entire upper wall flow channel with the mixed particle powder to form a porous particle bonding layer in the upper wall flow channel; Hot pressing and sintering a single heat exchanger plate to achieve metallurgical bonding between the porous medium particles in the mixed particle powder and between the porous medium particles and the inner wall of the upper wall flow channel, thereby forming a porous sintered layer of particles tightly bonded to the upper wall flow channel to produce a single-layer porous flow channel heat exchanger; The porous medium particles and the heat exchanger plates have similar melting points, so that metallurgical bonding is formed by atomic interdiffusion between the interfaces of the porous medium particles and the heat exchanger plates during hot pressing and sintering; Lower wall fins directly opposite to the upper wall flow channel are processed on the lower wall surface of at least part of the heat exchanger plate, and the lower wall fins are used to apply pressure to the porous bonding layer of particles in the upper wall flow channel after overlapping.

2. A method for processing a porous channel heat exchanger, characterized in that: include: At least one upper wall flow channel is machined on each heat exchanger plate; The porous medium particles are made into a viscous mixed particle powder; Filling each of the upper wall flow channels with the mixed particle powder to form a porous particle bonding layer within the upper wall flow channels; Multiple heat exchanger plates are stacked together in a completely opposite order with the upper wall flow channels facing the same direction, the stability of the stacking is maintained and longitudinal pressure is applied to make the adjacent heat exchanger plates closely contact each other, and hot pressing and sintering are performed while maintaining a stable and close contact state, so that metallurgical bonding is generated between the porous medium particles in the mixed particle powder, and between the porous medium particles and the inner wall of the upper wall flow channel and the lower wall of the adjacent heat exchanger plate, respectively, to form a porous sintered layer of particles that is closely bonded to the upper wall flow channel and the lower wall of the adjacent heat exchanger plate, so as to produce a multi-layer porous flow channel heat exchanger.

3. The processing method according to claim 2, characterized in that: Also includes: A cover plate made of the same material as the heat exchanger plates is installed on the uppermost layer of the stacked heat exchanger plates.

4. The processing method according to claim 1 or 2, characterized in that: The method of preparing the porous medium particles into a viscous mixed particle powder comprises: Adding three additives, namely, a plasticizer, a binder, and a lubricant, to the porous medium particles, weighing them in a mass ratio of 80%-90% of the porous medium particles and 20%-10% of the additives, and uniformly mixing and stirring to obtain a mixed particle powder; Wherein, the plasticizer can be selected from any one or more of paraffin wax and yellow wax; The binder can be any one or more of resin and polyvinyl alcohol; The lubricant may be any one or more of glycerin, stearic acid and graphite.

5. The processing method according to claim 4, characterized in that: The method further comprises the step of removing air from the porous bonding layer of the particles before hot pressing and sintering: The wall surface of the heat exchanger plate is heated to dry the porous bonding layer of particles, volatilize the organic solvent in the mixed particle powder, and discharge the air in the mixed particle powder so that the mixed particle powder is initially bonded to the upper wall flow channel.

6. A porous channel heat exchanger according to claim 1, characterized in that: have: Heat exchanger plates (7); A heat exchange channel (6) is formed on a wall surface of the heat exchanger plate (7); A fluid inlet (1 or 3) is formed on the heat exchange channel (6), and the fluid inlet (1 or 3) is used to introduce a cold fluid working medium or a hot fluid working medium; A granular porous sintered layer is formed by hot-pressing and sintering porous medium particles in the heat exchange channel (6), and the granular porous sintered layer is metallurgically bonded to the inner wall of the heat exchange channel (6); Wherein, any exposed surface of the porous sintered layer of particles in the heat exchange channel (6) is a fluid outlet (2 or 4).

7. A porous channel heat exchanger according to claim 2, characterized in that: have: At least two heat exchanger plates (7) stacked opposite to each other; A heat exchange channel (6) is formed on the wall surface on the same side of each heat exchanger plate (7), and the heat exchange channel (6) is used to pass a fluid working medium; The granular porous sintered layer is formed by hot-pressing and sintering porous medium particles in the heat exchange channel (6), and the granular porous sintered layer is metallurgically bonded to the inner wall of the heat exchange channel (6) and the wall surface of the adjacent contacting heat exchanger plate (7); A cover plate (5) is arranged on the outermost heat exchanger plate (7) exposed on the granular porous sintered layer, and a wall surface of the cover plate (5) is metallurgically bonded to the granular porous sintered layer; Wherein, the heat exchanger plates (7) of the odd-numbered layers and the even-numbered layers in sequence are respectively fed with cold and hot fluids; The heat exchanger plates (7) of the odd-numbered layers and the even-numbered layers are each provided with a set of fluid inlets (1 or 3) and fluid outlets (2 or 4) that are connected to all heat exchange flow channels that pass the same fluid working medium.

8. The porous channel heat exchanger according to claim 7, characterized in that: All the heat exchanger plates except the outermost heat exchanger plate and the cover plate are provided with ribs (8) directly opposite to the heat exchange channel (6), and the ribs (8) are used to compress the granular porous sintered layer in the heat exchange channel (6); The fins (8) are an integral structure matching the heat exchange channel (6), or a plurality of fins arranged intermittently along the direction of the heat exchange channel (6).

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