A printed circuit board type high-efficiency heat exchanger and core

Abstract

The present invention relates to the technical field of heat exchange devices, and specifically to a printed circuit board type high-efficiency heat exchanger and core. The printed circuit board type high-efficiency heat exchanger core comprises a first end plate and a second end plate arranged in parallel, a heat exchange core plate group periodically arranged between the first end plate and the second end plate, the heat exchange core plate group comprising a first plate body, an intermediate plate body, and a second plate body arranged in sequence, an intermediate plate body being arranged between two adjacent heat exchange core plate groups, the first plate body being provided with a first flow channel for a first working fluid to flow in a first direction, the second plate body being provided with a second flow channel for a second working fluid to flow in a second direction, and the intermediate plate body being provided with a receiving channel for accommodating a heat-conducting medium. The printed circuit board type high-efficiency heat exchanger core has existing interlayer leakage protection, and can continue to be put into operation after a leak occurs, while maintaining advantages such as a high heat transfer coefficient and a small size. Even after a leak occurs, it can continue to operate until the maintenance period of the thermal power plant unit is overhauled before maintenance can be carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange devices, and in particular to a printed circuit board type high-efficiency heat exchanger and a core. Background Art

[0002] Thermal power plants utilize a large number of heat exchangers within their power cycles, most of which are bilateral steam-water exchangers. However, another type of heat exchanger uses different media on the cold and hot sides. For example, one side uses natural gas, hydrogen, carbon dioxide, or other working fluids, while the other uses steam-water. The fluids on the cold and hot sides of these heat exchangers must not mix or leak into each other, as this poses a significant safety hazard. For example, the performance heater in a combined cycle power plant uses natural gas on the cold side and low-pressure hot water on the hot side. Internal leaks in this heat exchanger could result in natural gas carrying water, jeopardizing the safe operation of the gas turbine. Alternatively, natural gas could be mixed into the steam-water system, endangering the safe operation of the waste heat boiler and steam turbine. Similarly, plate heat exchangers, such as those used for closed-loop heat exchange between hydrogen and water in coal-fired power generation units, also present leakage risks.

[0003] Taking the combined cycle natural gas performance heater as an example, in operating units, this type of heat exchanger typically uses single-tube shell-and-tube heat exchangers, double-tube shell-and-tube heat exchangers, and printed circuit board heat exchangers (PCHE). Each of these heat exchangers has its advantages and disadvantages. Single-tube shell-and-tube heat exchangers offer a simple structure, thicker tube walls, larger size, higher thermal resistance, low cost, and mature technology. However, they are prone to leakage, making continued operation impossible and requiring shutdown for repair. Repairs typically involve on-site inspection and leak plugging. Larger leaks require return to the factory for repair, which is time-consuming and expensive. Double-tube shell-and-tube heat exchangers, with their complex structure, double-layered heat exchange tubes, high thermal resistance, large size, and high cost, are relatively mature technology, but they are also prone to leakage. They can continue to operate after a leak, waiting until the unit reaches its maintenance period before repairs can be performed. Due to their complex structure, repairs require the entire unit to be returned to the factory, which is time-consuming and expensive. Printed circuit board heat exchangers have a similar structure to plate heat exchangers, but utilize an etching process to create microchannels and a high-temperature infiltration process to weld the plates together. While simple in structure, compact, and with low thermal resistance, they are more expensive, require a longer manufacturing cycle, and are less prone to leaks. However, if a leak occurs, the unit cannot be operated and must be shut down for repair. This typically requires a complete return to the factory, resulting in a long and expensive repair process.

[0004] Based on the characteristics of these various heat exchangers, printed circuit board heat exchangers (PCB) have gained widespread acceptance in combined cycle power plants due to their compact size, low thermal resistance, high heat transfer coefficient, and minimal end-to-end heat transfer. They are often used in natural gas performance heaters. However, existing PCB heat exchangers still experience leakage, rendering them inoperable and requiring shutdown and repair, resulting in financial losses for power generation companies. Summary of the Invention

[0005] The object of the present invention is to provide a printed circuit board type high-efficiency heat exchanger core to solve the problem in the prior art that the printed circuit board type heat exchanger cannot continue to maintain high-efficiency heat exchange after leakage occurs.

[0006] In order to solve the above problems, the present invention proposes a printed circuit board type high-efficiency heat exchanger core, and the technical solution adopted is:

[0007] A printed circuit board type high-efficiency heat exchanger core comprises a first end plate and a second end plate arranged in parallel, a heat exchange core plate group is periodically arranged between the first end plate and the second end plate, the heat exchange core plate group comprises a first plate body, an intermediate plate body and a second plate body arranged in sequence, an intermediate plate body is arranged between two adjacent heat exchange core plate groups, the first plate body is provided with a first flow channel for a first working fluid to flow along a first direction, the second plate body is provided with a second flow channel for a second working fluid to flow along a second direction, and the intermediate plate body is provided with a accommodating channel for accommodating a heat-conducting medium.

[0008] Furthermore, the accommodating channel is composed of multiple accommodating microchannels on the surface of the intermediate plate body, the inlet and outlet of the accommodating microchannel are arranged at the same side position on the intermediate plate body and pass through the side position, and the accommodating microchannel is used to accommodate the heat-conducting medium.

[0009] Furthermore, the accommodating microchannels are first U-shaped microchannels, and the first U-shaped microchannels are diffusely arranged at equal intervals along the center position toward the edge position of the surface of the middle plate body.

[0010] Furthermore, the first flow channel has a first pressure, the second flow channel has a second pressure, and the accommodating channel is provided with a third pressure, and the third pressure is different from both the first pressure and the second pressure.

[0011] Furthermore, the first flow channel is composed of a plurality of first microchannels arranged in parallel at equal intervals on the surface of the first plate body, and the inlet and outlet of the first microchannel are respectively arranged at two sides of the first plate body perpendicular to the sides where the inlet and outlet of the microchannel are located, and pass through the two sides, and the first microchannel is used to transport the first working fluid.

[0012] Furthermore, the second flow channel is composed of a plurality of second microchannels on the surface of the second plate body, the inlet and outlet of the second microchannel are arranged at the same side position on the second plate body opposite to the inlet and outlet positions of the accommodating microchannel, and pass through the side position, and the second microchannel is used to transport the second working medium.

[0013] Furthermore, the second microchannels are second U-shaped microchannels, and the second U-shaped microchannels are diffusely arranged at equal intervals along the center position toward the edge position of the surface of the second plate.

[0014] Furthermore, there is only one intermediate plate between the adjacent first plate and second plate, and the first plate, the second plate and the intermediate plate are of equal thickness.

[0015] Furthermore, the shape of the first microchannel is any one of a straight line, a sine wave, a triangular wave, a square wave, a sawtooth wave, a wing fin shape, and an S-fin shape; the cross-sectional shape of the microchannel of the first flow channel is any one of a semicircular shape, a circular shape, a semi-elliptical shape, an elliptical shape, a U-shape, a rectangle, and a trapezoid.

[0016] Beneficial Effects: This invention is an improved invention. In a printed circuit board-type high-efficiency heat exchanger core, a heat exchange core plate group is periodically arranged between the first and second end plates. The heat exchange core plate group includes a first plate, an intermediate plate, and a second plate arranged in sequence. An intermediate plate is provided between two adjacent heat exchange core plate groups, so that an intermediate plate is provided between adjacent first and second plates. In this case, no two first and second plates are in direct contact. When the heat exchanger is in operation, a heat transfer medium is contained in the receiving channel on the intermediate plate. This heat transfer medium is in a stagnant state and is used only for heat conduction. If a first plate containing a first working fluid or a second plate containing a second working fluid leaks, the leaked first or second working fluid will not mix with the other working fluid due to the intermediate plate provided between the adjacent first and second plates. Instead, the leaked first or second working fluid will mix with the heat transfer medium on the intermediate plate. At the same time, the side without leakage remains in good condition, and the heat exchanger can continue to operate until the next maintenance cycle of the unit. The above-mentioned printed circuit board type high-efficiency heat exchanger core has both interlayer leakage protection and can continue to be put into operation after leakage occurs, while maintaining the advantages of high heat transfer coefficient and small size. Even after leakage, it can continue to operate until the maintenance cycle of the thermal power plant unit and then be repaired.

[0017] The accommodating channel is composed of multiple accommodating microchannels on the surface of the intermediate plate body. The inlet and outlet of the accommodating microchannel are arranged at the same side position on the intermediate plate body and pass through the side position, which facilitates the entry and outflow of the heat-conducting medium and the accommodating of the heat-conducting medium, while realizing the work of heat conduction and fusion leakage, and has a simple structure.

[0018] The accommodating microchannel is a first U-shaped microchannel, which is diffusely arranged at equal intervals from the center position to the edge position of the surface of the intermediate plate, so as to facilitate the heat conduction of the heat-conducting medium over the maximum area and avoid excessive pressure in the channel caused by the complexity and variability of the accommodating microchannel.

[0019] The first flow channel has a first pressure, the second flow channel has a second pressure, and the receiving channel has a third pressure. The third pressure is different from the first and second pressures, so that leaks can be detected promptly. When a leak occurs in the first plate or the second plate, the leaked first or second working fluid mixes with the heat transfer medium. As a result, the pressure in the receiving channel and the corresponding cavity side will no longer be maintained and will change to the same pressure as the leaking side. This allows the user to determine which side of the first or second plate in the heat exchanger is leaking.

[0020] The first flow channel is composed of a plurality of first microchannels arranged in parallel at equal intervals on the surface of the first plate body. The inlet and outlet of the first microchannel are respectively arranged at two sides of the first plate body perpendicular to the sides where the inlet and outlet of the microchannel are located, and pass through the two sides to facilitate the flow of one of the cold and hot fluids. It is specifically set according to the heat exchange requirements and supports direct flow through the two ends of the heat exchanger. After the heat exchange plates are stacked and penetrated and welded, it is convenient to install the head structure at both ends.

[0021] The second flow channel is composed of multiple second microchannels on the surface of the second plate. The inlet and outlet of the second microchannel are arranged on a side of the second plate opposite to the inlet and outlet of the microchannel, and pass through the side. The second microchannel is used to transport the second working fluid to facilitate the flow of the other of the cold and hot fluids to effectively achieve heat conduction, and is specifically set according to the heat exchange requirements.

[0022] The number of intermediate plates between the adjacent first and second plates is single, and the first, second and intermediate plates are of equal thickness, thereby preventing the problem of heat transfer being hindered due to an excessive number of intermediate plates between the adjacent first and second plates; at the same time, the first, second and intermediate plates are of equal thickness, thereby achieving a better heat transfer effect.

[0023] The present invention also proposes a printed circuit board type high-efficiency heat exchanger, and the technical solution adopted is: a printed circuit board type high-efficiency heat exchanger, including the printed circuit board type high-efficiency heat exchanger core.

[0024] Beneficial effects: This printed circuit board type high-efficiency heat exchanger has both the advantages of a printed circuit board type heat exchanger and the safety advantages of a double-tube shell and tube heat exchanger. It is a printed circuit board type high-efficiency heat exchanger with a sandwich leakage protection structure. It can continue to be put into operation after a leak occurs, and maintains the advantages of high heat transfer coefficient and small size. Even after a leak, it can continue to operate until the maintenance cycle of the thermal power plant unit and then be repaired. It solves the risks brought by the leak from the physical structure and reduces the economic losses caused by the leak for thermal power companies. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 11 is a schematic structural diagram of the heat exchanger core in Example 1 of the printed circuit board type high-efficiency heat exchanger core of the present invention;

[0026] Figure 2 1 is a schematic structural diagram of the stacked plates in the heat exchanger core of the printed circuit board type high-efficiency heat exchanger core of the present invention in Example 1;

[0027] Figure 3 This is a schematic structural diagram of the intermediate plate body in Example 1 of the printed circuit board type high-efficiency heat exchanger core of the present invention;

[0028] Figure 4 This is a schematic structural diagram of the first plate body in Example 4 of the printed circuit board type high-efficiency heat exchanger core of the present invention;

[0029] Figure 5 This is a schematic structural diagram of the second plate body in Example 5 of the printed circuit board type high-efficiency heat exchanger core of the present invention;

[0030] Figure 6 Schematic diagram of the appearance of the heat exchanger in Example 1 of the printed circuit board type high-efficiency heat exchanger of the present invention;

[0031] Figure 7 is a perspective view of the heat exchanger in Example 1 of the printed circuit board type high-efficiency heat exchanger of the present invention;

[0032] Figure 8 is a cross-sectional view of the heat exchanger in Example 1 of the printed circuit board type high-efficiency heat exchanger of the present invention;

[0033] In the figure, 1, first end plate; 2, second end plate; 3, first plate body; 31, first microchannel; 4, middle plate body; 41, accommodating microchannel; 5, second plate body; 51, second microchannel; 6, first head; 7, second head; 8, upper head; 9, lower head; 10, partition. DETAILED DESCRIPTION

[0034] As cited in the background art, the printed circuit board heat exchanger in the prior art cannot continue to maintain efficient heat exchange after leakage occurs. Therefore, the present invention provides a printed circuit board type high-efficiency heat exchanger core, comprising a first end plate and a second end plate arranged in parallel, the first end plate and the second end plate being used to seal the first plate body and the second plate body to prevent leakage of the first working fluid and the second working fluid perpendicular to the direction of the first plate body and the second plate body on the first plate body and the second plate body; a heat exchange core plate group is periodically arranged between the first end plate and the second end plate, the heat exchange core plate group comprises a first plate body, an intermediate plate body and a second plate body arranged in sequence, an intermediate plate body is arranged between two adjacent heat exchange core plate groups, so that an intermediate plate body is arranged between any two adjacent first plate bodies and second plate bodies, completely achieving a barrier between the first plate body and the second plate body, and preventing the first working fluid and the second working fluid from mixing. Among them, the first plate body is provided with a first flow channel for the first working fluid to flow along the first direction, for circulating the first working fluid; the second plate body is provided with a second flow channel for the second working fluid to flow along the second direction, for circulating the second working fluid, so as to realize the heat exchange of the heat exchanger; the middle plate body is provided with a receiving channel for accommodating a heat-conducting medium. When the heat exchanger is in the working state, the receiving channel is filled with a heat-conducting medium, and the heat-conducting medium is in a non-flowing state and is only used for heat conduction. If the first plate body containing the first working fluid or the second plate body containing the second working fluid leaks, the leaked first working fluid or second working fluid will mix with the heat-conducting medium. At the same time, the side without leakage is in good condition, and the heat exchanger can continue to work until the next maintenance cycle of the unit. The above-mentioned printed circuit board type high-efficiency heat exchanger core has an existing interlayer leakage protection. It can continue to be put into operation after a leak occurs, and maintains the advantages of high heat transfer coefficient and small size. Even after a leak, it can continue to operate until the maintenance cycle of the thermal power plant unit.

[0035] Specific embodiment 1 of the printed circuit board type high-efficiency heat exchanger core of the present invention:

[0036] In this embodiment, Figure 1 、 Figure 2As shown, the printed circuit board-type high-efficiency heat exchanger core includes a first end plate 1 and a second end plate 2, which are arranged parallel to each other in the vertical direction and are plates of the same size and material. Heat exchange core plate groups are periodically arranged between the first end plate 1 and the second end plate 2. The heat exchange core plates include a first plate body 3, an intermediate plate body 4, and a second plate body 5 arranged in sequence. An intermediate plate body 4 is provided between two adjacent heat exchange core plate groups, so that an intermediate plate body 4 is provided between any two adjacent first plates 3 and second plates 5. A first flow channel for a first working medium to flow in a first direction is provided on the surface of the first plate body 3, a second flow channel for a second working medium to flow in a second direction is provided on the surface of the second plate body 5, and a receiving channel 41 for accommodating a heat transfer medium is provided on the intermediate plate body 4. The first plate body 3, the middle plate body 4 and the second plate body 5 form the core plate of the printed circuit board type high-efficiency heat exchanger core with three etched fluid channels. The three heat exchange core plates are used to form hot and cold fluid channels and a leakage detection channel that can be injected with heat transfer oil. Among them, the first working fluid is a cold fluid; the second working fluid is a hot fluid.

[0037] The number of intermediate plates 4 in the heat exchange core plate group and the number of intermediate plates 4 between two adjacent heat core plate groups can be multiple, that is, multiple intermediate plates 4 are set between two adjacent first plates 3 and second plates 5. When the heat exchanger core is in normal use, the heat transfer medium in the receiving channels 41 of the multiple intermediate plates 4 is in a non-flowing state and is only used for heat conduction. If the first plate 3 filled with cold fluid or the second plate 5 filled with hot fluid leaks, the leaked cold fluid or hot fluid will mix with the heat transfer medium. However, due to the large number of intermediate plates 4, there is a problem of hindering heat transfer and the structure is complex. Therefore, in this embodiment, preferably, the number of intermediate plates 4 is one, which can not only conduct heat efficiently, but also mix leaked fluids and has a simple structure.

[0038] The thicknesses of the first plate 3, the second plate 5 and the intermediate plate 4 can be set unevenly, but when the thicknesses of the three are different, uneven heat dissipation may occur. Therefore, in this embodiment, preferably, the number of intermediate plates 4 between adjacent first plates 3 and second plates 5 is single, and the first plate 3, the second plate 5 and the intermediate plate 4 are set to the same thickness.

[0039] In this embodiment, Figure 3 As shown, the accommodating channel on the intermediate plate body 4 is composed of a plurality of accommodating microchannels 41 on the surface of the intermediate plate body 4. The inlet and outlet of the accommodating microchannel 41 are arranged at the same side position on the intermediate plate body 4, that is, the inlet and outlet of the accommodating microchannel 41 are arranged at the left position on the intermediate plate body 4 and pass through the side position for accommodating the heat-conducting medium.

[0040] In other embodiments, the inlet and outlet for accommodating the microchannel 41 may be disposed at the right side of the middle plate 4 and extend through the side. In other embodiments, the inlet and outlet for accommodating the microchannel 41 may be disposed at the upper side of the middle plate 4 and extend through the side. In other embodiments, the inlet and outlet for accommodating the microchannel 41 may be disposed at the lower side of the middle plate 4 and extend through the side.

[0041] Specific embodiment 2 of the printed circuit board type high-efficiency heat exchanger core of the present invention:

[0042] Based on the technical concept of the present invention described above, or based on the specific embodiment of the present invention described above, another embodiment is provided below.

[0043] The accommodating microchannels 41 may be V-shaped microchannels or irregularly curved; the accommodating microchannels 41 may be arranged in parallel on the surface of the intermediate plate 4. However, when the accommodating microchannels 41 are V-shaped microchannels and are arranged in parallel on the surface of the intermediate plate 4, since the inlet and outlet are located on the same side, there are fewer V-shaped microchannels and the heat conduction efficiency is low. When the accommodating microchannels are irregularly curved and are arranged in parallel on the surface of the intermediate plate 4, the pressure in the channel is too high due to the complexity and variability of the accommodating microchannels, which makes it difficult to blend the leaked fluid. In this embodiment, preferably, Figure 3 As shown, the accommodating microchannel 41 is a first U-shaped microchannel, the inlet and outlet of the first U-shaped microchannel are located on the left side of the middle plate 4, and the first U-shaped microchannel is diffused and arranged at equal intervals along the center position of the surface of the middle plate 4 to the edge position, so that the heat conduction area is maximized, the heat conduction of the heat conduction medium is more effectively realized, and the leaked fluid is facilitated to blend.

[0044] Specific embodiment 3 of the printed circuit board type high-efficiency heat exchanger core of the present invention:

[0045] Based on the technical concept of the present invention described above, or based on the specific embodiment of the present invention described above, another embodiment is provided below.

[0046] In this embodiment, a cold fluid is present in the first flow channel at a first pressure, a hot fluid is present in the second flow channel at a second pressure, a heat transfer medium, heat transfer oil, is injected into the receiving channel, and a certain third pressure is maintained. The corresponding pressure is selected based on the characteristics and hazards of the cold and hot fluids and the heat transfer oil. The third pressure is different from the first and second pressures and has a significant difference. During use, when the first plate 3 or the second plate 5 leaks, the leaked cold fluid or hot fluid mixes with the heat transfer medium, and the pressure on the receiving channel and the corresponding cavity side will not be maintained and will change to the same pressure as the leaking side. In this way, it is known which side of the first plate 3 or the second plate 5 in the heat exchanger is leaking. Therefore, the printed circuit board type high-efficiency heat exchanger core of this application can detect whether the heat exchanger has plate leakage online; at the same time, it can also be known which side of the cold or hot fluid is leaking.

[0047] Specific embodiment 4 of the printed circuit board type high-efficiency heat exchanger core of the present invention:

[0048] Based on the technical concept of the present invention described above, or based on the specific embodiment of the present invention described above, another embodiment is provided below.

[0049] In this embodiment, Figure 4 As shown, the first flow channel is composed of multiple first microchannels 31 arranged in parallel at equal intervals on the surface of the first plate 3. The inlet and outlet of the first microchannels 31 are respectively arranged on both sides of the first plate 3 perpendicular to the sides where the inlet and outlet of the microchannels are located. That is, the inlet of the first microchannel 31 is arranged at the upper side of the first plate 3, and the outlet is arranged at the lower side of the first plate 3, and the first microchannels 31 are used to transport cold fluid. Among them, the first microchannel 31 is a straight line along the upper and lower directions of the first plate 3, and the cross-section of the first microchannel 31 is semicircular, with a simple structure. The first microchannel 31 supports direct flow through the two ends of the heat exchanger. After the heat exchange plates are stacked and penetrated and welded, it is convenient to install the head structure at both ends.

[0050] In other embodiments, the shape of the first microchannel 31 can be any one of a sine wave, a triangular wave, a square wave, a sawtooth wave, a wing fin shape, and an S-fin shape; the cross-sectional shape of the first microchannel 31 can be any one of a circle, a semi-ellipse, an ellipse, a U-shape, a rectangle, and a trapezoid.

[0051] In other embodiments, when the inlet and outlet of the accommodating microchannel 41 are arranged at the upper position or the lower position on the middle plate 4, the inlet of the first microchannel 31 is arranged at the left position on the first plate 3, and the outlet is arranged at the right position on the first plate 3, and passes through the two sides. In other embodiments, when the inlet and outlet of the accommodating microchannel are arranged at the upper position or the lower position on the middle plate 4, the inlet of the first microchannel 31 is arranged at the right position on the first plate 3, and the outlet is arranged at the left position on the first plate 3, and passes through the two sides.

[0052] Specific embodiment 5 of the printed circuit board type high-efficiency heat exchanger core of the present invention:

[0053] In this embodiment, Figure 5 As shown, the second flow channel is composed of a plurality of second microchannels 51 on the surface of the second plate 5. The inlet and outlet of the second microchannel 51 are arranged on the side of the second plate 5 opposite to the inlet and outlet of the accommodating microchannel, that is, the inlet and outlet of the second microchannel 51 are arranged on the right side of the second plate 5 and pass through the side position. The second microchannel 51 is used to transport the second working medium. The second microchannel 51 is a second U-shaped microchannel. The second U-shaped microchannel is arranged at equal intervals along the center position of the surface of the second plate 5 to the edge position. At this time, the first flow channel is arranged perpendicular to the flow direction of the second flow channel and the accommodating channel. The second U-shaped microchannel requires a head with a corresponding structure to be set at one end of the heat exchanger, and a partition is set in the head to separate the inlet and outlet channels of the fluid.

[0054] In other embodiments, the flow directions of the first flow channel, the second flow channel and the accommodating channel may be arranged to be inclined and cross each other.

[0055] In other embodiments, when the inlet and outlet of the accommodating microchannel 41 are arranged at the right position on the middle plate body 4, the inlet and outlet of the second microchannel 51 are arranged at the left position on the second plate body 5. In other embodiments, when the inlet and outlet of the accommodating microchannel 41 are arranged at the upper position on the middle plate body 4, the inlet and outlet of the second microchannel 51 are arranged at the lower position on the second plate body 5. In other embodiments, when the inlet and outlet of the accommodating microchannel 41 are arranged at the lower position on the middle plate body 4, the inlet and outlet of the second microchannel 51 are arranged at the upper position on the second plate body 5.

[0056] Specific embodiment 1 of the printed circuit board type high-efficiency heat exchanger of the present invention:

[0057] In this embodiment, Figure 6 、 Figure 7 、 Figure 8As shown, the stacked heat exchanger cores are welded using a high-temperature penetration welding process to form a heat exchanger core. The heat exchanger core serves as the main heat exchange element. Second end caps 7 are installed on the upper and lower sides of the heat exchanger core. A first end cap 6 is installed on the left side of the heat exchanger core. A corresponding end cap is installed on the right side. A partition 10 is provided within the end cap to separate the end cap into an upper end cap 8 and a lower end cap 9, thereby separating the inlet and outlet channels of the fluid. This forms a printed circuit board-type high-efficiency heat exchanger with a sandwich leakage protection structure. In this printed circuit board-type high-efficiency heat exchanger, the core is a single unit and no longer suitable for disassembly. Leaking individual channels can only be repaired by plugging them. Therefore, a certain margin of heat exchange area should be reserved during heat exchanger design and calculation. This margin of heat exchange area can be increased by adding plates during the design and processing process. This can generally be achieved by adding an additional 10% to 20% of plate packs.

[0058] When the heat exchanger is in use, the cold fluid passes through the upper and lower second heads 7 to circulate in the first microchannels 31, achieving heat transfer. The first head 6 injects thermal oil from the left side into the receiving microchannels 41 of the middle plate 4. The hot fluid enters the upper head 8 on the right side. After being cooled by thermal conduction, the hot fluid flows out of the lower head 9. During use, the thermal oil in the receiving microchannels 41 is in a stagnant state and is used only for heat transfer. If the cold or hot fluid leaks, the leaked fluid enters the receiving microchannels 41 and mixes with the thermal oil. At the same time, the side without leakage is in good condition, and the heat exchanger can continue to operate until the next maintenance cycle of the unit.

[0059] In other embodiments, the hot fluid circulates in the first microchannel 31 through the upper and lower second heads 7. The first head 6 injects heat transfer oil from the left side into the receiving microchannel 41 of the intermediate plate 4. The cold fluid enters the lower head 9 on the right side. After being heated by heat conduction, the cold fluid flows out of the upper head 8. During use, the heat transfer oil in the receiving microchannel 41 is in a non-flowing state and is used only for heat conduction. If the cold fluid or the hot fluid leaks, the leaked fluid enters the receiving microchannel 41 and mixes with the heat transfer oil. At the same time, the side without leakage is in good condition, and the heat exchanger can continue to operate until the next maintenance cycle of the unit.

[0060] Through the above description of the specific embodiment of the printed circuit board type high-efficiency heat exchanger core of the present invention, it can be seen that the printed circuit board type high-efficiency heat exchanger core of the present invention includes a first end plate and a second end plate arranged in parallel, and the first end plate and the second end plate are used to seal the first plate body and the second plate body to prevent the first working fluid and the second working fluid from leaking perpendicularly to the direction of the first plate body and the second plate body on the first plate body and the second plate body; a heat exchange core plate group is periodically arranged in sequence between the first end plate and the second end plate, and the heat exchange core plate group includes a first plate body, an intermediate plate body and a second plate body arranged in sequence. The plate body is provided with an intermediate plate body between two adjacent heat exchange core plate groups, so that an intermediate plate body is provided between any two first plate bodies and the second plate body. The first plate body is provided with a first flow channel for the first working fluid to flow along the first direction, for circulating the first working fluid; the second plate body is provided with a second flow channel for the second working fluid to flow along the second direction, for circulating the second working fluid, to realize the heat exchange of the heat exchanger; the intermediate plate body is provided with a receiving channel for accommodating a heat-conducting medium. When the heat exchanger is in the working state, the receiving channel is filled with a heat-conducting medium, and the heat-conducting medium is in a non-flowing state and is only used for heat conduction. If the first plate body containing the first working fluid or the second plate body containing the second working fluid leaks, the leaked first working fluid or second working fluid will mix with the heat-conducting medium. At the same time, the side without leakage is in good condition, and the heat exchanger can continue to work until the next maintenance cycle of the unit. The above-mentioned printed circuit board type high-efficiency heat exchanger core has existing interlayer leakage protection. It can continue to be put into operation after a leak occurs, and maintain the advantages of high heat transfer coefficient and small size. Even after a leak, it can continue to operate until the maintenance cycle of the thermal power plant unit and then be repaired.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be based on the claims. Any equivalent structural changes made using the contents of the description and drawings of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A printed circuit board type high efficiency heat exchanger core, characterized in that:

18. The heat exchanger as claimed in claim 15, wherein the bridge has two parallel paths, the path of the bridge being of the first and second opposite directions, and the paths of the first and second directions being connected as one. The bridge has two parallel paths, and the path of the first and second directions being connected as one. The bridge has two parallel paths, and the path of the first and second directions being connected as one.

2. The printed circuit board type high-efficiency heat exchanger core according to claim 1, characterized in that: The first flow channel is composed of a plurality of first microchannels arranged in parallel at equal intervals on the surface of the first plate. The inlet and outlet of the first microchannel are respectively arranged at two sides of the first plate perpendicular to the sides where the inlet and outlet of the microchannel are located, and pass through the two sides. The first microchannel is used to transport the first working medium.

3. The printed circuit board type high-efficiency heat exchanger core according to claim 1, characterized in that: The second flow channel is composed of multiple second microchannels on the surface of the second plate body. The inlet and outlet of the second microchannel are arranged on the same side of the second plate body opposite to the inlet and outlet positions of the accommodating microchannel, and pass through the side position. The second microchannel is used to transport the second working medium.

4. The printed circuit board type high-efficiency heat exchanger core according to claim 3, characterized in that: The second microchannels are second U-shaped microchannels, and the second U-shaped microchannels are diffusely arranged at equal intervals along the center position toward the edge position of the surface of the second plate.

5. The printed circuit board type high efficiency heat exchanger core according to claim 1, characterized in that: There is only one intermediate plate between the adjacent first plate and second plate, and the first plate, the second plate and the intermediate plate are of equal thickness.

6. The printed circuit board type high efficiency heat exchanger core according to claim 2, characterized in that: The shape of the first microchannel is any one of a straight line, a sine wave, a triangular wave, a square wave, a sawtooth wave, a wing fin shape, and an S-fin shape; the cross-sectional shape of the first microchannel is any one of a semicircle, a circle, a semi-ellipse, an ellipse, a U shape, a rectangle, and a trapezoid.

7. A printed circuit board type high efficiency heat exchanger, characterized in that: It comprises the printed circuit board type high-efficiency heat exchanger core according to any one of claims 1-6.

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