A PCHE heat exchange core with a composite flow channel combination and a vehicle-mounted nuclear power source

Abstract

A PCHE heat exchange core and a vehicle-mounted nuclear power source with a composite flow channel combination relate to the field of heat exchange technology, and in particular to the field of heat exchanger technology. The problem of uneven flow distribution during operation of the PCHE heat exchange core, which leads to unbalanced heat exchange capacity, is solved. The present invention includes a heat exchange channel, which includes a Zigzag flow channel system, a semicircular cross-section sinusoidal flow channel system and a rectangular cross-section sinusoidal flow channel system; the Zigzag flow channel system is arranged at the center of the heat exchange core; the semicircular cross-section sinusoidal flow channel system is arranged around the Zigzag flow channel system; the rectangular cross-section sinusoidal flow channel system is arranged around the semicircular cross-section sinusoidal flow channel system. The present invention is applicable to the field of heat exchanger technology for vehicle-mounted nuclear power sources.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange, in particular to the technical field of heat exchangers. Background Art

[0002] Reheater is an important component of on-board nuclear power system. Optimizing reheater by enhancing heat transfer capacity and improving heat recovery is considered to be the key to improving the performance of on-board nuclear power system. Printed circuit board heat exchanger (PCHE), as a compact plate and shell heat exchanger, has the characteristics of high compactness, high heat transfer density and long-term stable and efficient operation under high pressure and high temperature environment. It is the first choice for reheater in on-board nuclear power system.

[0003] The manufacturing process of PCHE is similar to that of a circuit board. The flow channel shape is etched out on a heat exchange plate with a thickness of 1.5-2.0 mm by chemical corrosion, and then the multi-layer heat exchange plate is welded into a whole by diffusion welding technology. According to the internal flow channel characteristics of PCHE, PCHE can be divided into continuous flow channels and discontinuous flow channels. Continuous channels generally include straight flow channels, Zigzag flow channels, and S flow channels; discontinuous channels are caused by the discontinuity of the flow channel fins, generally including airfoil channels, diamond channels, and long hexagonal channels.

[0004] Usually, the microchannels inside the PCHE have a single structural characteristic. However, due to the existence of flow resistance along the way and local flow resistance during the flow of the working fluid, the pressure drop characteristics in the microchannels at different positions inside the PCHE are significantly different. The pressure drop difference between different microchannels causes the PCHE with a single channel structure to face the following problems during operation: (1) There are obvious differences in the working fluid flow rate and flow field pressure between different microchannels, which makes the PCHE microchannel fins under stress for a long time, eventually causing the flow channel to deform; (2) The temperature gradient inside the PCHE is large, and the fins between the microchannels need to withstand huge thermal stress, which makes the heat exchanger structure prone to deformation; (3) The overall heat exchange capacity of the PCHE decreases, which affects the performance of the on-board nuclear power system. Summary of the invention

[0005] The invention solves the problem that the flow distribution of a PCHE heat exchange core is uneven during operation, resulting in unbalanced heat exchange capacity.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A PCHE heat exchange core with a composite flow channel combination, the heat exchange core comprising a heat exchange channel, the heat exchange channel comprising a Zigzag flow channel system, a semicircular cross-section sinusoidal flow channel system and a rectangular cross-section sinusoidal flow channel system;

[0008] The Zigzag flow channel system is arranged at the center of the heat exchange core;

[0009] The semicircular cross-section sinusoidal flow channel system is arranged around the Zigzag flow channel system;

[0010] The rectangular cross-section sinusoidal flow channel system is arranged around the semicircular cross-section sinusoidal flow channel system.

[0011] Furthermore, in a preferred embodiment, the above-mentioned Zigzag flow channel system is composed of a group of n*n Zigzag flow channels, and the lateral distance between two adjacent Zigzag flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

[0012] Furthermore, in another preferred embodiment, the shape of the Zigzag flow channel is a sawtooth shape;

[0013] The period length l of the Zigzag flow channel is 15 mm;

[0014] The period height h of the Zigzag flow channel is 5 mm;

[0015] The flow cross section of the Zigzag flow channel is a semicircle, and the radius r of the semicircle is 0.5 mm.

[0016] Furthermore, there is a preferred embodiment in which the above-mentioned semicircular cross-section sinusoidal flow channel system is composed of at least one layer of semicircular cross-section sinusoidal flow channels, and the lateral distance between two adjacent semicircular cross-section sinusoidal flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

[0017] Furthermore, in another preferred embodiment, the period length l of the semicircular cross-section sinusoidal flow channel is 1 15mm;

[0018] The period height h of the semicircular cross-section sinusoidal flow channel 1 5mm;

[0019] The flow cross section of the semicircular cross-section sinusoidal flow channel is a semicircle. And the radius r of the semicircle 1 It is 0.5mm.

[0020] Furthermore, in a preferred embodiment, the above-mentioned rectangular cross-section sinusoidal flow channel system is composed of at least one layer of rectangular cross-section sinusoidal flow channels, and the lateral distance between two adjacent rectangular cross-section sinusoidal flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

[0021] Furthermore, in another preferred embodiment, the period length l of the rectangular cross-section sinusoidal flow channel is 2 15mm;

[0022] The period height h of the rectangular cross-section sinusoidal flow channel 2 5mm;

[0023] The flow cross-section of the rectangular cross-section sinusoidal flow channel is a square, and the side length a of the regular polygon is 0.75 mm.

[0024] Furthermore, in a preferred embodiment, the heat exchange core further comprises a shell, and the heat exchange channel is arranged inside the shell.

[0025] Furthermore, in a preferred embodiment, the shell is made of stainless steel.

[0026] A vehicle-mounted nuclear power source comprises a PCHE heat exchange core with a composite flow channel combination as described in any one of the above.

[0027] The beneficial effects of the present invention are as follows: the present invention provides a PCHE heat exchange core with a composite flow channel combination, which adopts microchannels with different structural characteristics to form the PCHE heat exchange core, realizes the regulation of the internal flow and heat exchange capacity of the PCHE heat exchange core, and solves the problems of uneven flow distribution and unbalanced heat exchange capacity during the operation of PCHE.

[0028] Compared with the existing technology, the following advantages are produced:

[0029] 1. The microchannel inside the traditional PCHE heat exchange core is a single structural characteristic. When the working fluid enters the traditional PCHE heat exchange core from the main route, the flow velocity at the center of the pipeline of the traditional PCHE heat exchange core is higher, and the flow velocity near the wall is lower, which leads to different pressure drops at the center of the pipeline and near the wall. This makes the fins of the microchannels in the PCHE heat exchange core under stress for a long time, and finally causes the flow channel to deform. The present invention provides a PCHE heat exchange core with a composite flow channel combination, which uses a Zigzag flow channel at the center of the pipeline and a rectangular cross-section sinusoidal flow channel near the wall, so that there is no difference in the working fluid flow rate and flow field pressure between different microchannels, avoiding the problem of long-term stress on the PCHE microchannel fins, which causes the flow channel to deform.

[0030] 2. The microchannels inside the traditional PCHE heat exchange core are single structural characteristics. The flow velocity at the center of the traditional PCHE heat exchange core pipeline is high, and the heat exchange capacity is strong. The flow velocity near the wall is low, and the heat exchange capacity is poor, resulting in a large temperature gradient inside the traditional PCHE heat exchange core. The fins between the microchannels need to withstand huge thermal stress, making the heat exchanger structure prone to deformation. The present invention provides a PCHE heat exchange core with a composite flow channel combination, which uses a Zigzag flow channel at the center of the pipeline and a rectangular cross-section sinusoidal flow channel near the wall, so that the flow velocity inside the PCHE heat exchange core is consistent, the heat exchange capacity is consistent, and a large temperature gradient will not be generated, reducing the force on the fins between the microchannels, and avoiding the risk of deformation of the heat exchanger structure under long-term operation conditions of the on-board nuclear power supply.

[0031] 3. The microchannels inside the traditional PCHE heat exchange core are single structural characteristics. When the working fluid enters the traditional PCHE heat exchange core from the main route, the flow velocity at the center of the traditional PCHE heat exchange core pipeline is higher, and the flow velocity near the wall is lower, which leads to different pressure drops at the center of the pipeline and near the wall, which reduces the overall heat exchange capacity of the PCHE heat exchange core and affects the performance of the on-board nuclear power system. The present invention provides a PCHE heat exchange core with a composite flow channel combination, which uses a semicircular cross-section sinusoidal flow channel at the center of the pipeline and a rectangular cross-section sinusoidal flow channel near the wall, so that there is no difference in the working fluid flow and flow field pressure between different microchannels, and regulates the heat exchange capacity of the microchannels in different areas of the heat exchange core, reduces the temperature gradient inside the PCHE, and improves the overall heat exchange capacity of the PCHE heat exchange core.

[0032] 4. The present invention provides a PCHE heat exchange core with a composite flow channel combination, in which a Zigzag flow channel is arranged at the center of the heat exchange core, a semicircular cross-section sinusoidal flow channel is arranged around the Zigzag flow channel, and a rectangular cross-section sinusoidal flow channel is arranged around the semicircular cross-section sinusoidal flow channel. The pressure drop of the sinusoidal flow channel is one-fifth of that of the Zigzag flow channel. When the working fluid is helium-xenon, the working fluid is 33m / s, and the inlet Reynolds number is 2500, after seven flow cycles, the pressure drop of the semicircular cross-section sinusoidal flow channel is 82700Pa, and the pressure drop of the Zigzag flow channel is 426219Pa. The Zigzag flow channel with a small pressure drop is used at the high flow velocity in the center of the PCHE heat exchange core pipeline, and the sinusoidal flow channel with a large pressure drop is used at the low flow velocity near the wall, so as to solve the problem of no difference in working fluid flow and flow field pressure between different microchannels.

[0033] The present invention is applicable to the technical field of heat exchangers for vehicle-mounted nuclear power sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is an external schematic diagram of a PCHE heat exchange core with a composite flow channel combination according to the first embodiment;

[0035] Figure 2 is an internal schematic diagram of a PCHE heat exchange core with a composite flow channel combination according to the first embodiment;

[0036] Figure 3 is a schematic diagram of the Zigzag flow channel described in Embodiment 2 and Embodiment 3;

[0037] Figure 4 is a schematic diagram of a semicircular cross-section sinusoidal flow channel described in Embodiment 4 and Embodiment 5;

[0038] Figure 5 It is a schematic diagram of the rectangular cross-section sinusoidal flow channel described in Embodiment 6 and Embodiment 7. Implementation

[0039] Implementation method 1. See Figure 1 and Figure 2 Description of this embodiment: This embodiment provides a PCHE heat exchange core with a composite flow channel combination, wherein the heat exchange core includes a heat exchange channel, and the heat exchange channel includes a Zigzag flow channel system, a semicircular cross-section sinusoidal flow channel system, and a rectangular cross-section sinusoidal flow channel system;

[0040] The Zigzag flow channel system is arranged at the center of the heat exchange channel;

[0041] The semicircular cross-section sinusoidal flow channel system is arranged around the Zigzag flow channel system;

[0042] The rectangular cross-section sinusoidal flow channel system is arranged around the semicircular cross-section sinusoidal flow channel system.

[0043] This embodiment provides a PCHE heat exchange core with a composite flow channel combination, wherein the heat exchange channel is composed of three different continuous channels, namely, a Zigzag flow channel system, a semicircular cross-section sinusoidal flow channel system, and a rectangular cross-section sinusoidal flow channel system. The Zigzag flow channel system is arranged at the center of the heat exchange channel, the semicircular cross-section sinusoidal flow channel system is arranged around the Zigzag flow channel system, and the semicircular cross-section sinusoidal flow channel system is composed of two layers of semicircular cross-section sinusoidal flow channels with smaller flow resistance, and the rectangular cross-section sinusoidal flow channel system is arranged around the semicircular cross-section sinusoidal flow channel system, and the rectangular cross-section sinusoidal flow channel system is composed of two layers of rectangular cross-section sinusoidal flow channels with smaller flow resistance. By using a Zigzag flow channel at the center of the pipeline and a rectangular cross-section sinusoidal flow channel near the wall, there is no difference in the working fluid flow rate and flow field pressure between different microchannels, thereby avoiding the problem of long-term stress on the PCHE microchannel fins, which causes flow channel deformation.

[0044] In actual application, in the flow field inside the pipeline, the velocity distribution of the flow field shows that the velocity is higher at the center of the pipeline and lower near the wall. Therefore, when the working fluid enters the PCHE heat exchange core from the main route, the inlet velocity at different positions of the PCHE heat exchange core is different. Under a fixed configuration, the internal pressure drop of the pipeline for the working fluid with the same velocity is the same. However, in the PCHE heat exchange core with a certain working fluid and the same structure, due to the different velocity distribution inside the pipeline, the flow resistance inside different channels must be different. The difference in flow resistance of different channels makes different channels have different flow rates and heat exchange capacities. From the definition of the Reynolds number, it can be found that the difference in flow rate will also directly affect the heat exchange capacity of each channel. Specifically, the higher the flow velocity inside the channel, the stronger the heat exchange capacity; on the contrary, the lower the flow velocity inside the channel, the worse the heat exchange capacity. The difference in heat exchange capacity of different channels inside the PCHE heat exchange core leads to a large temperature gradient in the heat exchange core body structure, which in turn induces large thermal stress. In order to evenly distribute the flow rate, the temperature distribution of the heat exchange core body and the pressure on the fins, this embodiment utilizes a combination of different flow channel structures to change the pressure drop characteristics inside the flow channel, thereby regulating the flow resistance and flow rate.

[0045] The microchannels inside the traditional PCHE heat exchange core are single structural characteristics. When the working fluid enters the traditional PCHE heat exchange core from the main route, the flow velocity at the center of the pipeline of the traditional PCHE heat exchange core is higher, and the flow velocity near the wall is lower, which leads to different pressure drops at the center of the pipeline and near the wall. This makes the fins of the microchannels in the PCHE heat exchange core under stress for a long time, and finally causes deformation of the flow channel. This embodiment provides a PCHE heat exchange core with a composite flow channel combination, which uses a Zigzag flow channel at the center of the pipeline and a rectangular cross-section sinusoidal flow channel near the wall, so that there is no difference in the working fluid flow rate and flow field pressure between different microchannels, avoiding the problem of long-term stress on the PCHE microchannel fins, which causes flow channel deformation.

[0046] The microchannels inside the traditional PCHE heat exchange core are single structural characteristics. The temperature gradient inside the PCHE heat exchange core is large. The fins between the microchannels need to withstand huge thermal stress, which makes the heat exchanger structure prone to deformation. This embodiment provides a PCHE heat exchange core with a composite flow channel combination, which effectively reduces the force on the fins by using the flow and flow resistance distribution between different microchannels, avoiding the risk of deformation of the heat exchanger structure under long-term operation of the vehicle-mounted nuclear power supply.

[0047] The microchannels inside the traditional PCHE heat exchange core are single structural characteristics. The flow velocity at the center of the traditional PCHE heat exchange core pipeline is high, and the heat exchange capacity is strong. The flow velocity near the wall is low, and the heat exchange capacity is poor, resulting in a large temperature gradient inside the traditional PCHE heat exchange core. The fins between the microchannels need to withstand huge thermal stress, making the heat exchanger structure prone to deformation. This embodiment provides a PCHE heat exchange core with a composite flow channel combination, using a Zigzag flow channel at the center of the pipeline and a rectangular cross-section sinusoidal flow channel near the wall, so that the flow velocity inside the PCHE heat exchange core is consistent, the heat exchange capacity is consistent, and a large temperature gradient will not be generated, reducing the force on the fins between the microchannels, and avoiding the risk of deformation of the heat exchanger structure under long-term operation conditions of the on-board nuclear power supply.

[0048] The microchannels inside the traditional PCHE heat exchange core are single structural characteristics. When the working fluid enters the traditional PCHE heat exchange core from the main route, the flow velocity at the center of the traditional PCHE heat exchange core pipeline is higher, and the flow velocity near the wall is lower, which leads to different pressure drops at the center of the pipeline and near the wall, which reduces the overall heat exchange capacity of the PCHE heat exchange core and affects the performance of the on-board nuclear power system. This embodiment provides a PCHE heat exchange core with a composite flow channel combination, which uses a semicircular cross-section sinusoidal flow channel at the center of the pipeline and a rectangular cross-section sinusoidal flow channel near the wall, so that there is no difference in the working fluid flow and flow field pressure between different microchannels, and regulates the heat exchange capacity of the microchannels in different areas of the heat exchange core, reduces the temperature gradient inside the PCHE, and improves the overall heat exchange capacity of the PCHE heat exchange core.

[0049] The present embodiment provides a PCHE heat exchange core with a composite flow channel combination, in which a Zigzag flow channel is arranged at the center of the heat exchange core, a semicircular cross-section sinusoidal flow channel is arranged around the Zigzag flow channel, and a rectangular cross-section sinusoidal flow channel is arranged around the semicircular cross-section sinusoidal flow channel. The pressure drop of the sinusoidal flow channel is one-fifth of that of the Zigzag flow channel. When the working fluid is helium-xenon, the working fluid is 33m / s, and the inlet Reynolds number is 2500, after seven flow cycles, the pressure drop of the semicircular cross-section sinusoidal flow channel is 82700Pa, and the pressure drop of the Zigzag flow channel is 426219Pa. The Zigzag flow channel with a small pressure drop is used at the high flow velocity in the center of the PCHE heat exchange core pipeline, and the sinusoidal flow channel with a large pressure drop is used at the low flow velocity near the wall, thereby solving the problem of no difference in working fluid flow and flow field pressure between different microchannels.

[0050] Implementation method 2. See Figure 3To explain this embodiment, this embodiment is an example of a Zigzag flow channel system in a PCHE heat exchange core with a composite flow channel combination described in Embodiment 1. The Zigzag flow channel system is composed of a group of n*n Zigzag flow channels, and the lateral distance between two adjacent Zigzag flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

[0051] In actual application of this embodiment, the Zigzag flow channel system is composed of a group of n*n Zigzag flow channels. As an optimal embodiment, the Zigzag flow channel system is composed of a group of 3×3 Zigzag flow channels. The lateral distance between two adjacent Zigzag flow channels is 2 mm, and the longitudinal distance is 1.5 mm. It can be flexibly selected according to actual needs on site.

[0052] Implementation method 3. See Figure 3 This embodiment is described. This embodiment is an example of a Zigzag flow channel in a PCHE heat exchange core with a composite flow channel combination described in Embodiment 2. The shape of the Zigzag flow channel is a sawtooth shape.

[0053] The period length l of the Zigzag flow channel is 15 mm;

[0054] The period height h of the Zigzag flow channel is 5 mm;

[0055] The flow cross section of the Zigzag flow channel is a semicircle, and the radius R of the semicircle is 0.5 mm.

[0056] In actual application, as an optimal embodiment, the shape of the Zigzag flow channel is set to be a sawtooth shape, and the period length l of the Zigzag flow channel is 15 mm; the period height h of the Zigzag flow channel is 5 mm; the flow cross-section of the Zigzag flow channel is a semicircle, and the radius R of the semicircle is 0.5 mm, which can be flexibly selected according to actual needs on site.

[0057] Implementation method 4. See Figure 4 To explain this embodiment, this embodiment is an example of a semicircular cross-section sinusoidal flow channel system in a PCHE heat exchange core with a composite flow channel combination described in Embodiment 1. The semicircular cross-section sinusoidal flow channel system is composed of at least one layer of semicircular cross-section sinusoidal flow channels, and the lateral distance between two adjacent semicircular cross-section sinusoidal flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

[0058] In actual application of this embodiment, the semicircular cross-section sinusoidal flow channel system is composed of at least one layer of semicircular cross-section sinusoidal flow channels. As an optimal embodiment, the semicircular cross-section sinusoidal flow channel system is composed of two layers of semicircular cross-section sinusoidal flow channels. The lateral distance between two adjacent semicircular cross-section sinusoidal flow channels is 2 mm, and the longitudinal distance is 1.5 mm. It can be flexibly selected according to actual needs on site.

[0059] Implementation method 5. See Figure 4 This embodiment is described as an example of a semicircular cross-section sinusoidal flow channel in a PCHE heat exchange core with a composite flow channel combination described in Embodiment 4. The period length l of the semicircular cross-section sinusoidal flow channel is 1 The flow cross section of the semicircular cross-section sinusoidal flow channel is a semicircle, and the radius r of the semicircle is 1 It is 0.5mm.

[0060] In practical application, this embodiment is used as an optimal embodiment to set the period length l of the semicircular cross-section sinusoidal flow channel to 1 The flow cross section of the semicircular cross-section sinusoidal flow channel is set to a semicircular shape, and the radius r of the semicircle is 1 It is 0.5mm and can be flexibly selected according to actual needs on site.

[0061] Implementation method 6. See Figure 5 To explain this embodiment, this embodiment is an example of a rectangular cross-section sinusoidal flow channel system in a PCHE heat exchange core with a composite flow channel combination as described in Embodiment 1. The rectangular cross-section sinusoidal flow channel system is composed of at least one layer of rectangular cross-section sinusoidal flow channels, and the lateral distance between two adjacent rectangular cross-section sinusoidal flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

[0062] In actual application of this embodiment, the rectangular cross-section sinusoidal flow channel system is composed of at least one layer of rectangular cross-section sinusoidal flow channels. As an optimal embodiment, the rectangular cross-section sinusoidal flow channel system is composed of two layers of rectangular cross-section sinusoidal flow channels. The lateral distance between two adjacent rectangular cross-section sinusoidal flow channels is 2 mm, and the longitudinal distance is 1.5 mm. The selection can be flexibly made according to actual needs on site.

[0063] Implementation method 7. See Figure 5 This embodiment is described as an example of a rectangular cross-section sinusoidal flow channel in a PCHE heat exchange core with a composite flow channel combination described in Embodiment 6. The period length l of the rectangular cross-section sinusoidal flow channel is 2 15mm;

[0064] The period height h of the rectangular cross-section sinusoidal flow channel 25mm;

[0065] The flow cross-section of the rectangular cross-section sinusoidal flow channel is a square, and the side length a of the regular polygon is 0.75 mm.

[0066] In practical application, as an optimal embodiment, the period length l of the rectangular cross-section sinusoidal flow channel is 2 Set to 15mm; the period height h of the rectangular cross-section sinusoidal flow channel 2 The flow cross-section shape of the rectangular cross-section sinusoidal flow channel is set to a regular polygon, and the side length a of the regular polygon is 0.75 mm. It can be flexibly selected according to the actual needs on site.

[0067] Embodiment 8. This embodiment adds a shell on the basis of the PCHE heat exchange core with a composite flow channel combination described in Embodiment 1, and the heat exchange channel is arranged inside the shell.

[0068] In actual application of this embodiment, the heat exchange channel is arranged inside the shell.

[0069] Embodiment 9. This embodiment is an example of the shell material in the PCHE heat exchange core with a composite flow channel combination described in Embodiment 8, and the material of the shell is stainless steel.

[0070] In actual application of this embodiment, the material of the shell is stainless steel, which has the advantages of heat resistance, high temperature resistance, chemical corrosion resistance and electrochemical corrosion resistance.

[0071] Embodiment 10. This embodiment provides a vehicle-mounted nuclear power source, which includes a PCHE heat exchange core with a composite flow channel combination as described in any one of Embodiments 1 to 9.

[0072] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A PCHE heat exchange core with a composite flow channel combination, characterized in that: The heat exchange core includes a heat exchange channel, and the heat exchange channel includes a Zigzag flow channel system, a semicircular cross-section sinusoidal flow channel system, and a rectangular cross-section sinusoidal flow channel system; The Zigzag flow channel system is arranged at the center of the heat exchange core; The semicircular cross-section sinusoidal flow channel system is arranged around the Zigzag flow channel system; The rectangular cross-section sinusoidal flow channel system is arranged around the semicircular cross-section sinusoidal flow channel system.

2. A PCHE heat exchange core with a composite flow channel combination according to claim 1, characterized in that: The Zigzag flow channel system consists of a group of n*n Zigzag flow channels, and the lateral distance between two adjacent Zigzag flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

3. The PCHE heat exchange core with a composite flow channel combination according to claim 2, characterized in that: The shape of the Zigzag flow channel is a sawtooth shape; The period length l of the Zigzag flow channel is 15 mm; The period height h of the Zigzag flow channel is 5 mm; The flow cross section of the Zigzag flow channel is a semicircle, and the radius r of the semicircle is 0.5 mm.

4. The PCHE heat exchange core with a composite flow channel combination according to claim 1, characterized in that: The semicircular cross-section sinusoidal flow channel system is composed of at least one layer of semicircular cross-section sinusoidal flow channels, and the lateral distance between two adjacent semicircular cross-section sinusoidal flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

5. The PCHE heat exchange core with a composite flow channel combination according to claim 4, characterized in that: The period length l1 of the semicircular cross-section sinusoidal flow channel is 15 mm; The period height h1 of the semicircular cross-section sinusoidal flow channel is 5 mm; The flow cross section of the semicircular cross-section sinusoidal flow channel is a semicircle, and the radius r1 of the semicircle is 0.5 mm.

6. The PCHE heat exchange core with a composite flow channel combination according to claim 1, characterized in that: The rectangular cross-section sinusoidal flow channel system is composed of at least one layer of rectangular cross-section sinusoidal flow channels, and the lateral distance between two adjacent rectangular cross-section sinusoidal flow channels is 2 mm, and the longitudinal distance is 1.5 mm.

7. The PCHE heat exchange core with a composite flow channel combination according to claim 6, characterized in that: The period length l2 of the rectangular cross-section sinusoidal flow channel is 15 mm; The period height h2 of the rectangular cross-section sinusoidal flow channel is 5 mm; The flow cross-section of the rectangular cross-section sinusoidal flow channel is a square, and the side length a of the square is 0.75 mm.

8. The PCHE heat exchange core with a composite flow channel combination according to claim 1, characterized in that: The heat exchange core further includes a shell, and the heat exchange channel is arranged inside the shell.

9. The PCHE heat exchange core with a composite flow channel combination according to claim 8, characterized in that: The material of the shell is stainless steel.

10. A vehicle-mounted nuclear power source, characterized in that: The vehicle-mounted nuclear power source comprises a PCHE heat exchange core with a composite flow channel combination as described in any one of claims 1-9.

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