Stirling engine heat exchanger for molten salt reactor and Stirling engine

Abstract

The invention belongs to the field of heat exchangers, and discloses a Stirling engine heat exchanger for a molten salt reactor and a Stirling engine, the Stirling engine heat exchanger for the molten salt reactor comprises a heat exchanger shell, a liquid inlet is formed in the top of the heat exchanger shell, and a liquid outlet is formed in the side wall of the bottom of the heat exchanger shell; the working medium cylinder is hermetically connected with the heat exchanger shell; the multiple first baffle plates are arranged in the heat exchanger shell at intervals in the height direction of the heat exchanger shell, and first channels are formed between the outer side walls of the first baffle plates and the inner side wall of the heat exchanger shell; a second baffle plate is arranged between every two adjacent first baffle plates, and a second channel is formed in the center of each second baffle plate; a plurality of U-shaped heat exchange pipes are arranged in the heat exchanger shell in an array mode along the circumference and penetrate through the first baffle plate and the second baffle plate, and the two ends of each U-shaped heat exchange pipe are inserted into the working medium barrel correspondingly. By arranging the baffle plates, the flowing direction of fused salt and a working medium is changed from parallel flowing to staggered flowing, the convective heat transfer coefficient of the fused salt side is increased, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, in particular to a Stirling engine heat exchanger for a molten salt reactor and a Stirling engine. Background Art

[0002] The Stirling engine is a closed-cycle engine that can utilize a variety of heat sources. It has the characteristics of high thermal efficiency, low noise, small size and good operating characteristics. Its operating temperature is above 500°C, which is a natural match with the high-temperature molten salt reactor nuclear energy system. Using the molten salt-Stirling power generation system as a thermoelectric conversion system can not only provide a stable power supply, but also meet the requirements of low noise and small size. It can be used in space-constrained scenarios such as small ships, aircraft and deep space exploration.

[0003] The Stirling engine heat exchanger is one of the heat exchange components of the Stirling engine. It is used to exchange heat from an external high-temperature heat source with an internal working fluid. After the working fluid absorbs heat, it expands and does work, converting thermal energy into mechanical energy. Among them, the coaxial heat exchanger is a form of Stirling engine heat exchanger, in which the heat exchanger is coaxially arranged with the regenerator and cooler. When the existing Stirling engine heat exchanger is applied to molten salt heat sources, it cannot fully utilize the thermal energy of high heat capacity molten salts, and there are problems such as low heat exchange efficiency and complex structure. Summary of the invention

[0004] The purpose of the present application is to provide a Stirling engine heat exchanger and a Stirling engine for a molten salt reactor, which are not only compact in structure but also can increase the heat exchange efficiency, so as to increase the heat absorption of the Stirling engine and improve the cycle efficiency.

[0005] The technical solutions provided by this application are as follows:

[0006] In one aspect, a Stirling engine heat exchanger for a molten salt reactor is provided, comprising:

[0007] The heat exchanger shell has a liquid inlet on the top and a liquid outlet on the bottom side wall;

[0008] A working medium cylinder is disposed below the heat exchanger shell and is sealed and connected to the heat exchanger shell;

[0009] A plurality of first baffles are arranged in the heat exchanger shell at intervals along the height direction of the heat exchanger shell, and there is a distance between the outer side wall of the first baffle and the inner side wall of the heat exchanger shell to form a first channel;

[0010] A plurality of second baffles are respectively arranged in the heat exchanger shell, and a second baffle is arranged between every two adjacent first baffles, and a through hole is arranged at the center of the second baffle to form a second channel;

[0011] A plurality of U-shaped heat exchange tubes are arranged in a circumferential array in the heat exchanger shell and pass through the first baffle and the second baffle. Both ends of the U-shaped heat exchange tubes extend out of the heat exchanger shell and are inserted into the working medium cylinder.

[0012] In some embodiments, the heat exchanger shell includes an upper cylinder and a flow equalizing chamber, the bottom of the upper cylinder is open, the flow equalizing chamber is sealed at the bottom opening of the upper cylinder, an annular flow channel is provided in the flow equalizing chamber, the top surface of the annular flow channel is provided with a guide hole connecting the annular flow channel and the upper cylinder, the side wall of the flow equalizing chamber is provided with the liquid outlet, and the liquid outlet is connected to the annular flow channel.

[0013] In some embodiments, the heat exchanger shell further includes a blocking block, the flow balancing chamber is annular, and the blocking block is disposed in an inner ring area of ​​the flow balancing chamber and is sealed and connected to the flow balancing chamber.

[0014] In some embodiments, the top of the blocking block is arc-shaped with the convex portion facing the upper cylinder.

[0015] In some embodiments, the top edge of the blocking block is flush with or higher than the top of the flow equalizing chamber.

[0016] In some embodiments, the bottom surface of the annular flow channel has a slope, so that the inner height of the annular flow channel is negatively correlated with the distance from the liquid outlet.

[0017] In some embodiments, the bottom slope of the annular flow channel is 3 to 5 degrees.

[0018] In some embodiments, the flow guide holes are evenly spaced at the top of the flow equalizing chamber along the circumference of the flow equalizing chamber, and the diameter of the flow guide holes is positively correlated with the distance from the liquid outlet.

[0019] In some embodiments, a connecting flange is further included, and the connecting flange is arranged at one end of the working medium cylinder away from the heat exchanger shell.

[0020] On the other hand, a Stirling engine is also provided, comprising the Stirling engine heat exchanger for a molten salt reactor as described in any of the above embodiments.

[0021] The technical effect of the present application is that the molten salt heat source is passed into a relatively efficient and compact heat exchanger to transfer heat with the working fluid of the Stirling engine, and by arranging baffles, the flow direction of the molten salt and the working fluid is changed from parallel flow to staggered flow, thereby increasing the convective heat transfer coefficient on the molten salt side, increasing the operating temperature of the Stirling engine working fluid as much as possible, increasing the heat absorption of the Stirling engine and improving the cycle efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present application is further described in detail below with reference to the accompanying drawings and specific implementation methods:

[0023] Figure 1 is a cross-sectional view of a Stirling engine heat exchanger for a molten salt reactor provided in a specific embodiment of the present application;

[0024] Figure 2 is a top view of a working medium cylinder provided in a specific embodiment of the present application;

[0025] Figure 3 is a structural schematic diagram of a first baffle provided in a specific embodiment of the present application;

[0026] Figure 4 is a schematic structural diagram of a second baffle provided in a specific embodiment of the present application;

[0027] Figure 5 It is a front view of the flow equalizing chamber provided in a specific embodiment of the present application;

[0028] Figure 6 It is a top view of the flow equalizing chamber provided in a specific embodiment of the present application.

[0029] Description of Figure Numbers:

[0030] 100, heat exchanger shell; 101, liquid inlet; 102, liquid outlet; 110, upper cylinder; 120, flow equalizing chamber; 121, annular flow channel; 122, flow guide hole; 130, blocking block; 200, working medium cylinder; 300, first baffle; 310, first channel; 400, second baffle; 410, second channel; 500, U-shaped heat exchange tube; 510, outer tube; 520, inner tube; 600, connecting flange. DETAILED DESCRIPTION

[0031] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0032] In order to more clearly illustrate the application embodiments or technical solutions in the prior art, the specific implementation methods of the present application will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0033] In order to simplify the drawings, only the parts related to the present application are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0034] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0035] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] In the embodiments shown in the drawings, directional indications (such as up, down, left, right, front, and back, etc.) are not absolute but relative when describing the structure and movement of each component, and are not used to limit the direction of the product in actual use.

[0037] In addition, in the description of the present application, ordinal numbers, such as "first", "second", etc., are only used to distinguish and describe related objects, and cannot be understood as indicating or implying the relative importance or order between the related objects.

[0038] Figure 1 A cross-sectional view of a Stirling engine heat exchanger for a molten salt reactor is shown; Figure 2 A top view of the working medium cylinder is shown; Figure 3 shows a schematic structural diagram of a first baffle; Figure 4 Schematic diagram of the structure of the second baffle is shown. Figures 1 to 4The Stirling engine heat exchanger for molten salt reactor includes a heat exchanger shell 100, a working medium cylinder 200, a plurality of first baffles 300, a plurality of second baffles 400 and a plurality of U-shaped heat exchange tubes 500. A liquid inlet 101 is provided at the top of the heat exchanger shell 100, and a liquid outlet 102 is provided at the bottom side wall. The molten salt enters the heat exchanger shell 100 from the liquid inlet 101 at the top of the heat exchanger shell 100 and is discharged from the liquid outlet 102 at the bottom side wall of the heat exchanger shell 100; a plurality of U-shaped heat exchange tubes 500 are arranged in a circumferential array in the heat exchanger shell 100, and the molten salt exchanges heat with the working medium in the U-shaped heat exchange tubes 500 in the heat exchanger shell 100. Because the molten salt has a high working temperature and is highly corrosive, the heat exchanger shell 100, the U-shaped heat exchange tubes 500 and other parts in contact with the molten salt are made of high temperature resistant and corrosion resistant alloy materials.

[0039] The working fluid cylinder 200 is arranged below the heat exchanger shell 100 and is sealed and connected to the heat exchanger shell 100; the working fluid cylinder 200 is coaxially arranged with the heat exchanger shell 100, and the working fluid cylinder 200 and the heat exchanger shell 100 can be welded together by argon arc welding. The two ends of the U-shaped heat exchange tube 500 extend out of the heat exchanger shell 100 and are inserted into the working fluid cylinder 200 respectively, and the side wall of the U-shaped heat exchange tube 500 is sealed and connected to the top of the working fluid cylinder 200. For example, the U-shaped heat exchange tube 500 and the working fluid cylinder 200 can be sealed and connected by brazing welding. In this embodiment, the U-shaped heat exchange tube 500 can adopt an integrated design and be directly welded to the working fluid cylinder 200, which simplifies the welding process. Both ends of the U-shaped heat exchange tube 500 are respectively connected to the working medium cylinder 200, one end of the U-shaped heat exchange tube 500 is the working medium inlet, and the other end of the U-shaped heat exchange tube 500 is the working medium outlet, wherein the working medium inlet is located in the central area of ​​the working medium cylinder 200, and the working medium outlet is located in the peripheral area of ​​the working medium cylinder 200. Figure 1 The arrows a and b in the middle indicate the direction of working fluid flow.

[0040] The working fluid flows from the working fluid cylinder 200 into the U-shaped heat exchange tube 500, and exchanges heat with the molten salt in the heat exchanger shell 100, absorbs heat to drive the Stirling engine to work, and then flows back from the U-shaped heat exchange tube 500 to the working fluid cylinder 200 to form a reciprocating motion. The number of U-shaped heat exchange tubes 500 can be set according to the size of the heat exchanger shell 100. The diameter of the U-shaped heat exchange tube 500 is 4 to 8 mm. Figure 2 As shown, the outer tubes 510 of the U-shaped heat exchange tubes 500 are evenly arranged along the same circumference, and the inner tubes 520 of the U-shaped heat exchange tubes 500 are evenly arranged along two circumferences in an alternating manner to form an equidistant tube bundle structure that does not interfere with each other, so as to set as many U-shaped heat exchange tubes 500 as possible, increase the number of U-shaped heat exchanger tubes 500, and thus improve the heat exchange efficiency.

[0041] A plurality of first baffles 300 are respectively disposed in the heat exchanger shell 100 and are spaced apart along the height direction of the heat exchanger shell 100. The outer diameter of the first baffle 300 is smaller than the inner diameter of the heat exchanger shell 100. There is a spacing between the outer wall of the first baffle 300 and the inner wall of the heat exchanger shell 100 to form a first channel 310. The first baffle 300 controls the molten salt to flow around. To facilitate the arrangement of the U-shaped heat exchange tube 500, the first baffle 300 is also provided with a first mounting hole for the U-shaped heat exchange tube 500 to pass through. The number and location of the first mounting hole are related to the number and arrangement of the U-shaped heat exchange tube 500.

[0042] A plurality of second baffles 400 are respectively arranged in the heat exchanger shell 100, and a second baffle 400 is arranged between every two adjacent first baffles 300, the outer diameter of the second baffle 400 is the same as the inner diameter of the heat exchanger shell 100, and there is no gap between the outer wall of the second baffle 400 and the inner wall of the heat exchanger shell 100, but a through hole is provided in the center of the second baffle 400 to form a second channel 410, and the second baffle 400 controls the molten salt to flow toward the center, and the first baffle 300 and the second baffle 400 are alternately arranged at a certain interval to control the flow direction of the molten salt. Similarly, in order to facilitate the arrangement of the U-shaped heat exchange tube 500, the second baffle 400 is also provided with a second mounting hole for the U-shaped heat exchange tube 500 to pass through, and the number and setting position of the second mounting hole are related to the number and arrangement of the U-shaped heat exchange tube 500.

[0043] The working process of the Stirling engine heat exchanger for the molten salt reactor of the present application is:

[0044] Figure 1 Arrows a and b in the middle are the flow direction of the working medium. For example, the working medium enters the U-shaped heat exchange tube 500 from the working medium cylinder 200 along arrow a, then exchanges heat with the molten salt in the heat exchanger shell 100, and then flows out from the U-shaped heat exchange tube 500. The outflow direction is shown by arrow b. The molten salt enters the heat exchanger shell 100 from the liquid inlet 101 at the top of the heat exchanger shell 100. The flow direction of the molten salt is changed by the first baffle 300 and the second baffle 400 inside the heat exchanger shell 100. After the molten salt exchanges heat with the working medium in the U-shaped heat exchange tube 500, it flows out from the liquid outlet 102 on the side wall of the heat exchanger shell 100.

[0045] In this embodiment, a first baffle 300 and a second baffle 400 are arranged in the heat exchanger shell 100, and a first channel 310 is formed between the first baffle 300 and the heat exchanger shell 100, and a second channel 410 is arranged on the second baffle 400. The molten salt entering the heat exchanger shell 100 first passes through the first channel 310, then passes through the second channel 410, and then passes through the first channel 310, and flows in this way until it is discharged from the heat exchanger shell 100. The molten salt can flow in a wave shape in the heat exchanger shell 100, changing the traditional parallel flow mode of the molten salt and the working fluid to form an interlaced flow, significantly increasing the contact area and fluid disturbance between the molten salt and the working fluid, thereby effectively improving the convective heat transfer coefficient on the molten salt side, and improving the heat transfer efficiency per unit volume, so that when the volume of the heat exchanger is reduced, sufficient heat exchange area can be guaranteed, which is suitable for application environments with limited space.

[0046] In some embodiments, Figure 1 As shown, the heat exchanger shell 100 includes an upper cylinder 110 and a flow equalizing chamber 120, the bottom of the upper cylinder 110 is open, and the flow equalizing chamber 120 is sealed at the bottom opening of the upper cylinder 110. An annular flow channel 121 is provided in the flow equalizing chamber 120, and a guide hole 122 connecting the annular flow channel 121 and the upper cylinder 110 is provided on the top surface of the annular flow channel 121. The side wall of the flow equalizing chamber 120 is provided with a liquid outlet 102, and the liquid outlet 102 is connected to the annular flow channel 121. The guide hole 122 provided on the top of the flow equalizing chamber 120 is used to control the flow distribution of molten salt at different positions, that is, the flow equalizing chamber 120 is provided at the bottom of the upper cylinder 110, which can ensure the flow uniformity of the molten salt at the bottom of the upper cylinder 110.

[0047] The upper cylinder 110 and the flow equalization chamber 120 can be welded together by argon arc welding. The upper cylinder 110 is a container with a hollow interior and an open bottom. The flow equalization chamber 120 is arranged at the bottom of the upper cylinder 110. The bottom of the upper cylinder 110 can be closed by the disc-shaped flow equalization chamber 120. Figure 5 and Figure 6 As shown, an annular flow channel 121 is arranged inside the flow equalizing chamber 120 , and a guide hole 122 is arranged on the top. The molten salt can enter the annular flow channel 121 through the guide hole 122 and then be discharged from the liquid outlet 102 .

[0048] In some embodiments, Figure 1As shown, the heat exchanger housing 100 also includes a blocking block 130, and the flow equalizing chamber 120 is annular. The blocking block 130 is arranged in the inner ring area of ​​the flow equalizing chamber 120 and is sealed and connected to the flow equalizing chamber 120. The blocking block 130 can isolate the molten salt from the working medium cylinder 200, and control the flow velocity of the molten salt at the welding position of the U-shaped heat exchange tube 500 and the working medium cylinder 200 to be close to zero, thereby reducing the corrosion rate of the molten salt on the weld of the U-shaped heat exchange tube 500. The top of the blocking block 130 is arc-shaped and the convex part faces the upper cylinder 110. The top of the blocking block 130 is set as a structure with a central upward protrusion, which can control the flow direction of the molten salt, so that the molten salt does not stay at the center of the blocking block 130, but flows to the surrounding outlets, thereby preventing the molten salt from accumulating at the top of the blocking block 130.

[0049] The top edge of the blocking block 130 is flush with or higher than the top of the flow equalizing chamber 120 to prevent molten salt from accumulating at the connection between the blocking block 130 and the flow equalizing chamber 120, so that the molten salt can smoothly enter the annular flow channel 121 of the flow equalizing chamber 120 from the flow guide hole 122 at the top of the flow equalizing chamber 120.

[0050] In some embodiments, Figure 5 As shown, the bottom surface of the annular flow channel 121 has a slope, so that the internal height of the annular flow channel 121 is negatively correlated with the distance from the liquid outlet 102; that is, the farther from the liquid outlet 102, the higher the inner bottom surface of the annular flow channel 121, and the smaller the internal height of the annular flow channel 121. The bottom surface of the annular flow channel 121 is designed with a slope, so that after the molten salt stops flowing, it flows out of the heat exchanger shell 100 passively under the action of gravity, preventing large pieces of molten salt from freezing in the heat exchanger shell 100, and facilitating the molten salt to flow out of the heat exchanger shell 100 completely. Among them, the bottom surface slope of the annular flow channel 121 is 3 to 5 degrees.

[0051] In some embodiments, Figure 6 As shown, the guide holes 122 are evenly spaced at the top of the flow equalizing chamber 120 along the circumference of the flow equalizing chamber 120, and the diameter of the guide holes 122 is positively correlated with the distance from the liquid outlet 102; that is, the farther from the liquid outlet 102, the larger the diameter of the guide holes 122. Because the farther the annular flow channel 121 is from the liquid outlet 102, the smaller the internal height of the annular flow channel 121, so the farther from the liquid outlet 102, the larger the diameter of the guide holes 122 is set, the more uniform the molten salt flow distribution can be. The specific diameter of the guide holes 122 can be determined by flow calculation.

[0052] In some embodiments, Figure 1As shown, it also includes a connecting flange 600, which is arranged at one end of the working fluid cylinder 200 away from the heat exchanger housing 100. The connecting flange 600 is assembled at the lower end of the working fluid cylinder 200, and the connecting flange 600 is installed at the lower end of the working fluid cylinder 200 before welding the flow equalization chamber 120, and the working fluid cylinder 200 is fastened to the fuselage. During the operation of the working fluid cylinder 200, the inside of the working fluid cylinder 200 will be subjected to the thermal stress caused by the alternating pressure of the working fluid and the uneven heating. The connection method of the connecting flange 600 plus bolts can ensure the reliable connection between the heat exchanger and the fuselage. In addition, the connecting flange 600 is fixed by bolts. In this way, the heat exchanger can be disassembled when the heat exchanger cannot be moved up.

[0053] In some embodiments, Figure 1 As shown, the top of the working medium cylinder 200 is arc-shaped and the convex part is arranged toward the heat exchanger shell 100. Since the working medium helium pressure in the working medium cylinder 200 is very high, reaching more than ten MPa, and the temperature is also very high, reaching 400°C, setting the top of the working medium cylinder 200 to be arc-shaped can reduce the stress on the top of the working medium cylinder 200 and avoid damage to the working medium cylinder 200.

[0054] The top of the working fluid cylinder 200 is arc-shaped. If the working fluid cylinder 200 and the heat exchanger shell 100 are not coaxially arranged, when the U-shaped heat exchange tube 500 is connected to the working fluid cylinder 200, part of the U-shaped heat exchange tube 500 will be far away from the top of the working fluid cylinder 200, resulting in a relatively long U-shaped heat exchange tube 500, which will affect the performance of the engine. Therefore, the working fluid cylinder 200 and the heat exchanger shell 100 are coaxially arranged to improve the performance of the engine. Because the temperature on the working fluid side can reach 400°C and the pressure can reach 13MPa, the working fluid cylinder 200 needs to withstand 400°C and 13MPa working fluid pressure. Therefore, the working fluid cylinder 200 needs to be made of high-strength high-temperature alloy material.

[0055] The present application also provides a Stirling engine, including the Stirling engine heat exchanger for a molten salt reactor described in any of the above embodiments. By using the Stirling engine heat exchanger for a molten salt reactor described in the above embodiments, the working temperature and heat absorption of the working fluid of the Stirling engine can be significantly improved, the cycle efficiency can be increased, and the safety and reliability of the heat exchange process can be ensured, providing important technical support for the development of molten salt reactor technology.

[0056] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0057] It should be noted that the above embodiments can be freely combined as needed. The above is only the preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present application, and these improvements and modifications should also be regarded as the protection scope of the present application.

Claims

1. A Stirling engine heat exchanger for a molten salt reactor, characterized in that: include: The heat exchanger shell has a liquid inlet on the top and a liquid outlet on the bottom side wall; A working medium cylinder is disposed below the heat exchanger shell and is sealed and connected to the heat exchanger shell; A plurality of first baffles are arranged in the heat exchanger shell at intervals along the height direction of the heat exchanger shell, and there is a distance between the outer side wall of the first baffle and the inner side wall of the heat exchanger shell to form a first channel; A plurality of second baffles are respectively arranged in the heat exchanger shell, and a second baffle is arranged between every two adjacent first baffles, and a through hole is arranged at the center of the second baffle to form a second channel; A plurality of U-shaped heat exchange tubes are arranged in a circumferential array in the heat exchanger shell and pass through the first baffle and the second baffle. Both ends of the U-shaped heat exchange tubes extend out of the heat exchanger shell and are inserted into the working medium cylinder.

2. A Stirling engine heat exchanger for a molten salt reactor according to claim 1, characterized in that: The heat exchanger shell includes an upper cylinder and a flow balancing chamber, the bottom of the upper cylinder is open, the flow balancing chamber is sealably arranged at the bottom opening of the upper cylinder, an annular flow channel is arranged in the flow balancing chamber, the top surface of the annular flow channel is provided with a guide hole connecting the annular flow channel and the upper cylinder, the side wall of the flow balancing chamber is provided with the liquid outlet, and the liquid outlet is connected to the annular flow channel.

3. A Stirling engine heat exchanger for a molten salt reactor according to claim 2, characterized in that: The heat exchanger shell further comprises a blocking block. The flow balancing chamber is annular. The blocking block is arranged in the inner ring area of ​​the flow balancing chamber and is sealed and connected to the flow balancing chamber.

4. A Stirling engine heat exchanger for a molten salt reactor according to claim 3, characterized in that: The top of the blocking block is arc-shaped with the convex portion facing the upper cylinder.

5. A Stirling engine heat exchanger for a molten salt reactor according to claim 4, characterized in that: The top edge of the blocking block is flush with or higher than the top of the flow balancing chamber.

6. A Stirling engine heat exchanger for a molten salt reactor according to claim 2, characterized in that: The bottom surface of the annular flow channel has a slope, so that the inner height of the annular flow channel is negatively correlated with the distance from the liquid outlet.

7. A Stirling engine heat exchanger for a molten salt reactor according to claim 6, characterized in that: The bottom surface slope of the annular flow channel is 3-5°.

8. A Stirling engine heat exchanger for a molten salt reactor according to claim 6, characterized in that: The flow guide holes are evenly spaced at the top of the flow equalizing chamber along the circumference of the flow equalizing chamber, and the diameter of the flow guide holes is positively correlated with the distance from the liquid outlet.

9. A Stirling engine heat exchanger for a molten salt reactor according to any one of claims 1 to 8, characterized in that: It also includes a connecting flange, which is arranged at one end of the working medium cylinder away from the heat exchanger shell.

10. A Stirling engine, characterized in that: A Stirling engine heat exchanger for a molten salt reactor comprising any one of claims 1-9.

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