Multi-rod-bundle high-temperature and high-pressure gas heat exchange experimental device and heat exchange characteristic experimental method

Abstract

The invention discloses a multi-rod-bundle high-temperature and high-pressure gas heat exchange experimental device and a heat exchange characteristic experimental method, and solves the problems of stable installation and central positioning of heating rods and sealing performance of a pressure container in the prior art. The device comprises a shell with a hollow cylindrical structure, a top sealing flange, a bottom sealing flange, a gas inlet, a gas outlet, a base body, a heating rod, a heating rod bracket, a heating rod mounting tray and a hanging bracket assembly, a high-pressure cavity is formed in the shell, the base body is located in the high-pressure cavity, a plurality of through holes are formed in the radial section of the base body, the heating rods are located in the through holes and are in clearance fit with the inner wall faces of the through holes, and the heating rod installation tray comprises a tray body and an installation platform located on the peripheral side of the tray body. The hanging bracket assembly comprises a plurality of hanging brackets and two positioning nuts arranged on each hanging bracket in a sleeving mode, the installation platform is clamped between the two positioning nuts, and the heating rods are installed in the through holes in a centering mode by adjusting the axial positions of the positioning nuts on the hanging brackets.

Description

Technical Field

[0001] The present invention relates to a gas-cooled micro-reactor simulation experimental device, in particular to a multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device and a heat exchange characteristic experimental method. Background Art

[0002] Gas-cooled microreactors have enormous potential for space applications. In recent years, researchers have focused on this type of reactor and conducted related research. The flow and heat transfer characteristics of high-temperature, high-pressure gas in the core of a gas-cooled microreactor, the cooling medium, have a significant impact on the reactor's safety performance.

[0003] Existing technologies for simulating the core of a nuclear reactor pressure vessel include two configurations: one with a substrate and one without a substrate. In a pressure vessel with a substrate, the electric heating device is generally a rod bundle structure, i.e., a bundle structure comprising multiple heating rods. The heating rods need to be installed in the substrate to study the gas flow and heat transfer characteristics of the rod bundle structure.

[0004] To accurately simulate the flow and heat transfer characteristics within the annular channel of the reactor core's matrix structure, multiple heating rods must be installed and fixed within the matrix structure. Furthermore, the heating rods must be stably mounted, centrally positioned, and the pressure vessel must be highly sealed. However, no experimental device currently meets these requirements. Chinese patent CN115616029, "A closed gas circulation flow and heat transfer experimental device and method," discloses an experimental assembly comprising an inlet cavity and an outlet cavity enclosed within the inlet cavity; the outlet cavity is provided with multiple outlet channels; the outlet channels communicate with the interior of the inlet cavity at their lower ends and with the outlet ends of the outlet cavity at their upper ends; and heating rods are provided within the outlet channels for heating the experimental gas. However, the technical solution disclosed in this patent document does not provide specific information on the stable mounting and central positioning of the heating rods, nor on the sealing of the pressure vessel. Failure to effectively address these issues will compromise the safety of the experimenter and hinder the acquisition of accurate and valid experimental data. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems of stable installation, center positioning and sealing of pressure vessels for heating rods that have not been solved in the prior art, and to provide a multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device and a heat exchange characteristics experimental method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device, which is special in that it includes a hollow cylindrical shell, a top sealing flange, a bottom sealing flange, a base, multiple heating rods, a heating rod mounting tray, and a hanger assembly;

[0008] The top of the housing is connected to the top sealing flange, and its bottom is connected to the bottom sealing flange to form a high-pressure chamber;

[0009] The top sealing flange is provided with a gas inlet and a gas outlet;

[0010] The substrate is located in the high-pressure chamber, and is axially provided with a plurality of circular through holes. The plurality of circular through holes are uniformly arranged in the radial direction of the substrate. One of the through holes is located at the central position, and one end of the substrate is connected to the top sealing flange; N blind holes are provided on the outer wall surface of the substrate, and the N blind holes are uniformly arranged along the same axial position, where N is a natural number greater than or equal to 3;

[0011] A plurality of the heating rods are respectively located in the through holes, and are in clearance fit with the inner wall surface of the through holes to form a gas flow channel. The lower ends of the heating rods extend out of the substrate, and a heating rod support is provided on the outer side wall, and the heating rod support protrudes from the outer wall surface of the heating rod;

[0012] The heating rod mounting tray includes a tray body and a mounting platform located on the periphery of the tray body. The tray body is provided with heating rod support holes, and the heating rod support holes are arranged in one-to-one correspondence with the through holes, and their hole diameters are adapted to the diameters of the heating rods, so that the heating rods can pass through the heating rod support holes, and the heating rod supports are lapped on the tray body, and mounting holes are provided on the mounting platform;

[0013] The hanger assembly includes a plurality of hangers and two positioning nuts sleeved on each hanger. The upper end of each hanger is connected to the top sealing flange; the heating rod mounting tray is mounted and positioned on the hanger through the mounting holes and the two positioning nuts, and the mounting platform is clamped between the two positioning nuts;

[0014] By adjusting the axial position of the positioning nuts on the hangers, the levelness of the heating rod mounting tray is adjusted so that the heating rods are centered and installed with the through holes on the substrate;

[0015] The bottom sealing flange is provided with a plurality of electrode structures for supplying power to the heating rods.

[0016] Further, the multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device further includes sealing bolts and high-pressure sealing plugs;

[0017] The top of the substrate has a mounting convex ring, and the mounting convex ring is threadedly connected to the top sealing flange through a plurality of the sealing bolts, and the top of each sealing bolt is sealed by one of the high-pressure sealing plugs.

[0018] Furthermore, the multi-rod high-temperature and high-pressure gas heat exchange experimental device further includes a sealing ring. The bottom wall of the sealing ring is located in the annular groove provided at the upper end of the base body, and the top wall of the sealing ring abuts against the inner wall surface of the top sealing flange.

[0019] Furthermore, a top flange gasket is arranged at the connection between the top of the housing and the top sealing flange, and a bottom flange gasket is arranged at the connection between the bottom of the housing and the bottom sealing flange. Both the top flange gasket and the bottom flange gasket are graphite gaskets, and the sealing ring is a copper sealing ring.

[0020] Furthermore, the base body is a hexagonal stainless steel base body.

[0021] Furthermore, the axial section of the heating rod bracket is a T-shaped structure, and the two protruding ends of its horizontal section are used for lapping on the heating rod installation tray to limit and install the heating rod on the heating rod installation tray.

[0022] Furthermore, there are multiple protrusions on the circumferential side of the top end of the heating rod, and the multiple protrusions are in the same radial plane. The top surface of each protrusion abuts against the inner wall surface of the through hole of the base body.

[0023] Furthermore, each of the multiple electrode structures is arranged in one-to-one correspondence with each of the multiple heating rods, or corresponds to at least two of the multiple heating rods. Each electrode structure includes an electrode installation tube, an electrode, an installation tube insulating sleeve, a bolt, an electrode installation base, an electrode lower flange, a bolt insulating sleeve, and an electrode sealing insulating pad;

[0024] The electrode installation tube penetrates through the bottom sealing flange, and its inner end face is flush with the inner end face of the bottom sealing flange and is fixedly connected to the bottom sealing flange;

[0025] The electrode is located inside the electrode installation tube. The electrode includes an electrode internal wiring terminal, an intermediate electrode section, and an electrode external wiring terminal. The electrode internal wiring terminal is located inside the housing and is used to connect the cable of the heating rod. The electrode external wiring terminal is located outside the housing and is used to connect an external power distribution cable;

[0026] The installation insulating sleeve is located between the electrode installation tube and the intermediate electrode section;

[0027] One end of the electrode installation base is connected to the electrode installation tube, and the other end is connected to the electrode lower flange through a bolt. The bolt insulating sleeve is sleeved on the outer circumference of the bolt;

[0028] An electrode sealing insulating pad is provided at the connection between the electrode installation base and the electrode lower flange.

[0029] Furthermore, the middle electrode segment and the electrode lower flange are welded by silver brazing.

[0030] The present invention also provides a method for testing the heat exchange characteristics of a multi-rod bundle high-temperature and high-pressure gas, which is special in that it includes the following steps:

[0031] S1: M thermocouples are evenly arranged in the heating rod in the through hole at the center of the substrate, and the axial position of each thermocouple corresponds to the position of the blind hole set on the substrate, and is used to collect the inner wall temperature of the central heating rod. X thermocouples are evenly spaced in the heating rods at other positions except the center position, and are used to collect the inner wall temperatures of multiple heating rods at other positions, where M and X are natural numbers greater than or equal to 3;

[0032] S2: K-type thermocouples are placed at the gas inlet and gas outlet to collect the gas inlet temperature and gas outlet temperature respectively;

[0033] S3: Thermocouples are installed in the blind holes on the outer wall of the substrate to collect the outer wall temperature of the substrate;

[0034] S4: Power the heating rod through the electrode structure;

[0035] S5: Obtaining the inner wall temperature of the central heating rod, the inner wall temperatures of multiple other heating rods, the outer wall temperature of the substrate, the gas inlet temperature, and the gas outlet temperature; analyzing and obtaining the inner wall temperature states of the heating rods at different positions in the substrate based on the inner wall temperature of the central heating rod and the inner wall temperatures of multiple other heating rods, and simultaneously calculating the outer wall temperature of each heating rod;

[0036] S6: Determine the experimental heat transfer coefficient through the gas inlet temperature, gas outlet temperature, the inner wall temperature of the central heating rod, the inner wall temperature of multiple other heating rods, and the outer wall temperature of the heating rod, and complete the multi-rod bundle high-temperature and high-pressure gas heat transfer characteristics experiment.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention designs a heating rod mounting tray structure, supports the heating rod on the heating rod mounting tray, and fixes the heating rod mounting tray through the clamping action of two positioning nuts on the hanger assembly, and adopts the axial adjustment function of the two positioning nuts to adjust the axial centerline position of the heating rod until the axial centerline of the heating rod is collinear with the axial centerline of the through hole, thereby ensuring the precise positioning of the multiple heating rod bundles in the hexagonal stainless steel matrix, and enabling the formation of a stable gas flow gap between the heating rod and the stainless steel matrix, thereby efficiently completing the experimental study on the heat exchange characteristics of high-temperature and high-pressure gas in the multi-rod bundle experimental section.

[0039] 2. By arranging a number of protrusions on the circumferential side of the top end of the heating rod, after installation, the top surface of the protrusions abuts against the inner wall surface of the through hole of the base body. Through multiple protrusions, the gas flow gap is accurately positioned to ensure that the width of each annular gas channel is the same, improving the accuracy of experimental data.

[0040] 3. Through the design of the sealing gasket, sealing bolts and high-pressure sealing plugs, the sealing performance of the overall device is greatly improved, ensuring the sealing of high-temperature and high-pressure gas flow, and thus enabling the experiment to be carried out safely.

[0041] 4. The centering installation structure of the multi-rod bundle heating rod of the present invention can be suitable for single or multiple heating rod forms, and the structural design is flexible.

[0042] 5. The electrode connection method of the present invention can achieve independent control of the power of the heating rod, simulate different powers of the heating rods at different positions, and thus carry out experiments on non-uniform radial power of the heating rod.

[0043] 6. The experimental method for the heat transfer characteristics of high-temperature and high-pressure gas of the multi-rod bundle provided by the present invention has reasonable distribution of thermocouples, accurate measurement of the temperature distribution state, and accurate calculation of the experimental heat transfer coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a schematic half-sectional structure view of an embodiment of a multi-rod bundle high-temperature and high-pressure gas heat transfer experiment device of the present invention;

[0045] Figure 2 is a schematic sectional structure view of an embodiment of a multi-rod bundle high-temperature and high-pressure gas heat transfer experiment device of the present invention;

[0046] Figure 3 is Figure 2 a partial enlarged view of;

[0047] Figure 4 is a schematic structure view of the heating rod installation tray of an embodiment of a multi-rod bundle high-temperature and high-pressure gas heat transfer experiment device of the present invention;

[0048] Figure 5 is a schematic structure view of the heating rod of an embodiment of a multi-rod bundle high-temperature and high-pressure gas heat transfer experiment device of the present invention;

[0049] Figure 6 is a schematic top-end structure view of the heating rod of an embodiment of a multi-rod bundle high-temperature and high-pressure gas heat transfer experiment device of the present invention.

[0050] Reference Numerals in the Drawings:

[0051] 1 - Gas outlet; 2 - Gas inlet; 3 - Top sealing flange; 4 - Sealing bolt; 5 - Sealing ring; 6 - Hanger; 7 - Substrate; 8 - Gas flow channel; 9 - Heating rod; 10 - Heating rod mounting tray; 11 - Heating rod support; 12 - Protrusion; 13 - Lock nut; 14 - High-pressure sealing plug; 15 - Housing; 16 - Bottom sealing flange; 17a - Top flange gasket; 17b - Bottom flange gasket; 18 - Internal wiring terminal of electrode; 19 - Electrode mounting tube; 20 - Insulating sleeve for mounting tube; 21 - Bolt; 22 - Insulating sleeve for bolt; 23 - Electrode mounting base; 24 - Electrode sealing insulating gasket; 25 - Lower flange of electrode; 26 - External wiring terminal of electrode. Detailed implementation mode

[0052] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0053] As Figures 1-6 shown, in order to stably and centrally locate and fix multiple heating rods on the substrate structure and improve the sealing performance of the pressure vessel, the present invention designs a multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device, including a gas outlet 1, a gas inlet 2, a top sealing flange 3, a sealing bolt 4, a sealing ring 5, a hanger 6, a hexagonal stainless steel substrate (i.e., substrate 7), a gas flow channel 8, a heating rod 9, a heating rod mounting tray 10, a heating rod support 11, a lock nut 13, a housing 15, and a bottom sealing flange 16;

[0054] The hexagonal stainless steel substrate is fastened to the top sealing flange 3 through the sealing bolt 4. A groove is designed at the top of the sealing bolt mounting hole. After the sealing bolt 4 is installed, the high-pressure sealing plug 14 is placed in the groove to independently seal the bolt mounting hole and prevent leakage. The sealing bolt 4 is generally a high-strength sealing bolt. A top flange gasket 17a made of graphite is provided at the connection between the hexagonal stainless steel substrate and the top sealing flange 3. The hexagonal stainless steel substrate is fixedly connected to the bottom sealing flange 16, and a bottom flange gasket 17b made of graphite is provided between the two.

[0055] The sealing ring 5 is a copper sealing ring located between the hexagonal stainless steel matrix and the top sealing flange 3. It adopts a hexagonal design and is adapted to the groove at the top of the hexagonal stainless steel matrix, so as to achieve effective high-pressure sealing and not fail at high temperatures. The sealing ring 5 has a certain height in the axial direction of the hexagonal stainless steel matrix, so as to form a gas collection cavity between the hexagonal stainless steel matrix and the inner wall surface of the top sealing flange 3, enabling the heated gas in the multiple gas flow channels 8 to collect here, and after collection, it is discharged from the gas outlet 1, improving the fluidity of the high-pressure gas.

[0056] The hanger 6 is a high-strength suspension rod used to fix the heating rod installation tray 10. The position of the heating rod installation tray 10 can be finely adjusted and tightly fixed through the threads on the hanger 6 and the matching nuts (i.e., the positioning nut 13).

[0057] The heating rod installation tray 10 is used for the cooperative installation of the heating rod 9 and the hexagonal stainless steel matrix, ensuring the installation depth of the heating rod 9 and the 1-mm gas annular flow channel (i.e., the gas flow channel 8) between the heating rod 9 and the hexagonal stainless steel matrix.

[0058] The heating rod support 11 is used to fix the heating rod 9 on the heating rod installation tray 10.

[0059] Thirty-seven holes with a diameter of 19 mm are opened on the hexagonal stainless steel matrix. Thirty-seven heating rods 9 are installed inside the hexagonal stainless steel matrix. The diameter of the heating rod is 17 mm, and a 1-mm gas annular flow channel is formed between the heating rod 9 and the hexagonal stainless steel matrix.

[0060] The heating rod support 11 adopts a T-shaped structure. The T-shaped support is laser-welded on the outer wall surface of the heating rod 9. The heating rod support 11 is used to fix the heating rod 9 on the heating rod installation tray 10.

[0061] Six support protrusions 12 with a diameter of 1 mm and a height of 1 mm are welded at the same radial cross-section height at the top of the heating rod 9 for the top positioning of the heating rod 9 to ensure a 1-mm gas annular flow channel. The addition of the protrusions 12 is in contact with the inner wall surface of the through hole of the hexagonal stainless steel matrix, ensuring the uniformity of the gas annular flow channel, enabling the cooling medium gas to be evenly distributed inside the hexagonal stainless steel matrix, and improving the heat exchange efficiency and heat exchange stability.

[0062] After the heating rod installation tray 10 is installed on the hanger 6, the levelness of the heating rod installation tray 10 is adjusted through two matching nuts on the hanger 6 to achieve the centering installation of the heating rod 9 and the hexagonal stainless steel matrix. This adjustment method is simple and convenient. After leveling, the heating rod installation tray 10 is fixed through the locked positioning nut 13 to ensure the stable installation of the heating rod 9 during the experiment.

[0063] The top of the sealing bolt 4 is designed as a high-pressure sealing chamber (i.e., a groove). Through the high-pressure sealing plug 14, the installation hole of the sealing bolt is independently sealed to prevent gas leakage.

[0064] The sealing ring 5 is a copper gasket between the hexagonal stainless steel matrix and the top sealing flange 3. It also adopts a hexagonal design. The copper sealing gasket ensures high-pressure sealing and does not fail at high temperatures.

[0065] The electrode is a copper conductive electrode. The electrode includes an internal wiring terminal 18 of the electrode, an intermediate electrode section, and an external wiring terminal 26 of the electrode. Both ends can be made in the form of external threads or internal threads according to the actual wiring situation. The internal wiring terminal 18 of the electrode is located inside the housing 15 and is used to connect the cable of the heating rod 9. The external wiring terminal 26 of the electrode is located outside the housing 15 and is used to connect the external power distribution cable. The intermediate electrode section and the lower electrode flange 25 are welded by silver brazing to weld the two together, playing a role in withstanding high temperature and high pressure.

[0066] The main function of the installation tube insulating sleeve 20 is to insulate the electrode from the stainless steel electrode installation tube 19 and play a role in fixing the electrode.

[0067] One end of the electrode installation base 23 is connected to the electrode installation tube 19, and the other end is connected to the lower electrode flange 25 through the bolt 21. A bolt insulating sleeve 22 is sleeved on the outer periphery of the bolt 21. An electrode sealing insulating pad 24 is provided at the connection between the electrode installation base 23 and the lower electrode flange 25.

[0068] Through this electrode connection method, the power of the heating rod can be controlled individually, simulating different powers of the heating rods at different positions, so as to carry out experiments on non-uniform radial power of the heating rods.

[0069] An experimental method for the heat transfer characteristics of a multi-rod bundle at high temperature and high pressure uses the above-mentioned multi-rod bundle high-temperature and high-pressure gas heat transfer experimental device; the special feature is that it includes the following steps:

[0070] S1: Seven thermocouples are evenly arranged in the heating rod 9 in the through hole at the center position of the matrix 7. The axial position of each thermocouple corresponds to the position of the blind hole provided on the matrix 7, and is used to collect the inner wall temperature of the central heating rod 9. Three thermocouples are evenly spaced in the heating rods 9 at other positions except the central position, and are used to collect the inner wall temperatures of multiple other heating rods 9. Among them, the diameter of the blind hole is 0.5 mm;

[0071] S2: K-type thermocouples are respectively arranged at the gas inlet 2 and the gas outlet 1, and are used to collect the temperature of the gas inlet 2 and the temperature of the gas outlet 1;

[0072] S3: Thermocouples are respectively installed in the blind holes on the outer wall surface of the matrix 7, and are used to collect the outer wall temperature of the matrix 7;

[0073] S4: Supply power to the heating rod 9 through the electrode structure;

[0074] S5: Obtain the inner wall surface temperature of the central heating rod, the inner wall surface temperatures of multiple other heating rods, the outer wall surface temperature of the substrate, the gas inlet temperature, and the gas outlet temperature; through the inner wall surface temperature of the central heating rod and the inner wall surface temperatures of multiple other heating rods, analyze and obtain the inner wall surface temperature distribution state of the heating rods 9 at different positions within the substrate 7, and simultaneously calculate the outer wall surface temperature of each heating rod 9;

[0075] S6: Determine the heat transfer coefficient of the experiment through the gas inlet temperature, the gas outlet temperature, the inner wall surface temperature of the central heating rod, the inner wall surface temperatures of multiple other heating rods, and the outer wall surface temperature of the heating rod 9, and complete the experiment on the heat transfer characteristics of a multi-rod bundle for high-temperature and high-pressure gas.

[0076] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claimed rights.

Claims

1. A multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device, characterized in that: It includes a housing (15) with a hollow cylindrical structure, a top sealing flange (3), a bottom sealing flange (16), a base body (7), a plurality of heating rods (9), a heating rod mounting tray (10), and a hanger assembly; The top of the housing (15) is connected to the top sealing flange (3), and its bottom is connected to the bottom sealing flange (16) to form a high-pressure chamber; The top sealing flange (3) is provided with a gas inlet (2) and a gas outlet (1); The base body (7) is located in the high-pressure chamber and is axially provided with a plurality of circular through holes. The plurality of circular through holes are uniformly arranged in the radial direction of the base body (7). One of the through holes is located at the central position, and one end of the base body (7) is connected to the top sealing flange (3); N blind holes are formed on the outer wall surface of the base body (7), and the N blind holes are uniformly arranged along the same axial position. N is a natural number greater than or equal to 3; The plurality of heating rods (9) are respectively located in the through holes and are in clearance fit with the inner wall surface of the through holes to form a gas flow channel (8). The lower end of the heating rod (9) extends out of the base body (7), and a heating rod bracket (11) is arranged on the outer side wall. The heating rod bracket (11) protrudes from the outer wall surface of the heating rod (9); The heating rod mounting tray (10) includes a tray body and a mounting platform located on the periphery of the tray body. The tray body is provided with heating rod support holes, and the heating rod support holes are arranged in one-to-one correspondence with the through holes, and their apertures are adapted to the diameter of the heating rod (9) so that the heating rod (9) can pass through the heating rod support holes, and the heating rod bracket (11) can be lapped on the tray body. The mounting platform is provided with mounting holes; The hanger assembly includes a plurality of hangers (6) and two positioning nuts (13) sleeved on each hanger (6). The upper end of each hanger (6) is connected to the top sealing flange (3); the heating rod mounting tray (10) is mounted and positioned on the hanger (6) through the mounting holes and the two positioning nuts (13), and the mounting platform is clamped between the two positioning nuts (13); By adjusting the position of the positioning nut (13) on the hanger (6), the levelness of the heating rod mounting tray (10) is adjusted so that the heating rod (9) is centered and installed with the through hole on the base body (7); The bottom sealing flange (16) is provided with a plurality of electrode structures for supplying power to the heating rod (9).

2. The multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device according to claim 1, characterized in that: It also includes a sealing bolt (4) and a high-pressure sealing plug (14); The top of the base body (7) has a mounting convex ring, and the mounting convex ring is threadedly connected to the top sealing flange (3) through a plurality of the sealing bolts (4), and the top of each sealing bolt (4) is sealed by one of the high-pressure sealing plugs (14).

3. The multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device according to claim 2, wherein: It also includes a sealing ring (5). The bottom wall of the sealing ring (5) is located in an annular groove provided at the upper end of the base body (7), and the top wall of the sealing ring (5) abuts against the inner wall surface of the top sealing flange (3).

4. The multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device according to claim 3, wherein: A top flange gasket (17a) is arranged at the connection between the top of the housing (15) and the top sealing flange (3), and a bottom flange gasket (17b) is arranged at the connection between the bottom of the housing and the bottom sealing flange (16). Both the top flange gasket (17a) and the bottom flange gasket (16) are graphite gaskets, and the sealing ring (5) is a copper sealing ring.

5. The multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device according to claim 1, wherein: The base body (7) is a hexagonal stainless-steel base body.

6. The multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device according to claim 1, characterized in that: The axial section of the heating rod bracket (11) is a T-shaped structure, and the two protruding ends of its horizontal section are used for lapping on the heating rod mounting tray (10) to limit and mount the heating rod (9) on the heating rod mounting tray (10).

7. The multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device according to claim 1, characterized in that: A plurality of protrusions (12) are provided on the circumferential side of the top end of the heating rod (9), and the plurality of protrusions (12) are in the same radial plane. The top surface of each protrusion (12) abuts against the inner wall surface of the through hole of the base body (7).

8. The multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device according to claim 1, characterized in that: Each of the plurality of electrode structures is arranged in one-to-one correspondence with each of the plurality of heating rods (9), or corresponds to at least two of the plurality of heating rods (9). Each electrode structure includes an electrode mounting tube (19), an electrode, a mounting tube insulating sleeve (20), a bolt (21), an electrode mounting base (23), an electrode lower flange (25), a bolt insulating sleeve (22), and an electrode sealing insulating pad (24); The electrode mounting tube (19) penetrates through the bottom sealing flange (16), its inner end surface is flush with the inner end surface of the bottom sealing flange (16), and is fixedly connected to the bottom sealing flange (16); The electrode is located inside the electrode mounting tube (19). The electrode includes an electrode internal wiring terminal (18), an intermediate electrode section, and an electrode external wiring terminal (26). The electrode internal wiring terminal (18) is located inside the housing (15) and is used to connect the cable of the heating rod (9). The electrode external wiring terminal (26) is located outside the housing (15) and is used to connect an external power distribution cable; The mounting insulating sleeve (20) is located between the electrode mounting tube (19) and the intermediate electrode section; One end of the electrode mounting base (23) is connected to the electrode mounting tube (19), and the other end is connected to the electrode lower flange (25) through a bolt (21). The outer circumference of the bolt (21) is sleeved with the bolt insulating sleeve (22); An electrode sealing insulating pad (24) is provided at the connection between the electrode mounting base (23) and the electrode lower flange (25).

9. The multi-rod bundle high-temperature and high-pressure gas heat exchange experimental device according to claim 8, characterized in that: The intermediate electrode section and the electrode lower flange (25) are welded by silver brazing.

10. An experimental method for heat transfer characteristics of a multi-rod bundle in high-temperature and high-pressure gas, which uses the multi-rod bundle high-temperature and high-pressure gas heat transfer experimental device described in any one of claims 1-9; characterized in that, Including the following steps: S1: Evenly arrange M thermocouples in the heating rod (9) in the through hole at the center position of the base body (7). The axial position of each thermocouple corresponds one-to-one to the position of the blind hole provided on the base body (7) for collecting the inner wall surface temperature of the central heating rod (9). X thermocouples are evenly arranged at equal intervals in the heating rods (9) at other positions except the central position for collecting the inner wall surface temperatures of the plurality of other-position heating rods (9), where M and X are natural numbers greater than or equal to 3; S2: Arrange K-type thermocouples at the gas inlet (2) and the gas outlet (1) respectively to collect the temperature of the gas inlet (2) and the temperature of the gas outlet (1). S3: Install thermocouples in the blind holes on the outer wall surface of the substrate (7) to collect the temperature of the outer wall surface of the substrate (7). S4: Supply power to the heating rod (9) through the electrode structure. S5: Obtain the inner wall surface temperature of the central heating rod, the inner wall surface temperatures of multiple other heating rods, the outer wall surface temperature of the substrate, the gas inlet temperature and the gas outlet temperature; through the inner wall surface temperature of the central heating rod and the inner wall surface temperatures of multiple other heating rods, analyze and obtain the inner wall surface temperature distribution state of the heating rods (9) at different positions in the substrate (7), and at the same time calculate the outer wall surface temperature of each heating rod (9). S6: Determine the heat transfer coefficient of the experiment through the gas inlet temperature, the gas outlet temperature, the inner wall surface temperature of the central heating rod, the inner wall surface temperatures of multiple other heating rods, and the outer wall surface temperature of the heating rod (9), and complete the experiment on the heat transfer characteristics of multi-rod bundle high-temperature and high-pressure gas.

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