A modular multi-purpose gas flow and heat exchange experimental section

Abstract

The present invention discloses a modular multi-purpose gas flow heat exchange experimental section, which includes a cooling ring cavity assembly, an experimental section heat exchange inner tube, inlet and outlet gas guide tubes and insulation layers, wall temperature measuring thermocouples, thermocouple fixing curved surfaces, outer ring cavity fixing collars, fixing bolts and flexible sealing materials. The experimental section heat exchange inner tube is a long tube made of high-temperature resistant alloy, with working gas and cooling medium inside and outside the tube respectively. Nano-insulation layers and gas flow ducts are built into both ends of the inner tube to reduce unnecessary gas heat exchange; the wall temperature measuring thermocouple is fixed to the tube wall by silver brazing to achieve accurate measurement of the wall temperature; in addition, the cooling ring cavity assembly is composed of two upper and lower pieces, which are connected by flanges and filled with flexible materials for sealing. During use, the experimental section can carry out flow heat exchange research on heating or cooling conditions according to needs. At the same time, its various components are installed in a modular manner to achieve flexible replacement and modification, which greatly improves reliability and scalability.

Description

Technical Field

[0001] The present invention relates to the technical field of experimental research on the flow and heat exchange characteristics of working gas used as a coolant in different channels in advanced reactor types such as high-temperature gas-cooled reactors, and in particular to a modular multi-purpose gas flow and heat exchange experimental section. Background Art

[0002] In the current nuclear energy sector, high-temperature gas-cooled reactors (HTGRs), an advanced reactor design, are attracting widespread attention for their high efficiency, safety, and versatility. These reactors use helium, a helium-xenon mixture, and other gases as their working fluid. During operation, heat generated in the reactor core is transferred to steam generators for various purposes, including power generation, hydrogen production, and heating. Therefore, in-depth research and optimization of gas flow and heat transfer processes are crucial for improving reactor reliability and economic efficiency.

[0003] Currently, many studies have been conducted at home and abroad on the heating and flow of various working gases, and corresponding models have been developed, but there are fewer studies on the cooling flow and heat transfer of gases. However, for gas-cooled reactors operating in a closed loop, how to efficiently and quickly cool the working gas to a point where it can be repeatedly re-entered into the core for re-heat exchange is a key link in improving the operating efficiency of the reactor and ensuring the safety and reliability of the reactor under accident conditions. In addition, the experimental sections currently used for flow and heat transfer research on working gases are mostly single-purpose, that is, they can only be used for heating experiments or cooling experiments, and it is not possible to conduct multiple studies based on the same experimental section; in addition, the gas flow and heat transfer experimental sections currently designed by researchers at home and abroad are mostly made once, and it is not possible to change the measurement points or repair bad points later, so they are relatively limited in actual use. Summary of the Invention

[0004] In order to carry out comparative experimental research on the heating and cooling flow heat transfer characteristics of the working fluid gas in the same channel based on the same experimental section, and at the same time meet the requirements of the main components of the experimental section being removable and replaceable, and the wall temperature measuring points being adjustable according to actual needs, the purpose of the present invention is to provide a modular multi-purpose gas flow heat exchange experimental section to meet the flow heat transfer experimental research of the working fluid gas in the constant power heating process and the constant wall temperature cooling process in the circular tube. The key parts of the experimental section such as the cooling chamber and the wall temperature measuring thermocouples can be removable and replaced to carry out different research conditions. At the same time, the experimental section can meet the requirements of insulation, sealing, etc., thereby ensuring the safety and reliability of the experimental section and realizing reusable experimental research on the flow heat transfer characteristics of the working fluid gas.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A modular multi-purpose gas flow heat exchange experimental section, which is used to conduct experimental research on the flow heat exchange behavior of the working gas in a high-temperature gas-cooled reactor, includes: an experimental section heat exchange inner tube A, an inlet gas guide tube J1, an inlet gas insulation layer G1, a cooling ring cavity inlet fixing ring H1, an inlet insulating sealing gasket M1, a cooling ring cavity upper side component S1, a cooling ring cavity lower side component S2, an inlet coolant medium flange B1, an outlet coolant medium flange B2, a thermocouple wire fixing upper left curved surface F1, a thermocouple wire fixing upper right curved surface F2, a thermocouple wire fixing lower left curved surface F3, a thermocouple wire fixing lower right curved surface F4, a temperature measuring thermocouple TA on the top of the heat exchange inner tube, a temperature measuring thermocouple TB on the side of the heat exchange inner tube, Thermocouple TC for measuring temperature at the bottom of the heat exchange inner tube, cooling ring cavity outlet fixing ring H2, outlet insulating sealing gasket M2, outlet gas guide tube J2, outlet gas insulation layer G2, cooling ring cavity axial seal left groove K1, cooling ring cavity axial seal right groove K2, cooling ring cavity left fixing bolt C, cooling ring cavity right fixing bolt D, experimental section inlet heating positive electrode E1 and experimental section outlet heating negative electrode E2; in the core heat exchange area of ​​the heat exchange inner tube A of the experimental section, the temperature measuring thermocouple TA at the top of the heat exchange inner tube, the temperature measuring thermocouple TB at the side of the heat exchange inner tube, and the temperature measuring thermocouple TC at the bottom of the heat exchange inner tube are fixed to the corresponding positions on the outer surface by silver brazing, and the thermocouple wires are fixed to the upper left curved surface F1 and the thermocouple wires are fixed The two ends of the upper right curved surface F2 are connected to the upper component S1 of the cooling ring cavity by welding, the thermocouple wire is fixed to the lower left curved surface F3, and the two ends of the thermocouple wire is fixed to the lower right curved surface F4 and connected to the lower component S2 of the cooling ring cavity by welding. The connecting wires of the temperature measuring thermocouple TA at the top of the heat exchange inner tube and the temperature measuring thermocouple TC at the bottom of the heat exchange inner tube pass through the coolant gap between each curved surface and the cooling ring cavity component, enter the gap between the curved surface and the component, and then deflect 90 degrees, and then lead out through the flange connection end face between the upper component S1 of the cooling ring cavity and the lower component S2 of the cooling ring cavity. At the same time, the connecting wire of the temperature measuring thermocouple TB along the side of the heat exchange inner tube is also led out through the left flange connection end face; thereafter, on the left side of the axial seal of the cooling ring cavity The groove K1 and the groove K2 on the right side of the cooling ring cavity axial seal are filled with flexible sealing material, and the cooling ring cavity upper component S1 and the cooling ring cavity lower component S2 are fastened by the cooling ring cavity left fixing bolt C and the cooling ring cavity right fixing bolt D to achieve sealing. The cooling ring cavity inlet fixing ring H1 and the cooling cavity outlet fixing ring H2 are installed at the end of the gradually expanding section at both ends of the inner tube by welding. The cooling ring cavity upper component S1 and the cooling ring cavity lower component S2 are fixed at the inlet and outlet positions of the heat exchange inner tube A in the experimental section by the cooling ring cavity inlet fixing ring H1 and the cooling ring cavity outlet fixing ring H2, and the high-temperature resistant inlet insulating sealing gasket M1 and outlet insulating sealing gasket M2 are filled in the metal fixing ring to achieve sealing;In addition, the inlet section UV and outlet section YZ of the experimental section heat exchange inner tube A are respectively installed with the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2. When using this experimental section to conduct gas heating flow heat exchange experiments, the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 are connected to a DC power supply to directly heat the experimental section heat exchange inner tube A.

[0007] When conducting cooling flow heat transfer experimental research in the experimental section, the working medium gas enters the experimental section heat exchange inner tube A made of high-temperature resistant alloy steel from one side of the inlet gas guide tube J1, reduces the difference caused by the gas inlet effect in the inlet area UW and flows into the core heat exchange section WX, generates forced convection heat transfer with the external constant temperature cooling medium through the metal wall surface in this section, and then flows out of the experimental section through the outlet gas guide tube J2; the cooling medium enters the cooling ring cavity upper component S1 and the cooling ring cavity lower component S2 and the experimental section heat exchange inner tube A through the inlet coolant medium flange B1. In the cooling medium annular cavity with the same structure, the heat exchange with the working fluid gas is completed through the metal wall and then flows out through the outlet coolant medium flange B2. The two types of fluids flow in counter-current directions to achieve better heat exchange effect. In addition, when conducting research on the heating flow heat exchange of the working fluid gas, the heating positive electrode E1 at the inlet of the experimental section and the heating negative electrode E2 at the outlet of the experimental section are connected to a DC power supply. At the same time, the upper component S1 and the lower component S2 of the cooling annular cavity are removed according to the actual working conditions, so that the heat exchange inner tube A of the experimental section is directly heated in the air, or the cooling medium is replaced with an insulating medium to carry out flow heat exchange experimental research.

[0008] The inner heat exchange tube A of the test section is made of high-temperature resistant alloy steel, which mainly includes an inlet section UV, a reduction section VW, a core heat exchange section WX, a gradual expansion section XY, and an outlet section YZ; at the same time, in order to reduce the heat dissipation of the working gas outside the core heat exchange section WX and the influence of the gas inlet effect on the heat exchange, an inlet gas guide pipe J1 and an inlet gas insulation layer G1 are added to the inlet area UW, and an outlet gas guide pipe J2 and an outlet gas insulation layer G2 are added to the outlet area XZ; in addition, a cooling ring cavity inlet fixing ring H1 and a cooling ring cavity outlet fixing ring H2 with a groove structure are added to the head of the gradual reduction section VW and the tail of the gradual expansion section XY by welding to achieve the axial position fixation of the cooling ring cavity, and at the same time, a high-temperature resistant insulating coating is sprayed on the inlet section UV and the outlet section YZ except for the experimental section inlet heating positive pole E1 and the experimental section outlet heating negative pole E2 to prevent direct contact and electric shock.

[0009] The upper component S1 of the cooling ring cavity and the lower component S2 of the cooling ring cavity are made of high-temperature resistant alloy steel. The end caps on both sides of the inner side of the component are fixed by welding to the upper left curved surface F1, the upper right curved surface F2, the lower left curved surface F3 and the lower right curved surface F4 of the thermocouple wire, which occupy 20% of the entire circle length. The cooling ring cavity is divided into the main flow channel of the heat exchange inner tube A of the cooling experimental section and the side flow channel accommodating the thermocouple connecting wire, ensuring that the flow channel area of ​​the experimental section meets the needs of the research object while minimizing the change in the coolant flow state caused by the thermocouple connecting wire. In addition, the lower component S2 of the cooling ring cavity is close to the outlet. The mouth section YZ is provided with an inlet coolant medium flange B1, and the upper component S1 of the cooling ring cavity is provided with an outlet coolant medium flange B2 near the position of the inlet section UV. The two are at a 90-degree angle to the cooling ring cavity. At the same time, in order to achieve quick installation and disassembly, the end of the pipeline is connected to the external coolant medium drive system in a flange manner; in addition, the left side fixing bolt C of the cooling ring cavity and the right side fixing bolt D of the cooling ring cavity and the left side axial sealing groove K1 and the right side axial sealing groove K2 of the cooling ring cavity are axially processed on the left and right sides of the cooling ring cavity upper component S1 and the cooling ring cavity lower component S2, thereby merging the upper and lower parts into a whole.

[0010] The two ends of the experimental section heat exchange inner tube A are connected to the pre-heating device and the exhaust gas heat exchange device by welding, thereby realizing sealing on the working medium gas side; in addition, when the upper and lower side components of the cooling ring cavity are installed, a sealing strip made of polytetrafluoroethylene is added to the left groove K1 of the cooling ring cavity axial seal and the right groove K2 of the cooling ring cavity axial seal. Thereafter, the strip is squeezed and deformed by tightening the left fixing bolt C of the cooling ring cavity and the right fixing bolt D of the cooling ring cavity, thereby completing the sealing of the cooling medium; in addition, the radial contact part between the cooling ring cavity and the experimental section heat exchange inner tube A is sealed by pre-welded cooling ring cavity inlet fixing ring H1 and cooling ring cavity outlet fixing ring H2 with a groove structure. During the installation process, the inlet insulating sealing gasket M1 and the outlet insulating sealing gasket M2 made of fluororubber are respectively installed in the grooves of the cooling ring cavity inlet fixing ring H1 and the cooling ring cavity outlet fixing ring H2, thereby realizing sealing in all directions of the experimental section cooling ring cavity.

[0011] In the flow heat transfer experiment, it is very important to measure the wall temperature of the core heat exchange section WX of the heat exchange inner tube A of the experimental section. The top of the thermocouple with temperature measurement function is placed in the 1.5mm pipe wall pit processed by CNC machine tools on the core heat exchange section WX. The pit is filled with a silver-based alloy with low welding temperature, so that the top of the thermocouple is completely buried in the metal pipe wall and the thermocouple will not fail due to excessive welding temperature. At the same time, due to the drastic temperature change of high-temperature gas at the inlet section, the core heat exchange section WX is measured every 20% of the length. A temperature measuring point is arranged in 5% of the total length, and a temperature measuring point is arranged every 10% of the total length in the remaining 80% area, with a total of 13 temperature measuring thermocouples arranged; in addition, in order to explore the influence of gravity on the flow and heat transfer of working gas in the horizontal tube, a temperature measuring point is arranged at the vertical top, vertical bottom and horizontal left end in the same cross-section of the core heat exchange section WX to realize the measurement of tube wall temperature in different directions; thus completing the installation of three rows of temperature measuring thermocouples: TA, TB and TC at the top of the heat exchange inner tube, the side of the heat exchange inner tube and the bottom of the heat exchange inner tube.

[0012] When conducting a heating experiment based on the experimental section, the experimental section heat exchange inner tube A is directly heated by installing the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 made of pure copper on the inlet section UV and outlet section YZ respectively, and connecting the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 to a DC power supply. During this process, the upper component S1 of the cooling ring cavity and the lower component S2 of the cooling ring cavity need to be removed, and the main equipment of the experimental section is insulated at the same time: the surface of the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 is sprayed with a high-temperature resistant insulating coating to ensure insulation while reducing the thermal insulation capacity, so as to ensure that the temperature of the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 can be controlled; for the inlet section UV and outlet section YZ areas of the experimental section heat exchange inner tube A that are not wrapped by the cooling chamber and not covered by the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2, zirconium oxide ceramic coating is sprayed and wrapped with polytetrafluoroethylene material to achieve pipe wall thermal insulation and insulation treatment.

[0013] When the flow heat exchange between the high-temperature working fluid gas and the constant temperature wall is carried out based on this experimental section, the cooling ring cavity upper component S1 and the cooling ring cavity lower component S2 are installed on the experimental section to form a cooling medium circulation chamber, so as to realize the construction of a constant temperature wall environment for convective heat exchange with the high-temperature gas by controlling the flow rate; when the flow heat exchange of the working fluid gas in the high-temperature pipeline is studied based on this experimental section, the cooling ring cavity upper component S1 and the cooling ring cavity lower component S2 are removed and a DC power supply is connected to realize the heating of the heat exchange inner tube A of the experimental section; in addition, during the experiment, the diameter and shape of the core heat exchange section WX of the experimental section are changed at any time according to different research objects through cutting and welding. At the same time, during the experiment, the position of the temperature measuring thermocouple TA on the top of the heat exchange inner tube, the temperature measuring thermocouple TB on the side of the heat exchange inner tube and the temperature measuring thermocouple TC on the bottom of the heat exchange inner tube are adjusted and the damaged thermocouples are replaced according to data feedback, so that it has the ability to be reused.

[0014] Compared with existing experimental devices at home and abroad, the present invention has the following advantages:

[0015] 1. The modular multi-purpose gas flow heat exchange experimental section of the present invention has a cooling chamber with an upper and lower two-petal structure. The cooling medium housing of the experimental section is detachably mounted using polytetrafluoroethylene strips and circumferential bolts tightened to seal it, thus facilitating the change of experimental research mode (heating or cooling experiment). Curved baffles welded to the left and right end caps isolate the main flow area of ​​the cooling medium from the thermocouple connection lines, providing a space with minimal interference for the flow of cooling medium in the core heat exchange section of the tube within the experimental section.

[0016] 2. The modular multi-purpose gas flow heat exchange experimental section of the present invention has thermocouples in the experimental section welded to the outer wall of the core heat exchange area through pre-machined surface pits by silver brazing. This ensures that the thermocouples are tightly fixed to the wall surface, while the temperature measuring heads of the thermocouples are buried inside the wall surface, isolating them from direct contact with the cooling medium, thereby improving temperature measurement accuracy. Furthermore, the combination of a detachable cooling chamber allows for flexible adjustment of the wall surface temperature measurement points according to research needs during the experiment and rapid replacement of damaged thermocouples, ensuring the integrity and reliability of experimental data.

[0017] 3. The modular multi-purpose gas flow heat exchange experimental section of the present invention adopts modular design in the overall design. Removable DC power supply heating electrodes are installed at the inlet and outlet sections of the inner tube of the experimental section, and a cooling chamber connected to the cooling circuit through a flange is installed on the periphery of the core heat exchange area. During experimental research, the accessories of the experimental section can be installed and removed according to different research purposes to complete the predetermined gas heating or cooling experiment, thereby realizing experimental research for multiple research purposes based on the same experimental section.

[0018] In summary, the modular multi-purpose gas flow heat exchange experimental section of the present invention has a modular design, and the cooling ring cavity, heating electrode, experimental section heat exchange inner tube, wall temperature measuring thermocouple and other components can be replaced separately, which can realize experimental research on various purposes such as gas cooling heat exchange and gas heating heat exchange. The distribution of wall temperature measuring points and damaged thermocouples can be flexibly adjusted and replaced, so that the experimental section can be reused as a whole while ensuring that the obtained data set is sufficient and reliable, thereby improving its economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a top cross-sectional view of the experimental section of the present invention.

[0020] Figure 2 for Figure 1 Front section view along AA direction.

[0021] Figure 3 for Figure 1 Side cross-sectional view along BB direction. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0023] like Figure 1 、 Figure 2 and Figure 3As shown, this embodiment provides a modular multi-purpose gas flow heat exchange experimental section, which is used to conduct experimental research on the flow heat exchange behavior of the working gas in the high-temperature gas-cooled reactor, including: an experimental section heat exchange inner tube A, an inlet gas guide tube J1, an inlet gas insulation layer G1, a cooling ring cavity inlet fixing ring H1, an inlet insulating sealing gasket M1, a cooling ring cavity upper side component S1, a cooling ring cavity lower side component S2, an inlet coolant medium flange B1, an outlet coolant medium flange B2, a thermocouple wire fixing upper left curved surface F1, a thermocouple wire fixing upper right curved surface F2, a thermocouple wire fixing lower left curved surface F3, a thermocouple wire fixing lower right curved surface F4, and a temperature measuring thermocouple TA on the top of the heat exchange inner tube, along the axial direction. There are 13 in total, namely TA1-TA13, the temperature measuring thermocouple TB on the side of the inner heat exchange tube, 13 in total along the axial direction, namely TB1-TB13, the temperature measuring thermocouple TC at the bottom of the inner heat exchange tube, 13 in total along the axial direction, namely TC1-TC13, the cooling ring cavity outlet fixing ring H2, the outlet insulating sealing gasket M2, the outlet gas guide pipe J2, the inlet gas insulation layer G2, the cooling ring cavity axial seal left groove K1, the cooling ring cavity axial seal right groove K2, the cooling ring cavity left side fixing bolt C, a total of 11, namely C1-C11, the cooling ring cavity right side fixing bolt D, a total of 11, namely D1-D11, the experimental section inlet heating positive electrode E1, the experimental section outlet heating negative electrode E2.In the core heat exchange area of ​​the heat exchange inner tube A in the experimental section, the temperature measuring thermocouple TA on the top of the heat exchange inner tube, the temperature measuring thermocouple TB on the side of the heat exchange inner tube, and the temperature measuring thermocouple TC on the bottom of the heat exchange inner tube are fixed to the corresponding positions on the outer surface by silver brazing. The thermocouple wires are fixed on the upper left curved surface F1 and the upper right curved surface F2 at both ends and are connected to the upper component S1 of the cooling ring cavity by welding. The thermocouple wires are fixed on the lower left curved surface F3 and the lower right curved surface F4 at both ends and are connected to the lower component S2 of the cooling ring cavity by welding. The connecting lines of the temperature measuring thermocouples TA1-TA13 on the top and TC1-TC13 on the bottom of the heat exchange inner tube pass through the coolant gap between each curved surface and the cooling ring cavity assembly, enter the gap between the curved surface and the assembly, deflect 90 degrees, and then lead out through the flange connection end face between the cooling ring cavity upper assembly S1 and the cooling ring cavity lower assembly S2. At the same time, the connecting lines of the temperature measuring thermocouples TB1-TB13 on the side of the heat exchange inner tube are also led out through the left flange connection end face; thereafter, the left groove K1 of the cooling ring cavity axial seal is connected to the cooling ring cavity axial seal. The groove K2 on the right side of the annular cavity axial seal is filled with flexible sealing material, and the cooling annular cavity upper component S1 and the cooling annular cavity lower component S2 are fastened to achieve sealing through the cooling annular cavity left side fixing bolts C1-C11 and the cooling annular cavity right side fixing bolts D1-D11. The cooling annular cavity inlet fixing ring H1 and the cooling cavity outlet fixing ring H2 are installed at the end of the gradually expanding section at both ends of the inner tube by welding. The cooling annular cavity upper component S1 and the cooling annular cavity lower component S2 are connected at the inlet and outlet of the heat exchange inner tube of the experimental section through the cooling annular cavity inlet fixing ring H1. It is fixed with the cooling ring cavity outlet fixing ring H2, and the high-temperature resistant inlet insulating sealing gasket M1 and outlet insulating sealing gasket M2 are filled in the metal fixing ring to achieve sealing; in addition, the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 are respectively installed at the inlet section UV and outlet section YZ of the experimental section heat exchange inner tube A. When using the experimental section to carry out the gas heating flow heat exchange experiment, the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 are connected to the DC power supply to realize direct heating of the experimental section heat exchange inner tube A.

[0024] When conducting cooling flow and heat exchange experimental research in the experimental section, the working fluid gas enters the experimental section heat exchange inner tube A made of high-temperature resistant alloy steel from one side of the inlet gas guide tube J1, reduces the difference caused by the gas inlet effect in the inlet area UW and flows into the core heat exchange section WX, generates forced convection heat exchange with the external constant temperature cooling medium through the metal wall surface in this section, and then flows out of the experimental section through the outlet gas guide tube J2; the cooling medium enters the cooling medium annular cavity composed of two cooling annular cavity upper components S1 and the cooling annular cavity lower component S2 and the experimental section heat exchange inner tube A through the inlet coolant medium flange B1, completes heat exchange with the working fluid gas through the metal wall surface, and flows out through the outlet coolant medium flange B2. The two types of fluids flow in opposite directions, which can achieve better heat exchange effect. In addition, when conducting research on the flow and heat transfer of working fluid gas heating, the heating positive electrode E1 at the inlet of the experimental section and the heating negative electrode E2 at the outlet of the experimental section are connected to a DC power supply. At the same time, the upper component S1 of the cooling ring cavity and the lower component S2 of the cooling ring cavity are removed according to the actual working conditions, so that the heat exchange inner tube A of the experimental section is directly heated in the air, or the cooling medium is replaced with an insulating medium to carry out flow and heat transfer experimental research.

[0025] The experimental section heat exchange inner tube A is made of high-temperature resistant alloy steel, which mainly includes an inlet section UV, a reduction section VW, a core heat exchange section WX, a gradual expansion section XY, and an outlet section YZ; at the same time, in order to reduce the heat dissipation of the working gas outside the core heat exchange section WX and the influence of the gas inlet effect on the heat exchange, an inlet gas guide pipe J1 and an inlet gas insulation layer G1 are added to the inlet area UW, and an outlet gas guide pipe J2 and an outlet gas insulation layer G2 are added to the outlet area XZ; in addition, a cooling ring cavity inlet fixing ring H1 and a cooling ring cavity outlet fixing ring H2 with a groove structure are added to the head of the gradual reduction section VW and the tail of the gradual expansion section XY by welding to achieve the axial position fixation of the cooling ring cavity, and at the same time, a high-temperature resistant insulating coating is sprayed on the inlet section UV and the outlet section YZ except for the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 to prevent direct contact and electric shock.

[0026] Preferably, the upper component S1 of the cooling ring cavity and the lower component S2 of the cooling ring cavity are made of high-temperature resistant alloy steel, and the thermocouple wire fixing surfaces F1-F4 occupying 20% ​​of the full circle length are fixed by welding at the end cap positions on both sides of the inner side of the component, so that the cooling ring cavity is divided into a main flow channel for the heat exchange inner tube A of the cooling experimental section and a side flow channel for accommodating the thermocouple connecting wires, ensuring that the flow channel area of ​​the experimental section meets the needs of the research object while minimizing the change in the coolant flow state caused by the entanglement of the thermocouple connecting wires; in addition, the lower component S2 of the cooling ring cavity is provided with an inlet coolant medium flange B1 near the outlet section YZ, The cooling ring cavity upper component S1 is provided with an outlet cooling medium flange B2 near the inlet section UV, and the two are at a 90-degree angle to the cooling ring cavity. At the same time, in order to achieve quick installation and disassembly, the end of the pipeline is connected to the external coolant medium drive system in a flange manner; in addition, the left and right sides of the cooling ring cavity upper component S1 and the cooling ring cavity lower component S2 are axially processed with 11 cooling ring cavity left side fixing bolts C and cooling ring cavity right side fixing bolts D and cooling ring cavity axial sealing left side groove K1 and cooling ring cavity axial sealing right side groove K2, thereby merging the upper and lower parts into a whole.

[0027] The experimental section heat exchange inner tube A is made of high-temperature resistant alloy steel, and its two ends are connected to the pre-heating device and the exhaust gas heat exchange device by welding, so as to achieve sealing on the working medium gas side; in addition, when the upper and lower side components of the cooling ring cavity are installed, a sealing strip made of polytetrafluoroethylene is added to the left groove K1 of the cooling ring cavity axial seal and the right groove K2 of the cooling ring cavity axial seal. Thereafter, by tightening the left fixing bolts C1-C11 of the cooling ring cavity and the right fixing bolts D1-D11 of the cooling ring cavity, the strip is squeezed and deformed to complete the sealing of the cooling medium; in addition, the radial contact part between the cooling ring cavity and the experimental section heat exchange inner tube A is sealed by a pre-welded fixing ring with a groove structure. During the installation process, the inlet insulating sealing gasket M1 and the outlet insulating sealing gasket M2 made of fluororubber are respectively installed in the grooves of the cooling ring cavity inlet fixing ring H1 and the cooling ring cavity outlet fixing ring H2, so as to achieve sealing in all directions of the cooling ring cavity of the experimental section.

[0028] In the flow heat transfer experiment, it is very important to measure the wall temperature of the core heat exchange section WX of the heat exchange inner tube A of the experimental section. The top of the thermocouple with temperature measurement function is placed in the 1.5mm pipe wall pit processed by CNC machine tools on the core heat exchange section WX. The pit is filled with a silver-based alloy with a relatively low welding temperature, so that the top of the thermocouple is completely buried in the metal pipe wall and the thermocouple will not fail due to excessive welding temperature. At the same time, due to the drastic temperature change of high-temperature gas at the inlet section, a thermocouple is arranged every 5% of the total length in the first 20% length of the core heat exchange section WX. The arrangement method of temperature measuring point is as follows: a temperature measuring point is arranged at the top, and a temperature measuring point is arranged every 10% of the total length in the remaining 80% area, with a total of 13 temperature measuring thermocouples; in addition, in order to explore the influence of gravity on the flow and heat transfer of working gas in the horizontal tube, a temperature measuring point is arranged at the vertical top, vertical bottom and horizontal left end in the same cross-section of the core heat exchange section WX to realize the measurement of tube wall temperature in different directions; thus completing the installation of three rows of temperature measuring thermocouples: TA1-TA13 at the top of the heat exchange inner tube, TB1-TB13 at the side of the heat exchange inner tube, and TC1-TC13 at the bottom of the heat exchange inner tube.

[0029] When conducting a heating experiment based on the experimental section, the inlet section UV and outlet section YZ of the experimental section heat exchange inner tube A are respectively installed with the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 made of pure copper, and the electrodes are connected to a DC power supply to achieve direct heating of the experimental section heat exchange inner tube A. During this process, the upper component S1 of the cooling ring cavity and the lower component S2 of the cooling ring cavity need to be removed, and the main equipment of the experimental section is insulated at the same time: the surfaces of the experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2 are sprayed with high-temperature resistant insulating coatings such as epoxy resin to ensure insulation while appropriately weakening the thermal insulation capacity to ensure that the electrode temperature is controllable; for the inlet section UV and outlet section YZ areas of the experimental section heat exchange inner tube A that are not wrapped by the cooling chamber and not covered by the electrodes, zirconium oxide ceramic coatings are sprayed and wrapped with polytetrafluoroethylene materials to achieve pipe wall thermal insulation and insulation treatment.

[0030] This experimental section is a modular, multi-purpose gas flow and heat exchange experimental section. When conducting flow and heat exchange between a high-temperature working gas and a constant-temperature wall surface based on this experimental section, the cooling annulus upper assembly S1 and the cooling annulus lower assembly S2 are installed in the experimental section to form a cooling medium circulation chamber. This allows for a constant-temperature wall environment for convective heat exchange with the high-temperature gas by controlling the flow rate. When studying the flow and heat exchange of working gas within a high-temperature pipeline based on this experimental section, the cooling annulus upper assembly S1 and the cooling annulus lower assembly S2 can be removed and a DC power supply connected to heat the experimental section's heat exchange inner tube A. In addition, during the experiment, the diameter and shape of the core heat exchange section WX can be changed at any time by cutting and welding according to different research objects. Simultaneously, during the experiment, the position of the temperature-measuring thermocouples TA1-TA13 on the top of the heat exchange inner tube, the temperature-measuring thermocouples TB1-TB13 on the side of the heat exchange inner tube, and the temperature-measuring thermocouples TC1-TC13 on the bottom of the heat exchange inner tube can be adjusted and damaged thermocouples replaced based on data feedback, thus providing a high degree of reusability.

[0031] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be considered that the specific embodiments of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions or substitutions without departing from the concept of the present invention, which should be regarded as belonging to the scope of patent protection determined by the submitted claims of the present invention.

Claims

1. A modular multi-purpose gas flow heat exchange experimental section, characterized by: The experimental section is used to conduct experimental research on the flow and heat transfer behavior of the working gas in the high-temperature gas-cooled reactor, including: the experimental section heat exchange inner tube (A), the inlet gas guide tube (J1), the inlet gas insulation layer (G1), the cooling ring cavity inlet fixing ring (H1), the inlet insulation sealing gasket (M1), the cooling ring cavity upper side component (S1), the cooling ring cavity lower side component (S2), the inlet coolant medium flange (B1), the outlet coolant medium flange (B2), the thermocouple wire fixing upper left curved surface (F1), the thermocouple wire fixing upper right curved surface (F2), the thermocouple wire fixing Fixed left lower curved surface (F3), thermocouple wire fixed right lower curved surface (F4), thermocouple for measuring temperature on the top of heat exchange inner tube (TA), thermocouple for measuring temperature on the side of heat exchange inner tube (TB), thermocouple for measuring temperature on the bottom of heat exchange inner tube (TC), cooling ring cavity outlet fixing ring (H2), outlet insulating sealing gasket (M2), outlet gas guide pipe (J2), outlet gas insulation layer (G2), cooling ring cavity axial seal left groove (K1), cooling ring cavity axial seal right groove (K2), cooling ring cavity left fixing bolt (C), cooling ring cavity right fixing bolt (D ), the positive electrode (E1) at the inlet of the experimental section and the negative electrode (E2) at the outlet of the experimental section; the core heat exchange area of ​​the heat exchange inner tube (A) of the experimental section is fixed with the temperature measuring thermocouple (TA) on the top of the heat exchange inner tube, the temperature measuring thermocouple (TB) on the side of the heat exchange inner tube, and the temperature measuring thermocouple (TC) on the bottom of the heat exchange inner tube at the corresponding positions on the outer surface by silver brazing, and the thermocouple wire is fixed on the upper left curved surface (F1) and the thermocouple wire is fixed on the upper right curved surface (F2). The two ends are connected to the upper side component (S1) of the cooling ring cavity by welding, and the thermocouple wire is fixed on the lower left curved surface (F3) and the thermocouple The two ends of the lower right curved surface (F4) are fixed by wire and connected to the lower side component (S2) of the cooling ring cavity by welding. The connecting wires of the temperature measuring thermocouple (TA) at the top of the heat exchange inner tube and the temperature measuring thermocouple (TC) at the bottom of the heat exchange inner tube pass through the coolant gap between each curved surface and the cooling ring cavity component, enter the gap between the curved surface and the component, deflect 90 degrees, and then lead out through the flange connection end face between the upper side component (S1) and the lower side component (S2) of the cooling ring cavity. At the same time, the connecting wire of the temperature measuring thermocouple (TB) along the side of the heat exchange inner tube is also led out through the left flange connection end face.Afterwards, flexible sealing material is filled into the left groove (K1) of the cooling ring chamber axial seal and the right groove (K2) of the cooling ring chamber axial seal, and the cooling ring chamber upper component (S1) and the cooling ring chamber lower component (S2) are fastened by the cooling ring chamber left fixing bolt (C) and the cooling ring chamber right fixing bolt (D) to achieve sealing, and the cooling ring chamber inlet fixing ring (H1) and the cooling chamber outlet fixing ring (H2) are installed at the end of the gradually expanding section at both ends of the inner tube by welding, and the cooling ring chamber upper component (S1) and the cooling ring chamber lower component (S2) are connected at the inlet and outlet positions of the heat exchange inner tube (A) of the experimental section through the cooling ring chamber inlet. The fixing ring (H1) and the cooling ring cavity outlet fixing ring (H2) are fixed in position, and a high-temperature resistant inlet insulating sealing gasket (M1) and outlet insulating sealing gasket (M2) are filled in the metal fixing ring to achieve sealing. In addition, the inlet section (UV) and outlet section (YZ) of the experimental section heat exchange inner tube (A) are respectively installed with the experimental section inlet heating positive electrode (E1) and the experimental section outlet heating negative electrode (E2). When using this experimental section to conduct a gas heating flow heat exchange experiment, the experimental section inlet heating positive electrode (E1) and the experimental section outlet heating negative electrode (E2) are connected to a DC power supply to achieve direct heating of the experimental section heat exchange inner tube (A).

2. A modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: When conducting cooling flow heat transfer experimental research in the experimental section, the working medium gas enters the experimental section heat transfer inner tube (A) made of high-temperature resistant alloy steel from one side of the inlet gas guide tube (J1), reduces the difference caused by the gas inlet effect in the inlet area (UW) and flows into the core heat transfer section (WX), generates forced convection heat transfer with the external constant temperature cooling medium through the metal wall surface in this section, and then flows out of the experimental section through the outlet gas guide tube (J2); the cooling medium enters the cooling ring cavity upper side component (S1) and the cooling ring cavity lower side component (S2) and the experimental section heat transfer inner tube ( A) in the cooling medium annular cavity formed by the metal wall, the heat exchange is completed with the working gas through the metal wall and then flows out through the outlet coolant medium flange (B2). The two types of fluids flow in counter-current directions to achieve a better heat exchange effect. In addition, when conducting research on the heating flow heat exchange of the working gas, the heating positive electrode (E1) at the inlet of the experimental section and the heating negative electrode (E2) at the outlet of the experimental section are connected to a DC power supply. At the same time, the upper component (S1) and the lower component (S2) of the cooling annular cavity are removed according to the actual working conditions, so that the heat exchange inner tube (A) of the experimental section is directly heated in the air, or the cooling medium is replaced with an insulating medium to carry out flow heat exchange experimental research.

3. The modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: The heat exchange inner tube (A) of the experimental section is made of high-temperature resistant alloy steel, which mainly includes the inlet section (UV), the reduction section (VW), the core heat exchange section (WX), the gradual expansion section (XY), and the outlet section (YZ); at the same time, in order to reduce the heat dissipation of the working gas outside the core heat exchange section (WX) and the influence of the gas inlet effect on the heat exchange, the inlet area (UW) is added with an inlet gas guide pipe (J1) and an inlet gas insulation layer (G1), and the outlet area (XZ) is added with an outlet gas guide pipe ( J2) and the outlet gas insulation layer (G2); in addition, a cooling ring cavity inlet fixing ring (H1) and a cooling ring cavity outlet fixing ring (H2) with a groove structure are installed at the head of the tapered section (VW) and the tail of the gradually expanding section (XY) by welding to achieve the axial position fixation of the cooling ring cavity, and at the same time, a high-temperature resistant insulating coating is sprayed on the inlet section (UV) and the outlet section (YZ) except for the experimental section inlet heating positive electrode (E1) and the experimental section outlet heating negative electrode (E2) to prevent direct contact and electric shock.

4. The modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: The upper component (S1) of the cooling ring cavity and the lower component (S2) of the cooling ring cavity are made of high-temperature resistant alloy steel. The end caps on both sides of the inner side of the component are fixed by welding to the upper left curved surface (F1) of the thermocouple wire, the upper right curved surface (F2) of the thermocouple wire, the lower left curved surface (F3) of the thermocouple wire and the lower right curved surface (F4) of the thermocouple wire, which occupy 20% of the entire circle length. The cooling ring cavity is divided into a main flow channel for the heat exchange inner tube (A) of the cooling experimental section and a side flow channel for accommodating the thermocouple connecting wire, ensuring that the flow channel area of ​​the experimental section meets the needs of the research object while minimizing the change in the coolant flow state caused by the entanglement of the thermocouple connecting wire. In addition, the lower component (S2) of the cooling ring cavity is close to the outlet section ( YZ) is provided with an inlet coolant medium flange (B1), and the upper component of the cooling ring cavity (S1) is provided with an outlet coolant medium flange (B2) near the inlet section (UV). The two are at a 90-degree angle with the cooling ring cavity. At the same time, in order to achieve rapid installation and disassembly, the end of the pipeline is connected to the external coolant medium drive system in a flange manner; in addition, the left side fixing bolt (C) of the cooling ring cavity and the right side fixing bolt (D) of the cooling ring cavity and the left side axial sealing groove (K1) of the cooling ring cavity and the right side axial sealing groove (K2) of the cooling ring cavity are axially processed on the left and right sides of the cooling ring cavity upper component (S1) and the cooling ring cavity lower component (S2), thereby merging the upper and lower parts into a whole.

5. The modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: The two ends of the experimental section heat exchange inner tube (A) are connected to the preheating device and the exhaust gas heat exchange device by welding, thereby realizing sealing on the working medium gas side; in addition, when the upper and lower side components of the cooling ring cavity are installed, a sealing strip made of polytetrafluoroethylene is added to the left groove (K1) of the cooling ring cavity axial seal and the right groove (K2) of the cooling ring cavity axial seal, and then the strip is squeezed and deformed by tightening the left fixing bolt (C) of the cooling ring cavity and the right fixing bolt (D) of the cooling ring cavity to complete the sealing of the cooling medium; in addition, the radial contact part between the cooling ring cavity and the experimental section heat exchange inner tube (A) is sealed by a pre-welded cooling ring cavity inlet fixing ring (H1) and a cooling ring cavity outlet fixing ring (H2) with a groove structure. During the installation process, an inlet insulating sealing gasket (M1) and an outlet insulating sealing gasket (M2) made of fluororubber are respectively installed in the grooves of the cooling ring cavity inlet fixing ring (H1) and the cooling ring cavity outlet fixing ring (H2), thereby realizing sealing of the experimental section cooling ring cavity in all directions.

6. The modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: In the flow heat transfer experiment, it is very important to measure the wall temperature of the core heat exchange section (WX) of the heat exchange inner tube (A) of the experimental section. The top of the thermocouple with temperature measurement function is placed in a 1.5mm pipe wall pit processed by a CNC machine tool on the core heat exchange section (WX). The pit is filled with a silver-based alloy with a low welding temperature, so that the top of the thermocouple is completely buried in the metal pipe wall and the thermocouple will not fail due to excessive welding temperature. At the same time, due to the drastic temperature change of high-temperature gas at the inlet section, the core heat exchange section (WX) is measured every 20% of the length. A temperature measuring point is arranged at 5% of the total length, and a temperature measuring point is arranged every 10% of the total length in the remaining 80% area, with a total of 13 temperature measuring thermocouples arranged; in addition, in order to explore the influence of gravity on the flow and heat transfer of working gas in the horizontal tube, a temperature measuring point is arranged at the vertical top, vertical bottom and horizontal left end in the same cross-section of the core heat exchange section (WX) to realize the measurement of tube wall temperature in different directions; thus completing the installation of three rows of temperature measuring thermocouples: the temperature measuring thermocouple (TA) on the top of the heat exchange inner tube, the temperature measuring thermocouple (TB) on the side of the heat exchange inner tube and the temperature measuring thermocouple (TC) at the bottom of the heat exchange inner tube.

7. The modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: When conducting a heating experiment based on the experimental section, the inlet section (UV) and outlet section (YZ) of the experimental section heat exchange inner tube (A) are respectively installed with the experimental section inlet heating positive electrode (E1) and the experimental section outlet heating negative electrode (E2) made of pure copper, and the experimental section inlet heating positive electrode (E1) and the experimental section outlet heating negative electrode (E2) are connected to a DC power supply to realize direct heating of the experimental section heat exchange inner tube (A). During this process, the upper side component (S1) and the lower side component (S2) of the cooling ring cavity need to be removed, and the main equipment of the experimental section need to be insulated: for the inlet of the experimental section The surfaces of the inlet heating positive electrode (E1) and the outlet heating negative electrode (E2) of the experimental section are sprayed with a high-temperature resistant insulating coating to ensure insulation while reducing the heat insulation capacity, so as to ensure that the temperature of the inlet heating positive electrode (E1) and the outlet heating negative electrode (E2) of the experimental section are controllable; for the inlet section (UV) and outlet section (YZ) areas of the experimental section heat exchange inner tube (A) that are not wrapped by the cooling chamber and not covered by the inlet heating positive electrode (E1) and the outlet heating negative electrode (E2) of the experimental section, zirconium oxide ceramic coating is sprayed and wrapped with polytetrafluoroethylene material to achieve pipe wall heat insulation and insulation treatment.

8. The modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: When the flow heat exchange between the high-temperature working fluid gas and the constant temperature wall is carried out based on the experimental section, the cooling ring cavity upper component (S1) and the cooling ring cavity lower component (S2) are installed on the experimental section to form a cooling medium circulation chamber, so as to realize the construction of a constant temperature wall environment for convective heat exchange with the high-temperature gas by controlling the flow rate; when the flow heat exchange of the working fluid gas in the high-temperature pipeline is studied based on the experimental section, the cooling ring cavity upper component (S1) and the cooling ring cavity lower component (S2) are removed and a DC power supply is connected to realize heating of the heat exchange inner tube (A) of the experimental section; in addition, during the experiment, the diameter and shape of the core heat exchange section (WX) of the experimental section are changed at any time according to different research objects through cutting and welding, and at the same time, during the experiment, the position of the temperature measuring thermocouple (TA) on the top of the heat exchange inner tube, the temperature measuring thermocouple (TB) on the side of the heat exchange inner tube and the temperature measuring thermocouple (TC) on the bottom of the heat exchange inner tube are adjusted and damaged thermocouples are replaced according to data feedback, so that the experimental section has the ability to be reused.

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