Modularized multipurpose gas flow heat exchange experiment section

Abstract

The invention discloses a modularized multipurpose gas flow heat exchange experiment section. The experiment section comprises a cooling ring cavity assembly, an experiment section heat exchange inner pipe, an inlet and outlet gas guide pipe, a heat insulation layer, a wall surface temperature thermocouple, a thermocouple fixing curved surface, an outer ring cavity fixing lantern ring, a fixing bolt and a flexible sealing material. An experiment section heat exchange inner pipe is a high-temperature-resistant alloy long pipe, working medium gas and a cooling medium are arranged inside and outside the pipe respectively, and a nanometer heat insulation layer and a gas circulation guide pipe are arranged in the two ends of the inner pipe so as to reduce unnecessary gas heat exchange; the wall surface temperature measuring thermocouple is fixed on the pipe wall in a silver brazing manner to realize accurate measurement of the wall surface temperature; in addition, the cooling ring cavity assembly is composed of an upper piece and a lower piece which are connected in a flange mode and filled with flexible materials for sealing. The experimental section can be used for carrying out flow heat exchange research on heating or cooling working conditions according to requirements in the use process, and meanwhile, each component is modularly mounted to realize flexible replacement and change, so that the reliability and the expandability are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of experimental research on flow and heat exchange characteristics of working gas used as 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 field, high temperature gas-cooled reactors, as an advanced reactor design, have attracted widespread attention due to their high efficiency, high safety and versatility. This type of reactor uses helium, helium-xenon mixed gas, etc. as the working gas. During operation, the heat generated by the reactor core is exported to the steam generator to achieve multiple uses such as power generation, hydrogen production, and heat supply. Therefore, in-depth research and optimization of gas flow and heat exchange processes are crucial to improving the reliability and economy of reactors.

[0003] At present, 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 few studies on the cooling flow heat exchange of gases. However, for gas-cooled reactors operating in a closed loop, how to efficiently and quickly cool the working gas to the 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, most of the experimental sections currently used for flow heat exchange research on working gases are single-purpose, that is, only heating experiments or cooling experiments can be carried out, and multiple studies cannot be carried out based on the same experimental section; in addition, most of the gas flow heat exchange experimental sections designed by researchers at home and abroad are made once, and it is impossible to change the measuring 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 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, which meets the flow heat transfer experimental research of the working gas in the constant power heating process and the constant wall temperature cooling process in a 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 and sealing, thereby ensuring the safety and reliability of the experimental section and realizing reusable experimental research on the flow heat transfer characteristics of the working gas.

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

[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 working gas in a 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 fixed upper left curved surface F1, a thermocouple wire fixed upper right curved surface F2, a thermocouple wire fixed lower left curved surface F3, a thermocouple wire fixed lower right curved surface F4, a heat exchange inner tube top temperature measuring thermocouple TA, a heat exchange inner tube side temperature measuring thermocouple TB, 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 thermocouple TA for measuring temperature at the top of the heat exchange inner tube, the thermocouple TB for measuring temperature at the side of the heat exchange inner tube, and the thermocouple TC for measuring temperature 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 to the upper left curved surface F2. 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, and 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 component S1 of the cooling ring cavity and the lower component S2 of the cooling ring cavity, and 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 expansion 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 the 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 the experimental section is used 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. ;

[0007] When conducting cooling flow heat transfer 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 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 exchange inner tube A through the inlet coolant medium flange B1. In the cooling medium annular cavity with the same structure, after completing heat exchange with the working gas through the metal wall, it flows out through the outlet coolant medium flange B2. The two types of fluids flow in the opposite direction 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 of the cooling annular cavity 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 realize 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 test section inlet heating positive electrode E1 and the test section outlet heating negative electrode 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 covers on both sides of the inner side of the components 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 for fixing the thermocouple wires, 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 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 thermocouple connecting wires. 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 inlet section UV. The two are at a 90-degree angle with 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 groove K1 and the right side groove K2 of the cooling ring cavity axial seal 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, so as to merge 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 front 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 installing the upper and lower side components of the cooling ring cavity, 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 sealing 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 the pre-welded cooling ring cavity inlet fixing ring H1 and the 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, so as to achieve sealing in all directions of the cooling ring cavity of the experimental section.

[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 tube 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 tube wall and the thermocouple will not fail due to excessive welding temperature. At the same time, because the temperature of the high-temperature gas changes drastically in 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, the installation of three rows of temperature measuring thermocouples TA at the top of the heat exchange inner tube, TB at the side of the heat exchange inner tube and TC at the bottom of the heat exchange inner tube is completed.

[0012] When the heating experiment is carried out 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 the DC power supply to realize direct heating of the experimental section heat exchange inner tube A. In 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 weakening the heat 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 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 experimental section inlet heating positive electrode E1 and the experimental section outlet heating negative electrode E2, the pipe wall is insulated and insulated by spraying zirconia ceramic coating and wrapping with polytetrafluoroethylene material.

[0013] 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 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 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 in position 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. A 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, which is sealed by tightening and fixing the circumferential bolts with polytetrafluoroethylene strips to achieve detachable installation of the cooling medium shell of the experimental section, thereby providing convenience for changing the experimental research mode (heating or cooling experiment); at the same time, the curved baffles welded to the left and right side end covers are used to isolate the cooling medium mainstream area from the thermocouple connection line, providing a space with less interference for the cooling medium flow in the core heat exchange section of the inner tube of the experimental section;

[0016] 2. A modular multi-purpose gas flow heat exchange experimental section of the present invention, the experimental section thermocouple is welded to the outer wall of the core heat exchange area by silver brazing through pre-processed surface pits, so that the thermocouple is tightly fixed to the wall surface, and the temperature measuring head of the thermocouple is buried inside the wall surface to isolate it from direct contact with the cooling medium, thereby improving the temperature measurement accuracy; at the same time, combined with a detachable cooling chamber, the wall temperature measurement point can be flexibly adjusted according to research needs during the experiment, and damaged thermocouples can be quickly replaced, ensuring the integrity and reliability of the experimental data;

[0017] 3. A modular multi-purpose gas flow heat exchange experimental section of the present invention adopts modular design in the overall design. Removable DC power 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. In experimental research, 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 can independently replace components such as the cooling ring cavity, the heating electrode, the experimental section heat exchange inner tube, and the wall temperature measuring thermocouple based on a modular design, so as to realize experimental research on gas cooling heat exchange, gas heating heat exchange and other purposes. 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.

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

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

[0023] like Figure 1 , Figure 2 and Figure 3As shown, the present embodiment is a modular multi-purpose gas flow heat exchange experimental section, which is used to conduct flow heat exchange behavior experimental research on 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, a temperature measuring thermocouple TA on the top of the heat exchange inner tube, and along the axial direction There are 13 in total, namely TA1-TA13, temperature measuring thermocouple TB on the side of the inner tube of heat exchange, 13 in total along the axial direction, namely TB1-TB13, temperature measuring thermocouple TC at the bottom of the inner tube of heat exchange, 13 in total along the axial direction, namely TC1-TC13, cooling ring cavity outlet fixing ring H2, outlet insulating sealing gasket M2, outlet gas guide pipe J2, inlet gas insulation layer G2, cooling ring cavity axial seal left groove K1, cooling ring cavity axial seal right groove K2, cooling ring cavity left side fixing bolt C, 11 in total, namely C1-C11, cooling ring cavity right side fixing bolt D, 11 in total, namely D1-D11, experimental section inlet heating positive electrode E1, 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 to 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 to 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 wires of the temperature measuring thermocouples TA1-TA13 on the top and the temperature measuring thermocouples 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 upper side assembly S1 of the cooling ring cavity and the lower side assembly S2 of the cooling ring cavity. At the same time, the connecting wires 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 and the cooling ring cavity axial seal are connected. The groove K2 on the right side of the annular cavity axial seal is filled with flexible sealing material, and the upper component S1 of the cooling annular cavity and the lower component S2 of the cooling annular cavity are fastened by the fixing bolts C1-C11 on the left side of the cooling annular cavity and the fixing bolts D1-D11 on the right side of the cooling annular cavity to achieve sealing. The cooling annular cavity inlet fixing ring H1 and the cooling cavity outlet fixing ring H2 are installed at the end of the expansion section at both ends of the inner tube by welding. The upper component S1 of the cooling annular cavity and the lower component S2 of the cooling annular cavity are connected at the inlet and outlet of the heat exchange inner tube of the experimental section by the cooling annular cavity inlet fixing ring H1. It is limited and fixed with the cooling ring cavity outlet fixing ring H2, and the metal fixing ring is filled with high-temperature resistant inlet insulating sealing gasket M1 and outlet insulating sealing gasket M2 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 the experimental section is used 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 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 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 components 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, and flows out through the outlet coolant medium flange B2. The two types of fluids flow in reverse, which can achieve a better heat exchange effect. In addition, when conducting research on the flow heat transfer of working 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 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, the inlet gas guide pipe J1 and the inlet gas insulation layer G1 are added to the inlet area UW, and the outlet gas guide pipe J2 and the 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 realize 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 cooling ring cavity upper component S1 and the cooling ring cavity lower component S2 are made of high temperature resistant alloy steel, and the thermocouple wire fixing curved 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 of the heat exchange inner tube A of the cooling experimental section and a 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 cooling ring cavity lower component S2 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 form a 90-degree angle with 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 by flange. 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 front 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, and then the strip is squeezed and deformed 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 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, 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, 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 tube 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 tube 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 in the inlet section, a thermocouple is arranged every 5% of the total length in the first 20% length area of ​​the core heat exchange section WX. The 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 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, the installation of three rows of temperature measuring thermocouples TA1-TA13 on the top of the heat exchange inner tube, TB1-TB13 on the side of the heat exchange inner tube and TC1-TC13 on the bottom of the heat exchange inner tube is completed.

[0029] When the heating experiment is carried out 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 the DC power supply to realize direct heating of the experimental section heat exchange inner tube A. In 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 electrode, the pipe wall is insulated and insulated by spraying zirconia ceramic coating and wrapping with polytetrafluoroethylene material.

[0030] This experimental section is a modular multi-purpose gas flow heat exchange experimental section. 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 can be removed and a DC power supply can be 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 this experimental section can be changed at any time according to different research objects by cutting and welding. At the same time, during the experiment, 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 the damaged thermocouples can be replaced according to data feedback, so that it has high reusability.

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

Claims

1. A modular multi-purpose gas flow heat exchange experimental section, characterized in that: The experimental section is used to conduct experimental research on the flow 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 The thermocouple wire fixes the lower left curved surface (F3), the thermocouple wire fixes the lower right curved surface (F4), the thermocouple for measuring the temperature on the top of the heat exchange inner tube (TA), the thermocouple for measuring the temperature on the side of the heat exchange inner tube (TB), the thermocouple for measuring the temperature on the bottom of the heat exchange inner tube (TC), the cooling ring cavity outlet fixing ring (H2), the outlet insulating sealing gasket (M2), the outlet gas guide pipe (J2), the outlet 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 fixing bolt (C), the 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 to the corresponding positions of the outer surface by silver brazing 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. The thermocouple wire is fixed to the upper left curved surface (F1) and the thermocouple wire is fixed to the upper right curved surface (F2). The two ends are connected to the upper side component (S1) of the cooling ring cavity by welding. The thermocouple wire is fixed to the lower left curved surface (F3) and the thermocouple The two ends of the lower right curved surface (F4) fixed by the wire are 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) of the cooling ring cavity 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, the left groove (K1) of the cooling ring chamber axial seal and the right groove (K2) of the cooling ring chamber axial seal are filled with flexible sealing material, and the upper component (S1) of the cooling ring chamber and the lower component (S2) of the cooling ring chamber are fastened by the left fixing bolt (C) of the cooling ring chamber and the right fixing bolt (D) of the cooling ring chamber to achieve sealing. The cooling ring chamber inlet fixing ring (H1) and the cooling chamber outlet fixing ring (H2) are installed at the end of the expansion section at both ends of the inner tube by welding. The upper component (S1) of the cooling ring chamber and the lower component (S2) of the cooling ring chamber 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 limited and fixed, 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 the experimental section is used 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). ; 2. A modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: When conducting cooling flow heat exchange experimental research in the experimental section, the working 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 ring cavity upper side component (S1) and the cooling ring cavity lower side component (S2) and the experimental section heat exchange inner tube ( A) together with the cooling medium annular cavity, the cooling medium completes heat exchange 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 the opposite direction to achieve a better heat exchange effect. In addition, when conducting a study 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 side component (S1) and the lower side 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 a flow heat exchange experimental study.

3. A 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 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 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 expanded section (XY) by welding to fix the axial position 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. A modular multi-purpose gas flow heat exchange experimental section according to claim 1, characterized in that: The upper cooling ring cavity component (S1) and the lower cooling ring cavity component (S2) are made of high temperature resistant alloy steel. The thermocouple wire fixing upper left curved surface (F1), the thermocouple wire fixing upper right curved surface (F2), the thermocouple wire fixing lower left curved surface (F3) and the thermocouple wire fixing lower right curved surface (F4) which occupy 20% of the whole 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 of the heat exchange inner tube (A) of the cooling experimental section and a side flow channel accommodating the thermocouple connecting wire, so as to ensure that the flow channel area of ​​the experimental section meets the needs of the research object while minimizing the change of the coolant flow state caused by the thermocouple connecting wire. In addition, the lower cooling ring cavity component (S2) 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), and 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 driving system in a flange manner; in addition, the left side fixing bolts (C) of the cooling ring cavity and the right side fixing bolts (D) of the cooling ring cavity and the left side groove (K1) of the cooling ring cavity axial seal and the right side groove (K2) of the cooling ring cavity axial seal 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), so as to install the upper and lower parts together as a whole.

5. A 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 front 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, and then the sealing 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 the pre-welded cooling ring cavity inlet fixing ring (H1) and the 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), based on which the sealing of the experimental section cooling ring cavity in all directions is achieved.

6. A 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 experimental section heat exchange inner tube (A). The top of the thermocouple with temperature measurement function is placed in a 1.5mm tube 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 tube 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 in the inlet section, the core heat exchange section (WX) is measured every 20% of the length. A total of 13 temperature measuring thermocouples are arranged in an arrangement manner, with one temperature measuring point arranged at 5% of the total length and one temperature measuring point arranged every 10% of the total length in the remaining 80% area; 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, the installation of three rows of temperature measuring thermocouples (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 is completed.

7. A 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 an experimental section inlet heating positive electrode (E1) and an experimental section outlet heating negative electrode (E2) made of pure copper, and the inlet heating positive electrode (E1) and the outlet heating negative electrode (E2) of the experimental section are connected to a DC power supply to realize direct heating of the experimental section heat exchange inner tube (A). In 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 needs to be insulated: for the inlet of the experimental section, the heating positive electrode (E1) and the outlet of the experimental section are connected to a DC power supply to realize direct heating of the experimental section heat exchange inner tube (A). The surfaces of 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 sprayed with a high-temperature resistant insulating coating to ensure insulation while weakening the heat insulation capacity, so as to ensure that the temperatures of 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 controllable; for the inlet section (UV) and outlet section (YZ) areas of the heat exchange inner tube (A) of the experimental section which are not wrapped by the cooling chamber and not covered by 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, the zirconium oxide ceramic coating is sprayed and wrapped with polytetrafluoroethylene material to achieve heat insulation and insulation treatment of the tube wall.

8. A 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 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, and at the same time, during the experiment, 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 in position and the damaged thermocouples are replaced according to data feedback, so that it has the ability to be reused.

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