A vertical tube bundle structure liquid lead bismuth-molten salt convection heat transfer experimental section and experimental method

Abstract

The present invention discloses a liquid lead-bismuth-molten salt convective heat exchange experimental section and experimental method of a vertical tube bundle structure. The heat exchange experimental section includes a heat exchange tube bundle; a plurality of heat exchange tubes and pull rods are arranged in the heat exchange tube bundle, which are fixed between the lead-bismuth inlet tube sheet and the lead-bismuth outlet tube sheet; the inlet end and the outlet end of the heat exchange tube bundle are respectively connected to the lead-bismuth inlet tube box and the lead-bismuth outlet tube box; the lead-bismuth inlet tube box and the lead-bismuth outlet tube box are respectively connected to the lead-bismuth inlet and the lead-bismuth outlet; the outer side of the heat exchange tube bundle is provided with a molten salt outlet annular distributor side plate and a molten salt inlet annular distributor side plate at the lower part of the lead-bismuth inlet tube box and the upper part of the lead-bismuth outlet tube box; the experimental section cylinder is arranged in the middle part of the outer side of the heat exchange tube bundle, and its two ends are respectively connected to the molten salt inlet and outlet annular distributor side plates. The present invention can obtain a uniform and fully developed flow field of sufficient length, and can concentrate the heat exchange on the longitudinal flushing tube bundle area of ​​the molten salt. In addition, the present invention can also conduct a study on the experimental mechanism of liquid lead-bismuth-molten salt coupled heat exchange.

Description

Technical Field

[0001] The invention relates to a liquid lead-bismuth-molten salt convection heat exchange experimental section and an experimental method with a vertical tube bundle structure, belonging to the field of liquid metal nuclear reactors. Background Art

[0002] The heat generated by the liquid metal reactor during normal operation is conducted away by the liquid metal coolant through the main heat exchanger. A typical main heat exchanger of a liquid lead-bismuth reactor adopts a shell-and-tube heat exchanger structure, in which liquid lead-bismuth flows on the tube side and liquid molten salt flows on the shell side. When the liquid lead-bismuth reactor is operating normally, the liquid lead-bismuth coolant flows through the tube side of the main heat exchanger, transferring heat to the molten salt medium on the shell side, ensuring the safe and normal operation of the reactor.

[0003] The coupled heat transfer capacity of lead-bismuth on the tube side and molten salt on the shell side is very important for the design of the heat exchanger. The longitudinal flushing and cooling heat transfer of molten salt on the shell side is a typical heat transfer mechanism of the heat exchanger. Therefore, it is necessary to experiment the coupled convection heat transfer characteristics of lead-bismuth-molten salt in the vertical tube bundle structure.

[0004] The design of the liquid lead-bismuth-molten salt convective heat transfer experimental section with a vertical tube bundle structure first needs to avoid ineffective heat exchange between the liquid molten salt and the tube bundle before it longitudinally flushes the cooling tube bundle. Secondly, a reasonable flow-averaging structure is required to enable the liquid molten salt to obtain a longer and fully developed flow field in the longitudinal flushing tube bundle area. Then a reasonable measurement system layout plan is required to achieve the measurement requirements of the experimental section parameters. Finally, a set of reasonable experimental methods is required to obtain the coupled heat transfer capacity of the liquid lead-bismuth-molten salt in the experimental section. Summary of the invention

[0005] The purpose of the present invention is to provide a liquid lead-bismuth-molten salt convective heat exchange experimental section and experimental method with a vertical tube bundle structure, which can greatly reduce the ineffective heat exchange between the molten salt fluid and the heat exchange tubes before flowing in the longitudinal scouring tube bundle, and enable the liquid molten salt to obtain a longer fully developed flow field in the longitudinal scouring tube bundle area, while obtaining the required experimental parameters.

[0006] The vertical tube bundle structure liquid lead bismuth-molten salt convection heat exchange experimental section for a liquid metal reactor provided by the present invention comprises a heat exchange tube bundle;

[0007] The heat exchange tube bundle is provided with a plurality of heat exchange tubes and tie rods, which are fixed between the lead-bismuth inlet tube sheet and the lead-bismuth outlet tube sheet;

[0008] The inlet end and the outlet end of the heat exchange tube bundle are respectively connected to the lead-bismuth inlet tube box and the lead-bismuth outlet tube box; the lead-bismuth inlet tube box and the lead-bismuth outlet tube box are respectively connected to the lead-bismuth inlet and the lead-bismuth outlet, and the lead-bismuth inlet tube box can play a role in buffering and flow redistribution of the lead-bismuth fluid flow;

[0009] The ends of the heat exchange tube bundle close to the lead-bismuth inlet tube box and the lead-bismuth outlet tube box are respectively provided with a lead-bismuth inlet insulation sleeve and a lead-bismuth outlet insulation sleeve;

[0010] The outer side of the heat exchange tube bundle is provided with a molten salt outlet annular distributor side plate and a molten salt inlet annular distributor side plate at the lower part of the lead-bismuth inlet tube box and the upper part of the lead-bismuth outlet tube box respectively;

[0011] An experimental section cylinder is arranged in the middle part of the outer side of the heat exchange tube bundle, and two ends of the experimental section cylinder are respectively connected to the molten salt inlet annular distributor side plate and the molten salt outlet annular distributor side plate by welding.

[0012] In the above-mentioned liquid lead-bismuth-molten salt convection heat transfer experimental section, the lead-bismuth inlet insulation sleeve and the lead-bismuth outlet insulation sleeve are both double-layer sleeve sandwich structures, which are insulation sleeve outer lining, insulation interlayer and insulation sleeve inner lining from outside to inside;

[0013] The outer lining of the heat-insulating sleeve and the inner lining of the heat-insulating sleeve are connected by welding, and the heat-insulating interlayer is filled with heat-insulating fibers.

[0014] In the above-mentioned liquid lead-bismuth-molten salt convective heat exchange experimental section, the lead-bismuth inlet insulation sleeve and the lead-bismuth outlet insulation sleeve are both fixed by the insulation sleeve cover plate and are detachable. After installation, they can effectively isolate the heat exchange of the covered part of the heat exchange tube.

[0015] In the above-mentioned liquid lead-bismuth-molten salt convection heat exchange experimental section, a molten salt outlet annular distributor chamber is provided outside the molten salt outlet annular distributor side plate, and a molten salt outlet is provided on the side wall of the molten salt outlet annular distributor chamber. The molten salt fluid enters the molten salt outlet annular distributor chamber from the shell side of the heat exchange tube bundle through the molten salt outlet annular distributor side plate, and then flows out through the molten salt outlet;

[0016] A molten salt inlet annular distributor chamber is provided outside the molten salt inlet annular distributor side plate, a molten salt inlet is provided on the side wall of the molten salt inlet annular distributor chamber, and the molten salt fluid enters the molten salt inlet annular distributor chamber through the molten salt inlet, and then enters the shell side of the heat exchange tube bundle through the molten salt inlet annular distributor side plate;

[0017] The molten salt inlet annular distributor side plate and the molten salt outlet annular distributor side plate are provided with a plurality of long strip grids unevenly distributed along the circumferential direction, which are used to improve the circumferential uniformity of the shell side molten salt fluid flushing the heat exchange tube bundle;

[0018] In the above-mentioned liquid lead-bismuth-molten salt convection heat exchange experimental section, the heat exchange tube bundle is provided with a molten salt inlet support equalizing plate, an intermediate support grid plate and a molten salt outlet support equalizing plate;

[0019] The molten salt inlet supporting flow equalizing plate is arranged at the connection between the molten salt inlet annular distributor side plate and the experimental section cylinder;

[0020] The intermediate support grid plate is arranged in the middle of the heat exchange tube bundle;

[0021] The molten salt outlet supporting flow equalizing plate is arranged at the connection between the molten salt outlet annular distributor side plate and the experimental section cylinder;

[0022] The molten salt inlet support flow equalizing plate and the molten salt outlet support flow equalizing plate have a plurality of long strip flow channels for the heat exchange tube bundle to pass through, and flow channels for the molten salt fluid to flow are opened at the edge, which can be used to support the heat exchange tube bundle and improve the radial uniformity of the shell side molten salt fluid flushing the heat exchange tube bundle;

[0023] The intermediate support grid plate is composed of a plurality of mutually staggered long strip grids, and is used to support the heat exchange tube bundle and improve the radial uniformity of the flow of the shell-side molten salt fluid flushing the heat exchange tube bundle;

[0024] The molten salt inlet annular distributor chamber, the molten salt inlet annular distributor side plate, the molten salt inlet support equalizing plate and the intermediate support grid plate together constitute a molten salt side flow distribution structure, which can enable the liquid molten salt to obtain a longer uniform and fully developed flow field in the longitudinal scouring tube bundle area.

[0025] Based on the above-mentioned vertical tube bundle structure liquid lead bismuth-molten salt convection heat exchange experimental section, the present invention provides a measurement system layout scheme for experimental measurement of the experimental section, including measurement point layout principles, measurement point section layout scheme and measurement point layout scheme in the measurement section.

[0026] The measuring point arrangement principles are as follows:

[0027] Principle 1: The influence of the measuring points on the flow field should be as small as possible, and they should be distributed as much as possible in the area where the flow field is fully developed;

[0028] Principle 2: Based on the symmetrical distribution of flow field and temperature field, the measuring points are dispersedly arranged to meet the measurement requirements of multiple types of measuring points at the same location in a small space;

[0029] Principle 3: Avoid interference between the lead holes of the measuring points and the ear seats and lateral supports of the test sections;

[0030] Principle 4: The measuring points should be able to verify the symmetry of the flow field and the insulation capacity of the insulation sleeve.

[0031] The measuring point section arrangement scheme can set 14 measuring point sections, namely, section J1 to section J14. The measuring functions to be undertaken by each measuring point section are as follows:

[0032] Function 1: Sections J11 and J12 measure the inlet and outlet temperatures and the inlet and outlet pressure difference of the molten salt on the shell side of the experimental section respectively;

[0033] Function 2: Sections J13 and J14 measure the lead and bismuth inlet and outlet temperatures and inlet and outlet pressure differences on the test section tube side respectively;

[0034] Function 3: The temperature measuring points of sections J1 and J10 measure the thermal insulation capacity of the thermal insulation sleeve;

[0035] Function 4: The temperature measuring points of section J2 and section J9 measure the fluid temperature of lead-bismuth on the tube side and molten salt on the shell side respectively;

[0036] Function 5: The temperature measuring points of sections J3 to J8 respectively measure the local wall temperature and fluid temperature at different axial positions of the heat exchange tube, and simultaneously measure the temperature of the heat exchange tube at different positions of the same section;

[0037] Function 6: The pressure difference measuring points of sections J5 and J8 measure the pressure drop characteristics outside the tube bundle;

[0038] Function 7: The velocity measurement point of section J7 measures the velocity of the inner channel and edge channel of the heat exchange tube bundle, and measures the circumferential uniformity of the velocity distribution at the same time;

[0039] Function 8: The temperature measuring point of section J5 can also measure the symmetry of the lead-bismuth heat exchange on the tube side; the temperature measuring point of section J8 can also measure the symmetry of the molten salt heat exchange on the shell side.

[0040] The measuring point section can measure the following parameters: measuring point type, measuring point layout specific location, measuring point number, measuring point lead opening location:

[0041] The types of measuring points include the outer wall temperature WO of the heat exchange tube, the inner wall temperature WI of the heat exchange tube, the molten salt fluid temperature FO outside the tube, the lead-bismuth fluid temperature FI inside the tube, the local flow velocity of the tube bundle, and the pressure difference measuring point; the specific locations of the measuring points are marked in the measuring point arrangement plan diagram of each section by solid circles of different colors;

[0042] The measuring point number content includes the measuring point cross-sectional position "J+number", the position of the heat exchange tube "R+value", the circumferential angle based on the heat exchange tube and the measuring point type;

[0043] The following is an example of the use of measuring point arrangement for measuring point section J8:

[0044] Example 1: R63-0-WO measures the outer wall temperature of the heat exchange tube, R64-0-WI measures the inner wall temperature of the heat exchange tube, and R44-FI measures the temperature of the fluid in the tube. Based on the principle of symmetrical arrangement of the flow field, the heat flux density of the heat exchange tube is calculated by R63-0-WO and R64-0-WI, and the convective heat transfer temperature difference in the heat exchange tube is calculated by R64-0-WI and R44-FI, and finally the convective heat transfer coefficient in the heat exchange tube is obtained.

[0045] Example 2: R62-180-FO measures the molten salt temperature of the heat exchange tube R62 at 180°, and R65-180-FO measures the outer wall temperature of the heat exchange tube R65 at 180°. The two can verify the symmetry of the temperature field outside the tube bundle.

[0046] The liquid lead-bismuth-molten salt convective heat transfer experimental section and the measurement system of the vertical tube bundle structure of the present invention are used to carry out the liquid lead-bismuth-molten salt coupled heat transfer experiment, which can be carried out in the following three modes:

[0047] Mode 1: Keep the lead-bismuth inlet and outlet temperatures of the tube side and the molten salt in the shell side of the experimental section at the rated values, and complete the coupled heat exchange experiment of the experimental section under different heat exchange powers;

[0048] Mode 2: Keep the shell side molten salt fluid inlet temperature and inlet mass flow rate of the experimental section at rated values, and keep the lead-bismuth inlet temperature in the tube of the experimental section unchanged, and complete the coupled heat exchange experiment of the experimental section under different lead-bismuth flow rates in the tube;

[0049] Mode three: maintaining the lead-bismuth fluid inlet temperature and inlet mass flow rate in the experimental section tube at rated values, while maintaining the molten salt inlet temperature outside the experimental section tube at constant values, and completing the coupled heat exchange experiment of the experimental section under different shell-side molten salt flow rates.

[0050] The present invention has the following advantages due to the adoption of the above technical solution:

[0051] 1. The present invention isolates the ineffective heat exchange between the liquid molten salt and the tube bundle before longitudinally flushing the heat exchange tube bundle through the lead-bismuth inlet insulation sleeve and the lead-bismuth outlet insulation sleeve, and concentrates the heat exchange process on the longitudinal flushing tube bundle section of experimental concern;

[0052] 2. The present invention provides a reasonable flow-equalizing structure by arranging a molten salt inlet annular distributor chamber, a molten salt inlet annular distributor, a molten salt inlet support flow-equalizing plate and an intermediate support grid plate, so as to achieve a longer fully developed flow field in the area where the liquid molten salt longitudinally scours the tube bundle;

[0053] 3. The present invention sets up a reasonable measurement system layout scheme to achieve the measurement requirements of the experimental section parameters;

[0054] 4. The present invention realizes the experimental study of the coupled heat transfer mechanism of liquid lead bismuth-molten salt in the convective heat transfer experimental section of the vertical tube bundle structure through three experimental modes. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a structural schematic diagram of the liquid lead-bismuth-molten salt convection heat exchange experimental section of the vertical tube bundle structure of the present invention (the right figure is a partial enlarged view;

[0056] Figure 2 is a schematic diagram of the thermal insulation sleeve structure;

[0057] Figure 3 It is a structural schematic diagram of the heat insulation sleeve cover plate;

[0058] Figure 4 It is a structural schematic diagram of the heat exchange tube bundle;

[0059] Figure 5 It is a structural schematic diagram of the side plate of the flow distributor;

[0060] Figure 6 Schematic diagram of the structure of the current balancing support plate;

[0061] Figure 7 A schematic diagram of the structure supporting the grid plate;

[0062] Figure 8 It is a schematic diagram of the cross section of the measuring point;

[0063] Fig. 9 Schematic diagram of the measurement point layout for each measurement section.

[0064] The reference numerals in the figures are as follows:

[0065] 1 is the lead-bismuth inlet; 2 is the lead-bismuth inlet pipe box; 3 is the lead-bismuth inlet tube sheet; 4 is the lead-bismuth inlet insulation sleeve cover; 5 is the lead-bismuth inlet insulation sleeve; 6 is the heat exchange tube bundle; 7 is the lead-bismuth outlet insulation sleeve; 8 is the lead-bismuth outlet insulation sleeve cover; 9 is the lead-bismuth outlet tube sheet; 10 is the lead-bismuth outlet pipe box; 11 is the lead-bismuth outlet; 12 is the molten salt inlet; 13 is the molten salt inlet annular distributor chamber; 14 is the molten salt inlet annular distributor side plate; 15 is the molten salt inlet support equalizing plate; 16 is the middle support grid plate; 17 is the experimental section cylinder; 18 is the molten salt outlet support equalizing plate; 19 is the molten salt outlet annular distributor side plate; 20 is the molten salt outlet annular distributor chamber; 21 is the molten salt outlet; 22 is the heat exchange tube; 23 is the pull rod; 24 is the insulation sleeve outer lining; 25 is the insulation sleeve inner lining; 26 is the insulation interlayer. DETAILED DESCRIPTION

[0066] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings.

[0067] like Figure 1As shown, the vertical tube bundle structure liquid lead-bismuth-molten salt convective heat exchange experimental section provided by the present invention includes: a lead-bismuth inlet 1, a lead-bismuth inlet tube box 2, a lead-bismuth inlet tube sheet 3, a lead-bismuth inlet insulation sleeve cover plate 4, a lead-bismuth inlet insulation sleeve 5, a heat exchange tube bundle 6, a lead-bismuth outlet insulation sleeve 7, a lead-bismuth outlet insulation sleeve cover plate 8, a lead-bismuth outlet tube sheet 9, a lead-bismuth outlet tube box 10, a lead-bismuth outlet 11, a molten salt inlet 12, a molten salt inlet annular distributor chamber 13, a molten salt inlet annular distributor side plate 14, a molten salt inlet support equalizing plate 15, an intermediate support grid plate 16, an experimental section cylinder 17, a molten salt outlet support equalizing plate 18, a molten salt outlet annular distributor side plate 19, a molten salt outlet annular distributor chamber 20, and a molten salt outlet 21.

[0068] Among them, the upstream of the lead-bismuth inlet pipe box 2 is connected to the lead-bismuth inlet 1, and the downstream of the lead-bismuth inlet pipe box 2 is connected to the lead-bismuth inlet insulation sleeve 5; the upstream of the heat exchange tube of the heat exchange tube bundle 6 is connected to the lead-bismuth inlet insulation sleeve 5, and the downstream of the heat exchange tube of the heat exchange tube bundle 6 is connected to the lead-bismuth outlet insulation sleeve 7; the upstream of the lead-bismuth outlet pipe box 10 is connected to the lead-bismuth outlet insulation sleeve 7, and the downstream of the lead-bismuth outlet pipe box 10 is connected to the lead-bismuth outlet 11. The upstream of the molten salt inlet annular distributor chamber 13 is connected to the molten salt inlet 12, and the downstream of the molten salt inlet annular distributor chamber 13 is connected to the shell side of the heat exchange tube bundle 6 through the molten salt inlet annular distributor side plate 14; the upstream of the molten salt outlet annular distributor chamber 20 is connected to the shell side of the heat exchange tube bundle 6 through the molten salt outlet annular distributor side plate 19, and the downstream of the molten salt outlet annular distributor chamber 20 is connected to the molten salt outlet 21; in addition, the molten salt inlet support equalizing plate 15, the intermediate support grid plate 16, and the molten salt outlet support equalizing plate 18 all play a role in fixing and supporting the heat exchange tube bundle 6 and distributing the molten salt flow field on the shell side.

[0069] In the above embodiments, preferably, Figure 4 As shown, the heat exchange tube bundle 6 is composed of a plurality of heat exchange tubes 22 and a plurality of tie rods 23, wherein the plurality of heat exchange tubes 22 are arranged in a triangle.

[0070] In the above embodiments, preferably, Figure 2 , Figure 3As shown, the lead-bismuth inlet insulation sleeve 5 and the lead-bismuth outlet insulation sleeve 7 both adopt a double-layer sleeve sandwich structure, which are respectively composed of an insulation sleeve outer lining 24, an insulation sleeve inner lining 25 and an insulation interlayer 26; preferably, the insulation sleeve outer lining 27 and the insulation sleeve inner lining 28 are connected and sealed by welding; preferably, the insulation interlayer 26 is filled with insulation fibers; preferably, the number of the lead-bismuth inlet insulation sleeves 5 is the same as the number of the heat exchange tubes 22, and they are respectively inserted into and close to the inlet end of the lead-bismuth side of the heat exchange tube 22, and are fixed by the lead-bismuth inlet insulation sleeve cover plate 4; preferably, the number of the lead-bismuth outlet insulation sleeves 7 is the same as the number of the heat exchange tubes 22, and they are respectively inserted into and close to the outlet end of the lead-bismuth side of the heat exchange tube 22, and are fixed by the lead-bismuth outlet insulation sleeve cover plate 8; preferably, the lead-bismuth inlet insulation sleeve 5 and the lead-bismuth outlet insulation sleeve 7 have a detachable function, and can effectively isolate the heat exchange of the covered part of the heat exchange tube after installation.

[0071] In the above embodiments, preferably, Figure 5 , Figure 6 , Figure 7 As shown, the molten salt inlet annular distributor chamber 13 and the molten salt inlet annular distributor side plate 14 can improve the circumferential distribution uniformity of the shell side molten salt fluid flow. The molten salt inlet annular distributor chamber 13 is arranged outside the molten salt inlet annular distributor side plate to form an annular cavity. The molten salt fluid enters the salt inlet annular distributor chamber 13 through the molten salt inlet 12, and then enters the shell side of the heat exchange tube bundle 6 through the grid on the molten salt inlet annular distributor side plate 14; the molten salt inlet support equalizing plate 15 and the intermediate support grid plate 16 can improve the radial distribution uniformity of the shell side molten salt fluid flow; the molten salt inlet annular distributor chamber 13, the molten salt inlet annular distributor side plate 14, the molten salt inlet support equalizing plate 15 and the intermediate support grid plate 16 together constitute the molten salt side flow distribution structure, which can enable the liquid molten salt to obtain a longer uniform and fully developed flow field in the longitudinal scouring tube bundle area.

[0072] Based on the vertical tube bundle structure liquid lead bismuth-molten salt convection heat exchange experimental section provided by the present invention, the present invention also proposes a measurement system layout scheme for experimental measurement of the experimental section, which includes measurement point layout principles, measurement point section layout scheme and measurement point layout scheme in the measurement section.

[0073] In the above embodiments, preferably, the following measurement point arrangement principles are adopted:

[0074] Principle 1: The influence of the measuring points on the flow field should be as small as possible, and they should be distributed as much as possible in the area where the flow field is fully developed;

[0075] Principle 2: Based on the symmetrical distribution of flow field and temperature field, the measuring points are dispersedly arranged to meet the measurement requirements of multiple types of measuring points at the same location in a small space;

[0076] Principle 3: Avoid interference between the lead holes of the measuring points and the ear seats and lateral supports of the test sections;

[0077] Principle 4: The measuring points should be able to verify the symmetry of the flow field and the insulation capacity of the insulation sleeve;

[0078] In the above embodiments, preferably, Figure 8 As shown in the figure, the measuring point section arrangement plan includes 14 measuring point sections from section J1 to section J14. The measuring functions of each measuring point section are as follows:

[0079] Function 1: Sections J11 and J12 measure the inlet and outlet temperatures and the inlet and outlet pressure difference of the molten salt on the shell side of the experimental section respectively;

[0080] Function 2: Sections J13 and J14 measure the lead and bismuth inlet and outlet temperatures and inlet and outlet pressure differences on the test section tube side respectively;

[0081] Function 3: The temperature measuring points of sections J1 and J10 measure the thermal insulation capacity of the thermal insulation sleeve;

[0082] Function 4: The temperature measuring points of section J2 and section J9 measure the fluid temperature of lead-bismuth on the tube side and molten salt on the shell side respectively;

[0083] Function 5: The temperature measuring points of sections J3 to J8 respectively measure the local wall temperature and fluid temperature at different axial positions of the heat exchange tube, and simultaneously measure the temperature of the heat exchange tube at different positions of the same section;

[0084] Function 6: The pressure difference measuring points of sections J5 and J8 measure the pressure drop characteristics outside the tube bundle;

[0085] Function 7: The velocity measurement point of section J7 measures the velocity of the inner channel and edge channel of the heat exchange tube bundle, and measures the circumferential uniformity of the velocity distribution at the same time;

[0086] Function 8: The temperature measuring point of section J5 can also measure the symmetry of the heat exchange of lead and bismuth on the tube side; the temperature measuring point of section J8 can also measure the symmetry of the heat exchange of molten salt on the shell side;

[0087] In the above embodiments, preferably, Fig. 9 As shown, the arrangement plan of each measuring point in the measuring section includes the type of measuring point, the specific location of the measuring point arrangement, the measuring point number, and the location of the measuring point lead hole.

[0088] In the above embodiments, preferably, Fig. 9 As shown, the types of measuring points include the outer wall temperature WO of the heat exchange tube, the inner wall temperature WI of the heat exchange tube, the molten salt fluid temperature FO outside the tube, the lead-bismuth fluid temperature FI inside the tube, the local flow velocity of the tube bundle, and the pressure difference measuring point; the specific locations of the measuring point arrangement are marked in the measuring point arrangement plan diagram of each section by solid circles of different colors;

[0089] In the above embodiments, preferably, Fig. 9 As shown, the measuring point number includes the measuring point cross-sectional position "J+number", the heat exchange tube position "R+value", the circumferential angle based on the heat exchange tube, and the measuring point type;

[0090] In the above embodiments, preferably, Fig. 9 As shown, the measurement point layout usage example of measurement point section J8 is as follows:

[0091] Example 1: R63-0-WO measures the outer wall temperature of the heat exchange tube, R64-0-WI measures the inner wall temperature of the heat exchange tube, and R44-FI measures the temperature of the fluid in the tube. Based on the principle of symmetrical arrangement of the flow field, the heat flux density of the heat exchange tube is calculated by R63-0-WO and R64-0-WI, and the convective heat transfer temperature difference in the heat exchange tube is calculated by R64-0-WI and R44-FI, and finally the convective heat transfer coefficient in the heat exchange tube is obtained.

[0092] Example 2: R62-180-FO measures the molten salt temperature of the heat exchange tube R62 at 180°, and R65-180-FO measures the outer wall temperature of the heat exchange tube R65 at 180°. The two can verify the symmetry of the temperature field outside the tube bundle.

[0093] When the liquid lead-bismuth-molten salt convective heat transfer experimental section and the measuring point arrangement scheme provided by the present invention are used to study the liquid lead-bismuth-molten salt coupled heat transfer experimental mechanism, the following three modes can be used:

[0094] Mode 1: Keep the lead-bismuth inlet and outlet temperatures of the experimental section tube side and the molten salt inlet and outlet temperatures of the shell side unchanged at the rated values, and complete the coupled heat exchange experiment of the experimental section under different heat exchange powers;

[0095] Mode 2: Keep the inlet temperature and inlet mass flow rate of the molten salt fluid on the shell side of the experimental section at the rated values, and keep the lead-bismuth inlet temperature in the tube of the experimental section unchanged, and complete the coupled heat exchange experiment of the experimental section under different lead-bismuth flow rates in the tube;

[0096] Mode 3: Keep the lead-bismuth fluid inlet temperature and inlet mass flow rate in the experimental section tube at the rated value, and keep the molten salt inlet temperature outside the experimental section tube unchanged, and complete the coupled heat exchange experiment of the experimental section under different shell-side molten salt flow rates;

[0097] The embodiments described above are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention described above, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A vertical tube bundle structure liquid lead bismuth-molten salt convection heat exchange experimental section for a liquid metal reactor, comprising a heat exchange tube bundle; The heat exchange tube bundle is provided with a plurality of heat exchange tubes and tie rods, which are fixed between the lead-bismuth inlet tube sheet and the lead-bismuth outlet tube sheet; The inlet end and the outlet end of the heat exchange tube bundle are respectively connected to the lead-bismuth inlet tube box and the lead-bismuth outlet tube box; the lead-bismuth inlet tube box and the lead-bismuth outlet tube box are respectively connected to the lead-bismuth inlet and the lead-bismuth outlet; the lead-bismuth inlet tube box can play a role in buffering and flow redistribution of the lead-bismuth fluid flow; The ends of the heat exchange tube bundle close to the lead-bismuth inlet tube box and the lead-bismuth outlet tube box are respectively provided with a lead-bismuth inlet insulation sleeve and a lead-bismuth outlet insulation sleeve; The outer side of the heat exchange tube bundle is provided with a molten salt outlet annular distributor side plate and a molten salt inlet annular distributor side plate at the lower part of the lead-bismuth inlet tube box and the upper part of the lead-bismuth outlet tube box respectively; An experimental section cylinder is arranged at the middle part of the outer side of the heat exchange tube bundle, and two ends of the experimental section cylinder are respectively connected to the molten salt inlet annular distributor side plate and the molten salt outlet annular distributor side plate by welding; A molten salt outlet annular distributor chamber is provided outside the molten salt outlet annular distributor side plate, a molten salt outlet is provided on the side wall of the molten salt outlet annular distributor chamber, and the molten salt fluid enters the molten salt outlet annular distributor chamber from the shell side of the heat exchange tube bundle through the molten salt outlet annular distributor side plate, and then flows out through the molten salt outlet; A molten salt inlet annular distributor chamber is provided outside the molten salt inlet annular distributor side plate, a molten salt inlet is provided on the side wall of the molten salt inlet annular distributor chamber, and the molten salt fluid enters the molten salt inlet annular distributor chamber through the molten salt inlet, and then enters the shell side of the heat exchange tube bundle through the molten salt inlet annular distributor side plate; The heat exchange tube bundle is provided with a molten salt inlet support equalizing plate, an intermediate support grid plate and a molten salt outlet support equalizing plate; The molten salt inlet supporting flow equalizing plate is arranged at the connection between the molten salt inlet annular distributor side plate and the experimental section cylinder; The intermediate support grid plate is arranged in the middle of the heat exchange tube bundle; The molten salt outlet supporting flow equalizing plate is arranged at the connection between the molten salt outlet annular distributor side plate and the experimental section cylinder; The molten salt inlet annular distributor side plate and the molten salt outlet annular distributor side plate are provided with a plurality of long strip grids unevenly distributed along the circumferential direction, which are used to improve the circumferential uniformity of the shell side molten salt fluid flushing the heat exchange tube bundle; The molten salt inlet support flow equalizing plate and the molten salt outlet support flow equalizing plate have a plurality of long strip channels for the heat exchange tube bundle to pass through, and channels for the molten salt fluid to flow are opened at the edge to support the heat exchange tube bundle and improve the radial uniformity of the shell side molten salt fluid flushing the heat exchange tube bundle; The intermediate support grid plate is composed of a plurality of mutually staggered long strip grids, and is used to support the heat exchange tube bundle and improve the radial uniformity of the flow of the shell-side molten salt fluid flushing the heat exchange tube bundle.

2. The liquid lead-bismuth-molten salt convection heat transfer experimental section according to claim 1 is characterized in that: The lead-bismuth inlet insulation sleeve and the lead-bismuth outlet insulation sleeve are both double-layer sleeve sandwich structures, which are insulation sleeve outer lining, insulation interlayer and insulation sleeve inner lining from outside to inside; The outer lining of the heat-insulating sleeve and the inner lining of the heat-insulating sleeve are connected by welding, and the heat-insulating interlayer is filled with heat-insulating fibers.

3. The liquid lead-bismuth-molten salt convection heat exchange experimental section according to claim 1 or 2, characterized in that: The lead-bismuth inlet insulation sleeve and the lead-bismuth outlet insulation sleeve are both fixed by insulation sleeve covers and are detachable.

4. A measurement system arrangement scheme for a liquid lead-bismuth-molten salt convection heat exchange experimental section with a vertical tube bundle structure according to any one of claims 1 to 3, comprising: Principles of measuring point arrangement, arrangement plan of measuring point sections and arrangement plan of each measuring point in the measuring section; The measuring point arrangement principles are as follows: Principle 1: The influence of the measuring points on the flow field should be as small as possible, and they should be distributed as much as possible in the area where the flow field is fully developed; Principle 2: Based on the symmetrical distribution of flow field and temperature field, the measuring points are dispersedly arranged to meet the measurement requirements of multiple types of measuring points at the same location in a small space; Principle 3: Avoid interference between the lead holes of the measuring points and the ear seats and lateral supports of the test sections; Principle 4: The measuring points can verify the symmetry of the flow field and the thermal insulation capacity of the thermal insulation sleeve; The measuring point section arrangement scheme can set 14 measuring point sections from section J1 to section J14. The measuring functions to be undertaken by each measuring point section are as follows: Function 1: Sections J11 and J12 measure the inlet and outlet temperatures and the inlet and outlet pressure difference of the molten salt on the shell side of the experimental section respectively; Function 2: Sections J13 and J14 measure the lead and bismuth inlet and outlet temperatures and inlet and outlet pressure differences on the test section tube side respectively; Function 3: The temperature measuring points of sections J1 and J10 measure the thermal insulation capacity of the thermal insulation sleeve; Function 4: The temperature measuring points of section J2 and section J9 measure the fluid temperature of lead-bismuth on the tube side and molten salt on the shell side respectively; Function 5: The temperature measuring points of sections J3 to J8 measure the local wall temperature and fluid temperature at different axial positions of the heat exchange tube, and measure the temperature of the heat exchange tube at different positions of the same section at the same time; Function 6: The pressure difference measuring points of sections J5 and J8 measure the pressure drop characteristics outside the tube bundle; Function 7: The velocity measurement point of section J7 measures the velocity of the inner channel and edge channel of the heat exchange tube bundle, and measures the circumferential uniformity of the velocity distribution at the same time; Function 8: The temperature measuring point of section J5 can also measure the symmetry of the heat exchange of lead and bismuth on the tube side; the temperature measuring point of section J8 can also measure the symmetry of the heat exchange of molten salt on the shell side; The measuring point section can measure the following parameters: measuring point type, measuring point layout specific location, measuring point number, measuring point lead opening location: The types of measuring points include the outer wall temperature WO of the heat exchange tube, the inner wall temperature WI of the heat exchange tube, the molten salt fluid temperature FO outside the tube, the lead-bismuth fluid temperature FI inside the tube, the local flow velocity of the tube bundle, and the pressure difference measuring point; the specific locations of the measuring point arrangements are marked in the measuring point arrangement plan diagram of each section by solid circles of different colors; The measuring point number content includes the measuring point cross-sectional position "J+number", the position of the heat exchange tube "R+value", the circumferential angle based on the heat exchange tube and the measuring point type.

5. A liquid lead-bismuth-molten salt coupled heat exchange experimental method based on the liquid lead-bismuth-molten salt convective heat exchange experimental section with a vertical tube bundle structure as described in any one of claims 1 to 3, comprising any one of the following steps 1) to 3): 1) Keeping the lead-bismuth inlet and outlet temperatures of the tube side and the molten salt in the shell side of the experimental section at the rated values ​​unchanged, complete the coupled heat exchange experiment of the experimental section under different heat exchange powers; 2) The shell side molten salt fluid inlet temperature and inlet mass flow rate of the experimental section are kept at rated values, and the lead-bismuth inlet temperature in the tube of the experimental section is kept constant, and the coupled heat exchange experiment of the experimental section under different lead-bismuth flow rates in the tube is completed; 3) The lead-bismuth fluid inlet temperature and inlet mass flow rate in the experimental section tube are maintained at rated values, while the molten salt inlet temperature outside the experimental section tube is maintained at a constant value, so as to complete the coupled heat exchange experiment of the experimental section under different shell-side molten salt flow rates.

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