Fuel salt reactor core flow heat transfer behavior visualization experiment system under ocean condition

Abstract

The utility model discloses a fuel salt reactor core flow heat transfer behavior visualization experiment system under ocean conditions. The system comprises a fuel salt reactor simulation experiment body, a six-degree-of-freedom motion platform for simulating the ocean conditions, a PIV optical measurement system and a cooling system, the fuel salt reactor simulation experiment body comprises a transparent experiment tank, heat conduction oil, a plurality of heat pipes, a plurality of electric heating wires and a plurality of thermocouples, the heat conduction oil is contained in the transparent experiment tank, the heat pipes and the electric heating wires are vertically arranged in the heat conduction oil, the condensation ends of the heat pipes are connected with the cooling system, and the heat pipes and the electric heating wires are arranged at intervals in the radial direction of the transparent experiment tank; the thermocouple is transversely arranged in the transparent experiment tank; the transparent experiment tank is installed on the six-degree-of-freedom motion platform. By introducing the low-temperature heat conduction oil as a low-temperature working medium for simulating the fuel salt, the system can realize the dynamic simulation of the flow and heat transfer characteristics of the fuel salt within a safe temperature range, and avoids the complexity and danger of a high-temperature experiment.

Description

TECHNICAL FIELD

[0001] The utility model belongs to nuclear energy technology and thermal hydraulic field, especially relates to a kind of marine conditions fuel salt reactor core flow heat transfer behavior visualization experimental system. BACKGROUND

[0002] Fuel salt reactor is a potential technology applied to future ship power, and it shows important advantages in meeting long time, high intensity operation demand with its high efficiency, stable characteristics.However, marine environment is complex and changeable, and the sway operation condition caused by wave can significantly affect the flow and heat transfer characteristics of fuel salt reactor.The natural convection and heat transfer characteristics of fuel salt in reactor core tube bundle area have not been fully revealed, and the law and micro mechanism that dynamic marine environment such as periodic motion and temperature difference fluctuation affect the flow pattern and heat transfer efficiency of fuel salt need to be further researched.

[0003] Directly using fuel salt to carry out experiment is the traditional method to study the operation characteristics of fuel reactor, but this method faces a series of technical challenges that are difficult to overcome.The preparation process of fuel salt is complex and expensive, and its physical characteristics determine that the experiment needs to meet the requirements of high temperature, high pressure and sealing.The corrosion and toxicity of fuel salt also cause the personnel to face safety risks.These problems increase the design difficulty of experimental equipment, and put forward very high requirements for laboratory environment and personnel safety, which limits the feasibility of experiment.

[0004] At the same time, the traditional high-temperature fuel salt experimental equipment usually lacks effective visualization technology, and cannot fully observe the transient characteristics of complex flow field, cannot fully capture the transient flow and heat transfer characteristics of fuel salt under complex dynamic conditions, and the research on vortex generation, boundary layer behavior and local heat transfer law is still insufficient. UTILITY MODEL CONTENT

[0005] In view of the above technical problems, the utility model provides a kind of marine conditions fuel salt reactor core flow heat transfer behavior visualization experimental system to solve the technical problems in high-temperature experiment of fuel salt, by introducing low-temperature heat conducting oil as low-temperature working medium to simulate fuel salt, the system can realize dynamic simulation of flow and heat transfer characteristics of fuel salt in safe temperature range, and avoid the complexity and danger of high-temperature experiment.

[0006] To achieve the above purpose, the technical scheme of the utility model is as follows:

[0007] A kind of marine conditions fuel salt reactor core flow heat transfer behavior visualization experimental system, including: fuel salt reactor simulation experiment body, six degrees of freedom motion platform of simulated marine conditions, PIV optical measurement system and cooling system;

[0008] The fuel salt reactor simulation experiment body comprises a transparent experiment tank, heat conducting oil, a plurality of heat pipes, a plurality of electric heating wires and a plurality of thermocouples, the transparent experiment tank contains the heat conducting oil, the heat pipes and the electric heating wires are vertically arranged in the heat conducting oil, the condensing end of the heat pipe is connected with the cooling system, and a valve is arranged on the pipeline connecting the condensing section of the heat pipe and the water inlet end of the cooling system.

[0009] The transparent experiment tank has at least a first circular ring, a second circular ring and a third circular ring in a transverse section, the heat pipes are arranged at the center of the transverse section, a plurality of electric heating wires are uniformly arranged at the first circular ring, a plurality of heat pipes are uniformly arranged at the second circular ring, and a plurality of electric heating wires are uniformly arranged at the third circular ring, and the thermocouples are transversely arranged in the transparent experiment tank.

[0010] The transparent experiment tank is installed on the six-degree-of-freedom motion platform.

[0011] In an embodiment, the heat conducting oil is Drakesol 260AT.

[0012] In an embodiment, the electric heating wire comprises an inner layer and an outer layer, and the inner layer and the outer layer input different powers to simulate the uneven power distribution phenomenon caused by the uneven neutron flux distribution in the fuel reactor core.

[0013] In an embodiment, the thermocouples are uniformly arranged in the transparent experiment tank to form a grid-shaped measurement system through cross distribution.

[0014] In an embodiment, a PIV optical system is arranged on the periphery of the fuel salt reactor simulation experiment body.

[0015] In an embodiment, the PIV optical system comprises a laser light source, a lens group and a light splitting element, the high-energy tube bundle emitted by the laser light source is reflected by the light splitting element and then the shape and size of the laser light beam are adjusted by the lens group, so that the laser light beam uniformly covers the fuel salt reactor simulation experiment body.

[0016] In an embodiment, a plurality of high-resolution digital cameras are further installed on the periphery of the fuel salt reactor simulation experiment body.

[0017] In an embodiment, the cooling system comprises a water tank, a compressor, an air cooler, an evaporator and a cooling jacket, the evaporator is arranged in the water tank, the outlet of the compressor is connected with the inlet of the air cooler, the outlet of the air cooler is connected with the outlet of the evaporator, and the outlet of the evaporator is connected with the inlet of the compressor.

[0018] The outlet of the water tank is connected with the inlet of the cooling jacket, the outlet of the cooling jacket is connected with the inlet of the water tank, and the cooling jacket is sleeved on the cold end of the heat pipe.

[0019] In the preferred embodiment of the utility model, the cooling system further comprises a centrifugal pump and a mass flow meter, the centrifugal pump is arranged at the outlet of the water tank, and the mass flow meter is arranged between the centrifugal pump and the inlet of the cooling jacket.

[0020] Compared with the prior art, the utility model has the following advantages and positive effects:

[0021] The utility model discloses low temperature heat conducting oil is used as low temperature working medium of simulated fuel salt, fills the heat conducting oil to the transparent experimental jar, simulates the state of fuel salt in the pipe bundle area of the reactor core, and the electric heating wire is vertically arranged in the heat conducting oil, simulates the heat release of the fuel salt reactor, and the heat pipe is also vertically arranged in the heat conducting oil, simulates the heat transfer characteristic of the fuel salt reactor. Further, the electric heating wire and the heat conducting oil are radially arranged, to maximize the proximity of the prototype reactor. The thermocouple is arranged in the experimental jar to capture the real-time temperature field distribution of the heat conducting oil, the transparent experimental jar is installed on the six degree of freedom motion platform, the six degree of freedom motion platform simulates the ocean swing condition, and the transient fluid characteristic and heat transfer rule under the dynamic working condition are researched.

[0022] The experimental system of the utility model ensures the accuracy and reliability of experimental data under multiple ocean conditions, and the experimental structure can provide important support for the performance optimization of equipment in ocean engineering, nuclear energy application and extreme environment, promote the technical progress in the related field, and improve the safety, reliability and energy utilization efficiency of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The utility model discloses a schematic diagram of the fuel salt reactor core flow and heat transfer behavior visualized experimental system under the ocean condition of embodiment;

[0024] Figure 2 The vertical section schematic diagram of the fuel salt reactor simulation experimental body of the utility model embodiment;

[0025] Figure 3 The horizontal section schematic diagram of the fuel salt reactor simulation experimental body of the utility model embodiment.

[0026] Mark the following: 1-fuel salt reactor simulation experimental body;101-transparent experimental jar;102-heat conducting oil;103-heat pipe;104-electric heating wire;105-multiple thermocouples;

[0027] 2-six degree of freedom motion platform;3-PIV optical measuring system;301-laser light source;302-lens group;303-diffractive element;

[0028] 4-cooling system; 401-water tank; 402-compressor; 403-air cooler; 404-evaporator; 405-cooling jacket; 406-centrifugal pump; 407-mass flow meter; 408-bypass valve; 5-high resolution digital camera. DETAILED DESCRIPTION

[0029] The visualized experimental system for the flow and heat transfer behavior of a fuel salt reactor core under marine conditions is further described in detail below in combination with the drawings and specific embodiments. The advantages and features of the present application will be more apparent according to the following description.

[0030] Reference Figure 1 A visualized experimental system for the flow and heat transfer behavior of a fuel salt reactor core under marine conditions, comprising: a fuel salt reactor simulation experimental body 1, a six-degree-of-freedom motion platform 2 simulating marine conditions, a PIV optical measurement system 3, and a cooling system 4.

[0031] The fuel salt reactor simulation experimental body 1 comprises a transparent experimental tank 101, heat conducting oil 102, a plurality of heat pipes 103, a plurality of electric heating wires 104, and a plurality of thermocouples 105. The heat conducting oil 102 is contained in the transparent experimental tank 101. The heat pipes 103 and the electric heating wires 104 are vertically arranged in the heat conducting oil 102. The condensing end of the heat pipe 103 is connected to the cooling system 4. The heat pipes 103 and the electric heating wires 104 are arranged at intervals along the radial direction of the transparent experimental tank 101. The thermocouples are transversely arranged in the transparent experimental tank 101.

[0032] The transparent experimental tank 101 is installed on the six-degree-of-freedom motion platform 2.

[0033] The low-temperature heat conducting oil 102 is used as a low-temperature working medium simulating fuel salt, and the low-temperature heat conducting oil 102 is filled into the transparent experimental tank 101 to simulate the state of the fuel salt in the core pipe bundle area of the reactor. The electric heating wires 104 and the heat pipes 103 are vertically arranged in the heat conducting oil 102. The electric heating wires 104 are used to simulate the heating area of the fuel salt. The electric heating wires 104 are longitudinally arranged in the fuel salt reactor simulation experimental body 1 and uniformly distributed along the longitudinal direction of the transparent experimental tank 101 to ensure the uniformity of the heat source distribution. The electric heating wires 104 are made of high-temperature resistant materials such as tungsten wires or nichrome wires, have high resistance, and can effectively provide stable heat sources. The heat pipes 103 are longitudinally distributed along the transparent experimental tank 101 in the heat conducting oil 102 to simulate the heat transfer characteristics of the fuel reactor to the outside.

[0034] Thermocouples are arranged in the fuel salt reactor simulation experiment body 1 in a cross-distribution manner at different positions of the fuel salt reactor simulation experiment body 1 to form an accurate temperature measurement matrix, so that the temperature change can be monitored in real time during the experiment, and the temperature field is accurately analyzed through a data processing system. The arrangement of the thermocouple wire at each measurement point takes into account the change of the temperature gradient, can effectively capture the local temperature change, and ensures the high accuracy of the experimental data.

[0035] The heat pipe 103 is vertically arranged in the heat conducting oil 102 to simulate the heat transfer characteristics of the fuel salt reactor. The cooling system 4 is connected to the cold end of the heat pipe 103, and the design of the cooling system 4 is the key to ensuring the stable operation of the reactor core simulation body.

[0036] The transparent experimental tank 101 is installed on the six-degree-of-freedom motion platform 2, and the six-degree-of-freedom motion platform 2 simulates the ocean rocking condition to study the transient fluid characteristics and heat transfer law under dynamic conditions. The six-degree-of-freedom motion platform 2 can simulate different types of ocean movements, such as periodic rolling, pitching and other motion modes, to study the influence of these movements on the flow and heat transfer process in the reactor core simulation body. The adjustment system of the six-degree-of-freedom motion platform 2 can accurately control the frequency, amplitude and direction of the rocking, and simulate the typical motion conditions in the ocean through the motion platform, so as to observe the transient changes of the heat conducting oil 102 flow and temperature distribution under the ocean movement. In the dynamic experiment, multiple data such as temperature, flow rate and pressure are collected in real time to analyze the influence of ocean movement on the reactor core natural convection, heat transfer and fluid dynamics characteristics. The fuel salt reactor simulation experiment body 1 is stably installed on the motion platform through the fixing device to ensure the integrity of the system and the safety of the experiment under dynamic environment.

[0037] Further, from the lateral cross section of the fuel salt reactor simulation experiment body 1, there are multiple circular rings with the center point as the center, at least a first circular ring, a second circular ring and a third circular ring, assuming that the heat pipe 103 is arranged at the center point, the electric heating wire 104 is uniformly arranged on the first circular ring, the heat pipe 103 is uniformly arranged on the third circular ring, and so on, so that the electric heating wire 104 and the heat pipe 103 are arranged in a radial direction. To maximize the proximity to the prototype reactor.

[0038] The position arrangement of the electric heating wire 104 and the heat pipe 103 is determined by the prototype reactor core fuel salt release power and the heat pipe 103 heat transfer power distribution. The prototype reactor core fuel salt releases heat at each position where the fuel salt is located. The utility model adopts the local position arrangement of the heating wire in the core to simulate the fuel salt heat release. In order to meet the power distribution in the simulation body and the prototype reactor, the core is divided into a plurality of control units along the radial direction. Based on the calculation results of the neutron dynamics core power distribution, the power density volume integral of the control unit is calculated, the heat release power and the heat pipe 103 heat transfer power of each control unit are calculated, and the relative power distribution of each control unit is obtained. On this basis, the experimental core simulation body is also divided into a plurality of control units along the radial direction, and the electric heating wire 104 and the heat pipe 103 are arranged in each control unit. The size of the heating wire needs to meet the requirement that the influence on the core flow field can be ignored, and at the same time, the power of the heating wire can meet the power requirement of the control unit. Therefore, numerical simulation of the flow in the core simulation body needs to be carried out before the experiment starts. Through the comparison of the flow field influence of a plurality of sizes of heating wires, the final applicable heating wire size is determined. The determination of the heating power and the heat transfer power of the heat pipe 103 needs to be based on the experimental modeling analysis. The determined heating power can meet the matching of the dimensionless heat source factor and other parameters between the experimental simulation body and the prototype reactor.

[0039] The electric heating wire 104 adopts a double-layer structure heating wire, and the inner layer and the outer layer input different powers to simulate the uneven power distribution phenomenon caused by the uneven neutron flux distribution in the fuel reactor core. The center area of the core has a large neutron flux and generates a large amount of heat, while the outer area has a small neutron flux and generates a small amount of heat. The power input of the inner layer heating wire and the outer layer heating wire of the double-layer structure is different. The power of the inner layer heating wire is high to simulate the high heat generation in the center area of the core. The power of the outer layer heating wire is low to simulate the low heat generation in the outer area of the core. The local power density difference can be realized in the core simulation body, thereby simulating the uneven power distribution caused by the different neutron fluxes in the actual molten salt reactor.

[0040] In the embodiment, the heat conducting oil 102 is the heat conducting oil Drakesol 260AT.

[0041] The calculation of the low-temperature modeling is the key to ensure that the heat conducting oil can effectively simulate the flow and heat transfer characteristics of the high-temperature fuel salt under low-temperature conditions. In the experimental system, the heat conducting oil Drakesol 260AT is selected as the substitute working medium. Based on the physical properties (density, specific heat capacity, thermal conductivity, viscosity, etc.) and flow characteristics of the high-temperature fuel salt (such as FLiBe), the dimensionless parameters such as the Prandtl number (Pr) and the Reynolds number (Re) are matched, thereby meeting the similarity in terms of physical properties. The Prandtl number (Pr) and the Reynolds number (Re) are calculated through the following relationship:

[0042] Prandtl number (Pr) defines the ratio of momentum diffusivity and thermal diffusivity of the fluid, and the expression is:

[0043]

[0044] where c p is the specific heat capacity, μ is the dynamic viscosity, v is the kinematic viscosity, and α is the thermal diffusivity.

[0045] The Reynolds number (Re) is defined as the ratio of inertial force and viscous force of the fluid, and the expression is:

[0046]

[0047] where ρ is the fluid density, v is the characteristic velocity of the fluid, and D is the characteristic length.

[0048] When designing the experiment, it is necessary to ensure that the working temperature of the working medium is consistent with the Prandtl number of the fuel salt in the working range. At the same time, the geometric size of the core simulation body is controlled to realize the similarity of the characteristic length under the scaling condition; and the motion intensity is determined according to the actual fuel salt flow range to ensure that the experimental conditions are consistent with the actual molten salt reactor operating state.

[0049] The PIV optical system is arranged on the periphery of the fuel salt reactor simulation experiment body 1, and a plurality of high-resolution digital cameras 5 are also installed on the periphery of the fuel salt reactor simulation experiment body 1. The PIV system irradiates the experimental area by high-energy laser, and captures the motion of tracer particles in the flow field by high-resolution digital camera, so as to calculate the velocity field of the fluid. The PIV technology can measure the flow velocity and flow characteristics of the fuel salt reactor simulation experiment body 1 in real time, and provide accurate flow data support.

[0050] The PIV optical system includes a laser light source 301, a lens group 302, and a light splitting element 303. The laser light source 301 provides a high-energy beam required for particle imaging velocimetry. The emitted high-energy beam is reflected by the light splitting element 303 and then adjusted by the lens to shape and size the laser beam, so that it uniformly covers the fuel salt reactor simulation experiment body 1. The high-resolution digital camera 5 is installed at multiple angles to record the detailed changes of the flow field inside the core in real time, providing a basis for subsequent data analysis.

[0051] In terms of temperature measurement, in order to accurately measure the temperature distribution in the fuel salt reactor simulation body, a multi-point temperature measurement technology is adopted, and a three-dimensional temperature distribution detection system for the fuel salt reactor simulation body is constructed. As Figures 2-3 shown, temperature measurement adopts two layers of thermocouples arranged above and below. The thermocouples are uniformly arranged on the upper and lower layers of the fuel salt reactor simulation body, and form a grid-shaped measurement system through cross distribution. Each measurement point monitors the temperature change in real time, forming an accurate temperature detection network, accurately capturing temperature changes at different positions in the fuel salt reactor simulation body, and constructing a three-dimensional temperature field of the core.

[0052] The cooling water jacket 405 and the cooling system 4 are designed to be in a constant temperature cycle. The cooling system 4 is designed to ensure the stable operation of the fuel salt reactor simulation body. The cooling water jacket 405 is installed at the cold end of the heat pipe 103, and the excess heat in the reactor simulation body is taken away by circulating cooling water to keep the temperature of the reactor simulation body stable. The water jacket design ensures that the cold end of the heat pipe 103 does not directly contact the cooling water, avoiding the influence of heat exchange between the cooling water and the heat pipe 103 on the experimental data. The cooling water jacket 405 and the heat pipe 103 are isolated by a gas environment to ensure that the ambient temperature outside the heat pipe 103 is constant, maintaining the cooling effect.

[0053] The cooling system 4 includes a water tank 401, a compressor 402, an air cooler 403, an evaporator 404, and a cooling water jacket 405. The evaporator 404 is arranged in the water tank 401. The outlet of the compressor 402 is connected to the inlet of the air cooler 403. The outlet of the air cooler 403 is connected to the outlet of the evaporator 404. The outlet of the evaporator 404 is connected to the inlet of the compressor 402. The compressor 402, the air cooler 403, and the evaporator 404 are used to cool the water in the water tank 401.

[0054] The outlet of the water tank 401 is connected to the inlet of the cooling water jacket 405. The outlet of the cooling water jacket 405 is connected to the inlet of the water tank 401. A valve is arranged on the connecting pipeline between the outlet of the cooling water jacket 405 and the inlet of the water tank 401. The cooling water jacket 405 is sleeved on the cold end of the heat pipe 103.

[0055] The cooling system 4 further includes a centrifugal pump 406 and a mass flow meter 407. The centrifugal pump 406 is arranged at the outlet of the water tank 401. The mass flow meter 407 is arranged between the centrifugal pump 406 and the inlet of the cooling water jacket 405. The cooling water in the cooling system 4 is provided with a stable flow rate by the centrifugal pump 406, and continuously flows through the circulation loop to take away the heat from the cold end of the heat pipe 103. The cooling system 4 is also designed with a mass flow meter 407 to adjust the water flow rate. The cooling system 4 is also designed with a bypass valve 408. A pipeline is arranged at the outlet of the centrifugal pump 406 and connected to the inlet of the water tank 401. The bypass valve 408 is arranged on the pipeline to adjust the cooling intensity of the cooling water and keep the temperature of the cooling water constant, ensuring the stability of the temperature in the experiment. The operating conditions and water flow control of the cooling system 4 can be adjusted according to different experimental requirements to ensure the stability and reliability of the temperature in the experiment.

[0056] The key point of the utility model lies in: through low temperature heat conducting oil 102 replaces high temperature fuel salt, its physical property parameter and high temperature fuel salt match, can simulate the flow and heat transfer characteristics of fuel salt under low temperature condition accurately;The experimental device adopts high-precision temperature measurement matrix and particle image velocimetry technology, can obtain the temperature field and flow field distribution of the core tube bundle area in real time, provides data support for the study of natural convection and its heat transfer mechanism;Six degrees of freedom motion platform 2 can simulate a variety of ocean wave conditions, study the influence of dynamic environment on fuel salt heat transfer characteristics, thereby comprehensively reveal the heat flow behavior of fuel salt under complex operating conditions.The system designs non-contact optical measurement system simultaneously, is used to monitor the fluid motion details of experimental area in high resolution, in-depth study fuel salt flow and heat transfer microscopic mechanism under dynamic conditions.

[0057] The experimental system of the utility model can research the natural convection heat transfer characteristics of fuel salt under static and dynamic conditions.In static experiment, the system measures the flow and heat transfer characteristics of fuel salt simulation working medium under constant temperature, as the benchmark data;In dynamic experiment, through six degrees of freedom motion platform 2 simulates a variety of ocean wave conditions, real-time acquisition of experimental data, studies the influence of wave environment on fuel salt heat transfer efficiency and fluid motion.The experimental results will reveal the natural convection law and heat transfer characteristics of fuel salt under dynamic conditions, provide important theoretical support and experimental basis for molten salt core design and performance optimization.

[0058] The above has made the detailed description to the embodiment of the utility model in combination with the drawings, but the utility model is not limited to the above embodiment.Even if various changes are made to the utility model, provided that these changes belong to the scope of the utility model claims and its equivalent technology, still fall into the protection scope of the utility model.

Claims

1. A visualization experimental system for the flow and heat transfer behavior of a fuel salt reactor core under marine conditions, characterized in that, include: The experimental setup includes a fuel salt pile simulator, a six-degree-of-freedom motion platform simulating ocean conditions, a PIV optical measurement system, and a cooling system. The fuel salt pile simulation test body includes a transparent test tank, heat transfer oil, multiple heat pipes, multiple electric heating wires and multiple thermocouples. The transparent test tank contains the heat transfer oil. The heat pipes and electric heating wires are arranged vertically inside the heat transfer oil. The condensing end of the heat pipe is connected to the cooling system. A valve is installed on the pipe connecting the condensing section of the heat pipe to the water inlet of the cooling system. The transparent experimental container has a transverse cross-section with at least a first ring, a second ring, and a third ring. The heat pipe is arranged at the center of the transverse cross-section. Multiple electric heating wires are evenly arranged at the first ring, multiple heat pipes are evenly arranged at the second ring, and multiple electric heating wires are evenly arranged at the third ring. The thermocouple is arranged transversely inside the transparent experimental container. The transparent experimental container is mounted on the six-degree-of-freedom motion platform.

2. The experimental system for visualizing the flow and heat transfer behavior of fuel salt reactor cores under marine conditions according to claim 1, characterized in that, The heat transfer oil is Drakesol 260AT.

3. The experimental system for visualizing the flow and heat transfer behavior of fuel salt reactor cores under marine conditions according to claim 1, characterized in that, The electric heating wire includes an inner layer and an outer layer, which are input with different powers to simulate the uneven power distribution caused by the uneven distribution of neutron flux in the fuel reactor core.

4. The experimental system for visualizing the flow and heat transfer behavior of fuel salt reactor cores under marine conditions according to claim 1, characterized in that, The thermocouples are evenly arranged in the transparent experimental container, forming a grid-like measurement system through cross-distribution.

5. The experimental system for visualizing the flow and heat transfer behavior of fuel salt reactor cores under marine conditions according to claim 1, characterized in that, A PIV optical system is arranged around the periphery of the fuel salt reactor simulation test body.

6. The experimental system for visualizing the flow and heat transfer behavior of fuel salt reactor cores under marine conditions according to claim 1, characterized in that, The PIV optical system includes a laser source, a lens group, and a beam splitter. The high-energy beam emitted by the laser source is reflected by the beam splitter and then the shape and size of the laser beam are adjusted by the lens group so that it uniformly covers the fuel salt pile simulation test body.

7. The experimental system for visualizing the flow and heat transfer behavior of fuel salt reactor cores under marine conditions according to claim 5, characterized in that, Multiple high-resolution digital cameras are also installed around the fuel salt pile simulation test body.

8. The experimental system for visualizing the flow and heat transfer behavior of fuel salt reactor cores under marine conditions according to claim 1, characterized in that, The cooling system includes a water tank, a compressor, an air cooler, an evaporator, and a cooling water jacket. The evaporator is located inside the water tank. The outlet of the compressor is connected to the inlet of the air cooler. The outlet of the air cooler is connected to the outlet of the evaporator. The outlet of the evaporator is connected to the inlet of the compressor. The outlet of the water tank is connected to the inlet of the cooling water jacket, and the outlet of the cooling water jacket is connected to the inlet of the water tank. The cooling water jacket is fitted onto the cold end of the heat pipe.

9. The experimental system for visualizing the flow and heat transfer behavior of fuel salt reactor cores under marine conditions according to claim 8, characterized in that, The cooling system also includes a centrifugal pump and a mass flow meter. The centrifugal pump is located at the outlet of the water tank, and the mass flow meter is located between the centrifugal pump and the inlet of the cooling water jacket.

Images