A test system and method for corrosion of materials in an in-pile water chemical environment

Abstract

The present invention provides an in-pile hydrochemical environment material corrosion testing system, comprising a high-temperature environment system, a water quality conditioning system connected to the high-temperature environment system, and a leakage monitoring system connected to the high-temperature environment system. The present invention also provides an in-pile hydrochemical environment material corrosion testing method. The in-pile hydrochemical environment material corrosion testing system and testing method provided by the present invention feature low thermal power loss, low flow resistance in the test section, high sample surface flow velocity, and a low failure frequency of the leak detection system.

Description

Technical Field

[0001] The present invention relates to the technical field of in-pile material corrosion testing, and in particular to an in-pile water chemical environment material corrosion testing system and a testing method thereof. Background Art

[0002] Reactor fuel cladding serves as the second barrier to nuclear fuel, and its performance is directly related to reactor safety. To study the behavior of cladding materials under service conditions, particularly their corrosion resistance, it is necessary to conduct in-reactor hydrochemical corrosion tests on the cladding materials under conditions of high temperature, high pressure, neutron radiation, and specific water quality.

[0003] However, the current in-pile water chemical environment material corrosion test system has problems such as complex system structure, large system thermal power loss, large test section flow resistance, low sample surface flow velocity, and high leakage detection system failure frequency.

[0004] Therefore, there is an urgent need for an in-pile water chemical environment material corrosion test system and its test method with low system thermal power loss, low test section flow resistance, high sample surface flow velocity, and low leakage detection system failure frequency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an in-pile water chemical environment material corrosion test system and its test method with low system thermal power loss, low test section flow resistance, high sample surface flow velocity and low leakage detection system failure frequency.

[0006] To solve the above technical problems, the present invention provides an in-pile water chemical environment material corrosion test system, comprising a high temperature environment system, a water quality adjustment system connected to the high temperature environment system, and a leakage monitoring system connected to the high temperature environment system;

[0007] The high-temperature environment system includes an in-pile irradiation device, the outlet of the in-pile irradiation device is connected to the inlet pipe of the first heating device, the outlet of the first heating device is connected to the inlet pipe of the circulation drive device, the outlet of the circulation drive device is connected to the inlet pipe of the second heating device, the outlet of the second heating device is connected to the inlet pipe of the in-pile irradiation device, and a parallel stabilizer is connected between the first heating device and the second heating device;

[0008] The water quality regulation system includes an integrated thermostat having a high-temperature section inlet connected to an outlet pipe of a circulation drive device, the high-temperature section outlet of the integrated thermostat being connected to a sampling device and an ultrafine filtration membrane inlet pipe respectively, the ultrafine filtration membrane outlet being connected in parallel to a plurality of ion exchange column inlet pipes, the ion exchange column outlet being connected to an inlet pipe of a water quality regulation box via a pressure reducing valve, the water quality regulation box outlet being connected to an inlet pipe of a low-temperature section of the integrated thermostat via a water injection pump, and the low-temperature section outlet of the integrated thermostat being connected to an inlet pipe of the circulation drive device;

[0009] A liquid adding device and a gas adding device are provided on the upper part of the water quality regulating box, a water quality regulating box heater is provided on the bottom of the water quality regulating box, and a liquid level monitor, a pressure monitor, a first temperature monitor, a pH value monitor, a dissolved oxygen concentration monitor, a dissolved hydrogen solubility monitor, a suspended matter concentration monitor, an impurity ion concentration monitor and a conductivity monitor are provided on the side of the water quality regulating box;

[0010] The leakage monitoring system includes a gas buffer tank connected to the in-pile irradiation device via an electric purge valve and a safety valve pipeline in sequence, a high-pressure inert gas bottle connected to the gas buffer tank via a second electric purge valve pipeline, and a vacuum pump connected to the in-pile irradiation device and the safety valve pipeline via a first isolation valve;

[0011] A temperature monitor, a pressure monitor and a humidity monitor are provided on the pipeline between the first isolation valve and the in-pile irradiation device.

[0012] Furthermore, the circulation drive device includes a first circulation drive device and a second circulation drive device, the inlets of the first circulation drive device and the second circulation drive device are respectively connected to the outlet pipe of the first heating device, and the outlets of the first circulation drive device and the second circulation drive device are respectively connected to the inlet pipe of the second heating device.

[0013] Furthermore, the in-pile irradiation device adopts a low-flow resistance in-pile test section design, and the test section includes four guide rods and a plurality of test section modules arranged between the four guide rods and interconnected. The test section module includes an outer ring member, end members arranged at both ends of the outer ring member, and a center member arranged at the center of the outer ring member and connected to the end members at both ends. A plurality of test samples are arranged radially from the center in the same plane between the center member and the outer ring member, and the two ends of each test sample are respectively connected to the center member and the outer ring member.

[0014] Furthermore, the end parts are of a hollow design, the ribs of the end parts correspond to the test samples respectively, the edge strips of the end parts correspond to and are fixedly connected to the end edges of the outer ring part, and the two ends of the center part are fixedly connected to the center holes of the end parts respectively;

[0015] The outer ring is connected to the guide rod via a circular ring structure with concave edges. A sector-shaped flow channel section on the surface of the test sample is formed between two adjacent test samples, the center piece, and the outer ring.

[0016] Furthermore, the first heating device and the second heating device adopt a built-in heating structure, including a cylindrical structure consisting of an upper head, a lower head and a cylinder connected between the upper head and the lower head.

[0017] Furthermore, a water inlet is provided at the center of the lower head, a water outlet is provided at the center of the upper head, an electric heater mounting seat extending into the cylinder is fixedly provided on the circumference around the water outlet of the upper head, and an immersion electric heater is sealedly connected to the electric heater mounting seat;

[0018] A mixing plate with a radius smaller than the inner diameter of the cylinder is provided in the cylinder, and a circular hole interface corresponding to the position of the electric heater mounting seat is provided on the mixing plate, and the end of each electric heater mounting seat is fixedly arranged in the corresponding circular hole interface;

[0019] The side wall of the upper head is provided with a second temperature monitor for monitoring the temperature of the liquid flow in the cylinder.

[0020] Furthermore, an external thread is provided at the end of the electric heater mounting seat extending out of the upper head portion, and an internal thread cover matching the external thread at the end of the electric heater mounting seat is fixedly provided on the electric heater. The electric heater is fixedly connected to the electric heater mounting seat by screwing the internal thread cover on the external thread at the end of the electric heater mounting seat, and a sealing gasket is provided between the internal thread cover of the electric heater and the end of the electric heater mounting seat for sealing.

[0021] Furthermore, the electric heater mounting seats are evenly arranged on the circumference around the water outlet of the upper head, the spacing between two adjacent electric heater mounting seats is 30-50 mm, the spacing between the upper end surface of the mixing plate and the inner surface of the upper head is not less than 50 mm, and the sealing gasket is a flexible graphite gasket.

[0022] Furthermore, the integrated thermostat includes a high-temperature section water inlet, a first high-temperature section straight pipe section connected to the high-temperature section water inlet, a high-temperature section water outlet, a second high-temperature section straight pipe section connected to the high-temperature section water outlet, a high-temperature section bent pipe section connected between the ends of the first high-temperature section straight pipe section and the second high-temperature section straight pipe section, the other ends of the first high-temperature section straight pipe section and the second high-temperature section straight pipe section are fixedly connected to the tube sheet, the high-temperature section water inlet is connected to the outlet pipe of the circulation drive device through a drain valve, and the high-temperature section water outlet is respectively connected to the sampling device and the ultrafine filtration membrane inlet pipe;

[0023] The first high-temperature straight pipe section is sheathed on the outside of the first low-temperature straight pipe section, and the second high-temperature straight pipe section is sheathed on the outside of the second low-temperature straight pipe section. The ends of the first low-temperature straight pipe section and the second low-temperature straight pipe section are sealed and connected to the bottom of the tube sheet. The other ends of the first low-temperature straight pipe section and the second low-temperature straight pipe section are connected to the pipe box, and the high-temperature bent pipe section is arranged in the pipe box with sufficient clearance between the pipe box and the bent pipe section.

[0024] The side of the straight pipe section of the first low-temperature section is connected to the low-temperature section water outlet, and the low-temperature section water outlet is connected to the circulation drive device inlet through the second isolation valve. The side of the straight pipe section of the second low-temperature section is connected to the low-temperature section water inlet, and the low-temperature section water inlet is connected to the water quality regulating box outlet through the water injection pump.

[0025] The present invention also provides a method for testing material corrosion in a hydrochemical environment within a reactor, comprising the following steps:

[0026] Fill the high-temperature environment system with water and increase the pressure step by step to detect leaks, ensuring that the pressure drop within 10 minutes of each step does not exceed 2.5%P;

[0027] When operating a high-temperature environment system, when the temperature rises to 180°C-220°C, drain the high-temperature environment system until the pressurizer liquid level is within a reasonable range, and maintain the high-temperature environment system temperature at 180°C-220°C;

[0028] When the high temperature environment system heats up, the water quality entering the high temperature environment system is monitored and regulated online through the water quality regulation system, so that the water quality obtained by online monitoring and offline sampling analysis meets the standards;

[0029] When operating the reactor and observing and controlling the temperature rise of the high-temperature environment system to no more than 40°C / h, switch the high-temperature environment system to automatic tracking control and record the operating monitoring parameters at intervals;

[0030] The reactor is shut down, the high-temperature environment system is cooled and reduced in pressure to the rated value, and the high-temperature environment system is switched to automatic tracking control, with operation monitoring parameters recorded at intervals;

[0031] The corrosion test of the test sample is carried out to the predetermined time, and the corrosion condition of the test sample is checked.

[0032] The present invention provides an in-pile water chemical environment material corrosion test system, which consists of an optimized high-temperature environment system, a water quality regulation system and a leakage monitoring system. It has the characteristics of simple system structure, high comprehensive performance and strong test reliability.

[0033] Among them, the high-temperature environment system of the present invention is a system that provides specific environmental water temperature and specific flow rate conditions for test samples. It eliminates the main heat exchanger of the traditional in-pile test loop. It forms a thermal balance through the heating of the reactor core, electric heating of the high-efficiency heating device, and natural heat dissipation of the pipeline system, optimizes the system configuration, and reduces the complexity of the system. In addition, the in-pile irradiation device of the high-temperature environment system adopts a low-resistance in-pile test section design scheme. The fan-shaped flow channel section on the surface of the test sample is composed of two adjacent test samples, a center piece, and an outer ring piece. The flow channel section has no resistance loss, so that the surface of the test sample can obtain a higher flow rate during the test, making the test more in line with the in-pile service conditions of the sample and improving the pertinence of the test. At the same time, the heating device of the high-temperature environment system adopts a new built-in heating structure, which improves the traditional pipe outer hoop heater into a built-in high-efficiency heating device, improves the use efficiency of the electric heater, saves operating costs and energy, and improves economic benefits.

[0034] The water quality regulation system of the present invention is used to regulate water quality in a high-temperature environment system. It has the functions of filtration, ion adsorption, gas addition, and liquid addition. The water quality regulation system has a pressure reducing valve located at the rear end of the ion exchange column, which can fully utilize the pressure head of the high-pressure system to overcome the pressure drop of the ultrafine filtration membrane and ion exchange column. Compared with the traditional system method of first reducing the pressure and then using a dedicated drive pump to drive the circulation, this simplifies the process and reduces the complexity of the system. In addition, the pressure reducing valve is arranged in parallel with two, which overcomes the disadvantage of the traditional system being unable to operate normally after a single unit fails, thereby improving the reliability of the system. At the same time, the integrated thermostat of the water quality regulation system combines the functions of the cooler and preheater of the existing process system to form a compact integrated thermostat. The high-temperature section can directly reduce the fluid temperature from high temperature to room temperature through heat exchange, and the low-temperature section can also be heated to medium temperature through heat exchange. The high-temperature and low-temperature sections adopt a single-channel countercurrent arrangement, and sufficient gaps are left between the pipe box and the high-temperature section bend to absorb the expansion of the high-temperature section pipe. While meeting the system's cooling and heating requirements, it simplifies the equipment configuration, improves the system's economic efficiency, and saves costs.

[0035] The leakage monitoring system of the present invention monitors the in-pile irradiation device for leaks and ensures reactor safety through temperature, pressure, and humidity monitoring devices, including those installed on the pipeline between the in-pile irradiation device and the high-temperature environment system. Furthermore, the leakage monitoring system of the present invention eliminates the gas circulation pump of the existing system and forms a static gas system through the gas buffer tank, electric bleed valve, the in-pile irradiation device's air cavity, and the pipelines between them. Furthermore, since parameters such as the temperature, pressure, and humidity of the in-pile irradiation device's air cavity under leakage conditions can still be monitored by the temperature, pressure, and humidity monitors installed on the pipelines, the present invention not only reduces system complexity but also improves system reliability. During operation, when the static gas system pressure falls below the operating limit, the electric bleed valve automatically opens to inflate the gas buffer tank. When the gas buffer tank pressure is detected to be too low, a second electric bleed valve automatically opens to inflate the gas buffer tank, achieving automated gas replenishment. Compared to the manual gas replenishment method of the existing system, this reduces the operator's operational workload and improves the system's automation level. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic structural diagram of an in-pile water chemical environment material corrosion test system provided by an embodiment of the present invention;

[0037] Figure 2 A schematic structural diagram of a low flow resistance in-pile test section of an in-pile irradiation device of an in-pile water chemical environment material corrosion test system provided by an embodiment of the present invention;

[0038] Figure 3A schematic structural diagram of an end component of a low-flow-resistance in-pile test section of an in-pile irradiation device in an in-pile water chemical environment material corrosion test system provided by an embodiment of the present invention;

[0039] Figure 4 A schematic structural diagram of a heating device for an in-pile water chemical environment material corrosion test system provided by an embodiment of the present invention;

[0040] Figure 5 A schematic diagram of the structure of a mixing plate in a heating device of an in-pile water chemical environment material corrosion test system provided by an embodiment of the present invention;

[0041] Figure 6 A schematic diagram of the structure of an integrated thermostat for an in-pile water chemical environment material corrosion test system provided by an embodiment of the present invention.

[0042] Reference numerals:

[0043] 1-1-01 In-pile irradiation device, 1-1-02 First heating device 1, 1-1-03 Voltage stabilizer, 1-1-04A First circulation drive device, 1-1-04B Second circulation drive device, 1-1-05 Second heating device; 1-2-01 Integrated thermostat, 1-2-02 Ultrafine filtration membrane, 1-2-03A First ion exchange column, 1-2-03B Second ion exchange column, 1-2-03C Third ion exchange column, 1-2-04A First pressure reducing valve, 1-2-04B Second pressure reducing valve, 1-2-05 Water quality regulating box, 1-2-06 Water quality regulating box heater, 1-2-07A First liquid adding device, 1-2-07B Second liquid adding device, 1-2-08A first gas addition device, 1-2-08B second gas addition device, 1-2-09A first water injection pump, 1-2-09B second water injection pump, 1-2-10 water quality adjustment system, 1-2-11 sampling device, 1-2-12 second isolation valve, I-1 liquid level monitor, I-2 first pressure monitor, I-3 first temperature monitor, I-4 pH monitor, I-5 dissolved oxygen concentration monitor, I-6 dissolved hydrogen solubility monitor Detector, I-7 suspended matter concentration monitor, I-8 impurity ion concentration monitor, I-9 conductivity monitor; 1-3-01 high-pressure inert gas bottle, 1-3-02 gas buffer tank, 1-3-03 first electric air release valve, 1-3-04A / B safety valve, 1-3-05 first isolation valve, 1-3-06 vacuum pump, 1-3-07 second electric air release valve, I-10 temperature monitor, I-11 pressure monitor, I-12 humidity monitor.

[0044] 2-1 Guide rod, 2-2 Sample, 2-3 Center piece, 2-3-01 Center piece groove, 2-4 Outer ring piece, 2-4-01 Outer ring piece groove, 2-5 End piece, 2-5-01 End piece rib, 2-5-02 End piece edge strip.

[0045] 3-1 upper head, 3-2 lower head, 3-3 cylinder, 3-4 immersion electric heater, 3-5 electric heater mounting base, 3-6 water inlet, 3-7 water outlet, 3-8 second temperature monitor, 3-9 mixing plate.

[0046] 4-1 high-temperature section water inlet, 4-2 high-temperature section water outlet, 4-7 first high-temperature section straight pipe section, 4-8 high-temperature section curved pipe section, 4-9 second high-temperature section straight pipe section, 4-3 low-temperature section water inlet, 4-4 low-temperature section water outlet, 4-6 first low-temperature section straight pipe section, 4-5 tube sheet, 4-10 second low-temperature section straight pipe section, 4-11 pipe box, 4-5-01 tube sheet first interface ring, 4-5-02 tube sheet second interface ring, 4-11-01 pipe box first nozzle, 4-11-02 pipe box second nozzle. DETAILED DESCRIPTION

[0047] See also Figure 1 An embodiment of the present invention provides an in-pile water chemical environment material corrosion test system, which includes a high-temperature environment system, a water quality adjustment system connected to the high-temperature environment system, and a leakage monitoring system connected to the high-temperature environment system. The high-temperature environment system provides samples with specific environmental water temperature, specific water flow rate and other conditions. The water quality adjustment system is used to adjust the water quality in the high-temperature environment system, and has multiple functions such as filtration, ion adsorption, gas addition, and liquid addition. The leakage monitoring system determines whether there is a leakage problem in the in-pile radiation device by monitoring specific parameters such as pressure of the high-temperature environment system, thereby ensuring the safety of the reactor. It has the characteristics of simple system structure, high comprehensive performance and strong reliability.

[0048] Among them, the high-temperature environment system includes an in-pile irradiation device 1-1-01, the outlet of the in-pile irradiation device 1-1-01 is connected to the inlet pipe of the first heating device 1-1-02, the outlet of the first heating device 1-1-02 is connected to the inlet pipe of the circulation drive device, the outlet of the circulation drive device is connected to the inlet pipe of the second heating device 1-1-05, the outlet of the second heating device 1-1-05 is connected to the inlet pipe of the in-pile irradiation device 1-1-01, and a parallel stabilizer 1-1-03 is connected between the first heating device 1-1-02 and the second heating device 1-1-05.

[0049] The water quality regulation system includes an integrated thermostat 1-2-01 whose high-temperature section inlet is connected to the circulation drive device outlet pipe, the high-temperature section outlet of the integrated thermostat 1-2-01 is respectively connected to the sampling device 1-2-11 and the ultrafine filtration membrane 1-2-02 inlet pipe, the ultrafine filtration membrane 1-2-02 outlet is connected in parallel with multiple ion exchange column inlet pipes, the ion exchange column outlet is connected to the water quality regulation box 1-2-05 inlet pipe through a pressure reducing valve, the water quality regulation box 1-2-05 outlet is connected to the low-temperature section inlet pipe of the integrated thermostat 1-2-01 through a water injection pump, and the low-temperature section outlet of the integrated thermostat 1-2-01 is connected to the circulation drive device inlet pipe.

[0050] A liquid adding device and a gas adding device are provided on the upper part of the water quality regulating tank 1-2-05, a water quality regulating tank heater 1-2-06 is provided on the bottom of the water quality regulating tank 1-2-05, and a liquid level monitor I-1, a pressure monitor I-2, a first temperature monitor I-3, a pH value monitor I-4, a dissolved oxygen concentration monitor I-5, a dissolved hydrogen solubility monitor I-6, a suspended matter concentration monitor I-7, an impurity ion concentration monitor I-8 and a conductivity monitor I-9 are provided on the side of the water quality regulating tank 1-2-05.

[0051] The leakage monitoring system includes a gas buffer tank 1-3-02 connected to the in-pile irradiation device 1-1-01 through an electric purge valve 1-3-03 and a safety valve pipeline in sequence, a high-pressure inert gas bottle 1-3-01 connected to the gas buffer tank 1-3-02 through a second electric purge valve 1-3-07 pipeline, and a vacuum pump 1-3-06 connected to the pipeline between the in-pile irradiation device 1-1-01 and the safety valve through a first isolation valve 1-3-05.

[0052] A temperature monitor I-10, a pressure monitor I-11 and a humidity monitor I-12 are installed on the pipeline between the first isolation valve 1-3-05 and the in-pile irradiation device 1-1-01.

[0053] Among them, there are at least two circulating drive devices. When the system is working, when one circulating drive device is put into operation, the other circulating drive device serves as a backup. When a circulating drive device suddenly fails, the other backup circulating drive device can be put into operation in time.

[0054] As a specific embodiment of the present invention, the circulation drive device includes a first circulation drive device 1-1-04A and a second circulation drive device 1-1-04B. The inlets of the first circulation drive device 1-1-04A and the second circulation drive device 1-1-04B are respectively connected to the outlet pipe of the first heating device 1-1-02, and the outlets of the first circulation drive device 1-1-04A and the second circulation drive device 1-1-04B are respectively connected to the inlet pipe of the second heating device 1-1-05.

[0055] Multiple ion exchange columns are provided to remove impurity ions from water entering the high-temperature environment system. Furthermore, when the impurity ion concentration monitor 1-8 detects that the impurity ion concentration in the water quality conditioning tank 1-2-05 is too high, additional ion exchange columns can be activated to rapidly reduce the impurity ion concentration in the water quality conditioning tank 1-2-05 to a predetermined level.

[0056] As a specific embodiment of the present invention, the ion exchange column includes a first ion exchange column 1-2-03A, a second ion exchange column 1-2-03B and a third ion exchange column 1-2-03C, so that the impurity ion concentration in the water quality regulating tank 1-2-05 is adjusted by starting one, two or three of the three ion exchange columns, and the impurity ion concentration in the water quality regulating tank 1-2-05 is controlled within a predetermined concentration range.

[0057] As a specific embodiment of the present invention, two pressure-reducing valves are provided at the outlet of the ion exchange column: a first pressure-reducing valve 1-2-04A and a second pressure-reducing valve 1-2-04B. By placing the pressure-reducing valve of the water quality conditioning system at the rear end of the ion exchange column, the present invention fully utilizes the pressure head of the high-pressure system to overcome the pressure drop across the ultrafine filtration membrane and ion exchange column. Compared to the conventional system that first reduces the pressure and then uses a dedicated drive pump to drive the circulation, this simplifies the process and reduces system complexity. Furthermore, by having two pressure-reducing valves connected in parallel, this overcomes the drawback of conventional systems where a single pressure-reducing valve fails and the system becomes inoperable, thereby improving system reliability.

[0058] As a specific embodiment of the present invention, two liquid addition devices and two gas addition devices are provided on the upper portion of the water quality regulating tank 1-2-05. The two liquid addition devices are a first liquid addition device 1-2-07A and a second liquid addition device 1-2-07B. When liquid solution is required, liquid is added via the first liquid addition device 1-2-07A and the second liquid addition device 1-2-07B. Furthermore, based on the liquid level within the water quality regulating tank 1-2-05 as monitored by the liquid level monitor I-1 provided on the water quality regulating tank 1-2-05, one or both of the first liquid addition device 1-2-07A and the second liquid addition device 1-2-07B can be selected to add liquid as needed.

[0059] Furthermore, two gas addition devices, first gas addition device 1-2-08A and second gas addition device 1-2-08B, are located above water quality conditioning tank 1-2-05. These devices are used to add oxygen and hydrogen, respectively, to water quality conditioning tank 1-2-05. When dissolved oxygen concentration monitor 1-5 and dissolved hydrogen solubility monitor 1-6 detect a need for increased dissolved oxygen and dissolved hydrogen in water quality conditioning tank 1-2-05, oxygen and hydrogen can be added via first gas addition device 1-2-08A and second gas addition device 1-2-08B.

[0060] The cooling water in the high-temperature environment system that needs to be regulated is sequentially flow-controlled through the drain valve 1-2-10, cooled to below 40°C by the integrated thermostat 1-2-01 (to meet the temperature requirements of subsequent processes), sampled before regulation by the sampling device 1-2-11, and removed of suspended matter and solid impurities by the ultra-fine filtration membrane 1-2-02. The water is then passed through the first ion exchange column 1-2-03A, the second ion exchange column 1-2-03B, and the third ion exchange column 1-2-03. C removes impurity ions, reduces the cooling water pressure to low pressure through the first pressure reducing valve 1-2-04A and the second pressure reducing valve 1-2-04B, enters the water quality regulating box 1-2-05 for water quality regulation, and then is pressurized and injected into the low-temperature section of the integrated thermostat 1-2-01 through the first water injection pump 1-2-09A and the second water injection pump 1-2-09B. After being heated to a high temperature (at least 200°C to reduce the thermal stress of the pipeline system) in the low-temperature section of the integrated thermostat 1-2-01, it returns to the high-temperature environment system.

[0061] Multiple parameter monitoring monitors are set on the water quality regulating tank 1-2-05, including liquid level monitor I-1, pressure monitor I-2, first temperature monitor I-3, pH value monitor I-4, dissolved oxygen concentration monitor I-5, dissolved hydrogen solubility monitor I-6, suspended matter concentration monitor I-7, impurity ion concentration monitor I-8, and conductivity monitor I-9. The above data can be monitored online in real time. When the temperature needs to be raised, the water quality regulating tank heater 1-2-06 is started. When liquid solution needs to be added, it is added through the first liquid adding device 1-2-07A and the second liquid adding device 1-2-07B. When the gas component (dissolved oxygen, dissolved hydrogen) content needs to be increased, it is added through the first gas adding device 1-2-08A and the second gas adding device 1-2-08B.

[0062] The first and second pressure-reducing valves 1-2-04A and 1-2-04B of the water quality regulation system are positioned at the rear ends of the first, second, and third ion exchange columns 1-2-03A, 1-2-03B, and 1-2-03C, respectively. This allows the high-pressure system's head pressure to be fully utilized to overcome the pressure drop across the ultrafine filtration membrane 1-2-02, the first, second, and third ion exchange columns 1-2-03A, 1-2-03B, and 1-2-03C. Compared to conventional systems that first reduce pressure and then employ a dedicated drive pump to drive circulation, the corrosion testing system of the present invention simplifies the process and reduces system complexity. Furthermore, the arrangement of two pressure-reducing valves in parallel—the first and second pressure-reducing valves 1-2-04A and 1-2-04B—overcomes the drawback of conventional systems where a single pressure-reducing valve fails and the system becomes inoperable, thereby improving system reliability.

[0063] See also Figure 2 The in-pile irradiation device 1-1-01 utilizes a low-resistance in-pile test section design, comprising four guide rods 2-1 and multiple interconnected test section modules arranged between the four guide rods 2-1. The test section modules comprise an outer ring 2-4, end pieces 2-5 disposed at either end of the outer ring 2-4, and a center piece 2-3 disposed at the center of the outer ring 2-4 and connected to the end pieces 2-5 at both ends. Multiple test samples 2-2 are radially arranged within the same plane between the center piece 2-3 and the outer ring 2-4, with each test sample 2-2 connected to the center piece 2-3 and the outer ring 2-4 at both ends.

[0064] As a specific embodiment of the present invention, there are eight test samples 2-2. In the test section module, the test samples 2-2 are arranged radially from the center, and the angle between two adjacent test samples 2-2 is 45°. In this way, eight test samples 2-2 can be arranged in the entire circumference. One side of the test sample 2-2 is inserted into a groove 2-3-01 of the center piece 2-3, and the other side of the test sample 2-2 is inserted into the groove 2-4-01 corresponding to the outer ring piece 2-4. In addition, in order to avoid the test sample 2-2 from being stuck when it is removed later, the surfaces of the test sample 2-2 in contact with the groove have at least a certain assembly gap, and at least a gap of 0.2mm is retained. Of course, according to the test requirements, the number of test samples 2-2 can be further increased. For example, ten test samples 2-2 can be arranged, so that the angle between two adjacent test samples 2-2 is 36°.

[0065] See also Figure 3The end piece 2-5 is a hollow design. The ribs 2-5-01 of the end piece 2-5 correspond to the test sample 2-2. The edge strips 2-5-02 of the end piece 2-5 correspond to the edges of the outer ring 2-4 and are fixedly connected by welding. That is, the ribs 2-5-01 of the end piece 2-5 correspond one-to-one with the test sample 2-2, and their projections overlap. The edge strips 2-5-02 of the end piece 2-5 overlap and are fixed to the outer ring 2-4. The two ends of the center piece 2-3 are fixedly connected to the center hole 2-5-03 of the end piece 2-5 by welding.

[0066] As a specific embodiment of the present invention, the outer ring member 2-4 is provided with a concave annular structure 2-4-02 at the location where it connects to the guide rod 2-1. The outer ring member 2-4 is connected to the guide rod 2-1 via its concave annular structure 2-4-02. Furthermore, to facilitate disassembly and installation, a gap of at least 1 mm is maintained between the concave annular structure 2-4-02 of the outer ring member 2-4 and the guide rod 2-1. The fan-shaped flow channel cross-section of the surface of the test sample 2-2 is formed between two adjacent test samples 2-2, the center member 2-3, and the outer ring member 2-4.

[0067] When the water meets the quality standards after being monitored and regulated by the water quality regulation system, it enters the high-temperature environment system from the integrated thermostat 1-2-01 through the second isolation valve 1-2-12, first passes through the first circulation drive device 1-1-04A and / or the second circulation drive device 1-1-04B and enters the second heating device 1-1-05. After being further heated by the second heating device 1-1-05, it enters the in-pile irradiation device 1-1-01. In the in-pile irradiation device 1-1-01, the test sample 2-2 is subjected to the corrosion test of the in-pile water chemical environment. After the water flowing through test sample 2-2 is discharged from in-pile irradiation device 1-1-01, it is heated by first heating device 1-1-02 and then driven by first circulation drive device 1-1-04A and / or second circulation drive device 1-1-04B into second heating device 1-1-05. After further heating by second heating device 1-1-05, it enters in-pile irradiation device 1-1-01 again. This cycle allows test sample 2-2 to be repeatedly circulated within in-pile irradiation device 1-1-01 to undergo corrosion testing in the in-pile water chemical environment. Because the fan-shaped flow channel cross-section on the surface of test sample 2-2, formed between two adjacent test samples 2-2, center piece 2-3, and outer ring piece 2-4, has no resistance loss, the test section has low flow resistance. This allows for a higher flow velocity on the surface of test sample 2-2 during the test, with the surface velocity reaching up to 10 m / s. This ensures that the test is more consistent with the in-pile service conditions of test sample 2-2, improving the test's pertinence and accuracy.

[0068] Furthermore, the present invention can not only heat the water used for the corrosion test of the test sample 2-2 by the first heating device 1-1-02 and the second heating device 1-1-05, but also perform a cyclic corrosion test on the test sample 2-2 by using the heat-balanced water formed by the nuclear heating of the reactor and the natural heat dissipation of the piping system, thereby providing a specific ambient water temperature and a specific liquid flow rate condition for the in-pile water chemical environment corrosion test of the test sample 2-2, which not only optimizes the system configuration, reduces the complexity of the system, and reduces the system thermal power loss, but also improves the authenticity of the in-pile water chemical environment corrosion test and the accuracy of the test.

[0069] See also Figure 4 The first heating device 1-1-02 and the second heating device 1-1-05 adopt a built-in heating structure, which includes a cylindrical structure consisting of an upper head 3-1, a lower head 3-2, and a cylinder 3-3 connected between the upper head 3-1 and the lower head 3-2. The upper end of the cylinder (3-3) and the upper head (3-1) are butt-welded together through an upper end weld (3-10) set on the straight cylinder wall, and the lower end of the cylinder (3-3) and the lower head (3-2) are butt-welded together through a lower end weld (3-11) set on the straight cylinder wall.

[0070] A water inlet 3-6 is located at the center of the lower end cap 3-2, and a water outlet 3-7 is located at the center of the upper end cap 3-1. An electric heater mounting base 3-5 is fixedly mounted around the circumference of the upper end cap 3-1, extending into the barrel 3-3. An immersion electric heater 3-4 is connected to the electric heater mounting base 3-5. The electric heater mounting base 3-5 is first assembled with the upper end cap 3-1 by cold fitting or expansion jointing. The electric heater mounting base 3-5 is then circumferentially welded to the inner and outer surfaces of the upper end cap 3-1.

[0071] As a specific embodiment of the present invention, the portion of the electric heater mounting base 3-5 extending from the upper head 3-1 is provided with an external thread, and the electric heater 3-4 is fixedly provided with an internal thread cover 3-4-01 that matches the external thread at the end of the electric heater mounting base 3-5. When the electric heater 3-4 is installed, the electric heater 3-4 is screwed onto the external thread at the end of the electric heater mounting base 3-5 via the internal thread cover 3-4-01, thereby fixing the electric heater 3-4 in the electric heater mounting base 3-5. Furthermore, in order to ensure the airtightness of the connection between the electric heater 3-4 and the electric heater mounting base 3-5, a sealing gasket 3-4-02 is provided between the internal thread cover 3-4-01 of the electric heater 3-4 and the end of the electric heater mounting base 3-5. The sealing gasket 3-4-02 is compressed by the thread cover 3-4-01 of the electric heater 3-4 and then screwed onto the external thread at the end of the electric heater mounting base 3-5 to seal.

[0072] As a specific embodiment of the present invention, the material of the sealing gasket 3-4-02 can be flexible graphite.

[0073] As a specific embodiment of the present invention, the electric heaters 3-4 are arranged in a uniform circular pattern along with the electric heater mounting base 3-5, and the distance between each two electric heaters 3-4 is not less than the size requirement of the electric heater threaded cover 3-4-01 operating tool, and is generally set to 30-50 mm.

[0074] See also Figure 5 A mixing plate 3-9 with a radius smaller than the inner diameter of the cylinder 3-3 is installed inside the cylinder 3-3. The mixing plate 3-9 is a solid circular plate. The mixing plate 3-9 is provided with a circular hole interface 3-9-01 corresponding to the assembly position of the electric heater mounting base 3-5. The end of each electric heater mounting base 3-5 is fixedly installed in the corresponding circular hole interface 3-9-01. After the electric heater mounting base 3-5 is inserted into the circular hole interface 3-9-01, the electric heater mounting base 3-5 and the circular hole interface 3-9-01 are fixedly connected together by welding.

[0075] Furthermore, in order to reduce the resistance to liquid flow, a certain distance needs to be maintained between the upper end surface of the mixing plate 3-9 and the inner surface of the upper head 3-1. As a specific embodiment of the present invention, the distance between the upper end surface of the mixing plate 3-9 and the inner surface of the upper head 3-1 should be at least 50 mm.

[0076] Furthermore, in order to monitor the liquid flow temperature in the first heating device 1-1-02 and the second heating device 1-1-05 at any time, a second temperature monitor 3-8 is provided on the side wall of the upper head 3-1 to monitor the liquid flow temperature in the cylinder 3-3.

[0077] See also Figure 6 The integrated thermostat 1-2-01 includes a high-temperature section and a low-temperature section. The high-temperature section includes a high-temperature section water inlet 4-1, a first high-temperature section straight pipe section 4-7 connected to the high-temperature section water inlet 4-1, a high-temperature section water outlet 4-2, and a second high-temperature section straight pipe section 4-9 connected to the high-temperature section water outlet 4-2. A high-temperature section elbow section 4-8 is connected between the ends of the first high-temperature section straight pipe section 4-7 and the second high-temperature section straight pipe section 4-9. The other ends of the first high-temperature section straight pipe section 4-7 and the second high-temperature section straight pipe section 4-9 are fixedly connected to the tube sheet 4-5. The high-temperature section water inlet 4-1, the high-temperature section water outlet 4-2, the first high-temperature section straight pipe section 4-7, the high-temperature section elbow section 4-8, and the second high-temperature section straight pipe section 4-9 are all butt-welded together. Among them, the high-temperature section water inlet 4-1 is connected to the outlet pipe of the circulation drive device through the drain valve 1-2-10, and the high-temperature section water outlet 4-2 is connected to the sampling device 1-2-11 and the ultrafine filtration membrane 1-2-02 inlet pipe respectively.

[0078] As a specific embodiment of the present invention, when the first high-temperature section straight pipe section 4-7 connected to the high-temperature section water inlet 4-1 and the second high-temperature section straight pipe section 4-9 connected to the high-temperature section water outlet 4-2 are respectively connected and assembled with the tube sheet 4-5, they are first installed by cold installation or expansion connection, and then circumferential welding is performed on the inner and outer surfaces of the tube sheet 4-5 respectively.

[0079] The low-temperature section includes a low-temperature section water inlet 4-3, a low-temperature section water outlet 4-4, a first low-temperature section straight pipe section 4-6, a tube sheet 4-5, a second low-temperature section straight pipe section 4-10, and a pipe box 4-11. The low-temperature section water inlet 4-3 is connected to the second low-temperature section straight pipe section 4-10, and the low-temperature section water outlet 4-4 is connected to the first low-temperature section straight pipe section 4-6. Furthermore, the first high-temperature section straight pipe section 4-7 is externally sheathed with the first low-temperature section straight pipe section 4-6, and the second high-temperature section straight pipe section 4-9 is externally sheathed with the second low-temperature section straight pipe section 4-10. One end of the first low-temperature section straight pipe section 4-6 is sealed connected to the tube sheet 4-5 through the first interface ring position 4-5-01 on the tube sheet 4-5, and the other end of the first low-temperature section straight pipe section 4-6 is sealed connected to the tube box 4-11 through the first nozzle position 4-11-01 on the tube box 4-11. One end of the second low-temperature section straight pipe section 4-10 is sealed connected to the tube sheet 4-5 through the second interface ring position 4-5-02 on the tube sheet 4-5, and the other end of the second low-temperature section straight pipe section 4-10 is sealed connected to the tube box 4-11 through the second nozzle position 4-11-02 on the tube box 4-11.

[0080] At the same time, the high temperature section bend 4-8 is arranged in the pipe box 4-11, and in order to ensure that the pipe box 4-11 absorbs the expansion of the high temperature section bend 4-8 when heated, there is enough gap between the pipe box 4-11 and the high temperature section bend 4-8.

[0081] Among them, the low-temperature section water outlet 4-4 is connected to the inlet of the circulation drive device through the second isolation valve 1-2-12, and the low-temperature section water inlet 4-3 is connected to the outlet of the water quality regulating tank 1-2-05 through the water injection pump.

[0082] The high-temperature section of the integrated thermostat 1-2-01 provided by the present invention can directly cool the fluid from a high-temperature liquid to room temperature, while the low-temperature section can raise the low-temperature liquid to a medium temperature. Furthermore, the high-temperature and low-temperature sections employ a single-channel countercurrent arrangement, with the high-temperature section water inlet 4-1 located near the low-temperature section water outlet 4-4, and the high-temperature section water outlet 4-2 located near the low-temperature section water inlet 4-3. This facilitates heat exchange between the high-temperature liquid entering the high-temperature section and the low-temperature liquid entering the low-temperature section.

[0083] Because traditional leakage monitoring systems use a gas circulation monitoring method, their gas circulation pump has a high failure rate, resulting in the system often being unable to operate normally. Therefore, the leakage monitoring system provided by the present invention eliminates the gas circulation pump and adopts a leakage monitoring system comprising a high-pressure inert gas bottle 1-3-01, a gas buffer tank 1-3-02, an electric purge valve 1-3-03, a first safety valve 1-3-04A, a second safety valve 1-3-04B, a first isolation valve 1-3-05, a vacuum pump 1-3-06, a second electric purge valve 1-3-07, a temperature monitor 1-10, a pressure monitor 1-11, and a humidity monitor 1-12.

[0084] A static gas system is formed by the gas buffer tank 1-3-02, the electric air release valve 1-3-03, the air cavity of the in-pile irradiation device 1-1-01 and the pipelines therebetween. However, the temperature, pressure, humidity and other parameters of the air cavity of the in-pile irradiation device 1-1-01 under leakage conditions can still be monitored by the temperature monitor I-10, pressure monitor I-11 and humidity monitor I-12 arranged on the pipeline. Therefore, the present invention not only reduces the complexity of the system, but also reduces the failure frequency of the leak detection system, thereby improving the reliability of the system.

[0085] During operation, the first electric bleed valve 1-3-03 is closed, the first isolation valve 1-3-05 is opened, and the vacuum pump 1-3-06 is turned on to evacuate the static gas system. Next, the vacuum pump 1-3-06 is turned off, the first isolation valve 1-3-05 is closed, and the first electric bleed valve 1-3-03 is opened to inflate the static gas system. Once the inflation pressure meets the required level, the first electric bleed valve 1-3-03 is closed. During operation, when the pressure in the static gas system falls below the operating limit, the first electric bleed valve 1-3-03 automatically opens to inflate the system. When the pressure in the gas buffer tank 1-3-02 is detected to be too low, the second electric bleed valve 1-3-07 automatically opens to inflate the gas buffer tank 1-3-02, achieving automated gas replenishment. In the event of a leak, the pressure in the static gas system will rise sharply, at which point the first safety valve 1-3-04A and / or the second safety valve 1-3-04B automatically opens. Since the present invention provides two safety valves, the first safety valve 1-3-04A and the second safety valve 1-3-04B, when one of the safety valves fails, the other safety valve can be quickly started, thereby ensuring the safety of system operation.

[0086] The present invention provides a method for testing material corrosion in an in-pile water chemical environment, comprising the following steps:

[0087] 1) Fill the high-temperature environment system with water and increase the pressure step by step to detect leaks, ensuring that the pressure drop within 10 minutes of each step does not exceed 2.5%P;

[0088] 2) When operating the high temperature environment system, when the temperature rises to 180℃-220℃, drain the high temperature environment system to the pressure regulator (1-1-03) so that the liquid level is within a reasonable range, and maintain the high temperature environment system temperature at 180℃-220℃;

[0089] 3) When the high-temperature environment system heats up, the water quality entering the high-temperature environment system is monitored and regulated online through the water quality regulation system, so that the water quality obtained by online monitoring and offline sampling analysis meets the standards;

[0090] 4) When operating the reactor and observing and controlling the temperature rise of the high-temperature environment system to no more than 40°C / h, switch the high-temperature environment system to automatic tracking control and record the operating monitoring parameters at intervals;

[0091] 5) When the reactor is shut down, the high-temperature environment system is cooled and depressurized to the rated value, and the high-temperature environment system is switched to automatic tracking control, with operation monitoring parameters recorded at intervals;

[0092] 6) Carry out the corrosion test on the test sample (2-2) until the predetermined time, and check the corrosion condition of the test sample (2-2).

[0093] Specifically, the present invention provides a method for testing material corrosion in a hydrochemical environment within a reactor, including a system pressure-boosting leak detection operation method, a system temperature-boosting operation method, a system water quality preparation method, a system steady-state operation method, and a system temperature- and pressure-reducing operation method. The test method steps and the overall operating principles involved are as follows.

[0094] (1) The boost leak detection operation method is as follows:

[0095] Step 1: After the system is assembled, first fill it with water and exhaust it until no gas is discharged from each drain port;

[0096] Step 2: For high-pressure systems, conduct leak detection at least at four pressure levels, such as 50%P, 75%P, 90%P, and 100%P, where P is the system operating pressure.

[0097] Step 3: After the pressure stabilizes, the pressure holding time of each stage shall not be less than 10 minutes. The qualified standard is that the pressure drop within 10 minutes shall not exceed 2.5%P.

[0098] (2) The system temperature rise operation method is as follows:

[0099] Step 1: Put high-efficiency heating device 1 and high-efficiency heating device 2 into operation. The input power shall not exceed 50% of the full power. At the same time, it is necessary to ensure that the system heating rate does not exceed 40℃ / h.

[0100] Step 2: When the system temperature rises to about 200℃, open the system drain valve to drain water until the liquid level of the pressurizer is observed to be within a reasonable range, then stop draining water;

[0101] Step 3: Reduce the power of high-efficiency heating device 1 and high-efficiency heating device 2 to maintain the current temperature of the system.

[0102] (3) System water quality preparation method is as follows:

[0103] Step 1: Start preparing the system water quality when the system starts to heat up;

[0104] Step 2: Use the online monitoring instrument of the water quality regulation system to determine the parameters that need to be adjusted. If the impurity ion concentration is too high, continue to add ion exchange columns. If the dissolved hydrogen content is low, continue to add hydrogenation equipment and increase the hydrogen pressure in the water tank of the water quality regulation system. If the suspended solids concentration is too high, continue to add filters for filtration.

[0105] Step 3: Further verify water quality indicators through offline sampling at intervals;

[0106] Step 4: Only when the online monitoring instrument and offline sampling analysis results meet the requirements can it be proved that the water quality requirements are met.

[0107] (IV) The system steady-state operation method is as follows:

[0108] Step 1: After the reactor is started, observe the temperature rise of the system. If the temperature rise exceeds 40°C / h, further reduce the power of high-efficiency heating device 1 and high-efficiency heating device 2 until the temperature rise rate does not exceed 40°C / h.

[0109] Step 2: After the system reaches the rated parameters, the electric heating control of the high-efficiency heating device 1 and the high-efficiency heating device 2 is switched to the automatic gear, and the system performs automatic tracking control;

[0110] Step 3: Manually record the system operation monitoring parameters at regular intervals.

[0111] (V) The system cooling and pressure reduction operation method is as follows:

[0112] Step 1: Cooling and depressurization operations are allowed only after the reactor is shut down;

[0113] Step 2: After the system reaches the rated parameters, the electric heating control of the high-efficiency heating device 1 and the high-efficiency heating device 2 is switched to the automatic gear, and the system performs automatic tracking control.

[0114] Step 3: Manually record system operation monitoring parameters every 2 hours.

[0115] (6) After the corrosion test of the test sample reaches the predetermined time, the corrosion test is stopped and the corrosion condition of the test sample can be checked.

[0116] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An in-pile water chemical environment material corrosion test system, characterized in that: It includes a high temperature environment system, a water quality regulation system connected to the high temperature environment system, and a leakage monitoring system connected to the high temperature environment system; The high-temperature environment system includes an in-pile irradiation device (1-1-01), the outlet of the in-pile irradiation device (1-1-01) is connected to the inlet pipe of the first heating device (1-1-02), the outlet of the first heating device (1-1-02) is connected to the inlet pipe of the circulation drive device, the outlet of the circulation drive device is connected to the inlet pipe of the second heating device (1-1-05), the outlet of the second heating device (1-1-05) is connected to the inlet pipe of the in-pile irradiation device (1-1-01), and a parallel stabilizer (1-1-03) is connected between the first heating device (1-1-02) and the second heating device (1-1-05); The water quality regulation system comprises an integrated thermostat (1-2-01) whose high-temperature section inlet is connected to an outlet pipe of a circulation drive device, the high-temperature section outlet of the integrated thermostat (1-2-01) is respectively connected to a sampling device (1-2-11) and an ultrafine filtration membrane (1-2-02) inlet pipe, the ultrafine filtration membrane (1-2-02) outlet is connected in parallel to a plurality of ion exchange column inlet pipes, the ion exchange column outlet is connected to an inlet pipe of a water quality regulation box (1-2-05) via a pressure reducing valve, the water quality regulation box (1-2-05) outlet is connected to a low-temperature section inlet pipe of the integrated thermostat (1-2-01) via a water injection pump, and the low-temperature section outlet of the integrated thermostat (1-2-01) is connected to an inlet pipe of the circulation drive device; A liquid adding device and a gas adding device are provided on the upper portion of the water quality regulating box (1-2-05); a water quality regulating box heater (1-2-06) is provided on the bottom portion of the water quality regulating box (1-2-05); and a liquid level monitor (I-1), a pressure monitor (I-2), a first temperature monitor (I-3), a pH value monitor (I-4), a dissolved oxygen concentration monitor (I-5), a dissolved hydrogen solubility monitor (I-6), a suspended matter concentration monitor (I-7), an impurity ion concentration monitor (I-8), and a conductivity monitor (I-9) are provided on the side portion of the water quality regulating box (1-2-05); The leakage monitoring system comprises a gas buffer tank (1-3-02) connected to the in-pile irradiation device (1-1-01) via an electric purge valve (1-3-03) and a safety valve pipeline in sequence, a high-pressure inert gas bottle (1-3-01) connected to the gas buffer tank (1-3-02) via a second electric purge valve (1-3-07) pipeline, and a vacuum pump (1-3-06) connected to the in-pile irradiation device (1-1-01) and the pipeline between the safety valve via a first isolation valve (1-3-05); A temperature monitor (I-10), a pressure monitor (I-11) and a humidity monitor (I-12) are provided on the pipeline between the first isolation valve (1-3-05) and the in-pile irradiation device (1-1-01).

2. The in-pile water chemical environment material corrosion test system according to claim 1 is characterized by: The circulation drive device includes a first circulation drive device (1-1-04A) and a second circulation drive device (1-1-04B), the inlets of the first circulation drive device (1-1-04A) and the second circulation drive device (1-1-04B) are respectively connected to the outlet pipe of the first heating device (1-1-02), and the outlets of the first circulation drive device (1-1-04A) and the second circulation drive device (1-1-04B) are respectively connected to the inlet pipe of the second heating device (1-1-05).

3. The in-pile water chemical environment material corrosion test system according to claim 2, characterized in that: The in-pile irradiation device (1-1-01) adopts a low-flow resistance in-pile test section design, the test section includes four guide rods (2-1) and a plurality of test section modules arranged between the four guide rods (2-1) and interconnected, the test section modules including an outer ring member (2-4), end members (2-5) arranged at both ends of the outer ring member (2-4), and a center member (2-3) arranged at the center of the outer ring member (2-4) and connected to the end members (2-5) at both ends, a plurality of test samples (2-2) are arranged in a central radial pattern in the same plane between the center member (2-3) and the outer ring member (2-4), and the two ends of each test sample (2-2) are respectively connected to the center member (2-3) and the outer ring member (2-4).

4. The in-pile water chemical environment material corrosion test system according to claim 3 is characterized by: The end member (2-5) is of hollow design, the ribs (2-5-01) of the end member (2-5) respectively correspond to the test sample (2-2), the edge strips (2-5-02) of the end member (2-5) correspond to the end edges of the outer ring member (2-4) and are fixedly connected, and the two ends of the center member (2-3) are respectively fixedly connected to the center hole (2-5-03) of the end member (2-5); The outer ring member (2-4) is connected to the guide rod (2-1) via a circular ring structure (2-4-02) with inward concave portions on all sides, and a fan-shaped flow channel section on the surface of the test sample (2-2) is formed between two adjacent test samples (2-2), the center member (2-3), and the outer ring member (2-4).

5. The in-pile water chemical environment material corrosion test system according to claim 2, characterized in that: The first heating device (1-1-02) and the second heating device (1-1-05) adopt a built-in heating structure, including a cylindrical structure consisting of an upper head (3-1), a lower head (3-2), and a cylinder (3-3) connected between the upper head (3-1) and the lower head (3-2).

6. The in-pile water chemical environment material corrosion test system according to claim 5, characterized in that: A water inlet (3-6) is provided at the center of the lower head (3-2), a water outlet (3-7) is provided at the center of the upper head (3-1), an electric heater mounting seat (3-5) extending into the cylinder (3-3) is fixedly provided on the circumference around the water outlet (3-7) of the upper head (3-1), and the electric heater mounting seat (3-5) is sealed and connected to an immersion electric heater (3-4); A mixing plate (3-9) having a radius smaller than the inner diameter of the cylinder (3-3) is provided in the cylinder (3-3); a circular hole interface (3-9-01) corresponding to the position of the electric heater mounting seat (3-5) is provided on the mixing plate (3-9); and the end of each electric heater mounting seat (3-5) is fixedly provided in the corresponding circular hole interface (3-9-01); A second temperature monitor (3-8) for monitoring the temperature of the liquid flow in the cylinder (3-3) is provided on the side wall of the upper head (3-1).

7. The in-pile water chemical environment material corrosion test system according to claim 6, characterized in that: An external thread is provided at the end of the electric heater mounting seat (3-5) extending out of the upper head (3-1); an internal thread cover (3-4-01) matching the external thread of the end of the electric heater mounting seat (3-5) is fixedly provided on the electric heater (3-4); the electric heater (3-4) is fixedly connected to the electric heater mounting seat (3-5) by screwing the internal thread cover (3-4-01) onto the external thread of the end of the electric heater mounting seat (3-5); a sealing gasket (3-4-02) is provided between the internal thread cover (3-4-01) of the electric heater (3-4) and the end of the electric heater mounting seat (3-5) for sealing.

8. The in-pile water chemical environment material corrosion test system according to claim 7, characterized in that: The electric heater mounting seats (3-5) are evenly arranged on the circumference around the water outlet (3-7) of the upper head (3-1), the spacing between two adjacent electric heater mounting seats (3-5) is 30-50 mm, the spacing between the upper end surface of the mixing plate (3-9) and the inner surface of the upper head (3-1) is not less than 50 mm, and the sealing gasket (3-4-02) is a flexible graphite gasket.

9. The in-pile water chemical environment material corrosion test system according to claim 1, characterized in that: The integrated thermostat (1-2-01) comprises a high-temperature section water inlet (4-1), a first high-temperature section straight pipe section (4-7) connected to the high-temperature section water inlet (4-1), a high-temperature section water outlet (4-2), and a second high-temperature section straight pipe section (4-9) connected to the high-temperature section water outlet (4-2); a high-temperature section curved pipe section (4-8) is connected between the ends of the first high-temperature section straight pipe section (4-7) and the second high-temperature section straight pipe section (4-9); the other ends of the first high-temperature section straight pipe section (4-7) and the second high-temperature section straight pipe section (4-9) are fixedly connected to the tube sheet (4-5); the high-temperature section water inlet (4-1) is connected to the outlet pipe of the circulation drive device through a drain valve (1-2-10); and the high-temperature section water outlet (4-2) is respectively connected to the sampling device (1-2-11) and the inlet pipe of the ultrafine filtration membrane (1-2-02); The first high-temperature section straight pipe section (4-7) is externally sleeved with the first low-temperature section straight pipe section (4-6), and the second high-temperature section straight pipe section (4-9) is externally sleeved with the second low-temperature section straight pipe section (4-10). The ends of the first low-temperature section straight pipe section (4-6) and the second low-temperature section straight pipe section (4-10) are sealed and connected to the bottom of the tube sheet (4-5). The other ends of the first low-temperature section straight pipe section (4-6) and the second low-temperature section straight pipe section (4-10) are connected to the pipe box (4-11), and the high-temperature section bent pipe section (4-8) is arranged in the pipe box (4-11) with sufficient clearance between the pipe box (4-11). The side of the first low-temperature section straight pipe section (4-6) is connected to the low-temperature section water outlet (4-4), and the low-temperature section water outlet (4-4) is connected to the inlet of the circulation drive device through the second isolation valve (1-2-12). The side of the second low-temperature section straight pipe section (4-10) is connected to the low-temperature section water inlet (4-3), and the low-temperature section water inlet (4-3) is connected to the outlet of the water quality regulating tank (1-2-05) through the water injection pump.

10. A method for testing material corrosion in an in-pile water chemical environment based on the in-pile water chemical environment material corrosion testing system according to any one of claims 1 to 9, characterized in that: The steps include: Fill the high-temperature environment system with water and increase the pressure step by step to detect leaks, ensuring that the pressure drop within 10 minutes of each step does not exceed 2.5%P; When operating a high-temperature environment system, when the temperature rises to 180°C-220°C, drain the high-temperature environment system to the pressure regulator (1-1-03) to ensure that the liquid level is within a reasonable range, and maintain the high-temperature environment system temperature at 180°C-220°C; When the high temperature environment system heats up, the water quality entering the high temperature environment system is monitored and regulated online through the water quality regulation system, so that the water quality obtained by online monitoring and offline sampling analysis meets the standards; When operating the reactor and observing and controlling the temperature rise of the high-temperature environment system to no more than 40°C / h, switch the high-temperature environment system to automatic tracking control and record the operating monitoring parameters at intervals; The reactor is shut down, the high-temperature environment system is cooled and reduced in pressure to the rated value, and the high-temperature environment system is switched to automatic tracking control, with operation monitoring parameters recorded at intervals; The corrosion test of the test sample (2-2) is carried out to a predetermined time, and the corrosion condition of the test sample (2-2) is checked.

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