A hydrogenation system and method for high temperature and high pressure irradiation test loop

Abstract

The invention discloses a hydrogenation system and a hydrogenation method for a high-temperature and high-pressure irradiation test loop. The hydrogenation system comprises a hydrogen supply unit, a flow control unit and a feeding unit which are connected in sequence; the flow control unit comprises an automatic adding unit and a manual adding unit which are arranged in parallel; the manual adding unit comprises a return water providing unit and at least two hydrogenation units, and the hydrogenation unit is connected to the feeding unit and the hydrogen supply unit; at least two hydrogenation units are arranged in parallel in at least two rows; each row of hydrogenation units is connected to the return water providing unit; each row of hydrogenation units is provided with a temperature measuring instrument, and a pressure measuring instrument is provided on a pipeline connecting the hydrogenation unit and the feeding unit; isolation valves are provided at both ends of each row of hydrogenation units; the operation is convenient, safe and reliable, the dissolved hydrogen concentration in the loop has a fast response speed, a high control accuracy, and a high hydrogen use efficiency, which meets the hydrogenation requirements in the high-temperature and high-pressure irradiation test loop.

Description

Technical Field

[0001] The invention relates to the technical field of radiation corrosion protection, and in particular to a hydrogenation system and a hydrogenation method for a high-temperature and high-pressure radiation test loop. Background Art

[0002] The high-temperature and high-pressure irradiation test loop is a necessary facility for the irradiation test of new fuel elements. It is used to simulate the high-temperature and high-pressure water operating conditions of the primary loop of a nuclear reactor and to conduct simulation tests on fuel elements under nuclear conditions. The irradiation test of fuel elements requires strict control of the loop water quality, especially the dissolved oxygen concentration. The dissolved oxygen concentration in the loop water needs to be controlled at an extremely low level to reduce the oxidative corrosion of the fuel element cladding material.

[0003] A better method to control dissolved oxygen concentration is the hydrogenation method. By adding a certain amount of high-purity hydrogen to the high-temperature and high-pressure irradiation test loop, the hydrogen is dissolved in the high-temperature and high-pressure water. At high temperature, hydrogen and oxygen react chemically to generate water, thereby reducing the dissolved oxygen concentration in the loop water. The advantage of the hydrogenation method is that it does not produce other substances except for the generated water, and does not affect the loop water quality. After hydrogenation, the loop water is in a reduced state, which can continuously suppress the dissolved oxygen concentration in the loop water.

[0004] In principle, hydrogenation in the loop can be divided into direct hydrogenation and indirect hydrogenation. The direct hydrogenation method is to inject high-pressure hydrogen directly into the loop; the indirect hydrogenation method is to dissolve hydrogen in water outside the loop first, and then use a high-pressure pump to inject hydrogen-containing water into the loop. The direct hydrogenation method has a rapid operation process. Hydrogen has a high solubility under high pressure and can be quickly dissolved in water. The concentration of dissolved hydrogen in the loop responds quickly, but the direct hydrogenation method is technically difficult and requires high control accuracy. For the indirect hydrogenation method, due to the low solubility of hydrogen in normal pressure water, the hydrogenation process takes a long time, the hydrogen concentration in the loop water responds slowly, and the adjustment accuracy is low. Both direct hydrogenation and indirect hydrogenation have been successfully applied in the primary loop system of the reactor. The typical direct hydrogenation method is to use desalted water transported from the outside and use a water pump to pressurize the hydrogen filled in the transfer tank and inject it into the primary loop of the reactor; the typical indirect hydrogenation method is to add hydrogen to the gas space of the volume control box of the reactor chemical volume system, dissolve the hydrogen in the water stored in the volume control box, and then use the charging pump to pressurize the hydrogen-containing water in the volume control box and inject it into the primary loop of the reactor.

[0005] Since the water volume of the high-temperature and high-pressure irradiation test loop is much smaller than that of the reactor primary loop, it cannot accept a large amount of external water injection, and the total amount of hydrogenation required is small, it is more sensitive to the quantitative error of hydrogenation, and has high requirements for the quantitative accuracy of hydrogenation. The existing hydrogenation method used in the reactor primary loop cannot meet the hydrogenation requirements of the high-temperature and high-pressure irradiation test loop. At present, there is no mature method for engineering application of hydrogenation in the high-temperature and high-pressure irradiation test loop. Summary of the invention

[0006] The purpose of the present invention is to provide a hydrogenation system for a high-temperature and high-pressure irradiation test loop, which solves the problem that the hydrogenation method does not meet the hydrogenation requirements in the high-temperature and high-pressure irradiation test loop. The hydrogenation system disclosed in the present invention forms a hydrogenation branch stream through a pressure difference, and the hydrogenation branch stream drives a certain amount of hydrogen into the loop, and the hydrogen is dissolved in high-temperature and high-pressure water in the loop.

[0007] Based on the above problems, another object of the present invention is to provide a hydrogenation method based on the above hydrogenation system to reduce the corrosion degree of the fuel element cladding material and meet the requirements of the fuel element irradiation test on the loop water quality.

[0008] In a first aspect, the present invention provides a hydrogenation system for a high-temperature and high-pressure irradiation test loop, comprising a hydrogen supply unit, a flow control unit, and a delivery unit connected in sequence;

[0009] Wherein, the flow control unit comprises an automatic adding unit and a manual adding unit arranged in parallel; the manual adding unit comprises a drainage unit, a return water supply unit and at least two hydrogenation units, and the hydrogenation unit is connected to the feeding unit and the hydrogen supply unit; at least two hydrogenation units are arranged in parallel in at least two rows; each row of hydrogenation units is connected to the return water supply unit;

[0010] A temperature measuring instrument is provided on each row of the hydrogenation units, and a pressure measuring instrument is provided on the pipeline connecting the hydrogenation unit and the feeding unit; isolation valves are provided at both ends of each row of the hydrogenation units; the drainage unit is connected to each of the hydrogenation units or to the hydrogenation unit in each row that first enters water.

[0011] When the above technical solution is adopted, the indirect hydrogenation method and the direct hydrogenation method are combined, and the reflux port of the hydrogenation system is connected to the inlet pipe of the main pump of the loop. Since the inlet pressure of the main pump is the lowest pressure point in the entire loop, the outlet pressure of the auxiliary heat exchanger is higher than the inlet pressure of the main pump. The hydrogenation system forms a hydrogenation branch with the help of this pressure difference. The hydrogenation branch drives a certain amount of hydrogen into the loop, and the hydrogen is dissolved in the high-pressure water in the loop. By setting two modes of automatic hydrogenation and manual hydrogenation, the automatic hydrogenation is aimed at the pressure of the hydrogen supply unit being significantly higher than the loop pressure (belonging to the direct hydrogenation method), and hydrogen is directly added to the high-temperature and high-pressure water; manual hydrogenation can be aimed at the pressure of the hydrogen supply unit and the loop pressure. The difference is not obvious, and it is dissolved in the high-pressure water and then returned to the pipeline. The operation is convenient, safe and reliable, the dissolved hydrogen concentration in the loop has a fast response speed, high control accuracy, and high hydrogen utilization efficiency, which meets the hydrogenation requirements in the high-temperature and high-pressure irradiation test loop.

[0012] During the manual hydrogenation process, high-pressure water comes from the high-temperature and high-pressure irradiation test circuit, so the water volume in the high-temperature and high-pressure irradiation test circuit will not be increased, which solves the problem that the high-temperature and high-pressure irradiation test circuit does not accept external water injection, and a pressure measuring instrument is set to accurately control the amount of hydrogen added to meet the corresponding error requirements.

[0013] As a possible implementation, the automatic addition unit includes a flow controller arranged on a pipeline connected to the hydrogen supply unit, isolation valves are provided at both ends of the flow controller, and the flow controller is connected to the hydrogen supply unit; it is used for adding hydrogen with high precision and accuracy and achieving stable hydrogenation.

[0014] As a possible implementation, the delivery unit includes a flow sensor and a disconnect valve disposed on a pipeline connected to the flow control unit, for implementing the addition and stop of hydrogen.

[0015] As a possible implementation manner, a second one-way valve is provided on the pipeline connecting the flow sensor and the disconnect valve, a third one-way valve is provided on the pipeline connecting the flow sensor and the hydrogen supply unit, and at least two second valves in series are provided on the pipeline at the discharge end of the disconnect valve to prevent the backflow of high-pressure water and avoid the backflow of high-pressure water caused by the failure of one of the valves.

[0016] As a possible implementation, the hydrogen supply unit includes a gas storage structure, the gas outlet end of the gas storage structure is connected to a first pressure reducing valve, the front and rear ends of the first pressure reducing valve are respectively provided with the pressure measuring instrument, the first pressure reducing valve is respectively connected to the automatic adding unit and each row of the hydrogenation units; and is respectively used to monitor the pressure of the gas storage structure before and after decompression.

[0017] As a possible implementation, the drainage unit includes a liquid storage tank connected to the hydrogenation unit, a second pressure reducing valve is provided on the water inlet pipeline of the liquid storage tank, and a drainage valve is provided at the liquid inlet end of the second pressure reducing valve; it is used to discharge the original accumulated water in the hydrogenation unit before hydrogen is configured to avoid affecting the volume storage of hydrogen.

[0018] As a possible implementation, a vent pipe is provided on the connecting pipeline between the return water supply unit and the hydrogenation unit, and an exhaust valve is provided on the vent pipe for exhausting the original air inside the hydrogenation unit during the debugging process.

[0019] As a possible implementation, the hydrogenation unit is a longitudinally arranged hydrogenation pipe, and the return water enters from the lower end of the hydrogenation pipe and contacts with the hydrogen in reverse direction, which is conducive to rapid mixing and improves the hydrogenation efficiency.

[0020] As a possible implementation, the return water providing unit includes an auxiliary heat exchanger connected to the hydrogenation unit, and a pipeline connecting the auxiliary heat exchanger and the hydrogenation unit is provided with at least two first valves and a first check valve connected in series, and the first check valve is close to the isolation valve;

[0021] Preferably, the hydrogenation system further comprises a hydrogen concentration monitor, and the hydrogen concentration monitor is arranged around the hydrogen supply unit.

[0022] In the second aspect, the present invention also provides a hydrogenation method based on the above-mentioned hydrogenation system, wherein the hydrogen supply unit supplies the required volume of hydrogen to the flow control unit, and when the hydrogen volume reaches the required amount, the hydrogen supply unit is disconnected. After disconnection, the flow control unit feeds the stored hydrogen into the loop main pump through the delivery unit to realize hydrogenation.

[0023] The beneficial effects of the present invention are as follows: the combination of automatic hydrogenation (direct hydrogenation method) and manual hydrogenation (indirect hydrogenation method) can not only meet the requirements of small amounts of hydrogenation, hydrogenation accuracy, fast response speed of dissolved hydrogen concentration and high hydrogen utilization efficiency, but also does not require an external water source, does not rely on external driving force, and is easy to operate, safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of a hydrogenation system for a high temperature and high pressure irradiation test loop in an embodiment of the present invention;

[0025] Among them, 1- auxiliary heat exchanger; 2- first valve; 3- third one-way valve; 4- inlet valve; 5- hydrogenation pipe; 6- hydrogen cylinder; 7- outlet main valve; 8- hydrogen pressure reducing valve; 9- pressure gauge; 10- hydrogen concentration monitor; 11- first one-way valve; 12- hydrogenation pipe hydrogen injection valve; 13- drain valve; 14- drain pressure reducing valve; 15- liquid storage tank; 16- exhaust valve; 17- pressure gauge; 18- thermometer; 19- spare hydrogenation pipe; 20- bottom isolation valve; 21- first isolation valve; 22- hydrogen flow controller; 23- hydrogenation pipe outlet valve; 24- third one-way valve; 25- second isolation valve; 26- flow sensor; 27- second one-way valve; 28- solenoid valve; 29- second valve; 30- loop main pump. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0029] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Since the water volume of the high-temperature and high-pressure irradiation test loop is much smaller than that of the reactor primary loop, it cannot accept a large amount of external water injection, and the total amount of hydrogenation required is small, it is more sensitive to the quantitative error of hydrogenation, and has high requirements for the quantitative accuracy of hydrogenation. The existing hydrogenation method used in the reactor primary loop cannot meet the hydrogenation requirements of the high-temperature and high-pressure irradiation test loop. At present, there is no mature method for engineering application of hydrogenation in the high-temperature and high-pressure irradiation test loop.

[0032] The hydrogenation system for a high-temperature and high-pressure irradiation test loop provided by the present invention comprises a hydrogen supply unit, a flow control unit and a delivery unit which are connected in sequence. The pressure of the hydrogen supply unit is the highest pressure in the entire hydrogenation system. Therefore, when the pipeline is connected, the hydrogen in the hydrogen supply unit will automatically enter the flow control unit to achieve quantitative and high-precision addition of hydrogen, thereby reducing quantitative errors. When the required hydrogen flow rate is accumulated in the flow control unit, the hydrogen supply unit and the flow control unit are disconnected to achieve non-intercommunication. The hydrogen accumulated in the flow control unit enters the delivery unit to achieve hydrogen transportation, and finally enters the high-temperature and high-pressure irradiation test loop.

[0033] In practical applications, the flow control unit includes an automatic adding unit and a manual adding unit arranged in parallel; the manual adding unit includes a return water providing unit and at least two hydrogenation units, and the hydrogenation unit is connected to the feeding unit and the hydrogen supply unit; at least two of the hydrogenation units are arranged in parallel in at least two rows; each row of the hydrogenation units is connected to the return water providing unit.

[0034] The automatic adding unit and the manual adding unit are not used at the same time. In actual application, the automatic adding unit or the manual adding unit is started according to the pressure of the above hydrogen supply unit. When the pressure of the hydrogen supply unit is high, the automatic adding unit is started to realize direct adding; when the pressure of the hydrogen supply unit is low, the manual adding unit is started to realize indirect adding.

[0035] The automatic adding unit uses the large pressure difference between the hydrogen supply unit and the high-temperature and high-pressure water circuit to quickly press hydrogen into the high-temperature and high-pressure water circuit to achieve hydrogenation. The manual adding unit uses the high-temperature and high-pressure water circuit water to melt hydrogen into water under high pressure after heat exchange and then return it to the high-temperature and high-pressure water circuit to achieve hydrogenation, and finally remove oxygen in the water circuit to achieve corrosion protection.

[0036] During manual hydrogenation, first connect the hydrogenation unit and the hydrogen supply unit, fill the required amount of hydrogen into the hydrogenation unit, disconnect the two when the hydrogen amount reaches the requirement, then open the return water supply unit, and allow the high-pressure return water to enter the hydrogenation unit to dissolve the hydrogen, and then enter the high-temperature and high-pressure return water pipeline through the delivery unit. This process does not require an external water source or external driving force, and is easy to operate, safe and reliable.

[0037] The water flow direction in the hydrogenation unit is from bottom to top, and the lower density of hydrogen than water is used to discharge all the hydrogen in the hydrogenation unit and inject it into the loop.

[0038] The manual addition unit also includes a drainage unit. A temperature measuring instrument is provided on each row of the hydrogenation units, and a pressure measuring instrument is provided on the pipeline connecting the hydrogenation unit and the feeding unit; isolation valves are provided at both ends of each row of the hydrogenation units; the drainage unit is connected to each of the hydrogenation units or to the hydrogenation unit in each row that first enters water.

[0039] Before hydrogen is introduced into the hydrogenation unit, the accumulated water in the hydrogenation unit is drained into the drainage unit to avoid affecting the storage and temperature of hydrogen, thereby affecting the amount of hydrogen added and reducing the number of unnecessary hydrogenation units.

[0040] In practical applications, the number of parallel rows of hydrogenation units and the number of hydrogenation units in each row are calculated based on the volume of hydrogen required for the hydrogenation process and the volume of a single hydrogenation unit. At least two of the hydrogenation units are arranged in parallel in at least two rows, which can increase the hydrogenation volume during operation. When the pressure of the hydrogen supply unit is low after a long period of use, a sufficient amount of hydrogen can still be configured at one time, thereby reducing the number of hydrogenation operations.

[0041] According to the ideal gas state equation PV=nRT, the total amount of hydrogen inside the hydrogenation tube can be obtained.

[0042] Calculation method of hydrogenation amount:

[0043] The mass of hydrogen that needs to be added is: m = M (C2-C1)

[0044] Where: M is the total water mass in the circuit, C2 is the target value of dissolved hydrogen concentration, C1 is the current actual value of dissolved hydrogen concentration, and there is a relationship: the lower limit of allowable hydrogen concentration ≤ C1 ≤ C2 ≤ the upper limit of allowable hydrogen concentration

[0045] The volume of hydrogen to be added under standard conditions is: V1 = m / ρ = M(C2-C1) / ρ

[0046] Where: ρ is the density of hydrogen under standard conditions

[0047] At room temperature, hydrogen can be approximately regarded as an ideal gas, which can meet the requirements of engineering calculations. According to the ideal gas state equation, the hydrogen pressure that needs to be set in the hydrogenation unit is:

[0048]

[0049] Where: P1 is the standard atmospheric pressure (0.101MPa), T1 is the standard temperature (273.15K), V2 is the volume of the hydrogenation unit, and T2 is the actual temperature in the hydrogenation unit.

[0050] In practical applications, the hydrogenation unit may be a hydrogenation pipe, which is used to configure a certain amount of hydrogen and is a pipe with a relatively large diameter.

[0051] In practical applications, the automatic adding unit includes a flow controller arranged on a pipeline connected to the hydrogen supply unit, isolation valves are arranged at both ends of the flow controller, and the flow controller is connected to the hydrogen supply unit.

[0052] The isolation valve is kept at a relatively small opening to make the hydrogen flow rate small and stable, so as to improve the accuracy of hydrogen flow control; the flow controller is used to measure the amount of hydrogen flowing through, and guides the disconnection of the isolation valve when the set value is reached.

[0053] In practical applications, the delivery unit includes a flow sensor and a disconnect valve which are arranged on a pipeline communicating with the flow control unit.

[0054] The disconnect valve is used to control the opening and closing of the hydrogenation branch flow and can be used for emergency stop operation during the hydrogenation process.

[0055] In a possible implementation, a second one-way valve is provided on the pipeline connecting the flow sensor and the disconnect valve, a third one-way valve is provided on the pipeline connecting the flow sensor and the hydrogen supply unit, and at least two second valves connected in series are provided on the pipeline at the discharge end of the disconnect valve.

[0056] The second one-way valve and the third one-way valve are both used to prevent the high-pressure water in the circuit from flowing back. At least two second valves are used as two-way isolation. The specific number of second valves can be increased according to actual needs.

[0057] In practical applications, the hydrogen supply unit includes a gas storage structure, the gas outlet end of the gas storage structure is connected to a first pressure reducing valve, the front and rear ends of the first pressure reducing valve are respectively provided with the pressure measuring instrument, and the first pressure reducing valve is respectively connected to the automatic addition unit and each row of the hydrogenation units.

[0058] The pressure measuring instruments are respectively arranged at the front and rear ends of the first pressure reducing valve, and are used to monitor the pressures before and after the pressure measuring instruments, respectively.

[0059] In a possible implementation, the drainage unit includes a liquid storage tank connected to the hydrogenation unit, a second pressure reducing valve is provided on the water inlet pipeline of the liquid storage tank, and a drainage valve is provided at the liquid inlet end of the second pressure reducing valve.

[0060] In a possible implementation, a vent pipe is provided on the connecting pipeline between the mixing unit and the hydrogenation unit, and an exhaust valve is provided on the vent pipe to exhaust the air in the hydrogenation unit to avoid the possibility of explosion after the air is mixed with hydrogen.

[0061] In a possible implementation, the mixing unit includes an auxiliary heat exchanger connected to the hydrogenation unit, and the pipeline connecting the auxiliary heat exchanger and the hydrogenation unit is provided with at least two first valves and a first check valve in series, and the first check valve is close to the isolation valve. At least two first valves serve as two-way isolation.

[0062] In a possible implementation, since hydrogen is a flammable gas, in order to avoid safety hazards caused by hydrogen leakage, the hydrogenation system is also provided with a hydrogen concentration monitor for monitoring the hydrogen content in the surrounding air. Since hydrogen has a low density and will float, the hydrogen concentration monitor is preferably installed at the top of the hydrogenation system to send out an alarm signal when hydrogen leakage occurs in the hydrogenation system.

[0063] Example

[0064] like Figure 1 As shown, the hydrogenation system sets a water inlet at the outlet pipe of the auxiliary heat exchanger 1 of the high-temperature and high-pressure loop, draws out the high-pressure loop water after cooling by the auxiliary heat exchanger 1 as the hydrogenation tributary, and sets two first valves 2 in series as double valve isolation. The high-pressure water drawn out through the water inlet passes through the third one-way valve 3 and the inlet valve 4 in sequence and enters the hydrogenation pipe 5. The hydrogenation pipe 5 is used to configure a certain amount of hydrogen. The hydrogenation pipe 5 is a pipe with a larger diameter. The hydrogenation pipe 5 is arranged vertically. The water flow direction in the hydrogenation pipe 5 is from bottom to top. The characteristic that the density of hydrogen is lower than that of water is used to realize that all the hydrogen in the hydrogenation pipe 5 is discharged and injected into the loop. The hydrogenation pipe 5 receives hydrogen from the hydrogen bottle 6 from the top. The hydrogen bottle 6 is equipped with a hydrogen pressure reducing valve 8 at its outlet main valve 7. Pressure gauges 9 are arranged before and after the hydrogen pressure reducing valve 8, which are respectively used to monitor the pressure of the hydrogen bottle 6 and the pressure of the hydrogen after pressure reduction. The hydrogen after being decompressed by the hydrogen pressure reducing valve 8 enters the hydrogenation pipe 5 through the first one-way valve 11 and the hydrogenation pipe hydrogen injection valve 12 in sequence. The first one-way valve 11 can prevent the high-pressure water from flowing back. Before the hydrogenation pipe 5 is configured with a quantitative hydrogen, the original accumulated water inside needs to be discharged. The bottom of the hydrogenation pipe 5 is also connected with a drain valve 13, a drain pressure reducing valve 14, and a liquid storage tank 15 in sequence. The outlet pipe of the drain pressure reducing valve 14 extends into the bottle mouth of the liquid storage tank 15. The top outlet pipe of the hydrogenation pipe 5 is provided with an exhaust valve 16 for discharging the original air inside the hydrogenation pipe 5 during the debugging process. The top outlet pipe of the hydrogenation pipe 5 is also provided with a pressure gauge 17 for measuring the internal pressure of the hydrogenation pipe 5. A thermometer 18 is provided in the middle of the hydrogenation pipe 5. The pressure of the hydrogen in the hydrogenation pipe 5 can be adjusted by the hydrogen pressure reducing valve 8 during operation.

[0065] The spare hydrogenation pipe 19 is connected in parallel with the hydrogenation pipe 5 to increase the hydrogenation volume during operation. When the pressure of the hydrogen cylinder 6 is low after a long period of use, a sufficient amount of hydrogen can still be configured at one time, thereby reducing the number of hydrogenation operations. Figure 1As shown, the standby hydrogenation pipe 19 is connected in parallel with the hydrogenation pipe 5 through the bottom isolation valve 20 and the second isolation valve 25, wherein the bottom isolation valve 20 is connected to the bottom inlet pipe of the hydrogenation pipe 5, and the second isolation valve 25 is connected to the top outlet pipe of the hydrogenation pipe 5. After the standby hydrogenation pipe 19 merges with the top outlet of the hydrogenation pipe 5, a hydrogenation pipe outlet valve 23 is provided, and a flow sensor 26 is connected to the back to monitor the flow of the hydrogenation branch. A second one-way valve 27 is provided after the flow sensor 26 to prevent the backflow of the high-pressure water in the loop. A solenoid valve 28 is provided after the second one-way valve to control the opening and closing of the hydrogenation branch, and can be used for emergency stop operation during the hydrogenation process. Two second valves 29 are provided in series at the rear end of the solenoid valve 28 as double valve isolation, and the reflux port of the hydrogenation system is connected to the inlet pipe of the loop main pump 30.

[0066] The automatic hydrogenation mode is remote control operation, and the amount of hydrogen added is accurately controlled by the hydrogen flow controller 22. An automatic hydrogenation branch is separated from the rear end of the hydrogen pressure reducing valve 8, and the automatic hydrogenation branch is provided with a hydrogen flow controller 22, and the first isolation valve 21 is provided before and after the hydrogen flow controller 22. The automatic hydrogenation branch merges at the rear end of the hydrogenation pipe outlet valve 23, and a third one-way valve 24 is provided before the confluence point to prevent high-pressure water from flowing back into the automatic hydrogenation branch. When the automatic hydrogenation mode is adopted, the two first isolation valves 21 before and after the hydrogen flow controller 22 need to be opened, and kept at a small opening, so that the hydrogen flow is small and stable, and the outlet pressure of the hydrogen pressure reducing valve 8 is pre-adjusted to be slightly higher than the loop pressure, and the high-pressure hydrogen flows through the hydrogen flow controller 22. After measuring the total amount of hydrogen added to the required amount, the hydrogen flow controller 22 will automatically close, and the injected high-pressure hydrogen will merge into the hydrogenation branch, and enter the loop under the drive of the hydrogenation branch.

[0067] The hydrogenation system is also provided with a hydrogen concentration monitor 10 for monitoring the hydrogen content in the surrounding air. Taking advantage of the fact that hydrogen has a low density and will float, the hydrogen concentration monitor 10 is installed at the top of the hydrogenation system and can send out an alarm signal when hydrogen leakage occurs in the hydrogenation system.

[0068] Automatic hydrogenation operation method:

[0069] When using the automatic hydrogenation method, it should be confirmed that the hydrogen cylinder is at a relatively high pressure, and the two first isolation valves 21 before and after the hydrogen flow controller 22 should be adjusted to a relatively small opening to make the hydrogen flow small and stable, and the outlet pressure of the hydrogen pressure reducing valve 8 should be adjusted to be slightly higher than the loop pressure. The valve status of the hydrogenation system is shown in Table 1:

[0070] Table 1

[0071] Serial number Valve Name Valve status 1 First Valve 2 open 2 Inlet valve 4 open 3 Outlet main valve 7 open 4 Hydrogen pressure reducing valve 8 open 5 Hydrogen filling pipe hydrogen injection valve 12 close 6 Drain valve 13 close 7 Drain pressure reducing valve 14 close 8 Exhaust valve 16 close 9 Bottom isolation valve 20, second isolation valve 25 close 10 First isolation valve 21 Smaller opening 11 Hydrogen flow controller 22 closure 12 Hydrogenation pipe outlet valve 23 close 13 Solenoid valve 28 open 14 Second valve 29 open

[0072] Automatic hydrogenation operation steps:

[0073] 1. Remotely set the total amount of hydrogen allowed to pass through the hydrogen flow controller 22;

[0074] 2. Remotely open the solenoid valve 28 and confirm that the reading of the flow sensor 26 is normal, then the hydrogenation branch flow is opened;

[0075] 3. The hydrogen flow controller 22 is remotely turned on. After the required total amount of hydrogen is added, the hydrogen flow controller 22 is automatically turned off, and the automatic hydrogenation process is completed;

[0076] 4. If the hydrogen flow controller 22 does not automatically close after the required total amount of hydrogen is added, an emergency stop operation is performed: remotely close the solenoid valve 28. Then check the cause of the fault and use manual hydrogenation before troubleshooting.

[0077] Manual hydrogenation operation method:

[0078] When the automatic hydrogenation fails or the hydrogen tank pressure is lower than the loop pressure, manual hydrogenation is required. When manual hydrogenation is used, the automatic hydrogenation branch should be closed and the valve status of the hydrogenation system should be confirmed as shown in Table 2:

[0079] Table 2

[0080] Serial number Valve Name Valve status 1 First Valve 2 open 2 Hydrogenation pipe inlet valve 4 open 3 Outlet main valve 7 close 4 Hydrogen pressure reducing valve 8 close 5 Hydrogen filling pipe hydrogen injection valve 12 close 6 Drain valve 13 close 7 Drain pressure reducing valve 14 close 8 Exhaust valve 16 close 9 Bottom isolation valve 20, second isolation valve 25 close 10 First isolation valve 21 close 11 Hydrogen flow controller 22 closure 12 Hydrogenation pipe outlet valve 23 open 13 Solenoid valve 28 close 14 Second valve 29 open

[0081] Manual hydrogenation operation steps:

[0082] 1. Calculate the total amount of hydrogen required, and calculate the pressure required for hydrogen filling based on the internal temperature and volume of the hydrogenation tube;

[0083] 2. Close the inlet valve 4 and outlet valve 23 of the hydrogenation pipe, and isolate the hydrogenation pipe 5 (if the pressure in the hydrogen cylinder is low and the volume of the hydrogenation pipe 5 is insufficient to configure a sufficient amount of hydrogen at one time, use the spare hydrogenation pipe 5, that is, open the bottom isolation valve 20 and the second isolation valve 25);

[0084] 3. Open the drain valve 13 at the bottom of the hydrogenation pipe, open the drain pressure reducing valve 14 to relieve the pressure of the hydrogenation pipe 5 and drain all the accumulated water inside, and then close the drain valve 13 and the drain pressure reducing valve 14;

[0085] 4. Open the hydrogen injection valve 12 of the hydrogenation pipe, open the outlet main valve 7 of the hydrogen cylinder 6, open and adjust the hydrogen pressure reducing valve 8 to release hydrogen until the reading of the pressure gauge 17 rises to the required pressure;

[0086] 5. Close the outlet main valve 7 of the hydrogen cylinder 6, close the hydrogen pressure reducing valve 8, and close the hydrogen injection valve 12 of the hydrogenation pipe;

[0087] 6. Open the inlet valve 4 of the hydrogenation pipe 5 and the outlet valve 23 of the hydrogenation pipe, and open the solenoid valve 28;

[0088] 7. Wait for a certain period of time until all the hydrogen in the hydrogenation pipe 5 is discharged, and then close the solenoid valve 28.

[0089] From the above examples, we can see that the indirect hydrogenation method and the direct hydrogenation method are combined. The reflux port of the hydrogenation system is connected to the inlet pipe of the main pump of the loop. Since the inlet pressure of the main pump is the lowest pressure point in the entire loop, the outlet pressure of the auxiliary heat exchanger is higher than the inlet pressure of the main pump. The hydrogenation system forms a hydrogenation branch with the help of this pressure difference. The hydrogenation branch drives a certain amount of hydrogen into the loop, and the hydrogen is dissolved in the high-pressure water in the loop. By setting the two modes of automatic hydrogenation and manual hydrogenation, the automatic hydrogenation is aimed at the pressure of the hydrogen supply unit is significantly higher than the loop pressure (belonging to the direct hydrogenation method), and hydrogen is directly added to the high-temperature and high-pressure water; manual hydrogenation can be aimed at the pressure of the hydrogen supply unit and the loop pressure is not significantly different, and it is dissolved in high-pressure water and then returned to the pipeline. It is easy to operate, safe and reliable, the dissolved hydrogen concentration in the loop has a fast response speed, high control accuracy, and high hydrogen utilization efficiency, which meets the hydrogenation requirements in the high-temperature and high-pressure irradiation test loop.

[0090] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hydrogenation system for a high temperature and high pressure irradiation test loop, characterized in that: It includes a hydrogen supply unit, a flow control unit and a delivery unit which are connected in sequence; Wherein, the flow control unit comprises an automatic adding unit and a manual adding unit arranged in parallel; the manual adding unit comprises a drainage unit, a return water supply unit and at least two hydrogenation units, and the hydrogenation unit is connected to the feeding unit and the hydrogen supply unit; at least two hydrogenation units are arranged in parallel in at least two rows; each row of hydrogenation units is connected to the return water supply unit; Each row of the hydrogenation units is provided with a temperature measuring instrument, and a pressure measuring instrument is provided on the pipeline connecting the hydrogenation unit and the feeding unit; both ends of each row of the hydrogenation units are provided with isolation valves; the drainage unit is connected with each of the hydrogenation units or with the hydrogenation unit in each row that first enters water; The automatic adding unit comprises a flow controller arranged on a pipeline connected to the hydrogen supply unit, both ends of the flow controller are provided with isolation valves, and the flow controller is connected to the hydrogen supply unit; The hydrogen supply unit comprises a gas storage structure, the gas outlet end of the gas storage structure is connected to a first pressure reducing valve, the front and rear ends of the first pressure reducing valve are respectively provided with the pressure measuring instrument, and the first pressure reducing valve is respectively connected to the automatic adding unit and each row of the hydrogenation units; The hydrogenation unit is a hydrogenation pipe arranged longitudinally, and return water enters from the lower end of the hydrogenation pipe.

2. The hydrogenation system for a high temperature and high pressure irradiation test loop according to claim 1, characterized in that: The delivery unit comprises a flow sensor and a disconnect valve which are arranged on a pipeline communicating with the flow control unit.

3. The hydrogenation system for a high temperature and high pressure irradiation test loop according to claim 2, characterized in that: A second one-way valve is arranged on the pipeline connecting the flow sensor and the disconnect valve, a third one-way valve is arranged on the pipeline connecting the flow sensor and the hydrogen supply unit, and at least two second valves in series are arranged on the pipeline at the discharge end of the disconnect valve.

4. The hydrogenation system for a high temperature and high pressure irradiation test loop according to claim 1, characterized in that: The drainage unit comprises a liquid storage tank connected to the hydrogenation unit, a second pressure reducing valve is arranged on the water inlet pipeline of the liquid storage tank, and a drainage valve is arranged at the liquid inlet end of the second pressure reducing valve.

5. The hydrogenation system for a high temperature and high pressure irradiation test loop according to claim 1, characterized in that: A vent pipe is provided on the connecting pipeline between the return water supply unit and the hydrogenation unit, and an exhaust valve is provided on the vent pipe.

6. The hydrogenation system for a high temperature and high pressure irradiation test loop according to claim 1, characterized in that: The return water providing unit includes an auxiliary heat exchanger connected to the hydrogenation unit, and at least two first valves and a first one-way valve connected in series are arranged on the pipeline connecting the auxiliary heat exchanger and the hydrogenation unit, and the first one-way valve is close to the isolation valve; the hydrogenation system also includes a hydrogen concentration monitor, and the hydrogen concentration monitor is arranged around the hydrogen supply unit.

7. A hydrogenation method based on the hydrogenation system according to any one of claims 1 to 6, characterized in that: The hydrogen supply unit supplies the required volume of hydrogen to the flow control unit, and is disconnected from the hydrogen supply unit when the hydrogen volume reaches the required amount. After disconnection, the flow control unit sends its stored hydrogen through the delivery unit into the loop main pump to achieve hydrogenation.

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