Graphite molten salt reactor, graphite molten salt reactor system, and methods of use thereof

Abstract

The application provides a graphite molten salt reactor, a graphite molten salt reactor system and a use method thereof. The graphite molten salt reactor comprises a graphite assembly, the graphite assembly is divided into multiple layers in the height direction of the graphite molten salt reactor, and each layer of graphite is isolated from each other. The graphite molten salt reactor system comprises the above graphite molten salt reactor. The graphite molten salt reactor, the graphite molten salt reactor system and the use method thereof can change the pressure of the molten salt in the graphite molten salt reactor and make the molten salt flow out of the graphite molten salt reactor naturally without the aid of other devices by dividing the graphite into multiple layers, reducing the pressure of the molten salt flowing through the graphite, and opening and closing the components such as pumps and valves.

Description

TECHNICAL FIELD

[0001] The present application relates to a graphite molten salt reactor, a graphite molten salt reactor system and a method for using the same. BACKGROUND

[0002] Graphite is widely used in high-temperature gas-cooled reactors and molten salt reactors as a nuclear reactor material. In a molten salt reactor, graphite has good compatibility with molten salt fuel and basically does not chemically react under high-temperature conditions. However, graphite is a porous material and there is a possibility that fuel salt will infiltrate the graphite. Infiltration of molten salt into graphite will cause local retention of fuel salt and result in local hot spots in the core. Meanwhile, the fission nuclei generated by the fission of the fuel salt itself have very high energy and will cause great damage to the internal structure of the graphite. Therefore, infiltration of fuel salt into graphite should be avoided as much as possible.

[0003] Currently, research on avoiding infiltration of fuel salt into graphite mainly focuses on modification of graphite materials, such as developing fine-particle graphite and coating the surface of graphite, so as to increase the infiltration pressure of molten salt into graphite and ensure that infiltration of fuel salt into graphite will not occur under the operating pressure of various conditions of the molten salt reactor. However, the above-mentioned methods have complex material processing technology, high technical requirements and high cost, and are not convenient for actual production and product promotion. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects in the prior art that part of the graphite of a graphite molten salt reactor is infiltrated by molten salt, and to provide a graphite molten salt reactor, a graphite molten salt reactor system and a method for using the same.

[0005] The present application solves the above technical problems by the following technical solutions:

[0006] The present application provides a graphite molten salt reactor, which comprises a graphite assembly, the graphite assembly is divided into multiple layers in the height direction of the graphite molten salt reactor, and the graphite in each layer is isolated from each other.

[0007] In the present technical solution, the graphite molten salt reactor loads molten salt by adjusting the gas pressure in the reactor, and the graphite divided into multiple layers can ensure that the gas pressure in each layer of graphite is different and matches the pressure change of the molten salt during the adjustment of the gas pressure, so that the molten salt can normally work in the reactor without infiltrating into the graphite.

[0008] Preferably, a molten salt passage is arranged on the graphite assembly, and the graphite molten salt reactor further comprises a circulation loop, which penetrates the upper end and the lower end of the graphite assembly through the molten salt passage.

[0009] In the present technical solution, the circulation loop penetrates the graphite assembly, and the graphite assembly plays a role of absorption to control the reaction rate.

[0010] Preferably, the graphite in each layer is a piece of graphite.

[0011] In the technical solution, the graphite in the reactor only needs to be simply stacked and perforated, thereby reducing the processing difficulty.

[0012] Preferably, the graphite in each layer is divided into multiple pieces of graphite.

[0013] In the technical solution, the single piece of graphite in the reactor has a small volume, thereby reducing the assembly difficulty.

[0014] Preferably, the circulating loop further comprises an upper chamber, a descending chamber, a lower chamber and an ascending chamber, the lower chamber is located below the graphite assembly, the descending chamber is located at the side of the graphite assembly, the upper chamber is located above the graphite assembly, the ascending chamber is formed by the molten salt passage, and the ascending chamber is connected with the upper chamber; when the molten salt flows in the circulating loop, the molten salt flows through the upper chamber, the descending chamber, the lower chamber and the ascending chamber in sequence.

[0015] In the technical solution, the molten salt circulates in the reactor and transmits the generated heat out for power generation or other purposes.

[0016] Preferably, the circulating loop further comprises a heat exchanger, the heat exchanger is located outside the graphite assembly, and the heat exchanger is at least partially located in the descending chamber.

[0017] In the technical solution, the pressure drop in the heat exchanger is the largest pressure drop in the circulating loop, and the heat exchanger is located outside the graphite assembly, thereby reducing the pressure of the molten salt in contact with the graphite assembly and correspondingly reducing the required air pressure.

[0018] Preferably, the circulating loop further comprises a circulating pump, and the circulating pump is arranged between the upper chamber and the descending chamber.

[0019] In the technical solution, the circulating pump pressurizes the molten salt flowing out of the upper chamber, thereby better maintaining the flow of the molten salt in the circulating loop.

[0020] Preferably, the circulating pump is arranged between the upper chamber and the heat exchanger.

[0021] In the technical solution, the molten salt flows through the heat exchanger after flowing through the circulating pump and then flows into the ascending chamber, so that the dynamic pressure of the molten salt is reduced before entering the ascending chamber, thereby reducing the pressure of the molten salt borne by the graphite assembly.

[0022] Preferably, the graphite molten salt reactor is provided with a gas exchange space above the circulating loop, an upper portion of the gas exchange space is provided with a first control valve and a second control valve, and the first control valve is connected with a first gas pump.

[0023] In the technical solution, the gas enters and exits the gas exchange space through the first control valve and the second control valve, so as to adjust the gas pressure in the reactor.

[0024] Preferably, a baffle is arranged between the upper chamber and the gas exchange space, and the baffle is a porous baffle.

[0025] In the technical solution, the gas flows through the holes in the baffle, and the molten salt in the upper chamber is prevented from splashing upward.

[0026] The application further provides a graphite molten salt reactor system, which comprises the graphite molten salt reactor as described above.

[0027] Preferably, the graphite molten salt reactor system comprises a charging tank, a feeding pipe is arranged between the charging tank and the graphite molten salt reactor, a feeding valve is arranged on the feeding pipe, a third control valve and a fourth control valve are arranged on the upper part of the charging tank, and the third control valve is connected with a second gas pump.

[0028] In the technical solution, the gas enters and exits the charging tank through the third control valve and the fourth control valve, so as to adjust the gas pressure in the charging tank, and the molten salt is gradually charged into the graphite molten salt reactor through cooperation with the feeding valve.

[0029] Preferably, the fourth control valve is connected with a third gas pump.

[0030] In the technical solution, when the molten salt is unloaded from the graphite molten salt reactor, the third gas pump can be started to reduce the gas pressure in the charging tank, so that the molten salt naturally flows to the charging tank.

[0031] Preferably, the outlet of the feeding pipe in the graphite molten salt reactor is located below the graphite assembly.

[0032] In the technical solution, the molten salt directly enters the circulation loop, so that splashing or leakage is avoided, and the molten salt can also be completely discharged through the feeding pipe when the molten salt is discharged after use, without the need to set other pipelines.

[0033] The application further provides a use method of the graphite molten salt reactor system, which uses the graphite molten salt reactor system as described above, and the use method comprises the following steps:

[0034] S1, a protective gas is introduced into the graphite molten salt reactor, and the pressure of the protective gas is continuously increased, the pressure of the protective gas is equal to or slightly greater than the maximum static pressure of the molten salt in the graphite molten salt reactor during operation, and the graphite assembly is statically placed for a period of time, so that the internal pressure of the graphite assembly and the pressure of the protective gas reach equilibrium;

[0035] S2, gradually press the molten salt into the graphite molten salt reactor, each stage raises the preset liquid level in the graphite molten salt reactor, and releases the air pressure in the graphite molten salt reactor, and the released air pressure is equivalent to the increment of static pressure caused by the liquid level rising; the liquid level in the graphite molten salt reactor is raised for multiple times until reaching the upper limit of the design required liquid level;

[0036] S3, after the molten salt loading is completed, the pressure of the protective gas is released to the design rated pressure.

[0037] In the technical solution, the air pressure in the graphite molten salt reactor is adjusted, so that the molten salt gradually flows into the reactor, which avoids the molten salt from penetrating into the graphite and avoids the high air pressure from causing the molten salt to flow poorly.

[0038] Preferably, the use method further comprises the following steps:

[0039] S4, when the graphite molten salt reactor is stopped, the molten salt is discharged by adjusting the air pressure difference between the graphite molten salt reactor and the outside.

[0040] In the technical solution, the air pressure difference between the graphite molten salt reactor and the outside is adjusted, so that the molten salt naturally flows out, and at the same time, the molten salt is prevented from penetrating into the graphite.

[0041] Preferably, the graphite molten salt reactor comprises a circulating loop, the graphite molten salt reactor system comprises a charging tank, a feed pipe is arranged between the charging tank and the graphite molten salt reactor, a feed valve is arranged on the feed pipe, a gas exchange space is arranged above the circulating loop in the graphite molten salt reactor, a first control valve and a second control valve are arranged on the upper part of the gas exchange space, the first control valve is connected with a first gas pump, and the step S1 comprises:

[0042] S11, the feed valve and the second control valve are closed, and the first control valve is opened;

[0043] S12, the first gas pump is opened, gas is continuously introduced into the circulating loop, the first control valve is closed after the circulating loop reaches a preset pressure, and the circulating loop is left to stand for a period of time, so that the internal pressure of the graphite assembly and the pressure of the protective gas reach balance.

[0044] In the technical solution, the graphite molten salt reactor has a certain air pressure before the salt is loaded, so that the molten salt is prevented from penetrating into the graphite after being loaded.

[0045] Preferably, the graphite molten salt reactor comprises a circulating loop, the graphite molten salt reactor system comprises a charging tank, a feeding pipe is arranged between the charging tank and the graphite molten salt reactor, a feeding valve is arranged on the feeding pipe, a gas exchange space is arranged above the circulating loop in the graphite molten salt reactor, a first control valve and a second control valve are arranged on the upper portion of the gas exchange space, the first control valve is connected with a first gas pump, a third control valve and a fourth control valve are arranged on the upper portion of the charging tank, the third control valve is connected with a second gas pump, and the step S2 comprises:

[0046] S21, the molten salt in the charging tank is fully mixed, the fourth control valve is closed, the third control valve and the second gas pump are opened, and the pressure in the charging tank is continuously increased, so that the gas pressure in the charging tank is slightly higher than the gas pressure in the circulating loop;

[0047] S22, the feeding valve is slowly opened, the molten salt in the charging tank flows into the circulating loop under the gas pressure difference on both sides, the feeding valve is closed after the liquid level rises to a preset value, the second control valve is controlled, the gas pressure in the circulating loop is correspondingly reduced, and then the second control valve is closed;

[0048] S23, the steps S21 and S22 are repeated until the liquid level in the circulating loop reaches a set value;

[0049] S24, the second control valve is opened, and the pressure of the gas exchange space is adjusted to a rated operating pressure.

[0050] In the technical solution, the gas pressure in the charging tank is adjusted, so that the molten salt naturally flows into the graphite molten salt reactor without the need of setting other devices for assistance, the pressure in the graphite pores is slightly greater than the static pressure of the molten salt at the same height, the gas in part of the graphite overflows, and finally the gas pressure in each layer of graphite is equal to the static pressure of the molten salt in contact.

[0051] Preferably, the graphite molten salt reactor system comprises a charging tank, a feeding pipe is arranged between the charging tank and the graphite molten salt reactor, a feeding valve is arranged on the feeding pipe, a third control valve and a fourth control valve are arranged on the upper portion of the charging tank, the third control valve is connected with a second gas pump, and the fourth control valve is connected with a third gas pump, and the step S4 comprises:

[0052] S41, the fourth control valve and the third gas pump are opened, and the gas pressure in the charging tank is reduced, so that the gas pressure in the charging tank is less than the gas pressure in the graphite molten salt reactor;

[0053] S42, the fourth control valve and the third gas pump are closed, and the feeding valve is opened, so that the molten salt in the graphite molten salt reactor flows into the charging tank under the gas pressure difference on both sides.

[0054] In the technical solution, the molten salt can flow out of the graphite molten salt reactor naturally by adjusting the air pressure in the charging tank, without the aid of other devices.

[0055] On the basis of common knowledge in the art, the above-mentioned preferred conditions can be combined arbitrarily, thereby obtaining preferred examples of the present application.

[0056] The positive progress effect of the present application is that:

[0057] The graphite molten salt reactor, the graphite molten salt reactor system and the use method thereof can make the molten salt pressure in the graphite molten salt reactor change correspondingly with the internal air pressure of the graphite by dividing the graphite into multiple layers, reducing the pressure of the molten salt flowing through the graphite, and opening and closing the pump, valve and other components, so that the graphite is not infiltrated by the molten salt, and the molten salt can flow into and out of the graphite molten salt reactor naturally without the aid of other devices. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 Fig. 1 is a structural schematic diagram of the graphite molten salt reactor of the present application.

[0059] Figure 2 Fig. 2 is a structural schematic diagram of the graphite molten salt reactor system of the present application.

[0060] REFERENCE SIGNS

[0061] Graphite assembly 1;

[0062] Graphite 11;

[0063] Circulation loop 2;

[0064] Upper chamber 21;

[0065] Lowering chamber 22;

[0066] Lower chamber 23;

[0067] Rising chamber 24;

[0068] Heat exchanger 25;

[0069] Circulation pump 26;

[0070] Gas exchange space 3;

[0071] Baffle 4;

[0072] First control valve 51;

[0073] Second control valve 52;

[0074] First gas pump 53;

[0075] Charging tank 6;

[0076] Third control valve 61;

[0077] Fourth control valve 62;

[0078] a second gas pump 63;

[0079] a third gas pump 64;

[0080] Feed pipe 7;

[0081] Feed valve 71. DETAILED DESCRIPTION

[0082] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0083] like Figures 1-2 As shown in FIG, there are embodiments of the graphite molten salt reactor, graphite molten salt reactor system and its use method of the present invention. Figure 1 As shown, the molten salt stack includes a graphite assembly 1, which is divided into multiple layers along the height of the stack. Each layer of graphite 11 is isolated from each other. The graphite 11 is divided into eight layers, and each layer 11 is connected and secured by a mortise and tenon joint structure. The molten salt stack is loaded by adjusting the internal pressure of the stack. The multiple layers of graphite 11 ensure that the pressure inside each layer of graphite 11 varies during the pressure adjustment process and matches the pressure changes of the molten salt. This ensures that the molten salt does not penetrate the graphite 11 while the stack operates normally.

[0084] In other embodiments, the graphite 11 may be divided into other numbers of layers; and each layer of graphite 11 may be connected in other ways.

[0085] The graphite assembly 1 is provided with a molten salt passage. The graphite molten salt stack further includes a circulation loop 2, which penetrates the upper and lower ends of the graphite assembly 1 through the molten salt passage. The circulation loop 2 penetrates the graphite assembly 1, and the graphite assembly 1 acts as an absorber to control the reaction rate.

[0086] Each layer of graphite 11 is divided into multiple graphite blocks 11 , and the volume of a single graphite block 11 in the reactor is relatively small, which reduces the difficulty of assembly.

[0087] In other embodiments, each layer of graphite 11 may also be a single piece of graphite 11 .

[0088] Circulation loop 2 also includes an upper chamber 21, a descending chamber 22, a lower chamber 23, and an ascending chamber 24. Lower chamber 23 is located below graphite assembly 1, descending chamber 22 is located on the side of graphite assembly 1, and upper chamber 21 is located above graphite assembly 1. Ascending chamber 24 is formed by a molten salt passage and is connected to upper chamber 21. As molten salt flows through the circulation loop, it sequentially passes through upper chamber 21, descending chamber 22, lower chamber 23, and ascending chamber 24. The molten salt circulates within the reactor, dissipating the generated heat for power generation or other purposes.

[0089] The circulating loop 2 also includes a heat exchanger 25, which is located outside the graphite assembly 1, and the descending cavity 22 penetrates the heat exchanger 25. The resistance pressure drops of the molten salt in the circulating loop 2 during operation are approximately as follows: in the heat exchanger 25, about 400 kPa; in the descending cavity 22, about 1.2 kPa; in the lower cavity 23, about 0.4 kPa; in the ascending cavity 24, about 4 kPa; and in the upper cavity 21, about 1 kPa. Except in the heat exchanger 25, the pressure drops of the other parts of the circulating loop 2 are low, and the total pressure drop from the lower cavity 23 to the upper cavity 21 is less than 6 kPa. Since the upper cavity 21 is in communication with the gas exchange space 3, the maximum resistance pressure drop borne by the graphite assembly 1 will be less than 6 kPa.

[0090] In the present embodiment, the total height of the circulating loop 2 is about 4 m, and the density of the molten salt is 3 g / cm3. Thus, the maximum static pressure of the molten salt is about 0.12 MPa, the maximum pressure of the gas exchange space 3 is controlled to be below 1 atmosphere, and the maximum external pressure borne by the graphite assembly 1 is about 0.12 + 0.1 + 0.006 = 0.223 MPa. The larger resistance pressure drop in the heat exchanger 25 is excluded from the graphite assembly 1, and the pressure borne by the graphite assembly 1 is mainly related to the static pressure of the molten salt.

[0091] The graphite assembly 1 in the present embodiment is an isotropic coarse-grained graphite IG110, which can bear a threshold pressure difference of about 2-3 atmospheres, which is 30-50 times the maximum pressure difference inside and outside the graphite during operation of the graphite-molten salt reactor.

[0092] In other embodiments, the resistance pressure drops of the parts of the circulating loop 2 during operation, the total height of the circulating loop 2, the density of the molten salt, and the maximum pressure of the gas exchange space 3 can also be other values, the heat exchanger 25 can also be located at other positions, and the material of the graphite assembly 1 can also be other types, without exceeding the threshold pressure difference that can be borne by the graphite assembly 1.

[0093] The circulating loop 2 also includes a circulating pump 26, which is arranged between the upper cavity 21 and the descending cavity 22. The circulating pump 26 pressurizes the molten salt flowing out of the upper cavity 21, thereby better maintaining the flow of the molten salt in the circulating loop 2.

[0094] The circulating pump 26 is arranged between the upper cavity 21 and the heat exchanger 25. The molten salt flows through the circulating pump 26 and then flows through the heat exchanger 25 into the ascending cavity 24, so that the dynamic pressure of the molten salt is reduced before entering the ascending cavity 24, thereby reducing the pressure of the molten salt borne by the graphite assembly 1.

[0095] The gas exchange space 3 is arranged above the circulating loop 2 in the graphite-molten salt reactor, the upper part of the gas exchange space 3 is provided with a first control valve 51 and a second control valve 52, and the first control valve 51 is connected to a first gas pump 53. Gas enters and exits the gas exchange space 3 through the first control valve 51 and the second control valve 52, thereby adjusting the gas pressure in the reactor.

[0096] A baffle 4 is provided between the upper chamber 21 and the ventilation space 3. The baffle 4 is a porous baffle. Gas flows through the holes on the baffle 4, while preventing the molten salt in the upper chamber 21 from splashing upward.

[0097] The upper chamber 21 is the lowest pressure area in the entire circulation loop 2, and is on the low-pressure side of the circulation pump 26; the circulation process of the fuel molten salt in the entire circulation loop 2 is: driven by the pressure of the circulation pump 26, the high-temperature molten salt in the upper chamber 21 is brought into the heat exchanger 25; the molten salt exchanges heat in the heat exchanger 25, and under pressure drive, passes through the descending chamber 22 into the lower chamber 23, and then enters the ascending chamber 24, where nuclear fission occurs to generate energy and is heated, and finally converges in the upper chamber 21; accordingly, the resistance pressure drop of the entire circulation loop 2 decreases successively as the molten salt flows out of the circulation pump 26, and is the lowest point in the upper chamber 21; the resistance pressure drop in the ascending chamber 21 is less than 2 atmospheres, and the maximum static pressure of the molten salt in the circulation loop 2 is less than 4 atmospheres.

[0098] In other embodiments, the resistance pressure drop in the rising chamber 21 and the maximum static pressure of the molten salt in the circulation loop 2 may also be other values ​​without exceeding the threshold pressure difference that the graphite assembly 1 can withstand.

[0099] like Figure 2 As shown, this embodiment also provides a graphite molten salt reactor system, including the graphite molten salt reactor as described above.

[0100] The graphite molten salt reactor system includes a charging tank 6. A feed pipe 7 is provided between the charging tank 6 and the graphite molten salt reactor. A feed valve 71 is provided on the feed pipe 7. A third control valve 61 and a fourth control valve 62 are provided above the charging tank 6. The third control valve 61 is connected to a second gas pump 63. Gas flows in and out of the charging tank 6 through the third and fourth control valves 61, 62, thereby regulating the air pressure within the charging tank 6. Gas, in conjunction with the feed valve 71, gradually loads the graphite molten salt reactor with salt.

[0101] The fourth control valve 62 is connected to a third gas pump 64. When unloading molten salt from the graphite molten salt pile, the third gas pump 64 can be turned on to reduce the gas pressure in the charging tank 6, thereby allowing the molten salt to flow naturally into the charging tank 6.

[0102] The outlet of the feed pipe 7 in the graphite molten salt pile is located below the graphite assembly 1. The molten salt directly enters the circulation loop 2 to avoid sputtering or leakage, and the molten salt can also be completely discharged through the feed pipe 71 when the salt is discharged after use without the need for setting up other pipes.

[0103] In other embodiments, the outlet of the feed pipe 7 in the graphite molten salt pile can also be set on the side of the graphite component 1 to introduce molten salt into the graphite molten salt pile, and a salt discharge pipe is set in the lower chamber 23 to discharge the molten salt after stopping work.

[0104] The embodiment also provides a method for using the graphite molten salt reactor system, using the graphite molten salt reactor system as described above, and the method comprises the following steps:

[0105] S1, introducing a protective gas into the graphite molten salt reactor, and continuously increasing the pressure of the protective gas, the pressure of the protective gas being equal to or slightly greater than the maximum static pressure of the molten salt in the graphite molten salt reactor during operation, and standing for a period of time to balance the internal pressure of the graphite assembly 1 with the pressure of the protective gas;

[0106] S2, gradually pressing the molten salt into the graphite molten salt reactor, and increasing the preset liquid level in the graphite molten salt reactor at each stage, while releasing the air pressure in the graphite molten salt reactor, the released air pressure being equivalent to the static pressure increment caused by the liquid level rising; the liquid level in the graphite molten salt reactor is increased multiple times until the upper limit of the design required liquid level is reached; the static pressure increase caused by each liquid level increase is controlled to be below 0.5 atm;

[0107] S3, after the molten salt loading is completed, the pressure of the protective gas is released to the designed rated pressure; the rated pressure is 0.5 atm.

[0108] By adjusting the air pressure in the graphite molten salt reactor, the molten salt is gradually flowed into the reactor, which avoids the penetration of the molten salt into the graphite and the poor flow of the molten salt caused by the excessively high air pressure.

[0109] In other embodiments, the rated pressure and the static pressure increment caused by each liquid level increase can also be other values without exceeding the threshold pressure difference that the graphite assembly 1 can withstand and without causing the liquid level to rise too fast.

[0110] Preferably, the method further comprises the following steps:

[0111] S4, when the graphite molten salt reactor is stopped, the molten salt is discharged by adjusting the air pressure difference between the graphite molten salt reactor and the outside, and the pressure in the circulation loop 2 is not more than 0.5 atm.

[0112] By adjusting the air pressure difference between the graphite molten salt reactor and the outside, the molten salt is naturally flowed out, while avoiding the penetration of the molten salt into the graphite 11.

[0113] In other embodiments, the pressure increase in the circulation loop 2 can also be other values without exceeding the threshold pressure difference that the graphite assembly 1 can withstand.

[0114] The graphite molten salt reactor comprises a circulation loop 2, and the graphite molten salt reactor system comprises a charging tank 6, wherein the charging tank 6 is provided with a feeding pipe 7 between the charging tank 6 and the graphite molten salt reactor, the feeding pipe 7 is provided with a feeding valve 71, the graphite molten salt reactor is provided with a gas exchange space 3 above the circulation loop 2, the upper portion of the gas exchange space 3 is provided with a first control valve 51 and a second control valve 52, the first control valve 51 is connected with a first gas pump 53, and the step S1 comprises:

[0115] S11, the feeding valve 71 and the second control valve 52 are closed, and the first control valve 51 is opened;

[0116] S12, the first gas pump 53 is opened, gas is continuously introduced into the circulation loop 2, the first control valve 51 is closed after the circulation loop 2 reaches a preset pressure 0.3 MPa, the circulation loop 2 is static for a period of time, the internal pressure of the graphite assembly 1 reaches balance with the pressure of the protective gas, and the gas pressure in the graphite 11 is close to 0.23 MPa.

[0117] In the technical solution, the graphite molten salt reactor has a certain gas pressure before the salt is filled, so that the molten salt is prevented from permeating into the graphite 11 after being filled.

[0118] In other embodiments, the preset pressure and the gas pressure in the graphite 11 can also be other values without exceeding the threshold pressure difference that can be borne by the graphite assembly 1.

[0119] The graphite molten salt reactor comprises a circulation loop 2, and the graphite molten salt reactor system comprises a charging tank 6, wherein the charging tank 6 is provided with a feeding pipe 7 between the charging tank 6 and the graphite molten salt reactor, the feeding pipe 7 is provided with a feeding valve 71, the graphite molten salt reactor is provided with a gas exchange space 3 above the circulation loop 2, the upper portion of the gas exchange space 3 is provided with a first control valve 51 and a second control valve 52, the first control valve 51 is connected with a first gas pump 53, the upper portion of the charging tank 6 is provided with a third control valve 61 and a fourth control valve 62, the third control valve 61 is connected with a second gas pump 63, and the step S2 comprises:

[0120] S21, the molten salt in the charging tank 6 is fully mixed, the fourth control valve 62 is closed, the third control valve 61 and the second gas pump 63 are opened, the pressure in the charging tank 6 is continuously increased, and the gas pressure in the charging tank 6 reaches 0.4 MPa, which is slightly higher than the gas pressure in the circulation loop 2;

[0121] S22, the feeding valve 71 is slowly opened, the molten salt in the charging tank 6 flows into the circulation loop under the gas pressure difference between the two sides, the feeding valve 71 is closed after the liquid level rises by about 0.33 m, the second control valve 52 is controlled, the gas pressure in the circulation loop 2 is correspondingly reduced by 0.01 MPa, and then the second control valve 52 is closed;

[0122] S23, the steps S21 and S22 are repeated until the liquid level in the circulation loop 2 reaches a set value, and the pressure in the gas exchange space 3 is about 0.13 MPa.

[0123] S24, open the second control valve 52, and adjust the pressure of the air exchange space 3 to the rated operation pressure 0.1 MPa.

[0124] By adjusting the air pressure in the charging tank 6, the molten salt can flow into the graphite molten salt reactor naturally without setting other devices to assist. The pressure in the pores of the graphite 11 is slightly greater than the static pressure of the molten salt at the same height, and part of the gas in the graphite 11 overflows, and finally the air pressure in each layer of the graphite 11 is equal to the static pressure of the molten salt in contact.

[0125] In other embodiments, the air pressure in the charging tank 6, the liquid level each time the value of the increase, the air pressure of the circulating loop 2 each time the value of the decrease, the rated operation pressure and the pressure in the air exchange space 3 can also be other values without exceeding the threshold pressure difference that the graphite assembly 1 can withstand and without causing the liquid level to rise too quickly.

[0126] The graphite molten salt reactor system comprises a charging tank 6, a feeding pipe 7 is arranged between the charging tank 6 and the graphite molten salt reactor, a feeding valve 71 is arranged on the feeding pipe, a third control valve 61 and a fourth control valve 62 are arranged on the upper part of the charging tank 6, the third control valve 61 is connected with a second gas pump 63, the fourth control valve 62 is connected with a third gas pump 64, and step S4 comprises:

[0127] S41, open the fourth control valve 62 and the third gas pump 64, and reduce the air pressure in the charging tank 6, so that the air pressure in the charging tank 6 reaches 0.05 MPa, which is less than the air pressure in the graphite molten salt reactor;

[0128] S42, close the fourth control valve 62 and the third gas pump 64, and open the feeding valve 71, and the molten salt in the graphite molten salt reactor flows into the charging tank 6 under the gas pressure difference on both sides.

[0129] By adjusting the air pressure in the charging tank 6, the molten salt can flow out of the graphite molten salt reactor naturally without setting other devices to assist.

[0130] In other embodiments, the air pressure in the charging tank 6 can also be other values under the condition that the molten salt can flow normally.

[0131] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, and such changes and modifications all fall within the protection scope of the present application.

Claims

1. A method for using a graphite molten salt reactor system, characterized in that: The graphite molten salt pile system comprises a graphite molten salt pile, wherein the graphite molten salt pile comprises a graphite assembly, wherein the graphite assembly is divided into multiple layers in the height direction of the graphite molten salt pile, and the graphite in each layer is isolated from each other; The method of use comprises the following steps: S1. A shielding gas is introduced into the graphite molten salt pile, and the pressure of the shielding gas is continuously increased. The pressure of the shielding gas is equal to or slightly greater than the maximum static pressure of the molten salt in the graphite molten salt pile during operation. The graphite assembly is allowed to stand for a period of time until the internal pressure of the graphite assembly reaches equilibrium with the pressure of the shielding gas. S2. gradually pressing the molten salt into the graphite molten salt pile, raising the preset liquid level in the graphite molten salt pile at each stage, and simultaneously releasing the air pressure in the graphite molten salt pile, wherein the released air pressure is equivalent to the static pressure increment caused by the liquid level rise; raising the liquid level in the graphite molten salt pile multiple times until the liquid level upper limit required by the design is reached; S3. After the molten salt is loaded, the pressure of the protective gas is released to the designed rated pressure.

2. The method for using the graphite molten salt reactor system according to claim 1, wherein: The graphite component is provided with a molten salt passage; the graphite molten salt pile further comprises a circulation loop, and the circulation loop passes through the upper end and the lower end of the graphite component through the molten salt passage.

3. The method for using the graphite molten salt reactor system according to claim 2, wherein: Each layer of graphite is a piece of graphite.

4. The method for using the graphite molten salt reactor system according to claim 2, wherein: Each layer of graphite is divided into multiple graphite pieces.

5. The method for using the graphite molten salt reactor system according to claim 2, wherein: The circulation loop further includes an upper chamber, a descending chamber, a lower chamber, and an ascending chamber, wherein the lower chamber is located below the graphite assembly, the descending chamber is located on the side of the graphite assembly, the upper chamber is located above the graphite assembly, the ascending chamber is formed by the molten salt passage, and the ascending chamber is connected to the upper chamber; When the molten salt flows in the circulation loop, the molten salt flows through the upper chamber, the descending chamber, the lower chamber, and the ascending chamber in sequence.

6. The method for using the graphite molten salt reactor system according to claim 5, wherein: The circulation loop further includes a heat exchanger, which is located outside the graphite assembly and at least partially located in the downcomer.

7. The method for using the graphite molten salt reactor system according to claim 6, wherein: The circulation loop further includes a circulation pump, which is arranged between the upper chamber and the descending chamber.

8. The method for using the graphite molten salt reactor system according to claim 7, wherein: The circulation pump is arranged between the upper chamber and the heat exchanger.

9. The method for using the graphite molten salt reactor system according to claim 5, wherein: A ventilation space is provided above the circulation loop in the graphite molten salt pile. A first control valve and a second control valve are provided on the upper portion of the ventilation space. The first control valve is connected to a first gas pump.

10. The method for using the graphite molten salt reactor system according to claim 9, wherein: A baffle is provided between the upper chamber and the ventilation space, and the baffle is a porous baffle.

11. The method for using the graphite molten salt reactor system according to claim 1, wherein: The graphite molten salt stack system includes a charging tank, a feed pipe is provided between the charging tank and the graphite molten salt stack, a feed valve is provided on the feed pipe, a third control valve and a fourth control valve are provided on the upper part of the charging tank, and the third control valve is connected to the second gas pump.

12. The method for using the graphite molten salt reactor system according to claim 11, wherein: The fourth control valve is connected to a third gas pump.

13. The method for using the graphite molten salt reactor system according to claim 11, wherein: An outlet of the feed pipe in the graphite molten salt pile is located below the graphite assembly.

14. The method for using the graphite molten salt reactor system according to claim 1, wherein: The method of use further comprises the following steps: S4. When the graphite molten salt pile is stopped, the molten salt is discharged by adjusting the pressure difference between the graphite molten salt pile and the outside.

15. The method for using the graphite molten salt reactor system according to claim 1, wherein: The graphite molten salt pile includes a circulation loop, and the graphite molten salt pile system includes a charging tank. A feed pipe is provided between the charging tank and the graphite molten salt pile, and a feed valve is provided on the feed pipe. A ventilation space is provided above the circulation loop in the graphite molten salt pile, and a first control valve and a second control valve are provided above the ventilation space. The first control valve is connected to a first gas pump. Step S1 includes: S11, closing the feed valve and the second control valve, and opening the first control valve; S12. Turn on the first gas pump and continuously introduce gas into the circulation loop until the gas reaches a preset pressure and then close the first control valve; the circulation loop is left to stand for a period of time until the internal pressure of the graphite assembly reaches equilibrium with the pressure of the protective gas.

16. The method for using the graphite molten salt reactor system according to claim 1, wherein: The graphite molten salt pile includes a circulation loop, and the graphite molten salt pile system includes a charging tank. A feed pipe is provided between the charging tank and the graphite molten salt pile, and a feed valve is provided on the feed pipe. A ventilation space is provided above the circulation loop in the graphite molten salt pile, and a first control valve and a second control valve are provided at the upper portion of the ventilation space, and the first control valve is connected to a first gas pump. A third control valve and a fourth control valve are provided at the upper portion of the charging tank, and the third control valve is connected to the second gas pump. Step S2 includes: S21, fully mixing the molten salt in the charging tank, closing the fourth control valve, opening the third control valve and the second gas pump, and continuously increasing the pressure in the charging tank so that the air pressure in the charging tank is slightly higher than the air pressure in the circulation loop; S22, slowly opening the feed valve to allow the molten salt in the charging tank to flow into the circulation loop under the pressure difference between the two sides of the gas, and closing the feed valve after the liquid level rises to a preset value; controlling the second control valve to reduce the gas pressure in the circulation loop accordingly, and then closing the second control valve; S23, repeating steps S21 and S22 until the liquid level in the circulation loop reaches a set value; S24. Open the second control valve to adjust the pressure of the ventilation space to the rated operating pressure.

17. The method for using the graphite molten salt reactor system according to claim 14, wherein: The graphite molten salt reactor system includes a charging tank, a feed pipe is provided between the charging tank and the graphite molten salt reactor, a feed valve is provided on the feed pipe, a third control valve and a fourth control valve are provided on the upper portion of the charging tank, the third control valve is connected to the second gas pump, and the fourth control valve is connected to the third gas pump. Step S4 includes: S41, opening the fourth control valve and the third gas pump to reduce the air pressure in the charging tank so that the air pressure in the charging tank is lower than the air pressure in the graphite molten salt pile; S42: Close the fourth control valve and the third gas pump, open the feed valve, and allow the molten salt in the graphite molten salt pile to flow into the charging tank under the pressure difference of the gases on both sides.

Images