A radioactive waste gas transfer and temporary storage system and its control method

Abstract

This invention relates to the field of waste gas transfer technology, specifically to a radioactive waste gas transfer and storage system and its control method. The system includes a buffer tank, a diaphragm compressor, a waste gas transfer pipeline, a gas supply pipeline, a feed pipeline, a pressurized exhaust pipeline, and a control interlock circuit. The inlet of the waste gas transfer pipeline is connected to the outlet of the buffer tank, and the outlet of the waste gas transfer pipeline is connected to the diaphragm compressor. The inlet of the gas supply pipeline is connected to the exhaust port of the upstream system, the inlet of the feed pipeline is connected to the outlet of the gas supply pipeline, and the outlet of the feed pipeline is connected to the inlet of the buffer tank. The inlet of the pressurized exhaust pipeline is connected to the outlet of the gas supply pipeline. This invention allows for pressurization via the diaphragm compressor when the upstream system's exhaust pressure is low, and for direct discharge via a safety valve when the upstream system's exhaust pressure is high, thus meeting the gas supply requirements of the waste gas treatment process section and improving the applicability and flexibility of the transfer process section.

Description

Technical Field

[0001] This invention relates to the field of waste gas transfer technology, specifically to a radioactive waste gas transfer and temporary storage system and its control method. Background Technology

[0002] Currently, radioactive waste gases generated by nuclear facilities are introduced into waste gas treatment systems via exhaust pressure or suction. Storage decay or retention adsorption technologies are used to continuously decay the radionuclides in the waste gases until they are released into the environment. Storage decay tanks and retention adsorption beds are atmospheric pressure devices, equipped with inlet, outlet, and outlet pipes. The pressure rating of the storage decay tanks is adjusted according to the upstream exhaust volume and plant space requirements. When the upstream system's exhaust conditions are unclear or when the upstream system operates under slight negative pressure, conventional transfer methods are insufficient to transfer the waste gas to the next process stage for treatment, and pressurized storage of the waste gas is not possible, resulting in large footprints and high maintenance costs for waste gas storage tanks. Summary of the Invention

[0003] The technical problem to be solved by this invention is the difficulty of waste gas transfer under conditions such as unstable upstream exhaust conditions or upstream slight negative pressure systems. The purpose is to provide a radioactive waste gas transfer and temporary storage system and its control method, which realizes the automated transfer of radioactive waste gas.

[0004] This invention is achieved through the following technical solution:

[0005] A radioactive waste gas transfer and temporary storage system, comprising:

[0006] A buffer tank, which has a feed inlet and an air outlet;

[0007] Diaphragm compressor;

[0008] The exhaust gas transfer pipeline has its inlet connected to the outlet of the buffer tank, and its outlet connected to the diaphragm compressor. An exhaust valve is installed on the exhaust gas transfer pipeline.

[0009] The air supply pipeline has its air inlet connected to the exhaust port of the upstream system;

[0010] The feed pipeline has an air inlet connected to the air outlet of the air supply pipeline, and the air outlet of the feed pipeline is connected to the feed inlet of the buffer tank. The feed pipeline is equipped with a feed valve.

[0011] A pressurized exhaust pipeline, the air inlet of which is connected to the air outlet of the air supply pipeline, and a safety valve is installed on the pressurized exhaust pipeline.

[0012] The control interlock circuit has its control terminals connected to the diaphragm compressor, the exhaust valve, and the feed valve, respectively.

[0013] The outlet of the pressurized exhaust pipeline and the outlet of the diaphragm compressor are both connected to the next process section.

[0014] Specifically, the buffer tank also has a liquid outlet, to which a waste liquid transfer pipeline is connected. A drain valve is installed on the waste liquid transfer pipeline, and the drain valve is electrically connected to the control terminal of the control interlock circuit.

[0015] Optionally, the feed inlet and the liquid outlet of the buffer tank are located at the upper part of the buffer tank, and the liquid outlet of the buffer tank is located at the bottom of the buffer tank.

[0016] Specifically, the control interlocking circuit includes: a first pressure sensor, a second pressure sensor, a third pressure sensor, and a PLC controller;

[0017] The first pressure sensor is used to detect the exhaust pressure in the air supply pipeline;

[0018] The second pressure sensor is used to detect the exhaust pressure inside the pressurized exhaust pipeline;

[0019] The third pressure sensor is used to detect the exhaust pressure inside the buffer tank;

[0020] The first pressure sensor, the second pressure sensor, the third pressure sensor, the feed valve, the exhaust valve, and the diaphragm compressor are all electrically connected to the PLC controller.

[0021] Furthermore, the control interlocking circuit also includes a continuous liquid level detector, which is used to detect the liquid level height of the waste liquid in the buffer tank.

[0022] Optionally, a check valve is provided on the gas supply line.

[0023] A control method for a radioactive waste gas transfer and temporary storage system includes:

[0024] Set the pressure value for status determination;

[0025] The first pressure value in the gas delivery pipeline is obtained by the first pressure sensor, and it is determined whether the first pressure value is less than the status judgment pressure value. If so, the control method corresponding to the low pressure state is executed; if not, the control method corresponding to the high pressure state is executed.

[0026] Specifically, the control method corresponding to the low-pressure state includes:

[0027] A1. Set the lower and upper negative pressure limits of the buffer tank and ensure that the check valve is in a usable state;

[0028] A2. Determine the status of the feed valve. If the feed valve is not fully closed, control the feed valve to be fully closed; if the feed valve is fully closed, control the exhaust valve to be opened.

[0029] A3. Determine the status of the exhaust valve. If the exhaust valve is not fully open, control the exhaust valve to be fully open; if the exhaust valve is fully open, control the diaphragm compressor to start.

[0030] A4. Obtain the third pressure value in the buffer tank through the third pressure sensor, and determine whether the third pressure value is ≤ the lower limit of negative pressure; if not, control the diaphragm compressor to continue pumping air out of the buffer tank; if so, control the exhaust valve to close.

[0031] A5. Open the feed valve and determine if there is a third pressure value ≥ the upper limit of negative pressure; if not, control the feed valve to remain open; if so, control the feed valve to close.

[0032] A6. Repeat steps A2-A5.

[0033] Specifically, the control method corresponding to the high-pressure state includes: ensuring that the check valve and safety valve are in an available state, closing the feed valve, and directly transferring the gas in the gas delivery pipeline to the next process section through the safety valve.

[0034] Furthermore, the control method also includes a waste liquid transfer method, the waste liquid transfer method comprising:

[0035] Set the upper limit value of the liquid level and obtain the waste liquid level in the buffer tank through a continuous liquid level detector; if the waste liquid level is greater than the upper limit value, control the feed valve to close.

[0036] Control the opening of the drain valve to discharge the waste liquid into the waste liquid treatment system.

[0037] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0038] This invention, by setting up a buffer tank, a diaphragm compressor, and a safety valve, and controlling the opening and closing of different gas paths through multiple valves, allows the diaphragm compressor to pressurize the gas when the upstream system's discharge pressure is low, and to discharge it directly through the safety valve when the upstream system's discharge pressure is high, thus meeting the gas supply requirements of the waste gas treatment process section and improving the applicability and flexibility of the transfer process section. Attached Figure Description

[0039] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, but do not constitute a limitation on the embodiments of the present invention.

[0040] Figure 1 This is a schematic diagram of a radioactive waste gas transfer and temporary storage system according to the present invention.

[0041] Figure 2 This is a schematic flowchart of a control method for a radioactive waste gas transfer and temporary storage system according to the present invention.

[0042] Attached reference numerals: 1-Check valve, 2-First pressure sensor, 3-Safety valve, 4-Second pressure sensor, 5-Feed valve, 6-Third pressure sensor, 7-Continuous level monitoring instrument, 8-Exhaust valve, 9-Diaphragm compressor, 10-Drain valve, 11-Gas supply line, 12-Feed line, 13-Pressurized exhaust line, 14-Waste gas transfer line, 15-Waste liquid transfer line, 16-Buffer tank. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0044] It should also be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0045] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0046] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] Where there is no conflict, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] Example 1

[0049] like Figure 1 As shown, a radioactive waste gas transfer and temporary storage system includes: a buffer tank 16, a diaphragm compressor 9, a waste gas transfer pipeline 14, a gas supply pipeline 11, a feed pipeline 12, a pressurized exhaust pipeline 13, and a control interlock circuit.

[0050] The buffer tank 16 has a feed inlet and an outlet. The inlet of the waste gas transfer pipeline 14 is connected to the outlet of the buffer tank 16, and the outlet of the waste gas transfer pipeline 14 is connected to the diaphragm compressor 9. An exhaust valve 8 is installed on the waste gas transfer pipeline 14. The inlet of the air supply pipeline 11 is connected to the exhaust port of the upstream system. The inlet of the feed pipeline 12 is connected to the outlet of the air supply pipeline 11, and the outlet of the feed pipeline 12 is connected to the feed inlet of the buffer tank 16. A feed valve 5 is installed on the feed pipeline 12. The inlet of the pressurized exhaust pipeline 13 is connected to the outlet of the air supply pipeline 11, and a safety valve 3 is installed on the pressurized exhaust pipeline 13. The control terminals of the control interlock circuit are connected to the diaphragm compressor 9, the exhaust valve 8, and the feed valve 5, respectively. The outlet of the pressurized exhaust pipeline 13 and the outlet of the diaphragm compressor 9 are both connected to the next process section.

[0051] The gas supply line 11 is directly connected to the exhaust port of the upstream system. The radioactive waste gas discharged from the upstream system enters the feed line 12 or the pressurized exhaust line 13 according to the subsequent selection. At the same time, in order to prevent the radioactive gas from flowing back, a check valve 1 is installed on the gas supply line 11.

[0052] If the exhaust gas pressure from the upstream system is low, it can be pressurized by the diaphragm compressor 9; if the exhaust gas pressure from the upstream system is high, it can be discharged directly through the safety valve 3.

[0053] In addition, the exhaust gas emitted from the upstream system may contain some liquid. Therefore, to prevent liquid from entering the diaphragm compressor 9, a buffer tank 16 is provided with a liquid outlet. A waste liquid transfer pipeline 15 is connected to the liquid outlet, and a drain valve 10 is installed on the waste liquid transfer pipeline 15. The drain valve 10 is electrically connected to the control terminal of the control interlock circuit. The entrained liquid will be collected in the buffer tank 16, and when the set value is reached, it will be discharged through the waste liquid transfer pipeline 15.

[0054] Therefore, in order to facilitate the entry and exit of gas and liquid into and out of buffer tank 16, the feed inlet and liquid outlet of buffer tank 16 are located at the upper part of buffer tank 16, and the liquid outlet of buffer tank 16 is located at the bottom of buffer tank 16.

[0055] To enable automated control of the entire device, the control interlocking circuit is set up to include: a first pressure sensor 2, a second pressure sensor 4, a third pressure sensor 6, and a PLC controller;

[0056] The first pressure sensor 2 is used to detect the exhaust pressure in the air supply pipeline 11;

[0057] The second pressure sensor 4 is used to detect the exhaust pressure in the pressurized exhaust pipeline 13;

[0058] The third pressure sensor 6 is used to detect the exhaust pressure inside the buffer tank 16;

[0059] The first pressure sensor 2, the second pressure sensor 4, the third pressure sensor 6, the feed valve 5, the exhaust valve 8, and the diaphragm compressor 9 are all electrically connected to the PLC controller.

[0060] A continuous liquid level detector is used to detect the liquid level height of waste liquid in buffer tank 16.

[0061] Multiple pressure sensors can be used to detect air pressure, and then the corresponding emission scheme can be selectively executed.

[0062] Example 2

[0063] like Figure 2 As shown, this embodiment provides a control method for a radioactive waste gas transfer and temporary storage system based on Embodiment 1, including:

[0064] The set state determination pressure value is generally the safety value of safety valve 3. However, in practice, the safety value of safety valve 3 can be satisfied with the state determination pressure value by adjusting or replacing safety valve 3.

[0065] The first pressure value in the gas supply pipeline 11 is obtained by the first pressure sensor 2, and it is determined whether the first pressure value is less than the state determination pressure value. If so, the control method corresponding to the low pressure state is executed; if not, the control method corresponding to the high pressure state is executed.

[0066] Control methods for low-pressure conditions include:

[0067] A1. Set the lower limit pressure value and the upper limit pressure value of the negative pressure of the buffer tank 16, and ensure that the check valve 1 is in an available state;

[0068] A2. Determine the state of feed valve 5. If feed valve 5 is not fully closed, control feed valve 5 to be fully closed; if feed valve 5 is fully closed, control exhaust valve 8 to be opened.

[0069] A3. Determine the state of exhaust valve 8. If exhaust valve 8 is not fully open, control exhaust valve 8 to be fully open; if exhaust valve 8 is fully open, control diaphragm compressor 9 to be turned on.

[0070] A4. Obtain the third pressure value in the buffer tank 16 through the third pressure sensor 6, and determine whether the third pressure value is ≤ the lower limit of negative pressure; if not, control the diaphragm compressor 9 to continue pumping out the air in the buffer tank 16; if so, control the closure of the exhaust valve 8.

[0071] A5. Open feed valve 5 and determine if there is a third pressure value ≥ negative pressure upper limit pressure value; if not, control feed valve 5 to continue to open; if so, control feed valve 5 to close.

[0072] A6. Repeat steps A2-A5.

[0073] The feed valve 5, exhaust valve 8, diaphragm compressor 9, and third pressure sensor 6 are all controlled by a PLC controller.

[0074] That is, firstly, the waste gas in the buffer tank 16 is discharged to bring it to a negative pressure state. Then, the low-pressure waste gas is collected into the buffer tank 16 by opening the feed valve 5. Once the upper limit of the negative pressure is reached, the feed valve 5 is closed and the exhaust valve 8 is opened, and the waste gas in the buffer tank 16 is discharged through the diaphragm compressor 9. This process is repeated so that waste gas that meets the pressure requirements of the next process stage can be discharged through the diaphragm compressor 9.

[0075] The control methods corresponding to the high pressure state include: ensuring that the check valve 1 and the safety valve 3 are in an available state, closing the feed valve 5, and transferring the gas in the gas supply pipeline 11 directly to the next process section through the safety valve 3. In practice, the pressure changes of the gas supply pipeline 11 and the pressurized exhaust pipeline 13 need to be detected in real time by the first pressure sensor 2 and the second pressure sensor 4 to avoid excessively high output pressure of exhaust gas.

[0076] In addition, to discharge the waste liquid in buffer tank 16, the control method also includes a waste liquid transfer method, which includes:

[0077] Set the upper limit value of the liquid level and obtain the waste liquid level in the buffer tank 16 through a continuous liquid level detector; if the waste liquid level is greater than the upper limit value, control the feed valve 5 to close.

[0078] Control the opening of drain valve 10 to discharge waste liquid to the waste liquid treatment system.

[0079] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0080] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0081] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above invention, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A radioactive waste air transfer staging system, characterized by, include: Buffer tank (16) has a feed inlet and an air outlet; Diaphragm compressor (9); The exhaust gas transfer pipeline (14) has its inlet connected to the outlet of the buffer tank (16), and its outlet connected to the diaphragm compressor (9). An exhaust valve (8) is provided on the exhaust gas transfer pipeline (14). An air supply line (11) is provided with an air inlet connected to the exhaust port of the upstream system, and a check valve (1) is provided on the air supply line (11). The feed line (12) has an air inlet connected to the air outlet of the air supply line (11), and the air outlet of the feed line (12) is connected to the feed inlet of the buffer tank (16). The feed line (12) is equipped with a feed valve (5). A pressurized exhaust pipeline (13) has its inlet connected to the outlet of the air supply pipeline (11), and a safety valve (3) is provided on the pressurized exhaust pipeline (13). The control interlock circuit is electrically connected to the diaphragm compressor (9), the exhaust valve (8), and the feed valve (5), respectively. The outlet of the pressurized exhaust pipeline (13) and the outlet of the diaphragm compressor (9) are both connected to the next process section; The control interlocking circuit includes: a first pressure sensor (2), a second pressure sensor (4), a third pressure sensor (6), a PLC controller, and a continuous liquid level detector; The first pressure sensor (2) is used to detect the exhaust pressure in the gas supply line (11); The second pressure sensor (4) is used to detect the exhaust pressure inside the pressurized exhaust pipeline (13); The third pressure sensor (6) is used to detect the exhaust pressure inside the buffer tank (16); The first pressure sensor (2), the second pressure sensor (4), the third pressure sensor (6), the feed valve (5), the exhaust valve (8), and the diaphragm compressor (9) are all electrically connected to the PLC controller; The continuous liquid level detector is used to detect the liquid level height of the waste liquid in the buffer tank (16).

2. A radioactive waste transfer staging system according to claim 1, wherein, The buffer tank (16) also has a liquid outlet, and a waste liquid transfer pipeline (15) is connected to the liquid outlet. A drain valve (10) is provided on the waste liquid transfer pipeline (15), and the drain valve (10) is electrically connected to the control terminal of the control interlock circuit.

3. A radioactive waste transfer staging system according to claim 2, wherein, The feed inlet and the air outlet of the buffer tank (16) are located at the upper part of the buffer tank (16), and the liquid outlet of the buffer tank (16) is located at the bottom of the buffer tank (16).

4. The control method of a radioactive waste gas transfer temporary storage system according to claim 3, characterized by, include: Set the pressure value for status determination; The first pressure value in the gas delivery pipeline (11) is obtained by the first pressure sensor (2), and it is determined whether the first pressure value is less than the state determination pressure value; if so, the control method corresponding to the low pressure state is executed. If not, then execute the control method corresponding to the high-voltage state; The control method corresponding to the low-pressure state includes: A1. Set the lower limit pressure value and upper limit pressure value of the negative pressure of the buffer tank (16), and ensure that the check valve (1) is in an available state; A2, judging the state of the feed valve (5), if the feed valve (5) is in a non-full closed state, controlling the feed valve (5) to be fully closed; if the feed valve (5) is in a fully closed state, controlling the exhaust valve (8) to be opened; A3, judging the state of the exhaust valve (8), if the exhaust valve (8) is in a non-full open state, controlling the exhaust valve (8) to be fully opened; if the exhaust valve (8) is in a fully open state, controlling the diaphragm compressor (9) to be opened; A4, obtaining the third pressure value in the buffer tank (16) through the third pressure sensor (6), and judging whether there is a third pressure value ≤ negative pressure lower limit pressure value; if not, controlling the diaphragm compressor (9) to continue pumping air in the buffer tank (16); if yes, controlling the exhaust valve (8) to be closed; A5, opening the feed valve (5), and judging whether there is a third pressure value ≥ negative pressure upper limit pressure value; if not, controlling the feed valve (5) to be continuously opened; if yes, controlling the feed valve (5) to be closed; A6, repeating steps A2-A5.

5. The control method of a radioactive waste gas transfer temporary storage system according to claim 4, characterized by, The control method corresponding to the high pressure state includes: ensuring that the check valve (1) and the safety valve (3) are in a usable state, closing the feed valve (5), and the gas in the gas sending pipeline (11) is directly transferred to the next process section through the safety valve (3).

6. The control method of a radioactive waste gas transfer temporary storage system according to claim 4, characterized by, It also includes a waste liquid transfer method, which includes: Setting an upper limit value of the liquid level, and obtaining the waste liquid level in the buffer tank (16) through a continuous liquid level detector; if the waste liquid level > the upper limit value of the liquid level, controlling the feed valve (5) to be closed; Controlling the liquid discharge valve (10) to be opened, and discharging the waste liquid to a waste liquid treatment system.

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