A sulfur hexafluoride gas analysis and tail gas recovery system and control method

Abstract

The present invention discloses a sulfur hexafluoride gas analysis and tail gas recovery system and control method. The system is provided with a first throttle valve and a negative pressure unit. Under the action of a control module, whether pressure fluctuations or airflow fluctuations occur inside a gas analyzer, the fluctuations can be smoothed by adjusting the opening of the first throttle valve and the air pressure of the negative pressure unit. Therefore, the gas analyzer can detect the target gas under stable air pressure and airflow, thereby ensuring the accuracy of the detection.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas processing, and in particular relates to a sulfur hexafluoride gas analysis and tail gas recovery system and a control method. Background Art

[0002] Sulfur hexafluoride (SF6) is colorless, odorless, and non-toxic, with excellent insulation and arc-extinguishing properties, making it widely used in electrical equipment. However, SF6 is also a greenhouse gas, with a global warming potential (GWP) 23,900 times that of CO2 and a natural lifespan of 3,200 years. It is one of the six greenhouse gases banned under the Kyoto Protocol, making the recovery and treatment of SF6 extremely important.

[0003] Existing online detection solutions for electrical insulation equipment make it difficult to accurately detect the decomposition products of SF6 gas in electrical equipment, and are unable to accurately judge the operating conditions of sulfur hexafluoride electrical equipment. In order to more accurately detect the decomposition products of SF6 gas inside operating electrical equipment, as a basis for judging the operating status of sulfur hexafluoride electrical equipment, it is usually necessary to collect the sampled gas from the site into a container and then send it to the laboratory for testing. Laboratory testing instruments have relatively high requirements for the input gas flow, pressure and temperature. On the other hand, the operation of the equipment will produce a variety of SF6 gas components, such as SO2, H2S, CO and HF, as well as SF4, SOF2, SO2F2, SOF4, S2F 10 (or S2OF 10 ) and other gas components, all of which have certain biotoxic properties. During on-site equipment testing, the indiscriminate discharge of test gas can endanger the personal safety of test personnel and pollute the atmospheric environment. Currently used SF6 gas composition detection devices lack consideration for personal safety and environmental protection. They simply connect a several-meter-long tailpipe to the downwind side and directly discharge the test exhaust gas. This simple exhaust treatment method not only affects the accuracy of gas composition analysis results, but also poses a risk of personal injury due to the rapid circulation of outdoor air and is detrimental to environmental protection. Summary of the Invention

[0004] The object of the present invention is to provide a sulfur hexafluoride gas analysis and tail gas recovery system and control method, which are used to solve the problem in the prior art that unstable airflow flowing through the detection instrument leads to inaccurate detection results.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a sulfur hexafluoride gas analysis and tail gas recovery system, comprising:

[0007] a first pressure gauge, a flow meter, a first throttle valve, a negative pressure unit, and a control module;

[0008] The first pressure gauge is connected to the inlet of the flow meter, one end of the first throttle valve is connected to the outlet of the flow meter, and the other end of the first throttle valve is connected to the inlet of the negative pressure unit;

[0009] The negative pressure unit, the first throttle valve, the first pressure gauge and the flow meter are electrically connected to the control module respectively;

[0010] The control module outputs a signal indicating the inlet pressure of the negative pressure unit and a signal indicating the opening of the first throttle valve based on the first flow and the first pressure, so that the pressure and flow at the inlet of the flowmeter are stabilized within a predetermined range, wherein the first flow is the flow passing through the flowmeter, and the first pressure is the pressure at the inlet of the flowmeter.

[0011] In one possible implementation, the negative pressure unit includes: a pressure stabilizing tank, a second throttle valve, a second pressure gauge, and a vacuum pump;

[0012] The inlet of the pressure stabilizing tank is communicated with the outlet of the first throttle valve, the outlet of the pressure stabilizing tank is communicated with the inlet of the second throttle valve, and the outlet of the second throttle valve is communicated with the inlet of the vacuum pump;

[0013] The second pressure gauge is used to indicate the pressure of the pressure stabilizing tank;

[0014] The second pressure gauge and the second throttle valve are electrically connected to the control module respectively;

[0015] The control module outputs a signal indicating the second throttle valve opening based on the second pressure and the signal indicating the inlet pressure of the negative pressure unit, so that the pressure of the pressure stabilizing tank is consistent with the signal indicating the inlet pressure of the negative pressure unit, wherein the second pressure is the pressure of the pressure stabilizing tank.

[0016] In one possible implementation, the sulfur hexafluoride gas analysis and tail gas recovery system further includes: a recovery box and a third pressure gauge, the inlet of the recovery box is connected to the outlet of the negative pressure unit, and the third pressure gauge is used to indicate the pressure of the recovery box.

[0017] In one possible implementation, the sulfur hexafluoride gas analysis and tail gas recovery system further includes a one-way valve, the inlet of the one-way valve is connected to the outlet of the negative pressure unit, and the outlet of the one-way valve is connected to the inlet of the recovery box.

[0018] In a second aspect, an embodiment of the present invention provides a method for analyzing sulfur hexafluoride gas and controlling tail gas recovery, comprising:

[0019] Obtaining a first flow rate and a first pressure, wherein the first flow rate is the flow rate flowing through the flow meter, and the first pressure is the pressure at the inlet of the flow meter;

[0020] A signal indicating the inlet pressure of the negative pressure unit and a signal indicating the opening of the first throttle valve are output according to a first formula, the first flow rate, and the first pressure. The first formula is:

[0021]

[0022] Where, is a signal indicating the first throttle valve opening, is the first opening proportional coefficient, is the first opening integral coefficient, is the function of the deviation between the first flow rate and the target flow rate changing with time, is a signal indicating the inlet pressure of the negative pressure unit, is the pressure proportionality coefficient, is the pressure integral coefficient, is the pressure differential coefficient, is a function of the deviation between the first pressure and the target pressure changing with time, the target pressure is the control target pressure of the inlet of the flowmeter, and the target flow is the control target flow of the flowmeter.

[0023] In one possible implementation, the sulfur hexafluoride gas analysis and tail gas recovery control method further includes:

[0024] A signal indicating the second throttle valve opening is output according to a second formula, a second pressure, and the signal indicating the inlet pressure of the negative pressure unit, wherein the second pressure is the pressure of the pressure stabilizing tank, and the second formula is:

[0025]

[0026] Where, is a signal indicating the second throttle valve opening, is the second opening proportional coefficient, is the second opening integral coefficient, is the second opening differential coefficient, It is a function of the time-varying difference between the pressure of the surge tank and the signal indicating the inlet pressure of the negative pressure unit.

[0027] In one possible implementation, the first opening proportional coefficient and the first opening integral coefficient are adjusted according to a predetermined flow range of the flow meter inlet;

[0028] The pressure proportional coefficient, the pressure integral coefficient, and the pressure differential coefficient are adjusted according to a predetermined pressure range at the inlet of the flowmeter.

[0029] In a third aspect, an embodiment of the present invention provides a sulfur hexafluoride gas analysis and tail gas recovery control device, which is applied to the sulfur hexafluoride gas analysis and tail gas recovery system as may be achieved in the first aspect, comprising:

[0030] a flow and pressure acquisition module, configured to acquire a first flow and a first pressure, wherein the first flow is the flow through the flow meter, and the first pressure is the pressure at the inlet of the flow meter;

[0031] as well as,

[0032] The flowmeter pressure adjustment module is configured to output a signal indicating the inlet pressure of the negative pressure unit and a signal indicating the opening of the first throttle valve according to a first formula, the first flow rate, and the first pressure, wherein the first formula is:

[0033]

[0034] Where, is a signal indicating the first throttle valve opening, is the first opening proportional coefficient, is the first opening integral coefficient, is the function of the deviation between the first flow rate and the target flow rate changing with time, is a signal indicating the inlet pressure of the negative pressure unit, is the pressure proportionality coefficient, is the pressure integral coefficient, is the pressure differential coefficient, is a function of the deviation between the first pressure and the target pressure changing with time, the target pressure is the control target pressure of the inlet of the flowmeter, and the target flow is the control target flow of the flowmeter.

[0035] In a fourth aspect, an embodiment of the present invention provides a control module comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements the steps of the method described in the second aspect or any possible implementation of the second aspect.

[0036] In a fifth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the method described in the first aspect or any possible implementation of the first aspect.

[0037] The beneficial effects of the present invention are as follows:

[0038] An embodiment of the sulfur hexafluoride gas analysis and tail gas recovery system of the present invention is provided with a first throttle valve and a negative pressure unit. Under the action of the control module, whether pressure fluctuations or airflow fluctuations occur inside the gas analyzer, the above-mentioned fluctuations can be smoothed by adjusting the opening of the first throttle valve and the air pressure of the negative pressure unit. Therefore, it can be ensured that the gas analyzer can detect the target gas under stable air pressure and airflow, thereby ensuring the accuracy of the detection.

[0039] The embodiment of the present invention is further provided with a pressure stabilizing box, a second throttle valve and a vacuum pump. Through the action of the vacuum pump and the second throttle valve, the pressure of the pressure stabilizing box is stabilized at a predetermined value, thereby reducing the pressure fluctuation of the negative pressure unit.

[0040] The embodiment of the sulfur hexafluoride gas analysis and tail gas recovery control method of the present invention separates the adjustment of the interconnected negative pressure unit and the throttle valve, which are respectively used to control the target gas pressure and the target flow, and respectively applies the proportional-integral strategy and the proportional-integral-differential strategy. Therefore, different control effects can be achieved by adjusting the coefficients in the strategy, and the steady-state error is small and the fluctuation is controllable.

[0041] The negative pressure unit air pressure regulation in the embodiment of the present invention is a hysteresis regulation, which adopts a proportional-integral-differential control strategy, which can solve the problem that the negative pressure unit air pressure lags behind the throttle valve opening, and ultimately achieves the stability of the analysis system air pressure and airflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0043] Figure 1 This is a schematic diagram of a sulfur hexafluoride gas analysis and tail gas recovery system provided by an embodiment of the present invention;

[0044] Figure 2 This is a flow chart of sulfur hexafluoride gas analysis and tail gas recovery control provided by an embodiment of the present invention;

[0045] Figure 3 This is a coefficient setting principle diagram provided by an embodiment of the present invention;

[0046] Figure 4 This is a functional block diagram of a sulfur hexafluoride gas analysis and tail gas recovery control device provided by an embodiment of the present invention;

[0047] Figure 5 It is a functional block diagram of a control module provided in an embodiment of the present invention.

[0048] In the figure: 101 sampling container; 102 heating device; 103 pressure reducing valve; 104 gas analyzer; 105 first pressure gauge; 106 flow meter; 107 first throttle valve; 108 pressure stabilizing box; 109 second pressure gauge; 110 second throttle valve; 111 vacuum pump; 112 one-way valve; 113 recovery box; 114 third pressure gauge. DETAILED DESCRIPTION

[0049] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0050] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise indicated, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0051] Example 1

[0052] Figure 1 This is a flow chart of a sulfur hexafluoride gas analysis and tail gas recovery system provided in an embodiment of the present invention.

[0053] like Figure 1 As shown, it shows a schematic diagram of a sulfur hexafluoride gas analysis and tail gas recovery system provided by an embodiment of the present invention, which is described in detail as follows:

[0054] A sulfur hexafluoride gas analysis and tail gas recovery system includes: a first pressure gauge 105, a flow meter 106, a first throttle valve 107, a negative pressure unit and a control module;

[0055] The first pressure gauge 105 is connected to the inlet of the flow meter 106 , one end of the first throttle valve 107 is connected to the outlet of the flow meter 106 , and the other end of the first throttle valve 107 is connected to the inlet of the negative pressure unit;

[0056] The negative pressure unit, the first throttle valve 107, the first pressure gauge 105 and the flow meter 106 are electrically connected to the control module respectively;

[0057] The control module outputs a signal indicating the inlet pressure of the negative pressure unit and a signal indicating the opening of the first throttle valve 107 based on the first flow and the first pressure, so that the pressure and flow at the inlet of the flowmeter 106 are stable within a predetermined range, wherein the first flow is the flow flowing through the flowmeter 106, and the first pressure is the pressure at the inlet of the flowmeter 106.

[0058] For example, Figure 1 As shown, the gas analyzer 104 receives the gas in the sampling container 101 at its air inlet, and analyzes the gas composition through the airflow of the gas to be tested released from the sampling container 101. In some application scenarios, a heating device 102 and a pressure reducing valve 103 are also provided at the air inlet of the gas analyzer 104, so that the pressure and temperature of the gas entering the gas analyzer 104 are within a more reasonable range.

[0059] However, as we know, the pressure reducing effect of the pressure reducing valve 103 is not stable and there will be a fluctuation range. In addition, due to the different connection methods of the gas outlet of the gas analyzer 104, the flow rate of the air flow cannot be guaranteed to meet the requirements of the detection specifications.

[0060] Therefore, an embodiment of the present invention provides a system for analyzing sulfur hexafluoride gas, which is connected to the gas outlet end of the gas analyzer 104. A first pressure gauge 105 and a flow meter 106 are provided on the side adjacent to the gas outlet of the gas analyzer 104, which are respectively used to detect the pressure and flow at the gas outlet of the gas analyzer 104. A first throttle valve 107 and a negative pressure unit are respectively connected to the outlet of the flow meter 106. The first throttle valve 107 is used to control the flow by adjusting the opening inside the valve, and the negative pressure unit is used to generate negative pressure. In addition to allowing the gas inside the gas analyzer 104 to flow out smoothly, this negative pressure also serves to balance the internal air pressure of the gas analyzer 104.

[0061] In addition to controlling the gas flow, the first throttle valve 107 also produces different fluid resistances at different openings, further causing pressure changes inside other analyzers. Therefore, the negative pressure unit needs to balance the pressure drop caused by the throttling effect.

[0062] That is, if flow fluctuations occur, the first throttle valve 107 will stabilize the flow within a predetermined range by changing its internal flow cross-sectional area. However, since the flow cross-sectional area changes, its flow resistance and flow pressure drop will also change accordingly, causing the internal pressure of the gas analyzer 104 to change. At this time, it is necessary to adjust the air pressure of the negative pressure unit so that the pressure inside the gas analyzer 104 meets the predetermined conditions.

[0063] On the other hand, if the pressure inside the gas analyzer 104 changes, the negative pressure unit will be adjusted accordingly. When the air pressure in the negative pressure unit changes, the amount of air flowing through the gas analyzer 104 will also change. At this time, it is necessary to adjust the opening of the first throttle valve 107, that is, the internal flow cross-sectional area thereof.

[0064] In summary, regardless of the pressure or flow inside the gas analyzer 104 fluctuating, the first throttle valve 107 and the negative pressure unit need to make adaptive adjustments. In the embodiment of the present invention, a control module is provided, which adjusts the opening of the first throttle valve 107 and the air pressure of the negative pressure unit in real time through the signals fed back by the first pressure gauge 105 and the flow meter 106, so that the gas analyzer 104 operates under predetermined working conditions.

[0065] In some embodiments, the negative pressure unit includes: a pressure stabilizing tank 108, a second throttle valve 110, a second pressure gauge 109, and a vacuum pump 111;

[0066] The inlet of the pressure stabilizing tank 108 is communicated with the outlet of the first throttle valve 107 , the outlet of the pressure stabilizing tank 108 is communicated with the inlet of the second throttle valve 110 , and the outlet of the second throttle valve 110 is communicated with the inlet of the vacuum pump 111 ;

[0067] The second pressure gauge 109 is used to indicate the pressure of the pressure stabilizing tank 108;

[0068] The second pressure gauge 109 and the second throttle valve 110 are electrically connected to the control module respectively;

[0069] The control module outputs a signal indicating the opening of the second throttle valve 110 based on the second pressure and the signal indicating the inlet pressure of the negative pressure unit, so that the pressure of the pressure stabilizing tank 108 is consistent with the signal indicating the inlet pressure of the negative pressure unit, wherein the second pressure is the pressure of the pressure stabilizing tank 108.

[0070] In some embodiments, the sulfur hexafluoride gas analysis and tail gas recovery system further includes: a recovery box 113 and a third pressure gauge 114 , wherein the inlet of the recovery box 113 is connected to the outlet of the negative pressure unit, and the third pressure gauge 114 is used to indicate the pressure of the recovery box 113 .

[0071] In some embodiments, the sulfur hexafluoride gas analysis and tail gas recovery system further includes a one-way valve 112 , the inlet of the one-way valve 112 is connected to the outlet of the negative pressure unit, and the outlet of the one-way valve 112 is connected to the inlet of the recovery box 113 .

[0072] For example, in some application scenarios, a pressure stabilizing tank 108 , a second throttle valve 110 , a second pressure gauge 109 and a vacuum pump 111 are provided.

[0073] As we all know, the air pressure at the inlet of the vacuum pump 111 fluctuates. If it is used as a negative pressure control terminal, it will cause air pressure fluctuations. Therefore, the embodiment of the present invention is equipped with a pressure stabilizing tank 108. A second throttle valve 110 is provided between the pressure stabilizing tank 108 and the vacuum pump 111. The second throttle valve 110 controls the pressure difference between the pressure stabilizing tank 108 and the vacuum pump 111 by changing the opening value, thereby controlling the pressure in the pressure stabilizing tank 108. Similarly, the control module receives the pressure signal fed back by the second pressure gauge 109 and controls the opening of the second throttle valve 110.

[0074] In addition, in some embodiments of the present invention, a recovery box 113 for recovering tail gas is provided to recover the gas exhausted from the gas analyzer 104 .

[0075] A one-way valve 112 is provided at the inlet of the recovery box 113 , which can automatically close the port of the recovery box 113 when the vacuum pump 111 stops.

[0076] An embodiment of the sulfur hexafluoride gas analysis and tail gas recovery system of the present invention is provided with a first throttle valve 107 and a negative pressure unit. Under the action of the control module, whether pressure fluctuations or airflow fluctuations occur inside the gas analyzer 104, the above-mentioned fluctuations can be smoothed by adjusting the opening of the first throttle valve 107 and the air pressure of the negative pressure unit. Therefore, it can be ensured that the gas analyzer 104 can detect the target gas under stable air pressure and airflow, thereby ensuring the accuracy of the detection.

[0077] The embodiment of the present invention is further provided with a pressure stabilizing box 108, a second throttle valve 110 and a vacuum pump 111. Through the action of the vacuum pump 111 and the second throttle valve 110, the pressure of the pressure stabilizing box 108 is stabilized at a predetermined value, thereby reducing the pressure fluctuation of the negative pressure unit.

[0078] A second aspect of the present invention further provides a sulfur hexafluoride gas analysis and tail gas recovery control method, which is applied to the sulfur hexafluoride gas analysis and tail gas recovery system as may be achieved in the first aspect, comprising:

[0079] Step 201: Obtain a first flow rate and a first pressure, wherein the first flow rate is the flow rate flowing through the flow meter 106 , and the first pressure is the pressure at the inlet of the flow meter 106 ;

[0080] Step 202: Output a signal indicating the inlet pressure of the negative pressure unit and a signal indicating the opening of the first throttle valve 107 according to a first formula, the first flow rate, and the first pressure. The first formula is:

[0081]

[0082] Where, is a signal indicating the opening of the first throttle valve 107, is the first opening proportional coefficient, is the first opening integral coefficient, is the function of the deviation between the first flow rate and the target flow rate changing with time, is a signal indicating the inlet pressure of the negative pressure unit, is the pressure proportionality coefficient, is the pressure integral coefficient, is the pressure differential coefficient, is a function of the deviation between the first pressure and the target pressure changing with time, the target pressure is the control target pressure of the inlet of the flowmeter 106 , and the target flow is the control target flow of the flowmeter 106 .

[0083] In some embodiments, a signal indicating the opening of the second throttle valve 110 is output based on a second formula, a second pressure, and the signal indicating the inlet pressure of the negative pressure unit, wherein the second pressure is the pressure of the surge tank 108, and the second formula is:

[0084]

[0085] Where, is a signal indicating the opening degree of the second throttle valve 110, is the second opening proportional coefficient, is the second opening integral coefficient, is the second opening differential coefficient, It is a function of the difference between the pressure of the surge tank 108 and the signal indicating the inlet pressure of the negative pressure unit over time.

[0086] In some embodiments, the first opening proportional coefficient and the first opening integral coefficient are adjusted according to a predetermined flow range at the inlet of the flow meter 106;

[0087] The pressure proportional coefficient, the pressure integral coefficient, and the pressure differential coefficient are adjusted according to a predetermined pressure range at the inlet of the flow meter 106 .

[0088] For example, as described in the first aspect, regardless of the internal air pressure fluctuation or flow fluctuation of the gas analyzer 104, it is necessary to adjust the pressure of the negative pressure unit and the opening of the first throttle valve 107, and the pressure of the negative pressure unit is controlled by the opening of the second throttle valve 110. This control process is a relatively complex and interconnected process, and due to the pressure stabilizing effect of the pressure stabilizing box 108, the change of the air pressure in the pressure stabilizing box 108 always lags behind the opening of the second throttle valve 110, which makes the control strategy very complicated.

[0089] The embodiments of the present invention adopt different control strategies according to different application scenarios. Since the throttle valve has very high real-time performance and the flow rate changes as the opening changes, a proportional-integral control strategy is adopted. Its input is the difference between the actual flow rate in the gas analyzer 104 and the predetermined flow rate, and the output is the opening of the first throttle valve 107.

[0090] For the negative pressure unit, a proportional-integral-differential control strategy is adopted. The input is the difference between the pressure in the gas analyzer 104 and the predetermined pressure, and the output is the pressure of the negative pressure unit. Therefore, a control formula is constructed as follows:

[0091]

[0092] Where, is a signal indicating the opening of the first throttle valve 107, is the first opening proportional coefficient, is the first opening integral coefficient, is the function of the deviation between the first flow rate and the target flow rate changing with time, is a signal indicating the inlet pressure of the negative pressure unit, is the pressure proportionality coefficient, is the pressure integral coefficient, is the pressure differential coefficient, is a function of the deviation between the first pressure and the target pressure changing with time, the target pressure is the control target pressure of the inlet of the flowmeter 106 , and the target flow is the control target flow of the flowmeter 106 .

[0093] In the above formula, by properly selecting each coefficient, the control module can output a more reasonable control signal.

[0094] In the control strategy using the pressure-surge tank 108, since the pressure in the pressure-surge tank 108 lags behind the opening of the second throttle valve 110, a proportional-differential control strategy or a proportional-integral-differential control strategy can be used. Regardless of which control strategy is used, the input is the difference between the air pressure value determined according to the previous formula and the current air pressure value in the pressure-surge tank 108, and the output is the opening of the second throttle valve 110. It is worth noting that when using the latter strategy, the control capability of the integral is greatly weakened to prevent overshoot. The expression of this control strategy is:

[0095]

[0096] Where, is a signal indicating the opening degree of the second throttle valve 110, is the second opening proportional coefficient, is the second opening integral coefficient, is the second opening differential coefficient, is a function of the difference between the pressure of the surge tank 108 and the signal indicating the inlet pressure of the negative pressure unit over time

[0097] Finally, we need to emphasize the setting of the coefficients, such as Figure 3 As shown in the figure, different setting coefficients will bring different effects. Curve 1 in the figure is a step fluctuation (air pressure or airflow fluctuation), curve 2 is the response curve of the first control strategy, curve 3 is the response curve of the second control strategy, and curve 4 is the response curve of the third control strategy. Straight line 6 expresses the maximum limit of the fluctuation. It can be seen that curve 2 responds very positively to the fluctuation, but overshoot will occur (higher than the fluctuation limit). Although curve 4 will not overshoot, the response speed is too slow. Only curve 3 can maintain the response speed and fluctuation, which is an excellent control strategy.

[0098] The sulfur hexafluoride gas analysis and tail gas recovery system embodiment of the present invention separates the adjustment of the interconnected negative pressure unit and the throttle valve, which are respectively used to control the target gas pressure and the target flow, and respectively applies the proportional-integral strategy and the proportional-integral-differential strategy. Therefore, different control effects can be achieved by adjusting the coefficients in the strategy, and the steady-state error is small and the fluctuation is controllable.

[0099] The negative pressure unit air pressure regulation in the embodiment of the present invention is a hysteresis regulation, which adopts a proportional-integral-differential control strategy, which can solve the problem that the negative pressure unit air pressure lags behind the throttle valve opening, and ultimately achieves the stability of the analysis system air pressure and airflow.

[0100] It should be understood that the size of the serial numbers of each step in the above embodiment does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0101] The following is an embodiment of the device of the present invention. For details not described in detail, please refer to the corresponding method embodiment described above.

[0102] Figure 4 This is a functional block diagram of the power metering equipment operation and maintenance device provided by the embodiment of the present invention, referring to Figure 4 The power metering equipment operation and maintenance device includes: a flow and pressure acquisition module 401 and a flow meter 106 pressure adjustment module 402.

[0103] The flow and pressure acquisition module 401 is configured to acquire a first flow and a first pressure, wherein the first flow is the flow through the flow meter 106 , and the first pressure is the pressure at the inlet of the flow meter 106 ;

[0104] The flow meter 106 pressure adjustment module 402 is configured to output a signal indicating the inlet pressure of the negative pressure unit and a signal indicating the opening of the first throttle valve 107 according to a first formula, the first flow rate, and the first pressure. The first formula is:

[0105]

[0106] Where, is a signal indicating the opening of the first throttle valve 107, is the first opening proportional coefficient, is the first opening integral coefficient, is the function of the deviation between the first flow rate and the target flow rate changing with time, is a signal indicating the inlet pressure of the negative pressure unit, is the pressure proportionality coefficient, is the pressure integral coefficient, is the pressure differential coefficient, is a function of the deviation between the first pressure and the target pressure changing with time, the target pressure is the control target pressure of the inlet of the flowmeter 106 , and the target flow is the control target flow of the flowmeter 106 .

[0107] Figure 5 This is a functional block diagram of the control module provided by the embodiment of the present invention. Figure 5 As shown, the control module 5 of this embodiment includes: a processor 500 and a memory 501, wherein the memory 501 stores a computer program 502 that can be run on the processor 500. When the processor 500 executes the computer program 502, the steps of the above-mentioned sulfur hexafluoride gas analysis and tail gas recovery system and the embodiment are implemented, such as Figure 2 Steps 201 to 202 are shown.

[0108] Illustratively, the computer program 502 may be divided into one or more modules / units, and the one or more modules / units are stored in the memory 501 and executed by the processor 500 to implement the present invention.

[0109] The control module 5 can be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The control module 5 can include, but is not limited to, a processor 500 and a memory 501. Those skilled in the art will understand that Figure 5 It is only an example of the control module 5 and does not constitute a limitation of the control module 5. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the control module may also include input and output devices, network access devices, buses, etc.

[0110] The processor 500 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0111] The memory 501 can be an internal storage unit of the control module 5, such as a hard drive or memory of the control module 5. The memory 501 can also be an external storage device of the control module 5, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. Furthermore, the memory 501 can include both the internal storage unit of the control module 5 and an external storage device. The memory 501 is used to store the computer program and other programs and data required by the control module. The memory 501 can also be used to temporarily store data that has been output or is about to be output.

[0112] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the implementation method can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method implementation method, and will not be repeated here.

[0113] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0114] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0115] In the embodiments provided by the present invention, it should be understood that the disclosed devices / control modules and methods can be implemented in other ways. For example, the device / control module embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0116] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of this embodiment.

[0117] In addition, the functional units in various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0118] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention can also implement all or part of the processes in the above-mentioned method embodiments by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the above-mentioned method and device embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium.

[0119] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for analyzing sulfur hexafluoride gas and recovering tail gas, characterized in that: Based on sulfur hexafluoride gas analysis and tail gas recovery system; The sulfur hexafluoride gas analysis and tail gas recovery system includes: a first pressure gauge, a flow meter, a first throttle valve, a negative pressure unit, and a control module; the first pressure gauge is connected to the inlet of the flow meter, one end of the first throttle valve is connected to the outlet of the flow meter, and the other end of the first throttle valve is connected to the inlet of the negative pressure unit; the negative pressure unit, the first throttle valve, the first pressure gauge, and the flow meter are electrically connected to the control module respectively; The sulfur hexafluoride gas analysis and tail gas recovery control method includes: obtaining a first flow rate and a first pressure, wherein the first flow rate is the flow rate flowing through a flow meter, and the first pressure is the pressure at the inlet of the flow meter; outputting a signal indicating the inlet pressure of a negative pressure unit and a signal indicating the opening of a first throttle valve according to a first formula, the first flow rate, and the first pressure. The first formula is: Where, is a signal indicating the opening of the first throttle valve, is the first opening proportional coefficient, is the first opening integral coefficient, is the function of the deviation between the first flow rate and the target flow rate changing with time, A signal indicating the inlet pressure of the negative pressure unit. is the pressure proportionality coefficient, is the pressure integral coefficient, is the pressure differential coefficient, is a function of the deviation between the first pressure and the target pressure varying with time, the target pressure is the control target pressure of the inlet of the flowmeter, and the target flow rate is the control target flow rate of the flowmeter; A signal indicating the second throttle valve opening is output according to the second formula, the second pressure, and the signal indicating the inlet pressure of the negative pressure unit, wherein the second pressure is the pressure of the surge tank, and the second formula is: Where, A signal indicating the opening of the second throttle valve. is the second opening proportional coefficient, is the second opening integral coefficient, is the second opening differential coefficient, is a function of the difference between the pressure of the surge tank and the signal indicating the inlet pressure of the negative pressure unit over time; The negative pressure unit includes: a pressure stabilizing box, a second throttle valve, a second pressure gauge and a vacuum pump; the inlet of the pressure stabilizing box is connected to the outlet of the first throttle valve, the outlet of the pressure stabilizing box is connected to the inlet of the second throttle valve, and the outlet of the second throttle valve is connected to the inlet of the vacuum pump; the second pressure gauge is used to indicate the pressure of the pressure stabilizing box; the second pressure gauge and the second throttle valve are electrically connected to the control module respectively.

2. The sulfur hexafluoride gas analysis and tail gas recovery control method according to claim 1, characterized in that: The sulfur hexafluoride gas analysis and tail gas recovery system further includes: a recovery box and a third pressure gauge, the inlet of the recovery box is connected to the outlet of the negative pressure unit, and the third pressure gauge is used to indicate the pressure of the recovery box.

3. The sulfur hexafluoride gas analysis and tail gas recovery control method according to claim 2, characterized in that: The sulfur hexafluoride gas analysis and tail gas recovery system further includes a one-way valve, the inlet of the one-way valve is connected to the outlet of the negative pressure unit, and the outlet of the one-way valve is connected to the inlet of the recovery box.

4. The sulfur hexafluoride gas analysis and tail gas recovery control method according to claim 1, characterized in that: The first opening proportional coefficient and the first opening integral coefficient are adjusted according to a predetermined flow range of the flow meter inlet; The pressure proportional coefficient, the pressure integral coefficient, and the pressure differential coefficient are adjusted according to a predetermined pressure range at the inlet of the flowmeter.

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