A pressure difference adjustment method and device

Abstract

The present invention relates to a pressure difference regulation method and device, wherein the device comprises: a regulating valve group connected to the output end of the gas in the electrolytic cell, the regulating valve group having at least two stages of pneumatic regulating valves connected in parallel; a valve positioning group having valve positioners corresponding to the number of pneumatic regulating valves, the valve positioners being electrically connected to the control ends of the corresponding pneumatic regulating valves respectively; a controller electrically connected to the valve positioners of the valve positioning group, for sending a control signal to the valve positioners, the valve positioners controlling the opening and closing degree of the corresponding pneumatic regulating valves step by step according to the control signal. The valve positioners can control the opening and closing degree of the corresponding pneumatic regulating valves step by step according to the size of the control signal sent by the controller, so that the regulation range in the pressure difference regulation device is wider, the accuracy and sensitivity are higher, and, on the basis of the existing structure, no additional control output points are added, ensuring simple and efficient control.

Description

Technical Field

[0001] The invention relates to the field of water electrolysis, and in particular to a pressure difference regulating method and device. Background Art

[0002] Energy is the most basic driving force for the development and economic growth of the entire world, and is the material basis for human survival. With the increasing consumption of fossil fuels and the decreasing reserves, the world has already seen three major problems: environmental pollution, climate anomalies, and energy shortages. Therefore, finding abundant sources of clean energy is the most urgent issue facing the world today.

[0003] Hydrogen is the most abundant element on earth, mainly in the form of water and hydrocarbons. Water is the main resource of the earth. 71% of the earth's surface is covered by water. Hydrogen can be produced on a large scale. Hydrogen energy is clean and has a high combustion value. The heat released by the combustion of 1 kg of hydrogen is 1.2×108J, which is equivalent to 3 times the combustion value of 1 kg of gasoline. When it burns, it only produces water and a small amount of hydrogen nitride, which will not pollute the environment. Therefore, the research and development of hydrogen energy is highly favored. It can be foreseen that hydrogen energy will become an important part of the energy system in the 21st century.

[0004] The preparation of hydrogen has a long history. In 1783, French physicist Charles proposed to use sulfuric acid and iron to produce hydrogen. In 1800, Nicholson and Carlisle discovered that electricity can decompose water, and realized the electrolysis of water to produce hydrogen. In the early 20th century, the production of hydrogen from water gas and the reforming of gas hydrocarbons and water vapor to produce hydrogen developed rapidly. In 1966, the first solid polymer electrolyte system (SPE system) was established. At present, the main methods of industrial hydrogen production are hydrogen production from mineral fuel conversion and water electrolysis, while hydrogen production from renewable energy sources such as thermal decomposition, photocatalytic hydrogen production, and biological hydrogen production are in the research stage.

[0005] With the development trend of hydrogen production from renewable energy, larger-scale water electrolysis hydrogen production equipment is needed. The volatility of renewable energy power sources tests an important device in water electrolysis hydrogen production equipment - the pressure difference regulating device. In the automatic control system of water electrolysis hydrogen production with a high degree of automation, the regulating valve, as the terminal actuator of the automatic regulation system, receives and controls the pressure and liquid level difference in the electrolyzer. Its action sensitivity and accuracy are directly related to the quality of the regulation system, the safety of the system and the quality of gas products. It plays a vital role in the automation of normal production and operation processes.

[0006] According to the current characteristics of renewable energy hydrogen production, combined with the full utilization rate of renewable energy and electrolytic hydrogen production equipment, it is necessary to reduce the energy conversion of a single electrolyzer to the minimum output requirement as much as possible; at the same time, in order to solve the problem of large-scale demand for hydrogen production by electrolysis of water, multiple electrolyzers are required to share an integrated processing framework, which requires a pressure difference regulation system that can operate safely and adapt to large-scale regulation, wide range regulation, high precision and sensitivity regulation to complete large-scale regulation and control of different outputs. Summary of the invention

[0007] Based on this, it is necessary to provide a pressure difference regulation method and device to meet the needs of a pressure difference regulation system that is urgently needed to be able to operate safely and adapt to large-scale regulation, wide range regulation, high precision and sensitivity regulation.

[0008] A pressure difference regulation method, comprising:

[0009] Obtain the total required flow rate of gas output by the electrolyzer;

[0010] Determine the required rated flow of the first pneumatic regulating valve according to the total required flow, wherein the rated flow is less than the total required flow;

[0011] Determining the number of pneumatic control valves connected in parallel and the rated flows of other pneumatic control valves according to the rated flow of the first pneumatic control valve;

[0012] According to the number of the required pneumatic control valves, determine the number and configuration information of the valve positioners, and connect the valve positioners to the control ends of the corresponding pneumatic control valves respectively, and the number of the valve positioners is equal to the number of the pneumatic control valves;

[0013] A control instruction is generated and sent to the valve positioner, so that the valve positioner controls the corresponding pneumatic regulating valve according to the control instruction, so as to control the opening and closing degree of the corresponding pneumatic regulating valve step by step.

[0014] The pressure difference regulation method in the above-mentioned embodiment can determine the required number of pneumatic control valves and the rated flow required for each pneumatic control valve according to the total required flow rate of the output gas of the connected electrolytic cell, and cooperate with the valve positioner to perform graded control on the corresponding pneumatic control valves to achieve precise control of the flow rate at low production.

[0015] In one preferred embodiment, the step of obtaining the total required flow rate of the gas output by the electrolyzer comprises:

[0016] Determine the total required flow rate according to the maximum regulating flow rate of the original pneumatic regulating valve;

[0017] In the above implementation, the existing single pneumatic regulating valve is improved, and the total demand for output gas of the pressure difference regulating device is determined according to the maximum regulating flow of the original pneumatic regulating valve.

[0018] In one preferred embodiment, determining the required rated flow of the first pneumatic regulating valve according to the total required flow includes:

[0019] According to the total required flow, determining the product of the total required flow and a first ratio as the minimum precise control flow of the original pneumatic regulating valve, wherein the first ratio is greater than 0 and less than 1;

[0020] Taking the second ratio, and determining the required rated flow of the first pneumatic regulating valve according to the minimum precise control flow of the original pneumatic regulating valve and the second ratio;

[0021] In the above implementation mode, the minimum precision control flow of the original pneumatic control valve is determined according to the inherent characteristics of the pneumatic control valve. When it is less than the minimum precision control flow, a large control error will occur in the control adjustment of the original pneumatic control valve. The second ratio is taken to determine the rated flow of the pneumatic control valve required by the method. Due to the inherent characteristics of the pneumatic control valve, the first ratio of each control valve is generally determined. In this way, as long as the second ratio is greater than the first ratio, the required pneumatic control valve will not be lower than its minimum precision control flow.

[0022] In one preferred embodiment, the sum of the rated flow rates of the pneumatic control valves is equal to the total required flow rate.

[0023] In this embodiment, the sum of the rated flow rates of the pneumatic control valves required is equal to the total required flow rate, ensuring that the control amount of each pneumatic control valve is fully utilized.

[0024] In one preferred embodiment, the configuration information of the valve positioner includes a receiving signal range and an output signal range. When the valve positioner receives a minimum receiving signal value, it outputs a minimum output signal value to control the opening and closing degree of the corresponding pneumatic control valve to be minimum. When the valve positioner receives a maximum receiving signal value, it outputs a maximum output signal value to control the opening and closing degree of the corresponding pneumatic control valve to be maximum.

[0025] The valve positioner in the above-mentioned embodiment controls the opening and closing degree of the corresponding pneumatic control valve according to the control signal sent by the controller, so that the adjustment range of the pressure difference regulating device in this embodiment is wider, the accuracy and sensitivity are higher, and, on the basis of the existing structure, no additional control output point is added, thereby ensuring simple and efficient control.

[0026] In one preferred implementation manner, the control signal corresponding to the control instruction is a voltage control signal.

[0027] The control in the above embodiment sends a voltage control signal to the valve positioner, and the valve positioner is classified according to the voltage range, which is easy for the operator to detect and control.

[0028] In one preferred embodiment, within the receiving signal range of the corresponding valve positioner, the signal receiving amount and the output amount of the valve positioner are in a linear relationship.

[0029] In one preferred embodiment, the pneumatic control valve and the valve positioner each have M output signals, and the output signal P of the nth valve positioner is n The voltage control signal U at the output of the controller satisfies the following formula:

[0030] When n=1:

[0031]

[0032] When n ≥ 2:

[0033]

[0034] Among them, k1, k n are constants, b1, b n is a constant, Vn min is the minimum value of the control signal range corresponding to the nth valve positioner, V nmax is the maximum value of the voltage signal range corresponding to the nth valve positioner, P nmin is the minimum output pressure of the nth valve positioner, P nmax is the maximum output pressure of the nth valve positioner, M is a positive integer greater than 1, and n is a positive integer not greater than M.

[0035] In the above embodiment, the output signal P of the nth valve positioner n The voltage control signal U output by the controller satisfies the above formula, thereby realizing linear regulation of the gas output amount in the electrolytic cell by the pneumatic regulating valve.

[0036] A pressure difference regulating device, comprising:

[0037] A regulating valve group connected to the output end of the gas in the electrolytic cell, wherein the regulating valve group comprises at least two stages of pneumatic regulating valves connected in parallel with each other;

[0038] A valve positioning group, comprising valve positioners corresponding to the number of the pneumatic regulating valves, wherein the valve positioners are electrically connected to the control ends of the corresponding pneumatic regulating valves respectively;

[0039] The controller is electrically connected to the valve positioner of the valve positioning group and is used to send a control signal to the valve positioner. The valve positioner controls the opening and closing degree of the corresponding pneumatic regulating valve step by step according to the control signal.

[0040] The pressure difference regulating device in the above embodiment has at least two-stage pneumatic regulating valves and valve positioners corresponding to the two-stage pneumatic regulating valves. The valve positioners can control the opening and closing degrees of the corresponding pneumatic regulating valves step by step according to the size of the control signal sent by the controller. In this way, the pressure difference regulating device in this embodiment has a wider adjustment range, higher accuracy and sensitivity, and, on the basis of the existing structure, no additional control output points are added, thereby ensuring simple and efficient control.

[0041] In one preferred embodiment, the sum of the rated flow rates of each pneumatic regulating valve of the regulating valve group is equal to the total required flow rate.

[0042] In the above implementation, the sum of the rated flow rates of each pneumatic control valve is equal to the total required flow rate, so that the control range of each pneumatic control valve is fully utilized.

[0043] In one preferred embodiment, the rated flow of each pneumatic regulating valve of the regulating valve group is determined according to the maximum regulating flow of the original pneumatic regulating valve, and the rated flow of each pneumatic regulating valve is less than the maximum regulating flow of the original pneumatic regulating valve.

[0044] In one preferred embodiment, the minimum precise control flow of each pneumatic regulating valve is smaller than the minimum precise control flow of the original pneumatic regulating valve, and the rated flow of each pneumatic regulating valve is smaller than the maximum regulating flow of the original pneumatic regulating valve.

[0045] In the above-mentioned embodiment, due to the inherent characteristics of the pneumatic control valve, the ratio of its minimum precise control flow rate to the maximum control flow rate is a constant. When the pneumatic control valve in this embodiment is smaller than the maximum control flow rate of the original control valve, then the minimum precise control flow rate of the pneumatic control valve in this embodiment will be smaller than the minimum precise control flow rate of the original control valve. In this way, low flow rate regulation can be achieved without causing control errors during low flow rate regulation, thereby achieving the effect of precise control.

[0046] In one preferred embodiment, if the control signal received by the corresponding valve positioner is less than or equal to the minimum value of the received control signal range, the minimum output signal value is output;

[0047] If the control signal received by the corresponding valve positioner is greater than or equal to the maximum value of the received control signal range, the maximum output signal value is output.

[0048] In the above-mentioned embodiment, the ranges of the controller signals received by each valve positioner are graded and continuous with each other, so that the flow rate of the gas in the electrolytic cell can be continuously and linearly controlled through the corresponding pneumatic regulating valve.

[0049] In the above embodiment, the output signal P of the nth valve positioner n The voltage control signal U output by the controller satisfies the above formula, thereby realizing linear regulation of the gas output amount in the electrolytic cell by the pneumatic regulating valve.

[0050] In one preferred embodiment, the regulating valve group comprises a first pneumatic regulating valve and a second pneumatic regulating valve, and the valve positioning group comprises a first valve positioner electrically connected to the first pneumatic regulating valve, and a second valve positioner electrically connected to the second pneumatic regulating valve.

[0051] In the above embodiment, a two-stage pneumatic regulating valve is used to make the adjustment range of the pressure difference regulating device wider, the accuracy and sensitivity higher, and the control structure is relatively simple and easy to use.

[0052] In one preferred embodiment, the controller is a PLC controller or a DCS controller.

[0053] Using PLC controller or DCS controller, the control structure is relatively mature and stable.

[0054] In one preferred embodiment, the valve positioner is an electric valve positioner.

[0055] The electric valve positioner is adopted, and the control structure is relatively mature and stable.

[0056] In one preferred embodiment, the pneumatic regulating valve is a pneumatic diaphragm regulating valve.

[0057] It adopts pneumatic diaphragm regulating valve, and the control structure is relatively mature and stable.

[0058] In one preferred embodiment, the pressure difference regulating device further comprises:

[0059] An instrument air source is connected to the valve positioner.

[0060] The above instrument gas source can supply gas to the valve positioner to enable the valve positioner to work normally and monitor the gas pressure of the valve positioner.

[0061] In one preferred embodiment, the pressure difference regulating device further comprises:

[0062] A filter pressure reducer is connected between the instrument air source and the valve positioner.

[0063] The filter pressure reducer can stabilize the pressure of the valve positioner and ensure the stability of the valve positioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 A schematic flow chart of a pressure difference regulating method in the first embodiment of the present invention;

[0065] Figure 2 A flowchart of subdivided steps in a pressure difference regulating method S20 in the first embodiment of the present invention;

[0066] Figure 3 This is a schematic diagram of the automatic control principle of a pressure difference regulating device in the second embodiment of the present invention;

[0067] Figure 4 This is a schematic structural diagram of a pressure difference regulating device in a second embodiment of the present invention;

[0068] Figure 5 Schematic diagram of the structure of a pressure difference regulating device in the second embodiment of the present invention. DETAILED DESCRIPTION

[0069] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0070] Combined with Figure 1 As shown, the first preferred embodiment of the present invention discloses a pressure difference regulation method, which includes:

[0071] S10: Obtaining the total required flow rate of gas output by the electrolyzer;

[0072] Specifically, the total required flow rate can be determined according to the gas output that can be decomposed by the electrolytic cell. In this embodiment, the existing pressure difference regulating device is improved, and the total required flow rate is determined according to the maximum regulating flow rate of the original pneumatic regulating valve on the existing pressure difference regulating device. For example, in Example 1, the maximum regulating flow rate of the original pneumatic regulating valve is 1000m 3 / h, then determine the 1000m 3 / h is the total demand flow mentioned above.

[0073] S20: Determine a required rated flow rate of the first pneumatic regulating valve according to the total required flow rate, wherein the rated flow rate is less than the total required flow rate;

[0074] The total required flow rate is determined based on the maximum regulating flow rate of the original pneumatic regulating valve on the existing pressure difference regulating device. Figure 1 and Figure 2 As shown, the above S20 of this embodiment includes the following specific sub-steps:

[0075] S21: According to the total required flow, determine the product of the total required flow and a first ratio as the minimum precise control flow of the original pneumatic regulating valve, wherein the first ratio is greater than 0 and less than 1;

[0076] Specifically, in the above sub-steps, according to the inherent characteristics of the pneumatic control valve, the ratio of the minimum precise control flow rate to the maximum control flow rate of the pneumatic control valve is a fixed value. 3 / h, the ratio of the minimum precise control flow rate of the pneumatic control valve to the maximum control flow rate is 10%, then the minimum precise control flow rate of the original pneumatic control valve is 100m 3 / h, the above first ratio is 10%.

[0077] S22: taking a second ratio, and determining a required rated flow rate of the first pneumatic control valve according to the minimum precise control flow rate of the original pneumatic control valve and the second ratio;

[0078] In this embodiment, the above sub-step S22 takes a second ratio, which is greater than the first ratio. According to the minimum precise control flow of the original pneumatic control valve and the second ratio, the second ratio is taken as 20% according to the above example 1, and the minimum precise control flow of the original pneumatic control valve is 100m 3 / h, then the rated flow rate of the first pneumatic control valve required is 100m 3 / h divided by 20% gives 500m 3 / h.

[0079] According to the inherent characteristics of the pneumatic control valve, the minimum precision control flow of the original pneumatic control valve is determined. When it is less than the minimum precision control flow, the control adjustment of the original pneumatic control valve will have a large control error. The second ratio is taken to determine the rated flow of the pneumatic control valve required by this method. Due to the inherent characteristics of the pneumatic control valve, the first ratio of each control valve is generally determined. Therefore, the second ratio in this embodiment is greater than the first ratio, and the required pneumatic control valve will not be lower than its minimum precision control flow.

[0080] S30: Determine the number of pneumatic control valves connected in parallel and the rated flows of other pneumatic control valves according to the rated flow of the first pneumatic control valve;

[0081] Continuing with Example 1 above, determine that the rated flow rate of one of the required pneumatic control valves is 500m 3 / h, the rated flow of other required pneumatic control valves is 500m / s based on the total demand minus the rated flow. 3 / h, and finally, a rated flow of 500m 3 / h, therefore, the number of pneumatic control valves required is two, and the rated flow rate of each pneumatic control valve is 500m 3 / h.

[0082] In this embodiment, the sum of the rated flow rates of the pneumatic control valves required is equal to the total required flow rate, ensuring that the control amount of each pneumatic control valve is fully utilized.

[0083] S40: Determine the number and configuration information of the valve positioners according to the number of the required pneumatic control valves, and connect the valve positioners to the control ends of the corresponding pneumatic control valves respectively, wherein the number of the valve positioners is equal to the number of the pneumatic control valves;

[0084] In this embodiment, the number of the valve positioners is equal to the number of the pneumatic control valves. Each valve positioner is connected to the control end of the corresponding pneumatic control valve, and each pneumatic control valve controls its opening and closing degree according to the output configuration information of the corresponding valve positioner. Each pneumatic control valve is individually controlled by the corresponding valve positioner, thereby ensuring the stability of the entire device.

[0085] The configuration information of the valve positioner includes a receiving signal range and an output signal range. When the valve positioner receives a minimum receiving signal value, it outputs a minimum output signal value. When the valve positioner receives a maximum receiving signal value, it outputs a maximum output signal value. The receiving signal ranges of each valve positioner are graded and continuous with each other.

[0086] Preferably, the electrical positioner of the valve positioner receives a voltage input signal and outputs a pressure output signal.

[0087] Continuing with the above example 1, if the number of the above pneumatic control valves is two, then the number of corresponding valve positioners can also be two. When the received voltage input signal is 1-3V, the pressure output signal of the first valve positioner is 20kpa-100kpa, that is, the first pneumatic control valve completes the opening and closing adjustment of 0-100%, and the pressure output signal of the second valve positioner is 20kpa, that is, the second pneumatic control valve is always at 0% opening and closing; when the received voltage input signal is 3-5V, the pressure output signal of the first valve positioner is 100kpa, that is, the opening and closing value of the first pneumatic control valve is always 100%, and the pressure output signal of the second valve positioner is 20kpa-100kpa, that is, the second pneumatic control valve completes the opening adjustment of 0-100%.

[0088] S50: Generate a control instruction and send it to the valve positioner, so that the valve positioner controls the corresponding pneumatic regulating valve according to the control instruction, so as to control the opening and closing degree of the corresponding pneumatic regulating valve step by step.

[0089] In this step, the control instruction can be sent by a controller, and the controller is electrically connected to each of the valve positioners to send a control signal. Since each of the valve positioners has a corresponding receiving signal range, when the control signal sent by the controller is lower than the receiving signal range of the corresponding valve positioner, the corresponding valve positioner outputs at a minimum amount to control the opening and closing degree of the corresponding pneumatic control valve to be minimum, thereby achieving a low flow output; when the control signal sent by the controller is higher than the receiving signal range of the corresponding valve positioner, the corresponding valve positioner outputs at a maximum amount, and at this time, the pneumatic control valve connected to the valve positioner achieves a maximum signal output within the output signal range, and the opening and closing degree of the pneumatic control valve connected to the valve positioner is maximum, thereby achieving a maximum rated flow output.

[0090] The valve positioner is controlled step by step according to the control signal. As the control signal sent by the controller gradually increases, when the receiving signal range of the first-level valve positioner is not reached, all valve positioners are at the lowest flow rate adjustment. When the receiving signal range of the first-level valve positioner is reached, the output signal of the first valve positioner gradually increases until the maximum output signal is output. When the receiving signal range of the second-level valve positioner is reached, the first valve positioner maintains the maximum output signal, and the output signal of the second valve positioner gradually increases. In this way, the purpose of controlling the opening and closing degree of the corresponding pneumatic control valve is achieved through multiple valve positioners.

[0091] More specifically, within the receiving signal range of the corresponding valve positioner, the signal receiving amount and the output amount of the valve positioner are in a linear relationship.

[0092] The pneumatic regulating valve and the valve positioner each have M output signals, and the output signal P of the nth valve positioner n The voltage control signal U at the output of the controller satisfies the following formula:

[0093] When n=1:

[0094]

[0095] When n ≥ 2:

[0096]

[0097] Among them, k1, k n are constants, b1, b n is a constant, V nminis the minimum value of the control signal range corresponding to the nth valve positioner, V nmax is the maximum value of the voltage signal range corresponding to the nth valve positioner, P nmin is the minimum output pressure of the nth valve positioner, P nmax is the maximum output pressure of the nth valve positioner, M is a positive integer greater than 1, and n is a positive integer not greater than M.

[0098] In the above embodiment, the output signal P of the nth valve positioner n The voltage control signal U output by the controller satisfies the above formula, thereby realizing linear regulation of the gas output amount in the electrolytic cell by the pneumatic regulating valve.

[0099] Continuing with the above example 1, the input signal range of the first valve positioner is 1-3V, and the output signal range is 20-100kpa. The input signal range of the second valve positioner is 3-5V, and the corresponding output signal range is 20-100kpa. When the voltage output signal sent by the above controller is lower than 1V, the output of the above first valve positioner and the second valve positioner is 20kpa, and the pneumatic control valves respectively connected to the first valve positioner and the second valve positioner have a 0 flow output. When the voltage output signal sent by the above controller is 1-3V, the output signal of the first valve positioner gradually increases, thereby gradually increasing the opening and closing degree of the pneumatic control valve connected to the first valve positioner, and the corresponding gas flow also gradually increases. The second valve positioner still outputs 20kpa. When the voltage output signal sent by the controller is 3-5V, the output signal of the first valve positioner reaches the maximum signal output of 100kpa, and the opening and closing degree of the pneumatic control valve connected to the first valve positioner reaches the maximum opening and closing degree. The output signal of the second valve positioner gradually increases, thereby gradually increasing the opening and closing degree of the pneumatic control valve connected to the second valve positioner, and the corresponding gas flow rate also gradually increases. When the voltage output signal sent by the controller is greater than 5V, the first valve positioner and the second valve positioner both output the maximum output signal of 100kpa, and the corresponding pneumatic control valves also reach the maximum opening and closing degree.

[0100] The pressure difference regulation method in the above embodiment can determine the number of required pneumatic regulating valves and the rated flow required for each pneumatic regulating valve according to the total required flow of the output gas of the connected electrolyzer, and cooperate with the valve positioner to control the corresponding pneumatic regulating valves in stages, so as to achieve accurate control of the flow at low production. The valve positioner controls the opening and closing degree of the corresponding pneumatic regulating valve according to the control signal sent by the controller, so that the pressure difference regulation device in this embodiment has a wider adjustment range, higher accuracy and sensitivity, and, on the basis of the existing structure, no additional control output points are added, ensuring simple and efficient control.

[0101] Combination Figure 3 and Figure 4 As shown, the second preferred embodiment of the present invention discloses a pressure difference regulating device 100 , which includes a regulating valve group 110 , a valve positioning group 120 and a controller 130 .

[0102] Specifically, the regulating valve group 110 is connected to the output end of the gas in the electrolytic cell, and the regulating valve group 110 has at least two pneumatic regulating valves connected in parallel. In other words, the regulating valve group 110 has n (n≥2, and n is a natural number) pneumatic regulating valves connected in parallel.

[0103] In more detail, the gas output end in the electrolytic cell is connected in parallel with n gas delivery pipelines, and the decomposed gas in the electrolytic cell can be delivered to the target location through the gas output end and any one of the n gas delivery pipelines. The n pneumatic regulating valves are respectively located in the corresponding gas delivery pipelines, and each pneumatic regulating valve can control the flow rate of gas delivery in the corresponding gas delivery pipeline mainly by controlling its opening and closing degree. When the pneumatic regulating valve is closed, the gas delivery pipeline where the pneumatic regulating valve is located stops delivering gas. When the pneumatic regulating valve is gradually opened, the flow rate of gas delivered by the corresponding gas delivery pipeline is also gradually increasing. When the pneumatic regulating valve is fully opened, the corresponding gas delivery pipeline is in a state where it can deliver the maximum amount of gas.

[0104] In this embodiment, the pneumatic regulating valve may be a pneumatic diaphragm regulating valve. In this embodiment, a pneumatic diaphragm regulating valve is used, and its control structure is relatively mature, thereby stabilizing the control process.

[0105] The configuration information and quantity of pneumatic control valves can be selected by referring to the following methods:

[0106] Obtain the total required flow rate of the gas output by the electrolytic cell; specifically, the total required flow rate can be determined based on the gas output that the electrolytic cell can decompose. In this embodiment, the existing pressure difference regulating device is improved, and the total required flow rate is determined based on the maximum regulating flow rate of the original pneumatic regulating valve on the existing pressure difference regulating device. For example, the maximum regulating flow rate of the original pneumatic regulating valve is 1000m 3 / h, then determine the 1000m 3 / h is the total demand flow mentioned above.

[0107] According to the total required flow rate, the rated flow rate of the required first pneumatic control valve is determined, and the rated flow rate is less than the total required flow rate; the total required flow rate is determined according to the maximum regulating flow rate of the original pneumatic control valve on the existing pressure difference regulating device. According to the total required flow rate, the minimum precision control flow rate of the original pneumatic control valve is determined, and the first ratio of the minimum precision control flow rate of the original pneumatic control valve to the total required flow rate is determined; specifically, in the above sub-steps, according to the inherent characteristics of the pneumatic control valve, the ratio of the minimum precision control flow rate of the pneumatic control valve to the maximum control flow rate is a constant.

[0108] For example, the original maximum adjustable flow rate is 1000m 3 / h, the ratio of the minimum precise control flow rate of the pneumatic control valve to the maximum control flow rate is 10%, so the original minimum precise control flow rate of the pneumatic control valve is 100m 3 / h, the above first ratio is 10%.

[0109] Take a second ratio, and determine the required rated flow of the first pneumatic control valve according to the minimum precise control flow of the original pneumatic control valve and the second ratio, wherein the second ratio is greater than the first ratio; for example, take the second ratio as 20%, the minimum precise control flow of the original pneumatic control valve is 100m 3 / h, then the rated flow rate of the first pneumatic control valve required is 100m 3 / h divided by 20% gives 500m 3 / h.

[0110] According to the inherent characteristics of the pneumatic control valve, the minimum precision control flow of the original pneumatic control valve is determined. When it is less than the minimum precision control flow, the control adjustment of the original pneumatic control valve will have a large control error. The second ratio is taken to determine the rated flow of the pneumatic control valve required by this method. Due to the inherent characteristics of the pneumatic control valve, the first ratio of each control valve is generally determined. In this way, as long as the second ratio is greater than the first ratio, the required pneumatic control valve will not be lower than its minimum precision control flow.

[0111] The valve positioning group 120 is connected to the regulating valve group 110. Specifically, the valve positioning group 120 has valve positioners corresponding to the number of pneumatic regulating valves. If the number of the pneumatic regulating valves is n, the number of the valve positioners is also n. The valve positioners are respectively connected to the control ends of the corresponding pneumatic regulating valves. The valve positioners can output control signals, thereby controlling the opening and closing degree of the corresponding pneumatic regulating valves, and thereby controlling the gas flow rate of the gas delivery pipeline where the pneumatic regulating valves are located.

[0112] The valve positioner can be an electric valve positioner. In this embodiment, an electric valve positioner is used, and the control structure is relatively mature, thereby making the control process stable. The electric valve positioner outputs a pressure control signal to the corresponding pneumatic control valve. The larger the pressure control signal output by the electric valve positioner, the larger the opening and closing degree of the corresponding pneumatic control valve, and the larger the controlled gas flow; on the contrary, the smaller the pressure control signal output by the electric valve positioner to the corresponding pneumatic control valve, the smaller the opening and closing degree of the corresponding pneumatic control valve, and the smaller the controlled gas flow.

[0113] Each valve positioner has an output signal range. Taking the above-mentioned electrical valve positioner as an example, the electrical valve positioner outputs a pressure control signal, and the output signal range of each valve positioner is P min To P max , where the above P min is the minimum pressure control signal of the valve positioner, P max is the maximum pressure control signal of the valve positioner. In this embodiment, the minimum pressure control signal P min It can be 0 or other values. min When the corresponding pneumatic control valve is in the closed state, when the valve positioner output signal is P max When , the corresponding pneumatic control valve is in a fully open state, and the corresponding gas delivery pipeline is at the maximum gas output.

[0114] The controller 130 is electrically connected to the pneumatic regulating valve of the valve positioning group 120 to send a control signal to the valve positioning group 120. The valve positioning group 120 controls the opening and closing degree of the corresponding pneumatic regulating valve step by step according to the control signal, thereby achieving the purpose of controlling the gas flow of the corresponding gas delivery pipe.

[0115] Specifically, the valve positioning group 120 has n valve positioners corresponding to the number of the pneumatic control valves. Each valve positioner of the valve positioning group 120 has a range for receiving the control signal. If the control signal received is less than or equal to the minimum value of the control signal range corresponding to the valve positioner, the output signal of the valve positioner is the minimum value P. min , and then the valve positioner controls the corresponding pneumatic regulating valve to be in a closed state; if the received control signal is greater than or equal to the maximum value of the control signal range corresponding to the above valve positioner, the output signal of the valve positioner is the maximum value P max , and then the valve positioner controls the corresponding pneumatic control valve to be in a fully open state.

[0116] The control signal sent by the controller 130 is a voltage control signal, and the range of the control signal received by each valve positioner is also the range of the voltage control signal. The corresponding valve positioner outputs a signal to the pneumatic control valve according to the received voltage control signal. The controller 130 sends a voltage control signal to the valve positioner.

[0117] Each valve positioner in the above-mentioned embodiment can continuously and linearly control the flow rate of the gas in the electrolytic cell through the corresponding pneumatic regulating valve.

[0118] Furthermore, in this embodiment, the n valve positioners of the valve positioning group linearly send control signals to the corresponding pneumatic control valves according to the received control signals. The output signal P of the nth valve positioner is n The voltage control signal U output by the above controller satisfies the following formula:

[0119] When n=1:

[0120]

[0121] When n ≥ 2:

[0122]

[0123] Among them, k1, k n are constants, b1, b n is a constant, V nmin is the minimum value of the control signal range corresponding to the nth valve positioner, V nmax is the maximum value of the voltage signal range corresponding to the nth valve positioner, P nmin is the minimum output pressure of the nth valve positioner, P nmax is the maximum output pressure of the nth valve positioner, M is a positive integer greater than 1, and n is a positive integer not greater than M.

[0124] In the above embodiment, the output signal P of the nth valve positioner is n The voltage control signal U output by the controller satisfies the above formula, thereby realizing linear regulation of the gas output in the electrolytic cell by the pneumatic regulating valve.

[0125] It should be noted that the range of the signal output by the controller 130 received by each valve positioner in this embodiment, or the range of the control signal output to the pneumatic control valve, may be the same or different.

[0126] The controller 130 may be a PLC controller or a DCS controller. The PLC controller or the DCS controller has a relatively mature and stable control structure.

[0127] In this embodiment, the differential pressure regulating device 100 further includes an instrument gas source 140, which is connected to the valve positioner. The instrument gas source can supply gas to the valve positioner to enable the valve positioner to work normally and monitor the gas pressure of the valve positioner.

[0128] In one preferred embodiment, the pressure difference regulating device further includes a filter pressure reducer 150 , and the filter pressure reducer 150 is connected between the instrument air source 140 and the valve positioner.

[0129] The filter pressure reducer can stabilize the pressure of the valve positioner and ensure the stability of the valve positioner.

[0130] The pressure difference regulating device in the above embodiment has at least two-stage pneumatic regulating valves and valve positioners corresponding to the two-stage pneumatic regulating valves. The valve positioners can control the opening and closing degrees of the corresponding pneumatic regulating valves step by step according to the size of the control signal sent by the controller. In this way, the pressure difference regulating device in this embodiment has a wider adjustment range, higher accuracy and sensitivity, and, on the basis of the existing structure, no additional control output points are added, thereby ensuring simple and efficient control.

[0131] Combination Figure 5 As shown, when n=2, the working process of the pressure difference regulating device 100 in the above embodiment is illustrated as follows:

[0132] When n=2, that is to say, the regulating valve group 110 has two-stage pneumatic regulating valves, namely the first pneumatic regulating valve 111 and the second pneumatic regulating valve 112. In more detail, the first pneumatic regulating valve 111 is connected to the gas output end of the electrolytic cell and is located in the first delivery pipeline connected to the gas output end, and is mainly used to control the opening and closing of the gas delivery in the first delivery pipeline connected to the gas output end. Similarly, the second pneumatic regulating valve 112 is connected to the gas output end of the electrolytic cell and is located in the second delivery pipeline connected to the gas output end. The first delivery pipeline and the second delivery pipeline are independently connected in parallel, so that the second pneumatic regulating valve 112 is connected in parallel with the first pneumatic regulating valve 111.

[0133] Similarly, the positioning valve group 110 has two-stage electrical valve positioners, namely a first valve positioner 121 and a second valve positioner 122, wherein the first valve positioner 121 is connected to the control end of the first pneumatic regulating valve 111, and the first pneumatic regulating valve 111 controls the flow rate of the gas in the corresponding first delivery pipeline according to the control signal output by the first valve positioner 121; the second valve positioner 122 is connected to the control end of the second pneumatic regulating valve 112, and the second pneumatic regulating valve 112 controls the flow rate of the gas in the corresponding second delivery pipeline according to the control signal output by the second valve positioner 122.

[0134] The controller 130 is electrically connected to the first valve positioner 121 and the second valve positioner 122 described above. The controller 130 sends a voltage control signal to the first valve positioner 121 and the second valve positioner 122. The voltage ranges received by the first valve positioner 121 and the second valve positioner 122 from the controller 122 are hierarchical and continuous.

[0135] In this embodiment, the range of the voltage control signal U sent by the controller 130 is 1 - 5V. The range of the voltage control signal U received by the first valve positioner 121 is 1V ≤ U ≤ 3V. The range of the voltage control U received by the second valve positioner 122 is 3V < U ≤ 5V

[0136] The range of the pressure control signal output by the first valve positioner 121 is 20 - 100 kPa. The range of the pressure control signal output by the second valve positioner 122 is also 20 - 100 kPa. When the voltage control signal U sent by the controller 130 is 1V, the pressure signal P1 output by the first valve positioner 121 is 20 kPa. When the control signal U output by the controller 130 is 3V, the pressure signal P1 output by the first valve positioner 121 is 100 kPa. When the voltage control signal U sent by the controller 130 is 1V < U < 3V, the pressure signal P1 output by the first valve positioner 121 is KU. During this process, the second valve positioner 122 always outputs the lowest pressure signal of 20 kPa.

[0137] When the pressure signal U output by the controller 130 is 3V, the pressure signal P1 output by the first valve positioner 121 is 100 kPa. The pressure signal P2 output by the second valve positioner 122 is 20 kPa. When the control signal U output by the controller 130 is 5V, the pressure signal P1 output by the first valve positioner 121 is 100 kPa, and the pressure signal P2 output by the second valve positioner 121 is 100 kPa. When the voltage control signal 3V < U < 5V sent by the controller 130, the pressure signal P1 output by the first valve positioner 121 is 100 kPa, and the pressure signal P2 output by the second valve positioner 122 is the output minimum value k(U - 3) of the second valve positioner.

[0138] The first pneumatic control valve 111 changes with the pressure signal output by the first valve positioner 121, and the second pneumatic control valve 112 changes with the pressure signal output by the second valve positioner 122, thereby controlling the flow rate of the corresponding gas transmission pipeline.

[0139] In the above embodiment, a two-stage pneumatic regulating valve is used to make the adjustment range of the pressure difference regulating device wider, the accuracy and sensitivity higher, and the control structure is relatively simple and easy to use.

[0140] The present invention is explained from the viewpoints of purpose of use, efficiency, progress and novelty, and its practical progress meets the functional enhancement and use requirements emphasized by the Patent Law. The above description and drawings of the present invention are only preferred embodiments of the present invention, and are not intended to limit the present invention. Therefore, all structures, devices, features, etc. that are similar or identical to the present invention, that is, all equivalent replacements or modifications made according to the scope of the patent application of the present invention, should fall within the scope of protection of the patent application of the present invention.

Claims

1. A pressure difference regulation method, characterized in that: include: Obtain the total required flow rate of gas output by the electrolyzer; Determine the required rated flow of the first pneumatic regulating valve according to the total required flow, wherein the rated flow is less than the total required flow; Determining the number of pneumatic control valves connected in parallel and the rated flows of other pneumatic control valves according to the rated flow of the first pneumatic control valve; According to the number of the required pneumatic control valves, determine the number and configuration information of the valve positioners, and connect the valve positioners to the control ends of the corresponding pneumatic control valves respectively, and the number of the valve positioners is equal to the number of the pneumatic control valves; A control instruction is generated and sent to the valve positioner, so that the valve positioner controls the corresponding pneumatic regulating valve according to the control instruction, so as to control the opening and closing degree of the corresponding pneumatic regulating valve step by step.

2. The pressure difference regulation method according to claim 1, characterized in that: The method of obtaining the total required flow rate of the gas output by the electrolyzer comprises: The total required flow rate is determined according to the maximum regulating flow rate of the original pneumatic regulating valve.

3. The pressure difference adjustment method according to claim 2, characterized in that: Determining the required rated flow of the first pneumatic regulating valve according to the total required flow includes: According to the total required flow, determining the product of the total required flow and a first ratio as the minimum precise control flow of the original pneumatic regulating valve, wherein the first ratio is greater than 0 and less than 1; The second ratio is taken, and the required rated flow of the first pneumatic control valve is determined according to the minimum precise control flow of the original pneumatic control valve and the second ratio.

4. The pressure difference regulation method according to claim 1, characterized in that: The sum of the rated flow rates of the pneumatic control valves is equal to the total required flow rate.

5. The pressure difference regulating method according to claim 1, characterized in that: The configuration information of the valve positioner includes a receiving signal range and an output signal range. When the valve positioner receives a minimum receiving signal value, it outputs a minimum output signal value to control the opening and closing degree of the corresponding pneumatic control valve to be minimum. When the valve positioner receives a maximum receiving signal value, it outputs a maximum output signal value to control the opening and closing degree of the corresponding pneumatic control valve to be maximum.

6. The pressure difference regulating method according to claim 5, characterized in that: The control signal corresponding to the control instruction is a voltage control signal.

7. The pressure difference regulating method according to claim 6, characterized in that: Within the receiving signal range of the corresponding valve positioner, the signal receiving amount and the output amount of the valve positioner are in a linear relationship.

8. The pressure difference regulating method according to claim 7, characterized in that: The pneumatic regulating valve and the valve positioner each have M output signals, and the output signal P of the nth valve positioner n The voltage control signal U at the output of the controller satisfies the following formula: When n=1: When n ≥ 2: Among them, k1, k n are constants, b1, b n is a constant, V nmin is the minimum value of the control signal range corresponding to the nth valve positioner, V nmax is the maximum value of the voltage signal range corresponding to the nth valve positioner, P nmin is the minimum output pressure of the nth valve positioner, P nmax is the maximum output pressure of the nth valve positioner, M is a positive integer greater than 1, and n is a positive integer not greater than M.

9. A pressure difference regulating device, characterized in that: include: A regulating valve group connected to the output end of the gas in the electrolytic cell, wherein the regulating valve group comprises at least two stages of pneumatic regulating valves connected in parallel with each other; A valve positioning group, comprising valve positioners corresponding to the number of the pneumatic regulating valves, wherein the valve positioners are electrically connected to the control ends of the corresponding pneumatic regulating valves respectively; The controller is electrically connected to the valve positioner of the valve positioning group and is used to send a control signal to the valve positioner. The valve positioner controls the opening and closing degree of the corresponding pneumatic regulating valve step by step according to the control signal.

10. The pressure difference regulating device according to claim 9, characterized in that: The sum of the rated flow rates of each pneumatic regulating valve of the regulating valve group is equal to the total required flow rate.

11. The pressure difference regulating device according to claim 9, characterized in that: The rated flow of each pneumatic regulating valve of the regulating valve group is determined according to the maximum regulating flow of the original pneumatic regulating valve, and the rated flow of each pneumatic regulating valve is less than the maximum regulating flow of the original pneumatic regulating valve.

12. The pressure difference regulating device according to claim 11, characterized in that: The minimum precise control flow of each pneumatic regulating valve is less than the minimum precise control flow of the original pneumatic regulating valve.

13. The pressure difference regulating device according to claim 9, characterized in that: If the control signal received by the corresponding valve positioner is less than or equal to the minimum value of the received control signal range, the minimum output signal value is output; If the control signal received by the corresponding valve positioner is greater than or equal to the maximum value of the received control signal range, the maximum output signal value is output.

14. The pressure difference regulating device according to claim 9, characterized in that: The regulating valve group comprises a first pneumatic regulating valve and a second pneumatic regulating valve, and the valve positioning group comprises a first valve positioner electrically connected to the first pneumatic regulating valve and a second valve positioner electrically connected to the second pneumatic regulating valve.

15. The pressure difference regulating device according to claim 9, characterized in that: The controller is a PLC controller or a DCS controller.

16. The pressure difference regulating device according to claim 9, characterized in that: The valve positioner is an electric valve positioner.

17. The pressure difference regulating device according to claim 9, characterized in that: The pneumatic regulating valve is a pneumatic diaphragm regulating valve.

18. The pressure difference regulating device according to claim 9, characterized in that: The pressure difference regulating device also includes: An instrument air source is connected to the valve positioner.

19. The pressure difference regulating device according to claim 18, characterized in that: The pressure difference regulating device also includes: A filter pressure reducer is connected between the instrument air source and the valve positioner.

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