WO2022162249A2

WO2022162249A2 - Differential pressure adjusting method and device

Info

Publication number: WO2022162249A2
Application number: PCT/EP2022/058165
Authority: WO
Inventors: Taiming DONG; Wei Zhou; Wenyou HE; Fengfeng LU
Original assignee: John Cockerill Hydrogen Belgium Sa
Priority date: 2021-01-27
Filing date: 2022-03-28
Publication date: 2022-08-04
Also published as: WO2022162249A3; CN112760679A; WO2022162249A8

Abstract

The invention relates to a differential pressure adjusting method and device, and the device comprises an adjusting valve group which is connected to the output end of gas in an electrolytic bath, and is provided with at least two stages of pneumatic adjusting valves which are connected in parallel; a valve positioning group which is provided with valve positioners corresponding to the pneumatic control valves in number, wherein the valve positioners are electrically connected with the control ends of the corresponding pneumatic control valves respectively; a controller which is electrically connected with the valve positioners of the valve positioning set and used for sending control signals to the valve positioners, wherein the valve positioners control the opening degree of the corresponding pneumatic adjusting valves step by step according to the control signals. The valve positioners can control the opening degree of the corresponding pneumatic control valves step by step according to the magnitude of control signals sent by the controller, so that the pressure difference adjusting device is wider in adjusting amplitude and higher in precision and sensitivity, no extra control output point is added on the basis of an existing structure, and it is guaranteed that control is simple and efficient.

Description

Differential pressure adjusting method and device

DESCRIPTION

TECHNICAL FIELD

The invention relates to the field of fluid circuit for example for electrolyzed water, in particular to a differential pressure adjusting method and a differential pressure adjusting device.

BACKGROUND ART

Energy is the most fundamental driving force for development and economic growth throughout the world, and is the physical basis on which humans rely for survival. With the increasing consumption and decreasing storage of fossil fuels, environmental pollution, climate abnormality and energy shortage occur all over the world, so that the search for clean energy with abundant sources is the most urgent problem facing the world today.

Hydrogen is the most abundant element on earth: it mainly exists in the form of water and hydrocarbon, etc., and water is the main resource of earth, 71% of earth surface is covered by water; hydrogen can be produced on a large scale. Hydrogen can have the characteristics of cleanness and high combustion value: the heat quantity released by IKg hydrogen combustion is 1.2X 108J, which is equivalent to 3 times of the combustion value of IKg gasoline; and only water and a small amount of hydrogen nitride are generated during combustion, thus not polluting the environment. Therefore, research and development of hydrogen energy are favored, and it is expected that hydrogen energy will become an important component of the energy system in the 21st century.

The preparation of hydrogen has been well established, and the French physical scientist Jacques Charles proposed in 1783 the preparation of hydrogen by the action of sulfuric acid and iron; in the 1800s, Nicholson and Carlisle found that water can be decomposed by electricity, and the hydrogen be prepared by water electrolysis; in the beginning of the twentieth century, preparation of hydrogen by water gas and preparation of hydrogen by gas hydrocarbon-steam reforming are rapidly developed; in 1966, the first solid polymer electrolyte system (SPE system) was established. At present, the main methods for industrial hydrogen production are mineral fuel conversion hydrogen production and water electrolysis hydrogen production; and renewable energy hydrogen production processes such as thermal decomposition hydrogen production, photocatalytic hydrogen production, biological hydrogen production and the like are in the research stage.

With the development trend of hydrogen production by renewable energy, larger-scale hydrogen production equipment by water electrolysis is required, and the fluctuation of a renewable energy power supply tests an important equipment - a pressure difference adjusting device in the hydrogen production equipment by water electrolysis. In automatic control system for hydrogen production by electrolyzing water with higher degree of automation, the regulating valve is used as an execution device of an automatic regulating system terminal, and the pressure and the liquid level difference in the electrolytic bath are regulated by giving and receiving control signals. Its action sensitivity and precision are directly related to the quality of regulating system, safety of system and quality of gas product; and plays a role in the automation of the normal production operation process.

According to the requirement of the current hydrogen production characteristic of renewable energy, the energy conversion of a single electrolytic cell needs to be reduced to the lowest yield as much as possible by combining the sufficient utilization rate of the renewable energy and electrolytic hydrogen production equipment; meanwhile, in order to solve the problem of large scale demand of hydrogen production by water electrolysis, a plurality of sets of electrolysis cells are required to share one comprehensive treatment frame, and a pressure difference adjusting system which can safely operate and is suitable for large-scale adjustment, wide-range adjustment and high-precision and sensitivity adjustment is required to complete adjustment and control of different yields in large proportion.

DISCLOSURE

Disclosure of Invention

In view of the above, it is necessary to provide a differential pressure adjusting method and device for meeting the urgent need of a differential pressure adjusting system that can operate safely, and is suitable for large-scale adjustment, wide-width adjustment, high-precision adjustment, and sensitivity adjustment.

A method of pressure differential regulation, comprising: acquiring a total required flow of the gas output by an electrolytic cell; determining the rated flow of a first pneumatic regulating (or control or adjusting) valve according to the total required flow, wherein the rated flow is smaller than the total required flow; determining the number of pneumatic regulating valves which are connected in parallel and the rated flow of other pneumatic regulating valves according to the rated flow of the first pneumatic regulating valve; determining the number and configuration information of valve positioners according to the number of the pneumatic regulating valves, and enabling the valve positioners to be respectively connected with control ports of the corresponding pneumatic regulating valves, wherein the number of the valve positioners is equal to the number of the pneumatic regulating valves; and generating a control command and sending the control command to the valve positioner so that the valve positioner controls the corresponding pneumatic regulating valve according to the control command to control the opening and closing degree of the corresponding pneumatic regulating valve step by step. The pressure difference adjusting method in the embodiment can determine the number of the required pneumatic adjusting valves and the rated flow required by each pneumatic adjusting valve according to the total required flow of the output gas of the butted electrolysis bath, and the pneumatic adjusting valves corresponding to the valve positioners are matched for step control, so that the accurate control of the flow in low yield is realized.

In one preferred embodiment, the obtaining of the total required flow rate of the gas output from the electrolysis cell comprises: determining the total required flow according to the maximum regulating flow of the original pneumatic regulating valve.

In the above embodiment, the regulation compared with the existing single pneumatic regulating valve is improved, and the total required amount of the output gas of the differential pressure regulating device is determined according to the maximum regulating flow of the original pneumatic control valve.

In one preferred embodiment, the determining the required rated flow of the first pneumatic regulating valve according to the total required flow includes: determining the product of the total demand flow and a first ratio as the minimum accurate control flow of the original pneumatic regulating valve according to the total required flow, wherein the first ratio is larger than 0 and smaller than 1; taking a second ratio, and determining the required rated flow of the first pneumatic regulating valve according to the minimum accurate control flow of the original pneumatic regulating valve and the second ratio.

In the above embodiment, the minimum accurate control flow of the original pneumatic regulating valve is determined according to the inherent characteristics of the pneumatic regulating valve, when the minimum accurate control flow of each pneumatic regulating valve in the present embodiment is smaller than the minimum accurate control flow of the original pneumatic regulating valve, a larger control error occurs in the control adjustment of the original pneumatic regulating valve, a second ratio is taken to determine the rated flow of the pneumatic regulating valve required by the method, because of the inherent characteristics of the pneumatic regulating valve, the first ratio of each regulating valve is generally determined, so that the required pneumatic regulating valve cannot be lower than the minimum accurate control flow as long as the second ratio is larger than the first ratio.

In one preferred embodiment, the sum of the rated flows of the pneumatic regulating valves is equal to the total demand flow .

The sum of the rated flow rates of the pneumatic regulating valves required in the embodiment is equal to the total required flow rate, and the control quantity of each pneumatic regulating valve is fully utilized.

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 the lowest receiving signal value, the lowest output signal value is output to control the minimum opening degree of the corresponding pneumatic regulating valve, and when the valve positioner receives the highest receiving signal value, the highest output signal value is output to control the maximum opening degree of the corresponding pneumatic regulating valve.

The valve positioner in the above 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 amplitude in the differential pressure adjusting device in the embodiment is wider, the accuracy and the sensitivity are higher, no additional control output point is added on the basis of the existing structure, and the control is simple and efficient. In one preferred embodiment, the control signal corresponding to the control command is a voltage control signal.

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

In one preferred embodiment, the valve positioner receives a signal in a linear relationship with the output over a range of signals received by the valve positioner.

In one preferred embodiment, the number of the pneumatic control valves and the valve positioner is M respectively, and the output signal P_n of the No. n valve positioner and the voltage control signal U output by the controller meet the following formula: when n =1:

wherein ki , k_n is a constant; bi , b_n is a constant;

Vn_min is the minimum value of the control signal range corresponding to the No. n valve positioner; Vn_max is the maximum value of the voltage signal range corresponding to the No. n valve positioner; Pn_min is the minimum pressure output by the No.n valve positioner; Pn_max is the maximum pressure output by the No.n valve positioner; M is a positive integer greater than 1; and n is a positive integer not greater than M.

In the above embodiment, the output signal P of the No. n valve positioner and the voltage control signal U output by the controller meets the aforementioned formula, so that the pneumatic regulating valve linearly regulates the volume of the gas output by the electrolyzer.

A differential pressure regulating device, wherein: the regulating valve group is connected with the output end of gas in the electrolytic cell and is provided with at least two pneumatic regulating valves which are mutually connected in parallel; the valve positioning group is provided with valve positioners corresponding to the number of the pneumatic regulating valves, and the valve positioners are respectively and electrically connected with the control ports of the corresponding pneumatic regulating valves; and the controller is electrically connected with the valve positioner of the valve positioning group and used for sending a control signal to the valve positioner, and the valve positioner controls the opening and closing degree of the corresponding pneumatic regulating valve step by step according to the control signal.

The pressure difference adjusting device in this embodiment is provided with at least two stages of pneumatic adjusting valves and the valve positioners corresponding to the two stages of pneumatic adjusting valves, and the valve positioners can control the opening and closing degrees of the corresponding pneumatic adjusting valves step by step according to the size of the control signal sent by the controller.

In one preferred embodiment, the sum of the rated flows of each pneumatic control valve of the set of control valves is equal to the total requested flow.

In the above embodiment, the sum of the rated flow rates of each pneumatic regulating valve is equal to the total required flow rate, and the control range of each pneumatic regulating valve is fully utilized.

In one preferred embodiment, the rated flow rate of each pneumatic regulating valve of the regulating valve group is determined according to the maximum regulating flow rate of the original pneumatic regulating valve, and the rated flow rate of each pneumatic regulating valve is smaller than the maximum regulating flow rate of the original pneumatic regulating valve.

In one preferred embodiment, the minimum accurate control flow rate of each pneumatic regulating valve is smaller than the minimum accurate control flow rate of the original pneumatic regulating valve, and the rated flow rate of each pneumatic regulating valve is smaller than the maximum regulating flow rate of the original pneumatic regulating valve.

In the above embodiment, because of the inherent characteristics of the pneumatic control valve, the ratio of the minimum accurate control flow to the maximum adjustment flow is a fixed value, and when the pneumatic control valve in the present embodiment is smaller than the maximum adjustment flow of the original control valve, the minimum accurate control flow of the pneumatic control valve in the present embodiment is smaller than the minimum accurate control flow of the original control valve, so that the low flow adjustment can be achieved, a control error during the low flow adjustment cannot be caused, and the accurate control effect can be achieved.

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 range of the received control signal, the lowest output signal value is output; and if the control signal received by the corresponding valve positioner is larger than or equal to the maximum value of the range of the received control signal, outputting the maximum output signal value.

The ranges of the controller signals received by each valve positioner in the above embodiments are graded and continuous, so that the flow rate of the gas in the electrolytic cell can be continuously and linearly controlled by the corresponding pneumatic regulating valve.

In the above embodiment, the output signal P of the nth valve positioner and the voltage control signal U output by the controller meets the formula, so that the pneumatic regulating valve linearly regulates the gas output quantity in the electrolytic cell.

In one preferred embodiment, the set of valves has a first pneumatic control valve and a second pneumatic control valve, and the valve positioning set includes a first valve positioner electrically connected to the first pneumatic control valve and a second valve positioner electrically connected to the second pneumatic control valve.

In the above embodiment, the two-stage pneumatic control valve is adopted, so that the pressure difference adjusting device has wider adjusting range, higher precision and sensitivity, and relatively simpler and easier control structure.

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

Adopt PLC controller or DCS controller, control structure is mature relatively, and control structure is stable.

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

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

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

And a pneumatic film regulating valve is adopted, so that the control structure is relatively mature and stable.

In one preferred embodiment, the differential pressure adjusting apparatus further includes: and the instrument air source is connected with the valve positioner.

The instrument gas source can supply gas to the valve positioner, so that the valve positioner works normally, and the gas pressure of the valve positioner is monitored.

In one preferred embodiment, the differential pressure adjusting apparatus further includes: a filtering pressure reducer connected between the instrument air source and the valve positioner.

The filtering pressure reducer can stabilize the pressure of the valve positioner and ensure the stability of the valve positioner.

DRAWINGS DESCRIPTION

FIG. 1 is a schematic flow diagram of a differential pressure regulation method according to a first embodiment of the present invention;

FIG. 2 is a schematic flow chart illustrating the subdivision steps in a pressure differential accommodating method S20 according to the first embodiment of the present invention;

FIG. 3 is a schematic view illustrating an automatic control principle of a differential pressure adjusting device according to a second embodiment of the present invention;

FIG. 4 is a schematic structural view of a differential pressure regulating device according to a second embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a differential pressure regulating device according to a second embodiment of the present invention. INVENTION MODE

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

Referring to fig. 1, a first preferred embodiment of the present invention discloses a differential pressure adjusting method, including: slO: acquiring the total required flow of the gas output by the electrolytic cell; specifically, the total demand flow rate may be determined according to the gas yield that can be decomposed by the electrolytic cell, and in this embodiment, the total demand flow rate is determined by modifying the existing differential pressure adjusting device and determining the maximum adjustment flow rate of the original pneumatic adjustment valve on the existing differential pressure adjusting device. By way of example only, it is possible to illustrate, in example 1, the maximum regulated flow of the original pneumatic regulating valve is 1000m³/h, then 1000m³/h is the total demand flow.

S20: determining the rated flow of the required first pneumatic regulating valve according to the total demand flow, wherein the rated flow is smaller than the total demand flow; the maximum regulating flow of the original pneumatic regulating valve on the existing differential pressure regulating device is determined as the total required flow. Referring to fig. 1 and 2, S20 in the present embodiment includes the following specific sub steps: s21: determining the product of the total demand flow and a first ratio as the minimum accurate control flow of the original pneumatic regulating valve according to the total demand flow, wherein the first ratio is more than 0 and less than 1; specifically, in the above sub-steps, according to the inherent characteristics of the pneumatic control valve, the ratio of the minimum accurate control flow rate to the maximum control flow rate of the pneumatic control valve is a fixed value, and the original maximum control flow rate is 1000m³ after the above example 1 is performed. The ratio of the minimum accurate control flow to the maximum control flow of the pneumatic regulating valve is 10%, so that the minimum accurate control flow of the original pneumatic regulating valve is 100m³-The first ratio is 10%.

S22: taking a second ratio, and determining the required rated flow of the first pneumatic regulating valve according to the minimum accurate control flow of the original pneumatic regulating valve and the second ratio; in this embodiment, the sub-step S22 is to take a second ratio, which is greater than the first ratio, and take the second ratio as 20% and the minimum accurate control flow 100m³ of the original pneumatic control valve according to the minimum accurate control flow of the original pneumatic control valve and the second ratio, as described in the above example 1, then the required rated flow of the first pneumatic regulating valve is 100m³/h divided by 20% to give 500m³/h.

Determining the minimum accurate control flow of the original pneumatic regulating valve according to the inherent characteristics of the pneumatic regulating valve, when the minimum accurate control flow is smaller than the minimum accurate control flow, generating a larger control error in the control adjustment of the original pneumatic regulating valve, taking a second ratio to determine the rated flow of the pneumatic regulating valve required by the method, wherein because the inherent characteristics of the pneumatic regulating valve and the first ratio of each regulating valve are generally determined, the second ratio in the embodiment is larger than the first ratio, the required pneumatic regulating valve cannot be lower than the minimum accurate control flow, s30: determining the number of the pneumatic regulating valves which are connected in parallel and the rated flow of other pneumatic regulating valves according to the rated flow of the first pneumatic regulating valve; as described in example 1 above, the rated flow rate of one of the required pneumatic control valves was determined to be 500m³. The rated flow of other required pneumatic regulating valves is 500m³/h subtracted from the total required quantity according to the rated flow is determined, and finally, a rated flow rate of 500m³/h is required, therefore, the number of the required pneumatic regulating valves is two, and the rated flow of each pneumatic regulating valve is 500m³/h. The sum of the rated flow rates of the pneumatic regulating valves required in the embodiment is equal to the total required flow rate, and the control quantity of each pneumatic regulating valve is fully utilized.

S40: determining the number and configuration information of the valve positioners according to the number of the required pneumatic regulating valves, and enabling the valve positioners to be respectively connected with the control ends of the corresponding pneumatic regulating valves, wherein the number of the valve positioners is equal to the number of the pneumatic regulating valves; in this embodiment, the number of the valve positioners is equal to the number of the pneumatic control valves. And each valve positioner is connected with the control port of the corresponding pneumatic regulating valve respectively, and each pneumatic regulating valve controls the opening and closing degree of the pneumatic regulating valve according to the output configuration information of the corresponding valve positioner. Each pneumatic control valve is respectively and independently controlled by the corresponding valve positioner, so that the stability of the whole device is ensured.

The configuration information of the valve positioner comprises a receiving signal range and an output signal range, when the valve positioner receives the lowest receiving signal value, the lowest output signal value is output, when the valve positioner receives the highest receiving signal value, the highest output signal value is output, and the receiving signal ranges of all the valve positioners are mutually classified and mutually continuous. Preferably, the electrical positioner of the valve positioner receives the voltage input signal and outputs the pressure output signal.

Continuing with example 1 above, if the number of pneumatic regulator valves is two, then the number of corresponding valve positioners may also be two. When the received voltage input signal is 1-3V, the pressure output signal of the first valve positioner is 20-100kpa, namely the first pneumatic regulating valve completes the opening degree regulation of 0-100%, and the pressure output signal of the second valve positioner is 20kpa, namely the first pneumatic regulating valve directly opens 0%; when the received voltage input signal is 3-5V, the pressure output signal of the first valve positioner is lOOkpa, namely the opening and closing degree value of the first pneumatic regulating valve is always 100%, and the pressure output signal of the second valve positioner is 2Okpa-l0Okpa, namely the second pneumatic regulating valve completes the opening degree regulation of 0-100%.

S50: and generating a control command and sending the control command to the valve positioner so that the valve positioner controls the corresponding pneumatic regulating valve according to the control command to control the opening and closing degree of the corresponding pneumatic regulating valve step by step.

In this step, the control command may be sent by a controller, the controller is electrically connected to each of the valve positioners and configured to send a control signal, and since each of the valve positioners has a corresponding signal receiving range, when the control signal sent by the controller is lower than the signal receiving range of the corresponding valve positioner, the corresponding valve positioner outputs a minimum amount to control the minimum opening and closing degree of the corresponding pneumatic control valve, thereby realizing 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 in the highest quantity, the pneumatic regulating valve connected with the valve positioner realizes the maximum signal output in the output signal range at the moment, and the pneumatic regulating valve connected with the valve positioner has the maximum opening degree, so that the maximum rated flow output is realized.

The valve positioner according to control signal controls step by step, along with the gradual grow of the control signal that above-mentioned controller sent, when the scope of the received signal of the valve positioner of first order is not reached, all valve positioners are minimum flow control, when reaching the received signal within range of the valve positioner of first order, the output signal of first valve positioner grow gradually, until exporting to the maximum output signal, in the received signal scope of the valve positioner of reaching the second level, first valve positioner keeps maximum output signal, the output signal of second valve positioner grow gradually. Therefore, the purpose of controlling the opening degree of the corresponding pneumatic regulating valve is achieved through the valve positioners.

More specifically, the valve positioner receives a signal in a linear relationship with the output over a range of signals received by the valve positioner.

The pneumatic regulating valve and the valve positioner are respectively provided with M valve positioners and the output signal P of the nth valve positioner. The voltage control signal U with the output of the controller satisfies the following formula: when n is i:

when n is more than or equal to 2:

wherein ki, k_n is a constant number; bi, b_n is a constant number; Vnmin is the minimum value of the control signal range corresponding to the nth valve positioner; Vnmax is the maximum value of the voltage signal range corresponding to the nth valve positioner; Pnmin is the output minimum pressure of the nth valve positioner; P_nmax is the output maximum pressure of the nth valve positioner; wherein M is a positive integer greater than 1; and n is a positive integer not greater than M.

In an embodiment, the output signal P_n of the nth valve positioner and the voltage control signal U output by the controller meets the formula, so that the pneumatic regulating valve linearly regulates the gas output quantity in the electrolytic cell.

Continuing with example 1 above, the input signal range of the first valve positioner is 1-3V, 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 20-100 kpa. When the voltage output signal that above- mentioned controller sent is less than IV, above-mentioned first valve positioner and second valve positioner output are 20kpa, and the pneumatic control valve of being connected respectively with first valve positioner and second valve positioner is 0 flow output, and when the voltage output signal that above-mentioned controller sent was 1 ~ 3V, the output signal of first valve locator grow gradually, and then makes the degree of opening and shutting of the pneumatic control valve that is connected with first valve locator grow gradually, and the gas flow who corresponds also grows gradually. And 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, the opening degree of the pneumatic regulating valve connected with the first valve positioner reaches the maximum opening degree, the output signal of the second valve positioner gradually increases, and then the opening degree of the pneumatic regulating valve connected with the second valve positioner gradually increases, 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 regulating valves both achieve the maximum opening degree. The pressure difference adjusting method in the embodiment can determine the number of the required pneumatic adjusting valves and the rated flow required by each pneumatic adjusting valve according to the total required flow of the output gas of the butted electrolysis bath, and the pneumatic adjusting valves corresponding to the valve positioners are matched for step control, so that the accurate control of the flow in low yield is realized. 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 regulating amplitude in the pressure difference regulating device in the embodiment is wider, the precision and the sensitivity are higher, no additional control output point is added on the basis of the existing structure, and the control is simple and efficient. Referring to fig. 3 and 4, a second preferred embodiment of the present invention discloses a differential pressure regulating device 100, wherein the differential pressure regulating device 100 includes a regulating valve set 110, a valve positioning set 120 and a controller 130.

Specifically, the regulating valve set 110 is connected to the output port of the gas in the electrolytic cell, and the regulating valve set 110 has at least two pneumatic regulating valves connected in parallel. In other words, the regulating valve set 110 has n (n is equal to or greater than 2, and n is a natural number) pneumatic regulating valves connected in parallel.

More specifically, n gas delivery pipes are connected in parallel to the gas outlet of the electrolytic cell, and the decomposed gas in the electrolytic cell can be delivered to a target position through the gas outlet and any one of the n gas delivery pipes. The n pneumatic control valves are respectively positioned in the corresponding gas conveying pipelines, and each pneumatic control valve can control the flow of gas conveying of the corresponding gas conveying pipeline mainly by controlling the opening and closing degree of each pneumatic control valve. When the pneumatic control valve is closed, the gas conveying pipeline where the pneumatic control valve is located stops conveying gas, when the pneumatic control valve is gradually opened, the flow rate of the gas conveyed by the corresponding gas conveying pipeline is gradually increased, and when the pneumatic control valve is completely opened, the corresponding gas conveying pipeline is in a state capable of conveying gas to the maximum.

In this embodiment, the pneumatic control valve may be a pneumatic diaphragm control valve. The pneumatic membrane regulating valve is adopted in the embodiment, the control structure is relatively mature, and the control process is stable.

The configuration information and the number of the pneumatic regulating valves can be selected according to the following modes: acquiring the total required flow of the gas output by the electrolytic cell; in particular, the total flow demand can be determined according to the gas yield that can be decomposed by the electrolyzer, in this embodiment, it is an improvement over the existing differential pressure regulating devices, according to which the maximum regulating flow of the original pneumatic regulating valve is determined as the total required flow. For example, the maximum regulating flow of the original pneumatic regulating valve is 1000m³/h, then determine the 1000m³/h of the total demand flow .

Determining the rated flow of the required first pneumatic regulating valve according to the total demand flow, wherein the rated flow is smaller than the total demand flow; the maximum regulating flow of the original pneumatic regulating valve on the existing differential pressure regulating device is determined as the total required flow. Determining the minimum accurate control flow of the original pneumatic regulating valve according to the total demand flow, and determining a first ratio of the minimum accurate control flow of the original pneumatic regulating valve to the total demand flow; specifically, in the foregoing sub-steps, according to the inherent characteristic of the pneumatic control valve, the ratio of the minimum accurate control flow to the maximum control flow of the pneumatic control valve is a fixed value.

For example, the original maximum regulated flow rate is 1000m³/h, the ratio of the minimum accurate control flow to the maximum control flow of the pneumatic regulating valve is 10%, so that the minimum accurate control flow of the original pneumatic regulating valve is 100m³/h. The first ratio is 10%.

Taking a second ratio, and determining the required rated flow of the first pneumatic regulating valve according to the minimum accurate control flow of the original pneumatic regulating valve and the second ratio, wherein the second ratio is greater than the first ratio; for example, the second ratio is 20%, and the minimum accurate control flow of the original pneumatic regulating valve is 100m³/h, then the required rated flow of the first pneumatic regulating valve is 100m³/h divided by 20% to give 500m³/h.

Determining the minimum accurate control flow of the original pneumatic regulating valve according to the inherent characteristics of the pneumatic regulating valve, when the minimum accurate control flow is smaller than the minimum accurate control flow, generating a larger control error in the control adjustment of the original pneumatic regulating valve, taking a second ratio to determine the rated flow of the pneumatic regulating valve required by the method, wherein due to the inherent characteristics of the pneumatic regulating valve, the first ratio of each regulating valve is generally determined, so that the required pneumatic regulating valve cannot be lower than the minimum accurate control flow thereof as long as the second ratio is larger than the first ratio, the valve positioning group 120 is connected to the adjustment valve group 110, and specifically, the valve positioning group 120 has valve positioners corresponding to the number of pneumatic adjustment valves, and if the number of pneumatic adjustment valves is n, the number of valve positioners is also n. The valve positioners are respectively connected with the control ports of the corresponding pneumatic regulating valves. The valve positioner can output a control signal, and then can control the degree of opening and closing of the corresponding pneumatic control valve, and then control the gas flow of the gas conveying pipeline where the pneumatic control valve is located.

The valve positioner may be an electrical valve positioner. In the implementation mode, the electric valve positioner is adopted, the control structure is relatively mature, and the control process is stable. The electropneumatic valve positioner outputs a pressure control signal to the corresponding pneumatic regulating valve, and the larger the pressure control signal output by the electropneumatic valve positioner is, the larger the opening degree of the corresponding pneumatic regulating valve is, and the larger the gas flow is controlled to be; conversely, the smaller the pressure control signal output by the electropneumatic valve positioner to the corresponding pneumatic regulating valve is, the smaller the opening degree of the corresponding pneumatic regulating valve is, and the smaller the gas flow is controlled to be.

Each valve positioner has a range of output signals, such as the electro-pneumatic valve positioner, which outputs a pressure control signal, and each valve positioner outputs a signal in a range of P_m±n to P_max wherein P_min is as defined above the minimum pressure control signal of the valve positioner, Pmax is the maximum pressure control signal of the valve positioner. The minimum pressure control signal Pmin may be 0 or may have another value. When the output signal of the valve positioner is Pmin, the corresponding pneumatic regulating valve is in a closed state, when the output signal of the valve positioner is Pmax, the pneumatic control valve is in a fully open state and the corresponding gas conveying pipeline is in the maximum gas output .

The controller 130 is electrically connected to the pneumatic control valves of the valve positioning set 120, and is configured to send a control signal to the valve positioning set 120, and the valve positioning set 120 controls the opening degree of the corresponding pneumatic control valve step by step according to the control signal, so as to achieve the purpose of controlling the gas flow of the corresponding gas delivery pipe.

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 set 120 has a range for receiving the control signal, and if the received control signal is smaller 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 Pmin and then the valve positioner controls the corresponding pneumatic regulating valve to be in a closed state; if the received control signal is larger than or equal to the maximum value of the control signal range corresponding to the valve positioner, the output signal of the valve positioner is the maximum value Pmax and then the valve positioner controls the corresponding pneumatic regulating valve to be in a fullopen state.

The control signal sent by the controller 130 is a voltage control signal, and the range of each valve positioner receiving the control signal is also the range of the voltage control signal. And the corresponding valve positioner outputs signals to the pneumatic regulating valve according to the received voltage control signals. The controller 130 sends a voltage control signal to the valve positioner.

Each valve positioner in the above embodiments is capable of continuously and linearly controlling the flow of gas within the electrolysis cell via the corresponding pneumatic regulator valve.

Further, 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_n of the nth valve positioner and the voltage control signal U output by the controller satisfy the following formula: when n is i:

when n is more than or equal to 2:

wherein ki, k_n is a constant number; bi, b_n is a constant number; Vnmin is the minimum value of the control signal range corresponding to the nth valve positioner; Vnmax is the maximum value of the voltage signal range corresponding to the nth valve positioner; Pnmin is the output minimum pressure of the nth valve positioner; Pnmax is the output maximum pressure of the nth valve positioner; wherein M is a positive integer greater than 1; and n is a positive integer not greater than M.

In the above embodiment, the output signal P_n of the nth valve positioner and the voltage control signal U output by the controller meets the formula, so that the pneumatic regulating valve linearly regulates the gas output quantity in the electrolytic cell.

It should be noted that the range of the signal output by each valve positioner receiving controller 130, or the range of the control signal output to the pneumatic regulator valve in this embodiment, may be the same, or may be different. The controller 130 may be a PLC controller or a DCS controller. With PLC controller or DCS controller, control structure is relatively mature, and control structure is stable.

In this embodiment, the differential pressure adjusting apparatus 100 further includes an instrument air source 140, and the instrument air source 140 is connected to the valve positioner. The instrument gas source can supply gas to the valve positioner, so that the valve positioner works normally, and the gas pressure of the valve positioner is monitored.

In one preferred embodiment, the pressure differential accommodating device further comprises a filter reducer 150, the filter reducer 150 being coupled between the instrument gas source 140 and the valve positioner.

The pressure difference adjusting device in the embodiment is provided with at least two stages of pneumatic adjusting valves and the valve positioners corresponding to the two stages of pneumatic adjusting valves, and the valve positioners can control the opening and closing degrees of the corresponding pneumatic adjusting valves step by step according to the size of the control signal sent by the controller.

Referring to fig. 5, when n is 2, the operation of the differential pressure adjustment device 100 in the above embodiment is illustrated: when n is 2, that is, the regulating valve group 110 has two pneumatic regulating valves, namely, a first pneumatic regulating valve 111 and a second pneumatic regulating valve 112. In more detail, the first pneumatic control valve 111 is connected to the gas output port of the electrolytic cell, is located in the first conveying pipe connected to the gas output port, and is mainly used for controlling the opening and closing of the gas conveying in the first conveying pipe connected to the gas output port. Similarly, the second pneumatic control valve 112 is connected to the gas outlet of the electrolytic cell and is located in a second delivery line connected to the gas outlet, and the first delivery line is independently connected in parallel with the second delivery line, so that the second pneumatic control valve 112 is connected in parallel with the first pneumatic control valve 111.

Similarly, the positioning valve set 110 has two stages of electric 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 port 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 conveying pipeline according to the control signal output by the first valve positioner 121; the second valve positioner 122 is connected to a control port of the second pneumatic control valve 112, and the second pneumatic control valve 112 controls the flow rate of the gas in the corresponding second delivery pipe according to a control signal output by the second valve positioner 122.

The controller 130 is electrically connected to the first valve positioner 121 and the second valve positioner 122, the controller 130 sends a voltage control signal to the first valve positioner 121 to the second valve positioner 122, and the voltage ranges of the controller 122 received by the first valve positioner 121 and the second valve positioner 122 are mutually classified and continuous.

In this embodiment, the range of the voltage control signal U transmitted by the controller 130 is 1-5V, the range of the voltage control signal U received by the first valve positioner 121 is IV = U Is 3V, and the range of the voltage control signal U received by the second valve positioner 122

The first valve positioner 121 outputs a pressure control signal in the range of 20-100kpa, and the second valve positioner 122 outputs a pressure control signal in the range of 20-100 kpa. When the voltage control signal U sent by the controller 130 is IV, the pressure signal P output by the first valve positioner 121 is 20kpa; when the control signal U output by the controller 130 is 3V, the pressure signal P output by the first valve positioner 121 is 100 kpa. When the voltage control signal U sent by the controller 130 is IV < U < 3V, the pressure signal P output by the first valve positioner 121 is KU. In this process, the second valve positioner 122 outputs the minimum pressure signal 20kpa at all times.

When the pressure signal U output by the controller 130 is 3V, the pressure signal Pi output by the first valve positioner 121 is 100 kpa, and the pressure signal P2 output by the second valve positioner 122 is 20kpa. When the control signal U output by the controller 130 is 5V, the pressure signal Pi output by the first valve positioner 121 is 100 kpa, and the pressure signal P2 output by the second valve positioner 122 islOO kpa. When the voltage control signal sent by the controller 130 meets 3V<U<5V, the pressure signal Pi output by the first valve positioner 121 is lOOkpa, and the second valve positioner 122 outputs a pressure signal P2 at the minimum value k(U-3) of the output of the corresponding second valve positioner.

The first pneumatic control valve 111 changes with the change of the pressure signal output by the first valve positioner 121, and the second pneumatic control valve 112 changes with the change of the pressure signal output by the second valve positioner 122, so as to control the flow rate of the corresponding gas delivery pipe.

The present invention has been described in terms of its practical and advantageous aspects, such as its performance, efficiency, progress, and novelty, which are determined by the requirements of the patent laws, functional improvements and operational requirements, and it is understood that the above description and drawings are merely exemplary embodiments of the invention and are not intended to limit the invention thereto.

In particular, the number of flow regulating valve can be superior to 2.

In an embodiment, the total demand flow of the gas output by the electrolytic cell is acquired and the rated flow of one original pneumatic regulating valve (i.e. a single one as used in the prior art) is determined based on the total demand flow. In the embodiment, the original pneumatic regulating valve is to be replaced by a number of pneumatic regulating valves which are connected in parallel and the rated flow of said pneumatic regulating valves connected in parallel is determined based on the rated flow of the single original pneumatic regulating valve.

Claims

1. A method of differential pressure regulation, comprising: acquiring the total demand flow of the gas output by the electrolytic cell; determining the rated flow of the required first pneumatic regulating valve based on the total demand flow, wherein the rated flow is smaller than the total demand flow; determining the number of the pneumatic regulating valves which are connected in parallel and the rated flow of other pneumatic regulating valves based on the rated flow of the first pneumatic regulating valve; determining the number and configuration information of the valve positioners based on the number of the required pneumatic regulating valves, and enabling the valve positioners to be respectively connected with the control ends of the corresponding pneumatic regulating valves, wherein the number of the valve positioners is equal to the number of the pneumatic regulating valves; and generating a control command and sending the control command to the valve positioner, so that the valve positioner controls the corresponding pneumatic regulating valve on the control command, to control the opening degree of the corresponding pneumatic regulating valve step by step.

2. The differential pressure regulation method of claim 1, wherein the process of obtaining the total required flow of gas output by the electrolyzer comprises: determining the total required flow based on the maximum regulation flow of the original pneumatic regulating valve.

3. The differential pressure regulation method of claim 2, wherein determining a desired rated flow rate of the first pneumatic regulator valve based on the total demand flow rate comprises: determining the product of the total demand flow and a first ratio as the minimum accurate control flow of the original pneumatic regulating valve according to the total demand flow, wherein the first ratio is more than 0 and less than 1; and taking a second ratio, and determining the required rated flow of the first pneumatic regulating valve according to the minimum accurate control flow of the original pneumatic regulating valve and the second ratio.

4. The differential pressure regulation method of claim 1, wherein a sum of rated flows of the pneumatic regulator valve is equal to the total demand flow.

5. The differential pressure adjustment method according to claim 1, wherein the configuration information of the valve positioner includes a receiving signal range and an output signal range, when the valve positioner receives the lowest receiving signal value, the lowest output signal value is output to control the minimum opening degree of the corresponding pneumatic regulating valve, and when the valve positioner receives the highest receiving signal value, the highest output signal value is output to control the maximum opening degree of the corresponding pneumatic regulating valve.

6. The differential pressure regulation method according to claim 5, wherein the control signal corresponding to the control command is a voltage control signal.

7. The differential pressure regulation method of claim 6, wherein the valve positioner receives a signal in a linear relationship to the output over a range of signals received by the corresponding valve positioner.

8. The differential pressure regulation method according to claim 7, wherein the pneumatic regulator valve and the valve positioner have M, respectively, output signal P_n of the nth valve positioner and the voltage control signal U with the output of the controller satisfies the following formula: when n is i:

when n is more than or equal to 2:

wherein ki - k_n is a constant number, b₁ ~~ b_n is a constant number, Vnmin is the minimum value of the control signal range corresponding to the nth valve positioner, Vnmax is the maximum value of the voltage signal range corresponding to the nth valve positioner, Pnmin is the output minimum pressure of the nth valve positioner, P_nmaxis the output maximum pressure of the nth valve positioner, wherein M is a positive integer greater than 1, and n is a positive integer not greater than M.

9. A differential pressure regulating device, comprising: the regulating valve group is connected with the output end of gas in the electrolytic cell and is provided with at least two pneumatic regulating valves which are mutually connected in parallel; the valve positioning group is provided with valve positioners corresponding to the number of the pneumatic regulating valves, and the valve positioners are respectively and electrically connected with the control ends of the corresponding pneumatic regulating valves; and the controller is electrically connected with the valve positioner of the valve positioning group and used for sending a control signal to the valve positioner, and 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 differential pressure regulating device according to claim 9, wherein the sum of rated flows of each pneumatic regulating valve of the regulating valve group is equal to a total demand flow.

11. The differential pressure regulating device according to claim 9, wherein a rated flow rate of each pneumatic regulating valve of the regulating valve group is determined according to a maximum regulating flow rate of an original pneumatic regulating valve, and the rated flow rate of each pneumatic regulating valve is smaller than the maximum regulating flow rate of the original pneumatic regulating valve.

12. The differential pressure regulating device as claimed in claim 11, wherein the minimum accurate control flow rate of each pneumatic regulating valve is smaller than the minimum accurate control flow rate of the original pneumatic regulating valve.

13. A differential pressure regulating device as recited in claim 9, wherein if the control signal received by the corresponding valve positioner is less than or equal to the minimum value of the range of received control signals, a minimum output signal value is output; and if the control signal received by the corresponding valve positioner is larger than or equal to the maximum value of the range of the received control signal, outputting the maximum output signal value.

14. The differential pressure regulating device of claim 9, wherein the regulating valve set comprises a first pneumatic regulating valve and a second pneumatic regulating valve, and the valve positioning set 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 differential pressure regulation device of claim 9, wherein the controller is a PLC controller or a DCS controller.

16. The differential pressure regulating device of claim 9, wherein the valve positioner is an electrical valve positioner.

17. The differential pressure regulating device according to claim 9, wherein the pneumatic regulating valve is a pneumatic diaphragm regulating valve.

18. The differential pressure regulating device as claimed in claim 9, further comprising: and the instrument air source is connected with the valve positioner.

19. The differential pressure regulation device of claim 18, further comprising: and the filtering pressure reducer is connected between the instrument air source and the valve positioner.