阅读说明：本技术 一种压差调节方法及装置 (Differential pressure adjusting method and device ) 是由 董太明 周巍 贺文有 陆峰峰 于 2021-01-27 设计创作，主要内容包括：本发明涉及一种压差调节方法及装置,其中装置包括：调节阀门组,连接于所述电解槽内气体的输出端,所述调节阀门组具有至少两级相互并联的气动调节阀；阀门定位组,具有与气动调节阀数量对应的阀门定位器,所述阀门定位器分别与对应的气动调节阀的控制端电性连接；控制器,与所述阀门定位组的阀门定位器电性连接,用以向所述阀门定位器发出控制信号,所述阀门定位器根据所述控制信号逐级控制对应的所述气动调节阀的开合度。阀门定位器可根据控制器所发出的控制信号的大小逐级控制对应的气动调节阀的开合度,这样压差调节装置中的调节幅度更宽、精度及灵敏度更高,并且,在现有结构的基础上,没有增加额外的控制输出点,保证控制简单高效。(The invention relates to a differential pressure regulating method and a differential pressure regulating device, wherein the differential pressure regulating device comprises: the regulating valve group is connected with the output end of the 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. The valve positioner can control the degree of opening and shutting of the pneumatic control valve that corresponds step by step according to the size of the control signal that the controller sent, and the regulation range in the pressure differential adjusting device is wideer like this, precision and sensitivity are higher to, on the basis of current structure, do not increase extra control output point, guarantee to control simply high-efficiently.)

1. A method of differential pressure regulation, comprising:

acquiring the total required flow of the gas output by the electrolytic cell;

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;

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;

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;

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

2. The differential pressure regulation method of claim 1, wherein the obtaining of the total required flow of gas output by the electrolyzer comprises:

and determining the total required flow according to 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, n-th valve positioners output signals P_nThe voltage control signal U with the output of the controller satisfies the following formula:

when n is 1:

when n is more than or equal to 2:

wherein k is₁、k_nIs a constant number, b₁、b_nIs a constant number, V_nminIs the minimum value, V, of the control signal range corresponding to the nth valve positioner_nmaxIs the maximum value, P, of the voltage signal range corresponding to the nth valve positioner_nminIs the output minimum pressure, P, of the nth valve positioner_nmaxAnd 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.

Technical Field

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

Background

Energy is the most fundamental driving force for development and economic growth throughout the world, and is the material 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, mainly exist 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, and hydrogen can have the characteristics of cleanness and high combustion value, the heat quantity released by 1Kg hydrogen combustion is 1.2X 108J, which is equivalent to 3 times of the combustion value of 1Kg 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 21 st century.

The preparation of hydrogen has been well established, and the physical scientist of france in 1783 in summer theory proposed the preparation of hydrogen by the action of sulfuric acid and iron; in 1800 years, Nicholson and Carlisle find that water can be decomposed by electricity, and the hydrogen is prepared by water electrolysis; in the beginning of the twentieth century, the preparation of hydrogen by water gas and the 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 research stages.

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 the automatic control system for hydrogen production by electrolyzing water with higher automation degree, the regulating valve is used as an executing 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. Plays a role in promoting the weight 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 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 the total required flow of the gas output by the electrolytic cell;

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;

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;

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;

and generating a control instruction and sending the control instruction to the valve positioner so that the valve positioner controls the corresponding pneumatic regulating valve according to the control instruction 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 existing single pneumatic control 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 demand 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 demand 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 control valve is determined according to the inherent characteristics of the pneumatic control valve, when the minimum accurate control flow is smaller than the minimum accurate control flow, a larger control error occurs in the control adjustment of the original pneumatic control valve, a second ratio is taken to determine the rated flow of the pneumatic control valve required by the method, because of the inherent characteristics of the pneumatic control valve, the first ratio of each control valve is generally determined, so that the required pneumatic control 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 control 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 pneumatic control valve and the valve positioner each have M, respectively, output signals P of the nth valve positioner_nWith a voltage control signal Ufull of the output of the controllerSufficient for the following equation:

when n is 1:

when n is more than or equal to 2:

wherein k is₁、k_nIs a constant number, b₁、b_nIs a constant, Vn_minIs the minimum value, V, of the control signal range corresponding to the nth valve positioner_nmaxIs the maximum value, P, of the voltage signal range corresponding to the nth valve positioner_nminIs the output minimum pressure, P, of the nth valve positioner_nmaxAnd 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 of the nth valve positioner_nAnd 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.

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.

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.

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 demand 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_nAnd 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:

and the filtering pressure reducer is 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

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.

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:

s10: 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,example 1 is the maximum regulated flow of the original pneumatic regulating valve is 1000m³H, then determine the 1000m³And/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 1000m after the above example 1 is performed³The 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 100m³The 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 100m 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 1³H, then the required rated flow of the first pneumatic regulating valve is 100m³H 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 can not 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 500m³The rated flow of other required pneumatic regulating valves is 500m subtracted from the total required quantity according to the rated flow³H is determined, and finally, a rated flow rate of 500m is required³H, 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 end 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 100kpa, 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 20kpa-100kpa, namely the second pneumatic regulating valve completes the opening degree regulation of 0-100%.

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

In this step, the control instruction 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 locator 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 locator of first order is not reached, all valve locators are minimum flow control, when reaching the received signal within range of the valve locator of first order, the output signal of first valve locator grow gradually, until exporting to the maximum output signal, in the received signal scope of the valve locator of reaching the second level, first valve locator keeps maximum output signal, the output signal of second valve locator 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_nThe voltage control signal U with the output of the controller satisfies the following formula:

when n is 1:

when n is more than or equal to 2:

wherein k is₁、k_nIs a constant number, b₁、b_nIs a constant number, V_nminIs the minimum value, V, of the control signal range corresponding to the nth valve positioner_nmaxIs the maximum value, P, of the voltage signal range corresponding to the nth valve positioner_nminIs the output minimum pressure, P, of the nth valve positioner_nmaxAnd 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.

The above-mentioned fruitIn an embodiment, the output signal P of the nth valve positioner_nAnd 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 1V, above-mentioned first valve locator and second valve locator output are 20kpa, and the pneumatic control valve of being connected respectively with first valve locator and second valve locator 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 end 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 whichThe 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 1000m³H, then determine the 1000m³And/h is 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 1000m³The 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 100m³The 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 100m³H, then the required rated flow of the first pneumatic regulating valve is 100m³H 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 ends 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_minTo P_maxWherein P is as defined above_minIs the minimum pressure control signal, P, of the valve positioner_maxThe minimum pressure control signal P is the maximum pressure control signal of the valve positioner_minMay be 0 or may have another value. When the output signal of the valve positioner is P_minWhen the corresponding pneumatic regulating valve is in a closed state, the output signal of the valve positioner is P_maxAnd when the pneumatic control valve is in a fully open state, 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 P_minAnd 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 P_maxAnd then the valve positioner controls the corresponding pneumatic regulating valve to be in a full-open 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 of the nth valve positioner_nThe voltage control signal U output by the controller satisfies the following formula:

when n is 1:

when n is more than or equal to 2:

wherein k is₁、k_nIs a constant number, b₁、b_nIs a constant number, V_nminIs the minimum value, V, of the control signal range corresponding to the nth valve positioner_nmaxIs the maximum value, P, of the voltage signal range corresponding to the nth valve positioner_nminIs the output minimum pressure, P, of the nth valve positioner_nmaxAnd 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 of the nth valve positioner_nAnd 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. Adopt PLC controller or DCS controller, control structure is mature relatively, 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 filtering pressure reducer can stabilize the pressure of the valve positioner and ensure the stability of 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 end of the electrolytic cell, is located in the first conveying pipe connected to the gas output end, and is mainly used for controlling the opening and closing of the gas conveying in the first conveying pipe connected to the gas output end. 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 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 conveying pipeline according to the control signal output by the first valve positioner 121; the second valve positioner 122 is connected to a control end 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 1V ≦ U ≦ 3V, and the range of the voltage control signal U received by the second valve positioner 122 is 3V ≦ U ≦ 5V

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 1V, the pressure signal P output by the first valve positioner 121₁20kpa, when the control signal U output by the controller 130 is 3V, the pressure signal P output by the first valve positioner 121₁Is 100 kpa. When the voltage control signal U sent by the controller 130 is 1V < U < 3V, the pressure signal P output by the first valve positioner 121₁Is KU. In this process, the second valve positioner 122 outputs the minimum pressure signal 20kpa at all times.

When the pressure signal U outputted by the controller 130 is 3V, the pressure signal P outputted by the first valve positioner 121₁Is 100 kpa. The pressure signal P output by the second valve positioner 122₂20kpa, when the control signal U output by the controller 130 is 5V, the pressure signal P output by the first valve positioner 121₁A pressure signal P of 100kpa output from the second valve positioner 121₂Is 100 kpa. When the voltage control signal 3V is sent by the controller 130<U<At 5V, the pressure signal P output by the first valve positioner 121₁At 100kpa, the second valve positioner 122 outputs a pressure signal P₂Is the corresponding minimum value k (U-3) of the output of the 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.

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.

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.