阅读说明：本技术 一种氯化氢合成炉氯氢自动配比控制方法、系统及合成炉 (Automatic chlorine-hydrogen ratio control method and system for hydrogen chloride synthesis furnace and synthesis furnace ) 是由 张明 王福华 苏志成 侯守慧 李秀恩 李刚 李炳新 王月诚 于 2019-09-17 设计创作，主要内容包括：本公开提供了一种氯化氢合成炉氯氢自动配比控制方法、系统及合成炉,对氯气流量通过低位选择进行限制,对氢气流量通过高位选择进行限制,当氢气的气体流量发生波动且波动量低于第一氢气设定阈值或氯气的气体流量发生波动且波动量低于第一氯气设定阈值时,通过高位选择和低位选择使氢气流量与氯气流量相互感知和锁定,在负荷调整和流量扰动发生时保证氢气比例过量且大于安全低限,不产生游离氯；采用基于交叉限制原理的控制策略,实现合成炉氯气氢气比值自动调节的功能,在确保安全生产的条件下实现氯化氢合成炉氯气氢气流量配比远程自动控制,规避了现场安全风险隐患,并可实现自动化减人和换人的目的。(The invention provides a chlorine-hydrogen automatic proportioning control method and system for a hydrogen chloride synthesis furnace and the synthesis furnace, wherein the chlorine flow is limited through low-level selection, the hydrogen flow is limited through high-level selection, when the gas flow of hydrogen fluctuates and the fluctuation quantity is lower than a first hydrogen set threshold value or the gas flow of chlorine fluctuates and the fluctuation quantity is lower than a first chlorine set threshold value, the hydrogen flow and the chlorine flow are mutually sensed and locked through the high-level selection and the low-level selection, and the hydrogen proportion is ensured to be excessive and greater than the safety low limit without generating free chlorine during load adjustment and flow disturbance; the control strategy based on the cross restriction principle is adopted to realize the function of automatically adjusting the chlorine-hydrogen ratio of the synthesis furnace, realize the remote automatic control of the chlorine-hydrogen flow ratio of the hydrogen chloride synthesis furnace under the condition of ensuring the safe production, avoid the potential safety hazard of the site and realize the purposes of automatic person reduction and person replacement.)

1. A chlorine-hydrogen automatic proportioning control method for a hydrogen chloride synthesis furnace is characterized in that chlorine flow is limited through low-level selection, hydrogen flow is limited through high-level selection, when the gas flow of hydrogen fluctuates and the fluctuation quantity is lower than a first hydrogen set threshold or the gas flow of chlorine fluctuates and the fluctuation quantity is lower than a first chlorine set threshold, the hydrogen flow and the chlorine flow are sensed and locked mutually through the high-level selection and the low-level selection, excessive hydrogen proportion and higher than a safe low limit are guaranteed when load adjustment and flow disturbance occur, and free chlorine is not generated.

2. The automatic chlorine-hydrogen ratio control method of a hydrogen chloride synthesis furnace according to claim 1, wherein the chlorine flow rate is restricted by the hydrogen flow rate during load increase and is not increased, and the hydrogen regulating valve is actuated when the hydrogen set value and the load target value are increased synchronously, and the chlorine set value is increased and actuated when the measured hydrogen is increased.

3. The automatic chlorine-hydrogen ratio control method for a hydrogen chloride synthesis furnace according to claim 2, wherein when the load is reduced, the hydrogen set value is not immediately reduced because of the locking restriction of the measured chlorine amount, the chlorine set value is reduced with the reduction of the target value, the chlorine regulating valve is operated, and when the measured chlorine amount is reduced, the hydrogen set value is reduced, and the hydrogen regulating valve is operated.

4. The automatic hydrogen chloride proportioning control method of the hydrogen chloride synthesis furnace of claim 1, wherein when the fluctuation value of the gas flow of the hydrogen is larger than the second set threshold of the hydrogen, the automatic change is made to a manual state, and the manual intervention control is performed on site or remotely.

5. The automatic chlorine-hydrogen ratio control method for the hydrogen chloride synthesizing furnace according to claim 4, characterized in that at least three safety levels of hydrogen pressure drop are set, and the interlocking protection of the synthesizing furnace is stopped when the pressure of a hydrogen main pipe cannot be ensured to be higher than the safety critical pressure by manual intervention.

6. An automatic chlorine-hydrogen proportioning control system of a hydrogen chloride synthesis furnace is characterized by at least comprising a low-level selector, a high-level selector, a first controller and a second controller;

the low-level selector is used for limiting the chlorine flow, the high-level selector is used for limiting the hydrogen flow, when the hydrogen gas flow fluctuates and the fluctuation amount is lower than a first hydrogen set threshold or the chlorine gas flow fluctuates and the fluctuation amount is lower than a first chlorine set threshold, the hydrogen gas flow and the chlorine gas flow are mutually sensed and locked through high-level selection and low-level selection, and the hydrogen gas proportion is ensured to be excessive and greater than a safety low limit and free chlorine is not generated when load adjustment and flow disturbance occur;

when the load is increased, the chlorine flow is limited by the locking of the hydrogen flow and cannot be increased, when the hydrogen set value and the load target value are increased synchronously, the hydrogen regulating valve of the first controller acts, and after the measured hydrogen is increased, the chlorine set value is increased along with the measured hydrogen, and the chlorine regulating valve of the second controller acts.

When the load is reduced, the hydrogen set value is locked and limited by the actually measured chlorine amount and cannot be reduced immediately, the chlorine set value is reduced along with the reduction of the target value, the second controller controls the action of the chlorine regulating valve, the hydrogen set value is reduced along with the reduction of the actually measured chlorine flow amount, and the first controller controls the action of the hydrogen regulating valve.

7. The automatic hydrogen chloride proportioning control system of the hydrogen chloride synthesis furnace of claim 6, wherein when the fluctuation value of the gas flow of the hydrogen is larger than the second set threshold of the hydrogen, the automatic change is made to a manual state for on-site or remote manual intervention control.

8. The automatic chlorine-hydrogen ratio control system of the hydrogen chloride synthesizing furnace according to claim 7, wherein at least three safety levels of pressure drop of hydrogen and chlorine are set, and the interlocking protection of the synthesizing furnace is stopped when the pressure of a hydrogen main pipe cannot be guaranteed to be larger than the safety critical pressure by manual intervention.

9. The automatic chlorine-hydrogen ratio control system of the hydrogen chloride synthesis furnace according to claim 6, wherein the flow rates of the hydrogen and the chlorine are detected by gas flow meters respectively, and the detected flow rates of the hydrogen and the chlorine are transmitted to the first controller and the second controller in real time; when the hydrogen and chlorine flow is measured, temperature and pressure compensation is carried out, and the hydrogen measuring device is arranged at a position close to the top end of the hydrogen pipeline, so that the measurement is prevented from being influenced by condensed water;

or, the output of the first controller and the second controller is limited, and the valve positions of hydrogen flow reduction and chlorine flow increase are locked;

or, a load adjustment climbing assignment function is set to avoid disturbance caused by errors in manual input at a load input end;

or a one-key stop switch is arranged for stopping the furnace in emergency.

10. A hydrogen chloride synthetic furnace, characterized in that, the chlorine-hydrogen automatic proportioning control method of the hydrogen chloride synthetic furnace of any claim 1-5 is used;

or, comprising the chlorine-hydrogen automatic proportioning control system of the chlorine-hydrogen synthetic furnace of any claim 6-9.

Technical Field

The disclosure relates to the technical field of chemical synthesis equipment, in particular to a chlorine-hydrogen automatic proportioning control method and system for a hydrogen chloride synthesis furnace and the synthesis furnace.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

In the production process of the hydrogen chloride synthesis procedure in the chlor-alkali industry, dangerous gases such as hydrogen, chlorine, hydrogen chloride and the like are involved, the automation degree in the traditional production mode is low, and the air supply operation mainly comprises field manual operation and remote manual operation.

The inventor of the present disclosure finds that the following disadvantages exist in manual operation: (1) the untimely regulation of the furnace pressure of the synthesis furnace causes the imbalance of the proportion of hydrogen and chlorine entering the furnace, and if the hydrogen is excessive during gas supply, the conversion rate of the subsequent working section is influenced; when gas is supplied, if the chlorine is excessive and the free chlorine exceeds the standard, the chlorine reacts with acetylene gas in a VCM conversion process to generate chloroethylene which is very explosive and emit a large amount of heat, thereby causing great threat to safe and stable production; (3) the automation degree of the hydrogen chloride gas supply process is relatively lagged, the labor intensity is high, the accident rate is high, and production accidents caused by improper manual operation sometimes occur.

In addition, the industry has also designed an automatic control method of double closed-loop ratio loop control, as shown in fig. 1, which still has problems and potential safety hazards, summarized as the following two points: (1) the hydrogen has low molecular weight and good escape performance, and the measurement is easily interfered by the condensed water contained in the hydrogen; (2) under the automatic control state, the hydrogen compressor suddenly stops, the problem of excessive chlorine in the hydrogen chloride gas cannot be avoided, and the potential safety hazard of the production system still exists.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a chlorine-hydrogen automatic ratio control method and system for a hydrogen chloride synthesis furnace and the synthesis furnace, wherein the function of automatically adjusting the chlorine-hydrogen ratio of the synthesis furnace is realized by adopting a control strategy based on a cross restriction principle, the remote automatic control of the chlorine-hydrogen flow ratio of the hydrogen chloride synthesis furnace is realized under the condition of ensuring the safe production, the potential safety risk hazard on site is avoided, and the purposes of automatic person reduction and person replacement can be realized.

In order to achieve the purpose, the following technical scheme is adopted in the disclosure:

in a first aspect, the present disclosure provides a chlorine-hydrogen automatic proportioning control method for a hydrogen chloride synthesis furnace;

a chlorine-hydrogen automatic proportioning control method for a hydrogen chloride synthesis furnace limits chlorine flow through low-level selection and limits hydrogen flow through high-level selection, and when the gas flow of hydrogen fluctuates and the fluctuation amount is lower than a first hydrogen set threshold or the gas flow of chlorine fluctuates and the fluctuation amount is lower than a first chlorine set threshold, the hydrogen flow and the chlorine flow are sensed and locked mutually through the high-level selection and the low-level selection, so that excessive hydrogen proportion and higher than a safe low limit are ensured during load adjustment and flow disturbance, and free chlorine is not generated.

As some possible realization modes, the chlorine flow is limited by the locking of the hydrogen flow during the load increase and cannot be increased, when the hydrogen set value and the load target value are synchronously increased, the hydrogen regulating valve is actuated, and after the measured hydrogen is increased, the chlorine set value is increased along with the increase of the hydrogen, and the chlorine regulating valve is actuated.

As a further limitation, when the load is reduced, the hydrogen set value is locked and limited by the measured chlorine amount, and does not decrease immediately, the chlorine set value decreases with a decrease in the target value, and the chlorine regulating valve operates.

And as some possible implementation manners, when the fluctuation value of the hydrogen gas flow is greater than the second set threshold of hydrogen, automatically switching to a manual state, and carrying out on-site or remote manual intervention control.

As a further limitation, at least three safety levels of hydrogen pressure reduction are set, and when manual intervention cannot ensure that the pressure of a hydrogen main pipe is greater than the safety critical pressure, the synthesis furnace is interlocked to protect shutdown.

In a second aspect, the present disclosure provides an automatic chlorine-hydrogen proportioning control system for a hydrogen chloride synthesis furnace;

an automatic chlorine-hydrogen proportioning control system for a hydrogen chloride synthesis furnace at least comprises a low-level selector, a high-level selector, a first controller and a second controller;

the low-level selector is used for limiting the chlorine flow, the high-level selector is used for limiting the hydrogen flow, when the hydrogen gas flow fluctuates and the fluctuation amount is lower than a first hydrogen set threshold or the chlorine gas flow fluctuates and the fluctuation amount is lower than a first chlorine set threshold, the hydrogen gas flow and the chlorine gas flow are mutually sensed and locked through high-level selection and low-level selection, and the hydrogen gas proportion is ensured to be excessive and greater than a safety low limit and free chlorine is not generated when load adjustment and flow disturbance occur;

when the load is increased, the chlorine flow is limited by the locking of the hydrogen flow and cannot be increased, when the hydrogen set value and the load target value are increased synchronously, the hydrogen regulating valve of the first controller acts, and after the measured hydrogen is increased, the chlorine set value is increased along with the measured hydrogen, and the chlorine regulating valve of the second controller acts.

When the load is reduced, the hydrogen set value is locked and limited by the actually measured chlorine amount and cannot be reduced immediately, the chlorine set value is reduced along with the reduction of the target value, the second controller controls the action of the chlorine regulating valve, the hydrogen set value is reduced along with the reduction of the actually measured chlorine flow amount, and the first controller controls the action of the hydrogen regulating valve.

And as some possible implementation manners, when the fluctuation value of the hydrogen gas flow is greater than the second set threshold of hydrogen, automatically switching to a manual state, and carrying out on-site or remote manual intervention control.

As a further limitation, at least three safety levels of hydrogen pressure reduction are set, and when manual intervention cannot ensure that the pressure of a hydrogen main pipe is greater than the safety critical pressure, the synthesis furnace is interlocked to protect shutdown.

As some possible implementation manners, the flow rates of the hydrogen and the chlorine are detected by using gas flow meters respectively, and the detected flow rates of the hydrogen and the chlorine are transmitted to a first controller and a second controller in real time; when the hydrogen and chlorine flow is measured, temperature and pressure compensation is carried out, and the hydrogen measuring device is arranged at a position close to the top end of the hydrogen pipeline, so that the measurement is prevented from being influenced by condensed water;

as some possible implementations, the output of the first and second controllers are clipped to lock the valve positions for hydrogen flow reduction and chlorine flow increase.

As some possible implementation manners, the load adjustment climbing assignment function is set to avoid disturbance caused by mistake in manual input at the load input end.

As some possible realization modes, a one-key shutdown switch is provided for shutdown in emergency.

In a third aspect, the present disclosure provides a hydrogen chloride synthesis furnace, and a method for controlling the automatic hydrogen chloride ratio of the hydrogen chloride synthesis furnace according to the present disclosure is utilized.

In a fourth aspect, the present disclosure provides a hydrogen chloride synthesis furnace, which includes the hydrogen chloride automatic proportioning control system of the hydrogen chloride synthesis furnace.

Compared with the prior art, the beneficial effect of this disclosure is:

the hydrogen chloride synthesis furnace disclosed by the invention is stable in operation, realizes field unattended operation, reduces the potential safety hazard caused by manual operation misoperation and greatly reduces the accident rate.

The content of the disclosure can be stably operated when the load is adjusted, the purity of the hydrogen chloride is hardly changed, the purity of the hydrogen chloride is tested immediately after the load is not required to be adjusted, and the labor load of operators is reduced.

The content of the disclosure ensures that when any one of the chlorine flow and the hydrogen flow fluctuates in a small amplitude, the system can automatically balance the proportion of the chlorine flow and the hydrogen flow, and the intrinsic safety of the adjusting process is realized.

The hydrogen pressure subsection interlocking control function is arranged, when the hydrogen pressure is abnormally fluctuated, and when the pressure of the main pipe is lower than the hydrogen safety level pressure, the corresponding synthesis furnace is automatically interlocked and shut down, and the risk of excessive chlorine is effectively solved.

According to the hydrogen measuring device, the installation position of the hydrogen measuring device is properly raised, so that condensed water contained in hydrogen can be drained timely and smoothly, and the influence of the condensed water on the measuring result is avoided.

The content of this disclosure has set up one key parking function, has improved artifical emergency operation's flexibility.

Drawings

Fig. 1 is a schematic flow chart of an automatic control method of dual closed-loop ratio loop control in the prior art described in the background of the present disclosure.

Fig. 2 is a schematic flow chart of a method for controlling automatic hydrogen chloride proportioning of a hydrogen chloride synthesis furnace according to embodiment 1 of the disclosure.

Fig. 3 is an operation interface of the cascade control loop in embodiment 1 of the present disclosure.

Fig. 4 is an operator monitoring screen in embodiment 1 of the present disclosure.

Fig. 5 is an operation screen of interlock protection in embodiment 1 of the present disclosure.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.