CN118110938A - Method and system for determining turn-off time of toxic gas protection device - Google Patents

Abstract

The invention belongs to the technical field of oil gas gathering and transportation, and relates to a method and a system for determining turn-off time of a toxic gas protection device, wherein the method comprises the following steps: developing diffusion dynamic simulation aiming at the toxic gas leakage working condition, and simulating the concentration change condition of toxic gas in a field; calculating the injury rate of each toxic component in the field according to the concentration change condition of the toxic gas; obtaining dangerous areas of each toxic gas according to the injury rate; judging whether a reference point exists in the dangerous area of the toxic gas, if so, shortening the turn-off time, and repeating the steps until the reference point does not exist in the dangerous area of the toxic gas, and if not, outputting the toxic gas protection turn-off time. The method can objectively, quantitatively and accurately determine the reasonable turn-off time under the condition of toxic gas leakage in the field.

Description

Method and system for determining turn-off time of toxic gas protection device

Technical Field

The invention relates to a method and a system for determining turn-off time of a toxic gas protection device, and belongs to the technical field of oil gas gathering and transportation.

Background

In the development process of oil and gas fields, produced oil and gas may contain toxic components such as hydrogen sulfide, carbon monoxide and the like. In the oil gas gathering and transportation process, equipment or pipelines are leaked due to corrosion perforation, manual misoperation, sealing failure and the like, so that toxic gas is led to enter a site, and threat is brought to site operators. In order to ensure safe operation of the oil and gas gathering and transportation process, a monitoring probe is usually arranged in a gathering and transportation site containing toxic gas. When toxic gas leaks, the monitoring probe responds to the alarm, and the toxic gas safety protection device is locked in parallel to trigger the shutdown, so that the source of the toxic gas is cut off, the leakage amount of the toxic gas is reduced as much as possible, the accident hazard consequence is reduced, and the on-site operators are protected. The turn-off time is too long, namely the leakage of the toxic gas source is not cut off in time, so that the volume concentration of the toxic gas in an accident is increased, the toxic hazard is increased, and the toxic death risk is high; the shorter the off-time, the better of course. But without quantitative analysis it is not possible to determine to what extent it can be. And the shorter the off time requirement, the higher the requirement on valve selection, the higher the investment cost and the lower the economy. At present, the turn-off time of the toxic gas safety protection device is short of corresponding guidelines or recommended methods, qualitative judgment is often carried out according to past experience, and a quantitative and objective method for determining the turn-off time of the toxic gas safety protection device is short.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a method and a system for determining the shutdown time of a toxic gas protection device, which can objectively, quantitatively and accurately determine the reasonable shutdown time under the condition of toxic gas leakage in a field.

In order to achieve the above purpose, the present invention proposes the following technical solutions: a method of determining a shutdown time of a toxic gas protection device, comprising the steps of: developing diffusion dynamic simulation aiming at the toxic gas leakage working condition, and simulating the concentration change condition of toxic gas in a field; calculating the damage rate of each toxic component in the field according to the concentration change condition of the toxic gas; obtaining dangerous areas of each toxic gas according to the injury rate; judging whether a reference point exists in the dangerous area of the toxic gas, if so, shortening the turn-off time, and repeating the steps until the reference point does not exist in the dangerous area of the toxic gas; if not, outputting the turn-off time of the toxic gas protection device.

Further, the calculation formula of the injury rate is as follows:

Wherein D _n is the injury rate of each toxic component of the gas; a and B are poisoning empirical coefficients; t is the exposure time of toxic gas; q is the concentration of toxic gas; c is the characteristic coefficient of the toxic component, and x is the independent variable of the injury rate function solution.

Further, the method for simulating the concentration change condition of the toxic gas in the field comprises the following steps: the established toxic gas leakage model is enabled to stably run for a plurality of times when no gas leaks; then, setting gas leakage at a certain position in the toxic gas leakage model, and setting gas leakage flow; and monitoring the concentration change condition of toxic gas components at various positions in the toxic gas leakage model field in the whole leakage process.

Further, according to the concentration change condition of the toxic gas components, the concentration change condition of each toxic gas component in the toxic gas leakage model site along with time is plotted, and a toxic gas component concentration record chart is generated.

Further, the diffusion dynamic simulation may be implemented by fluid simulation software Fluent, flics, or KFX.

Further, the method for obtaining the dangerous area of each toxic gas according to the injury rate comprises the following steps: setting the upper limit of the injury rate of each position in the toxic gas leakage model field; calculating the injury rate of each toxic gas component at each position of the field; marking the position where the damage rate reaches the upper limit of the damage rate; and connecting all positions of which the injury rate reaches the upper limit of the injury rate to form a closed area, wherein the closed area is a dangerous area of each toxic gas.

Further, the position of the reference point is determined according to the range and frequency of the human activity in the field.

Further, the toxic gas includes: carbon monoxide and hydrogen sulfide.

The invention also discloses a system for determining the turn-off time of the toxic gas protection device, which comprises: the dynamic simulation module is used for carrying out diffusion dynamic simulation aiming at the toxic gas leakage working condition and simulating the concentration change condition of toxic gas in the field; the injury rate calculation module is used for calculating the injury rate of each toxic component in the field according to the concentration change condition of the toxic gas; the dangerous area obtaining module is used for obtaining dangerous areas of various toxic gases according to the upper limit of the injury rate; the turn-off time determining module is used for judging whether a reference point exists in the dangerous area of the toxic gas, if so, the turn-off time is shortened, and the steps are repeated until the reference point does not exist in the dangerous area of the toxic gas; if not, outputting the turn-off time of the toxic gas protection device.

The invention also discloses a computer readable storage medium having stored thereon a computer program for execution by a processor to implement the method of determining the shutdown time of a toxic gas protection device of any of the above.

Due to the adoption of the technical scheme, the invention has the following advantages:

1. According to the scheme, the reasonable turn-off time of the protection device under the condition of toxic gas leakage in the field can be objectively, quantitatively and accurately determined, the distribution condition of the concentration of the toxic gas can be rapidly obtained through the toxic gas component recording diagram, the area where the toxic gas exceeds the upper limit of the injury rate can be obtained, injury caused by the situation that staff mistakenly enter a dangerous area is avoided, and the safety of the staff is ensured.

2. The scheme of the invention solves the problem that the conventional qualitative analysis method only depends on experience, and the conventional quantitative calculation method avoids the risk of toxic hazard increase and personnel toxic death due to overlong turn-off time by determining reasonable turn-off time; and meanwhile, the shutdown time is not recommended to be too short, the type selection redundancy of the shutdown valve is avoided, and the economic cost is excessively input.

Drawings

FIG. 1 is a schematic diagram of a method for determining shutdown time of a toxic gas protection device in accordance with an embodiment of the present invention;

FIG. 2 is a graph showing a reference point distribution diagram according to an embodiment of the present invention, wherein S is a toxic gas leakage position, and R1 is a reference point 1; r2 is a reference point 2; r3 is a reference point 3; r4 is a reference point 4;

FIG. 3 is a schematic diagram of a carbon monoxide risk area A1 with a shutdown time of 60s according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a hydrogen sulfide hazard zone A2 at a shutdown time of 60s in an embodiment of the present invention;

FIG. 5 is a schematic diagram of a carbon monoxide risk area A1 with a shutdown time of 45s according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a hydrogen sulfide hazard zone A2 with a 45s off time in accordance with one embodiment of the present invention;

FIG. 7 is a schematic diagram of a carbon monoxide risk area A1 with a shutdown time of 30s in an embodiment of the present invention;

FIG. 8 is a schematic diagram of a hydrogen sulfide hazard zone A2 with a shutdown time of 30s, in accordance with one embodiment of the present invention.

Detailed Description

The invention is depicted in detail by specific examples in order to provide a better understanding of the technical solution of the invention to those skilled in the art. It should be understood, however, that the detailed description is presented only to provide a better understanding of the invention, and should not be taken to limit the invention. In the description of the present invention, it is to be understood that the terminology used is for the purpose of description only and is not to be interpreted as indicating or implying relative importance.

In order to solve the problems that the prior art lacks guidance or recommended practice of response to the turn-off time of the toxic gas safety protection device, is often qualitatively judged according to past experience, and lacks a quantitative and objective method for determining the turn-off time of the toxic gas safety protection device, the invention provides a method and a system for determining the turn-off time of the toxic gas safety protection device. According to the concentration change of the toxic gas at each position in the field in the leakage process, the damage rate of the toxic gas components at each position in the field can be calculated; according to the upper limit of the injury rate, combining the calculation results of the injury rate of the toxic gas at each position in the field, and obtaining a dangerous area of the toxic gas component; depending on the coverage of the hazardous area of toxic gas, it can be observed whether there is a hazard at the reference point. The invention can be widely applied to determining the turn-off time of the toxic gas protection device in danger. The following describes the invention in more detail by way of examples with reference to the accompanying drawings.

Example 1

The embodiment discloses a method for determining the turn-off time of a toxic gas protection device, as shown in fig. 1, comprising the following steps:

s1, firstly, setting initial turn-off time delta t1 of a toxic gas protection device, and simulating concentration change conditions of toxic gas in a field for carrying out diffusion dynamic simulation aiming at toxic gas leakage working conditions;

As shown in FIG. 2, the simulated field was a rectangular field 45m long and 28m wide, and it was assumed that toxic gas leakage occurred at the toxic gas leakage position, i.e., position S, with a leakage port size of 60mm, gas pressure of 8.1MPa, and temperature of 52 ℃. The gas components are: 74% of methane, 22% of ethane, 3.3% of propane, 0.3% of butane, 0.3% of carbon monoxide and 0.1% of hydrogen sulfide. In this embodiment, toxic gas components include, but are not limited to: at least one of methane, ethane, propane, butane, carbon monoxide and hydrogen sulfide may be one of the gases or a combination of several gases, and the toxic gases that can be used in the embodiment are not limited to the listed gases. The position of the reference point in this embodiment is determined according to the range and frequency of the movement of the personnel in the field. In this embodiment, four reference points are determined in total, that is, R1 is reference point 1; r2 is a reference point 2; r3 is a reference point 3; r4 is reference point 4.

The method for simulating the concentration change condition of toxic gas in the field comprises the following steps: the established toxic gas leakage model is enabled to stably operate for a plurality of times when no gas leakage exists, and the stable operation is preferably carried out for 2 minutes when no gas leakage exists in the embodiment; then, gas leakage is set somewhere in the toxic gas leakage model, namely gas leakage occurs at S in the site, the gas leakage flow is set, the leakage gas flow is set to 86221kg/h, and the leakage gas flow is kept unchanged in the simulation process; after 60s from the beginning of gas leakage, the toxic gas protection device in the field starts to respond, the gas source is cut off by interlocking and the system cut-off time is 60s; and (3) starting to monitor the concentration change condition of toxic gas components at various positions in the leakage model field of the concentration of toxic gas components such as carbon monoxide and hydrogen sulfide in the whole leakage process. And according to the concentration change condition of the toxic gas components, plotting the time change condition of each toxic gas component in the toxic gas leakage model site to generate a toxic gas component record graph, namely a time change graph of the concentration of carbon monoxide and hydrogen sulfide components. And visualizing the model optimization result.

In this embodiment, the software for developing diffusion dynamic simulation under the toxic gas leakage condition is configured as process dynamic simulation software Fluent. However, the present invention is not limited thereto, and in other embodiments, software for developing diffusion dynamic simulation for toxic gas leakage conditions may be replaced with Flacs and KFX, for example.

S2, calculating the damage rate of each toxic component in the field according to the concentration change condition of the toxic gas;

the calculation formula of the injury rate is as follows:

Wherein D _n is the injury rate of each toxic component of the gas; a and B are poisoning empirical coefficients; t is the exposure time of toxic gas; q is the concentration of toxic gas; c is a characteristic coefficient of a toxic component, and x is an independent variable of the injury rate function solution. A. The empirical coefficients of B and C are shown in Table 1.

TABLE 1 empirical coefficient table of several common toxic gas components for oil and gas exploitation

Toxic gas component	A	B	C
				Carbon monoxide	-42.98	3.7	1.0
Hydrogen sulfide	-36.42	3.0	1.4
				Chlorine gas	-13.29	0.9	2.0
Toluene (toluene)	-11.79	0.4	2.5
				Chlorine gas	-13.29	0.9	2.0

S3, according to the injury rate and the upper limit Df _n of the injury rate of each toxic gas component, obtaining a dangerous area An of each toxic gas, wherein the obtained carbon monoxide dangerous area A1 is shown in figure 3, and the obtained hydrogen sulfide dangerous area A2 is shown in figure 4;

The method for obtaining the dangerous areas of each toxic gas according to the injury rate comprises the following steps: setting the upper limits of injury rates Df1, df2 and Df3 of each toxic gas component in a leakage model site, wherein the upper limits of injury rates Dfn at reference points in the site are respectively as follows: carbon monoxide df1=8%, hydrogen sulfide df2=5%; calculating the damage rate D1, D2 … … Dn of each toxic gas component at each position of the field; marking the position where the damage rate reaches the upper limit of the damage rate; and connecting all positions of which the injury rate reaches the upper limit of the injury rate to form a closed area, wherein the closed area is a dangerous area A1, A2 … … An of each toxic gas. As shown in fig. 3, the positions d1=df1 in the field are connected to form a closed shadow area A1 (left oblique shadow in fig. 3), all positions D1> Df1 in the shadow area, and all positions D1< Df1 outside the shadow area. The closed shadow area A1 is a carbon monoxide dangerous area A1, and in the same way, in fig. 4, the positions of d2=df2 in the field are connected to form a closed shadow area A2, all positions D2> Df2 in the shadow area, and all positions D2< Df2 outside the shadow area. The closed shadow area A2 is the hydrogen sulfide hazard area A2. In this embodiment, the upper limit of the rate of injury to a defined toxic component is fixed and independent of location within a scene. The injury rate is different at different positions, but the upper limit of the injury rate of the component is unique.

S4, judging whether a reference point exists in the dangerous area of the toxic gas, if the reference point distribution diagram is shown in the figure 2, shortening the turn-off time, repeating the steps until the reference point does not exist in the dangerous area of the toxic gas, indicating that the turn-off time meets the protection requirement, and if the reference point does not exist, outputting a toxic gas protection turn-off time delta t 1.

As shown in fig. 3 and 4, the carbon monoxide dangerous area A1 in fig. 3 includes three monitoring points R2, R3 and R4, and the hydrogen sulfide dangerous area A2 in fig. 4 includes two monitoring points R2 and R3, which do not meet the requirements, and the calculation needs to be restarted, and the steps 1,2 and 3 are repeated.

In the case of the other parameters being unchanged, the off-time is modified to 45s. Recording the changes of the concentrations of carbon monoxide and hydrogen sulfide components at various positions in a site along with time, and obtaining a carbon monoxide dangerous area A1 shown in figure 5 and a hydrogen sulfide dangerous area A2 shown in figure 6 according to the changes of the concentrations of the carbon monoxide and the hydrogen sulfide components along with time;

the carbon monoxide dangerous area A1 in FIG. 5 comprises a monitoring point R2, and the hydrogen sulfide dangerous area A2 in FIG. 6 does not comprise the monitoring point, namely the carbon monoxide dangerous area is not satisfactory yet, calculation needs to be restarted, and the hydrogen sulfide dangerous area is satisfactory yet.

The recalculation is performed for carbon monoxide, and the off time is modified to 30s without changing other parameters. Recording the changes of the concentrations of carbon monoxide and hydrogen sulfide components at various positions in a site along with time, and obtaining a carbon monoxide dangerous area A1 shown in figure 7 and a hydrogen sulfide dangerous area A2 shown in figure 8 according to the changes of the concentrations of the carbon monoxide and the hydrogen sulfide components along with time;

the carbon monoxide hazard zone A1 in fig. 7 does not include a monitoring point, nor does the hydrogen sulfide hazard zone A2 in fig. 8 include a monitoring point, i.e., both the carbon monoxide hazard zone and the hydrogen sulfide hazard zone are satisfactory. The calculation process is ended, and the output off time is 30s.

According to the method for determining the turn-off time of the toxic gas protection device, the dangerous area of the toxic gas and the reasonable turn-off time of the protection device can be determined according to the calculation result of the dangerous area of the toxic gas through dynamic simulation.

Example two

Based on the same inventive concept, the invention also discloses a system for determining the turn-off time of the toxic gas protection device, which comprises:

the dynamic simulation module is used for carrying out diffusion dynamic simulation aiming at the toxic gas leakage working condition and simulating the concentration change condition of toxic gas in the field;

The injury rate calculation module is used for calculating the injury rate of each toxic component in the field according to the concentration change condition of the toxic gas;

the dangerous area obtaining module is used for obtaining dangerous areas of each toxic gas according to the injury rate;

the turn-off time determining module is used for judging whether a reference point exists in the dangerous area of the toxic gas, if so, the turn-off time is shortened, the steps are repeated until the reference point does not exist in the dangerous area of the toxic gas, and if not, the toxic gas protection turn-off time is output.

Example III

Based on the same inventive concept, the invention also discloses a computer readable storage medium, wherein a computer program is stored on the computer readable storage medium, and the computer program is executed by a processor to realize the method for determining the turn-off time of the toxic gas protection device according to any one of the above.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present application and not for limiting the same, and although the present application has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the application without departing from the spirit and scope of the application, which is intended to be covered by the claims. The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily appreciate variations or alternatives within the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims (10)

1. A method of determining the shutdown time of a toxic gas protection device, comprising the steps of:

developing diffusion dynamic simulation aiming at toxic gas leakage working conditions, and simulating concentration change conditions of toxic gas components in a field;

Calculating the injury rate of each toxic component in the field according to the concentration change condition of the toxic gas component;

obtaining dangerous areas of various toxic gas components according to the injury rate;

judging whether a reference point exists in the dangerous area of the toxic gas component, if so, shortening the turn-off time, and repeating the steps until the reference point does not exist in the dangerous area of the toxic gas component, and if not, outputting the toxic gas protection turn-off time.

2. The method of determining the shutdown time of a toxic gas protection device of claim 1, wherein the injury rate is calculated as:

Wherein D _n is the injury rate of each toxic component of the gas; a and B are poisoning empirical coefficients; t is the exposure time of toxic gas; q is the concentration of toxic gas; c is the characteristic coefficient of the toxic component, and x is the independent variable of the injury rate function solution.

3. The method for determining the turn-off time of a toxic gas protection device according to claim 1, wherein the method for simulating the concentration change of the toxic gas in the field comprises the steps of:

The established toxic gas leakage model is enabled to stably run for a plurality of times when no gas leaks;

Then, setting gas leakage at a certain position in the toxic gas leakage model, and setting gas leakage flow;

and monitoring the concentration change condition of toxic gas components at various positions in the toxic gas leakage model field in the whole leakage process.

4. The method for determining the shutdown time of a toxic gas protection device according to claim 3, wherein each toxic gas component in the toxic gas leakage model site is plotted with time according to the concentration change condition of the toxic gas component, and a toxic gas component record chart is generated.

5. The method of determining the shutdown time of a toxic gas protection device of any of claims 1-4, wherein the diffusion dynamic simulation is implemented by fluid simulation software Fluent, flics, or KFX.

6. The method for determining the shutdown time of a toxic gas protection device according to any one of claims 1 to 4, wherein the method for obtaining the dangerous area of each toxic gas according to the injury rate is as follows:

Setting the upper limit of the injury rate of each position in the toxic gas leakage model field;

calculating the injury rate of each toxic gas component at each position of the field;

Marking the position where the damage rate reaches the upper limit of the damage rate;

And connecting all positions of which the injury rate reaches the upper limit of the injury rate to form a closed area, wherein the closed area is a dangerous area of each toxic gas.

7. The method of determining the shutdown time of a toxic gas protection device of any of claims 1-4, wherein the location of the reference point is determined based on the range of human activity and frequency within the venue.

8. The method of determining the shutdown time of a toxic gas protection device of any of claims 1-4, wherein the toxic gas comprises: carbon monoxide and hydrogen sulfide.

9. A system for determining a shutdown time of a toxic gas protection device, comprising:

the dynamic simulation module is used for carrying out diffusion dynamic simulation aiming at the toxic gas leakage working condition and simulating the concentration change condition of toxic gas in the field;

the injury rate calculation module is used for calculating the injury rate of each toxic component in the field according to the concentration change condition of the toxic gas;

The dangerous area obtaining module is used for obtaining dangerous areas of each toxic gas according to the injury rate;

The turn-off time determining module is used for judging whether a reference point exists in the dangerous area of the toxic gas, if so, the turn-off time is shortened, the steps are repeated until the reference point does not exist in the dangerous area of the toxic gas, and if not, the toxic gas protection turn-off time is output.

10. A computer readable storage medium having stored thereon a computer program for execution by a processor to implement the method of determining a toxic gas protection device off-time of any one of claims 1-8.