CN110389608B - Inert gas flow control method and system - Google Patents
Inert gas flow control method and system Download PDFInfo
- Publication number
- CN110389608B CN110389608B CN201810352152.6A CN201810352152A CN110389608B CN 110389608 B CN110389608 B CN 110389608B CN 201810352152 A CN201810352152 A CN 201810352152A CN 110389608 B CN110389608 B CN 110389608B
- Authority
- CN
- China
- Prior art keywords
- relative humidity
- gas
- humid air
- acetylene
- calcium carbide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D27/00—Simultaneous control of variables covered by two or more of main groups G05D1/00 - G05D25/00
- G05D27/02—Simultaneous control of variables covered by two or more of main groups G05D1/00 - G05D25/00 characterised by the use of electric means
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Treating Waste Gases (AREA)
Abstract
The invention discloses an inert gas flow control method, wherein the inert gas is used for diluting the concentration of acetylene gas released by calcium carbide when meeting moisture, and the method comprises the following steps: introducing humid air with a certain volume and a relative humidity reaching a preset value into a gas-phase space of the calcium carbide dust, recording reaction data in the process, and determining the relationship between the acetylene gas release rate and the relative humidity change of the humid air according to a recording result; based on the relationship between the acetylene gas release rate and the relative humidity change of the humid air, the protective inert gas inlet flow rate for diluting the acetylene gas concentration in the contact area of the calcium carbide dust and the humid air is calculated, so that the control of fire hazard potential safety hazard caused by the fact that the acetylene is released when the calcium carbide dust is wet is completed. The invention provides a theoretical basis for fire explosion safety control of calcium carbide in a wet inflammable dangerous area and a device, and has considerable application and popularization values in calcium carbide production enterprises along with gradual improvement of production safety technologies of calcium carbide related enterprises in China.
Description
Technical Field
The invention relates to the field of chemical engineering, in particular to a method and a system for controlling the flow of inert gas for diluting acetylene released by calcium carbide when the calcium carbide is wet.
Background
The calcium carbide is prepared by electrolyzing and smelting coke and lime at high temperature, is widely applied to the production of organic chemical products such as synthetic benzene, rubber, polyvinyl chloride, polyacetylene and the like, belongs to class 4.3 inflammable materials which can react rapidly when meeting moisture to generate acetylene. The explosion limit of acetylene in air is 2.3-81%, the ignition energy is only 0.019mJ, and the acetylene is very easy to ignite. Therefore, the calcium carbide has potential safety hazards of fire explosion after being wetted, and even causes serious fire explosion accidents.
According to three factors causing fire, the basic factors for analyzing the fire explosion caused by the fact that the calcium carbide releases acetylene gas when meeting humid air are mainly calcium carbide, combustion-supporting gas, water/humid air, an ignition source, a closed space and the like by combining the moisture danger of the calcium carbide, the prevention measures are considered by eliminating the above components, and the most economical and effective method for comprehensively analyzing and reducing the concentration of the acetylene gas is to dilute the inert gas by using protective inert gas to areas or equipment which are likely to generate acetylene by combining the actual situation of a calcium carbide production device. The most commonly used inert gas is nitrogen, and particularly, the concentration of acetylene in a gas phase space is diluted to be below the lower explosion limit by using the nitrogen, which has very important significance for guaranteeing the production safety of calcium carbide enterprises.
Calcium carbide blocks generated in a calcium carbide furnace need to be crushed in the calcium carbide production process, dust removal systems are installed in calcium carbide crushing processes in most domestic enterprises, the calcium carbide dust removal systems serve as dust hazards in the calcium carbide discharging process, and the key role is played in guaranteeing the occupational health of dust removal workers. However, the dust contains unreacted calcium carbide, and carbon monoxide and hydrogen in the calcium carbide furnace may be partially brought out along with the calcium carbide discharging process, so that the calcium carbide dust removal system has certain burning explosion danger.
At present, certain work is also done to the safety of the calcium carbide production process in China, and related standards are formed, but the common standards only provide some standard requirements for calcium carbide production, indicate the danger in the calcium carbide production process, do not have related safety prevention and control measure requirements for the dangerous characteristics of calcium carbide production, and cannot adapt to the requirements of the current production process of the calcium carbide industry on a new and advanced basis. Therefore, calcium carbide dust explosion hazard characteristics and countermeasure research are developed, safety prevention and control measure suggestions are provided, and the method has very important significance for guaranteeing calcium carbide production safety and monitoring the physical and mental activities of enterprise staff.
Disclosure of Invention
In order to solve the technical problem, an embodiment of the present invention provides an inert gas flow control method, where an inert gas is used to dilute the concentration of acetylene gas released by calcium carbide when the calcium carbide is wet, and the flow control method includes the following steps: the method comprises the steps of obtaining the acetylene release amount, namely introducing a certain volume of humid air with relative humidity reaching a preset value into a gas-phase space of calcium carbide dust, recording reaction data in the process, and determining the relationship between the acetylene gas release rate and the relative humidity change of the humid air according to the recording result; and a protective gas flow control step, namely calculating the protective inert gas inlet flow for diluting the concentration of the acetylene gas in the contact area of the calcium carbide dust and the humid air based on the relationship between the acetylene gas release rate and the relative humidity change of the humid air, so as to control the potential safety hazard of fire hazard caused by the fact that the acetylene is released when the calcium carbide dust is wet.
Preferably, in the protective gas flow rate control step, the method further comprises: a related parameter obtaining step, namely determining the space volume of a contact area of calcium carbide dust and humid air and the current relative humidity value of the humid air in a gas phase space; and calculating the gas inflow, namely obtaining a calculation formula of the inert gas inflow by utilizing the relationship between the acetylene gas release rate and the relative humidity of the humid air, the space volume of the contact area of the calcium carbide dust and the humid air and a preset inert gas protection flow coefficient, and calculating the inert gas protection demand under the current relative humidity of the humid air based on the calculation formula.
Preferably, in the shielding gas flow rate controlling step, a calculation formula of the inert gas intake flow rate is expressed by an expression:
wherein Q represents the inert gas intake flow rate, ε represents the inert gas shielding flow coefficient,
r represents the release rate of acetylene gas,
and (3) representing the relative humidity value of the current humid air in the gas phase space, a and b representing the fitting coefficients of the curve of the acetylene gas release rate along with the change of the relative humidity of the humid air, and V representing the space volume of the contact area of the calcium carbide dust and the humid air.
Preferably, the acetylene release amount obtaining step further includes a relative humidity change characterizing step of plotting a relative humidity decrease amount in the gas phase space with respect to time, and characterizing an increase amount of the acetylene gas per unit time using the plot; and characterizing the acetylene gas release rate, namely acquiring the slope of each data point in a time variation curve of the relative humidity reduction amount of the gas phase space, further drawing a variation curve of the acetylene gas release rate along with the relative humidity of the humid air, and fitting the curve to obtain a variation relation of the acetylene gas release rate along with the relative humidity of the humid air.
Preferably, in the step of characterizing the variation in relative humidity, further comprising: the method comprises the following steps of utilizing the relation that the relative humidity reduction amount of calcium carbide dust contacting humid air is in direct proportion to the increase amount of acetylene gas, carrying out linear fitting on a time-dependent change curve of the relative humidity reduction amount in a gas-phase space to obtain the relative humidity reduction amount of the humid air, namely the time-dependent change relation of the increase amount of the acetylene gas, and expressing the relation by the following expression:
V'＝a0ln(t)-b0
wherein V' represents the increase of acetylene gas in humid air, t represents time, a0、b0A fitting coefficient representing a curve of the decrease in relative humidity with time.
In another aspect, there is provided an inert gas flow control system for diluting the concentration of acetylene gas released by calcium carbide when it is wet, the flow control system comprising: the acetylene release amount acquisition module is used for introducing a certain volume of humid air with relative humidity reaching a preset value into a gas phase space of the calcium carbide dust, recording reaction data in the process, and determining the relationship between the acetylene gas release rate and the relative humidity change of the humid air according to a recording result; and the protective gas flow control module is used for calculating the protective inert gas inlet flow for diluting the concentration of the acetylene gas in the contact area of the calcium carbide dust and the humid air based on the relationship between the acetylene gas release rate and the relative humidity change of the humid air, so that the control of fire hazard potential caused by the fact that the acetylene is released when the calcium carbide dust is wet is completed.
Preferably, the shielding gas flow rate control module further comprises: the relevant parameter acquisition unit is used for determining the space volume of a contact area of the calcium carbide dust and the humid air and the current relative humidity value of the humid air in the gas phase space; and the intake flow calculation unit is used for obtaining a calculation formula of the intake flow of the inert gas by utilizing the relationship between the acetylene gas release rate and the relative humidity of the humid air, the space volume of the contact area of the calcium carbide dust and the humid air and a preset inert gas protection flow coefficient, and calculating the required quantity of the inert gas under the current relative humidity of the humid air based on the calculation formula.
Preferably, in the shielding gas flow rate control module, a calculation formula of the inert gas intake flow rate is expressed by an expression:
wherein Q represents the sameAn inert gas inlet flow rate, epsilon represents the inert gas protection flow coefficient,
r represents the release rate of acetylene gas,
and (3) representing the relative humidity value of the current humid air in the gas phase space, a and b representing the fitting coefficients of the curve of the acetylene gas release rate along with the change of the relative humidity of the humid air, and V representing the space volume of the contact area of the calcium carbide dust and the humid air.
Preferably, the acetylene release amount obtaining module further includes: a relative humidity change characterization unit which draws a curve of the relative humidity reduction amount in the gas phase space with the change of time, and utilizes the curve to characterize the increase amount of the acetylene gas in unit time; and the acetylene gas release rate characterization unit is used for acquiring the slope of each data point in the time variation curve of the relative humidity reduction amount of the gas phase space, further drawing a variation curve of the acetylene gas release rate along with the relative humidity of the humid air, and fitting the curve to obtain the variation relation of the acetylene gas release rate along with the relative humidity of the humid air.
Preferably, in the relative humidity change characterization unit, a linear fitting is performed on a curve of the change of the relative humidity reduction amount in the gas phase space with time by further using a relationship that the relative humidity reduction amount of the calcium carbide dust contacting the humid air is proportional to the increase amount of the acetylene gas, so as to obtain the change relationship of the relative humidity reduction amount of the humid air, that is, the increase amount of the acetylene gas with time, and the change relationship is represented by the following expression:
V'＝a0ln(t)-b0
wherein V' represents the increase of acetylene gas in humid air, t represents time, a0、b0A fitting coefficient representing a curve of the decrease in relative humidity with time.
Compared with the prior art, one or more embodiments in the above scheme can have the following advantages or beneficial effects:
the invention provides a flow control method of protective inert gas for diluting calcium carbide to release acetylene when the calcium carbide is wet, provides a theoretical basis for fire and explosion safety prevention and control of a device and a flammable dangerous area when the calcium carbide is wet, and has certain requirements on enterprises engaged in calcium carbide production. With the gradual improvement of the production safety technology of calcium carbide related enterprises in China, the method has considerable application and popularization values in the calcium carbide production enterprises.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:
fig. 1 is a step diagram of an inert gas flow control method for diluting calcium carbide to release acetylene when wet according to an embodiment of the present application.
Fig. 2 is a specific flowchart of an inert gas flow control method for diluting calcium carbide to release acetylene when wet according to an embodiment of the present application.
Fig. 3 is a graph showing the variation of relative humidity with time of the inert gas flow control method for diluted calcium carbide releasing acetylene when wet according to the embodiment of the present application.
Fig. 4 is a graph showing the decrease of the relative humidity with time in the inert gas flow control method for diluting calcium carbide to release acetylene when wet according to the embodiment of the present application.
Fig. 5 is a graph showing the acetylene gas increase rate with the relative humidity change in the inert gas flow control method for diluting calcium carbide to release acetylene when wet according to the embodiment of the present application.
Fig. 6 is a block diagram of an inert gas flow control system for diluting calcium carbide to release acetylene when wet according to an embodiment of the present application.
Detailed Description
The following detailed description of the embodiments of the present invention will be provided with reference to the drawings and examples, so that how to apply the technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented. It should be noted that, as long as there is no conflict, the embodiments and the features of the embodiments of the present invention may be combined with each other, and the technical solutions formed are within the scope of the present invention.
The embodiment of the application relates to a flow control method of protective inert gas for diluting acetylene released by calcium carbide when meeting moisture. The method is characterized in that the release amount of acetylene gas generated by the calcium carbide when meeting humid air is represented by the variation of the relative humidity of the humid air, after the concentration of the acetylene gas in a gas phase space is determined, the concentration value of the acetylene gas is diluted to be outside an explosion range (namely below the lower limit of the explosion concentration), and meanwhile, the air inlet flow of protective inert gas to be introduced is calculated, so that a theoretical basis is provided for fire explosion safety control of a humid flammable dangerous area and a device of the calcium carbide. It should be noted that the type of inert gas introduced for dilution is not particularly limited, and may be nitrogen, helium, neon, or the like.
Fig. 1 is a step diagram of an inert gas flow control method for diluting calcium carbide to release acetylene when wet according to an embodiment of the present application. Fig. 2 is a specific flowchart of an inert gas flow control method for diluting calcium carbide to release acetylene when wet according to an embodiment of the present application. Referring to fig. 1 and 2, in step S110 (acetylene release amount obtaining step), moist air with a certain volume of relative humidity reaching a predetermined value is introduced into a gas-phase space of calcium carbide dust, after the moist air reacts with the calcium carbide dust to generate acetylene gas, reaction data of the process is recorded, specifically, data of the change of the relative humidity with time is recorded, a curve of the change of the decrease amount of the relative humidity in the gas-phase space with time is drawn, and a relation of the acetylene gas release rate (i.e., the acetylene gas release amount in unit time) with the change of the relative humidity of the moist air is determined according to a recording (testing) result.
Specifically, firstly, in a closed test environment, introducing a certain volume of humid air with relative humidity reaching 100% RH into a gas phase space containing calcium carbide dust, and recording the data of the change of the relative humidity of the humid air along with time to obtain a relative humidity change curve along with time. Fig. 3 is a graph showing the variation of relative humidity with time of the inert gas flow control method for diluted calcium carbide releasing acetylene when wet according to the embodiment of the present application. As shown in fig. 3, the relative humidity gradually decreases due to the reaction between the calcium carbide dust and the water vapor in the humid air, so that the water content in the air decreases, and the amount of acetylene gas generated correspondingly increases.
It should be noted that, in order to ensure the safety of the test, the test environment should have sealing, antistatic and explosion-proof functions, and the experimental device should be placed in a ventilation facility with micro negative pressure during the test process. In addition, when the experiment is initial, moist air with relative humidity reaching a preset value needs to be introduced into the gas-phase space of the calcium carbide dust. In this example, the relative humidity of the humid air is preset to 100% RH, which is not specifically limited in this application, and the skilled person can set this parameter according to actual needs.
Then, (relative humidity change characterization step) on the basis of fig. 3, the relationship that the relative humidity reduction amount of the calcium carbide dust contacting the humid air is proportional to the increase amount of the acetylene gas is utilized, and the increase amount of the acetylene gas in the air in unit time can be characterized by using a time-varying relationship curve of the reduction amount of the relative humidity of the humid air, so as to obtain a time-varying curve of the relative humidity reduction amount of the calcium carbide dust contacting the humid air in the gas-phase space.
Fig. 4 is a graph showing the decrease of the relative humidity with time in the inert gas flow control method for diluting calcium carbide to release acetylene when wet according to the embodiment of the present application. Referring to fig. 4, the curve was fitted linearly to obtain a plot of the amount of decrease in relative humidity of humid air (i.e., the amount of increase in acetylene gas) as a function of time. The amount of increase of acetylene gas in the gas phase space is expressed by the following expression:
V'＝a0ln(t)-b0 (1)
wherein V' represents the increase of acetylene gas in humid air, t represents time, a0、b0Fitting coefficients representing a curve of the decrease in relative humidity with time.
Next, the procedure proceeds to an acetylene gas release rate characterization step. In the step, after a curve of the relative humidity reduction amount in the gas phase space changing with time is drawn, the slope of each data point on the curve is obtained, the slope value represents the release rate of acetylene gas in the air, and then the curve of the release rate of acetylene gas changing with the relative humidity of the humid air environment is further drawn by combining the formula (1).
Fig. 5 is a graph showing the acetylene gas increase rate with the relative humidity change in the inert gas flow control method for diluting calcium carbide to release acetylene when wet according to the embodiment of the present application. As shown in fig. 5, the curve (the solid line is the curve before fitting) is continuously fitted to obtain a relationship between the release rate of acetylene gas in air and the relative humidity of humid air, and a fitted curve (as shown by the dashed line in fig. 5), and the curve is expressed by the following formula:
wherein r represents the acetylene gas release rate, m3/s·m3；
Representing the current relative humidity value of the humid air in the gas phase space; a. b represents the fitting coefficient of the curve of the acetylene gas release rate with the relative humidity of the humid air.
In summary, as can be seen from fig. 4 and the equation (2) obtained by fitting, the release rate of the acetylene gas generated in the contact reaction process of the calcium carbide dust with the humid air is in a linear relationship with the relative humidity change of the humid air, and the release amount of the acetylene gas in unit time can be directly calculated according to the equation (2) and the current relative humidity value of the humid air, so as to enter step S120.
Referring to fig. 1 again, in step S120 (protective gas flow control step), based on the relationship between the acetylene gas release rate and the relative humidity of the humid air, the protective inert gas inlet flow rate for diluting the acetylene gas concentration in the contact region between the calcium carbide dust and the humid air is calculated, so as to complete the control of the potential fire hazard of the acetylene released by the calcium carbide dust when wet.
Specifically, (the related parameter obtaining step) is to determine the space volume of a certain area or equipment (namely, the contact area of the calcium carbide dust and humid air) with the burning explosion risk of releasing the B gas when the calcium carbide dust is wet, and obtain the relative humidity value of the humid air in the gas phase space of the current calcium carbide dust. Then, in the step of calculating the gas inflow, a calculation formula of the inert gas inflow is obtained by utilizing the relationship (including a relational expression and/or a relational curve) between the acetylene gas release rate and the relative humidity of the humid air, the space volume of the contact area of the calcium carbide dust and the humid air and a preset inert gas protection flow coefficient, and the required quantity of the inert gas under the current relative humidity of the humid air can be calculated on the basis. The flow rate of the inert gas which needs to be introduced at present is expressed by the following formula:
wherein Q represents the inlet gas flow of inert gas, epsilon represents the protective flow coefficient of inert gas, and V represents the space volume of the contact area of calcium carbide dust and humid air. The inert gas shielding flow rate coefficient is a multiple of the inert gas introduction flow rate with respect to the acetylene gas produced. In the practical application process, in order to ensure the safety of the production environment, the gas inlet flow of the inert gas is larger than the product of the multiple and the release amount of acetylene gas in a unit gas phase space.
The following describes the process of determining the inert gas shielding flow coefficient.
And carrying out a critical environment humidity experiment that acetylene gas is subjected to burning explosion in humid air under the conditions of different environment humidity within the temperature range of 10-40 ℃. After the calcium carbide reacts with water vapor in the air of the closed space to generate acetylene gas, the concentration of the acetylene gas in the closed air is calculated (the calcium carbide is excessive), and the concentration of the acetylene gas generated under different environmental humidity conditions is obtained (shown in table 1).
Table concentration of acetylene gas generated under different ambient humidity conditions within the range of 110-40 deg.C
As shown in table 1, the dark gray area is the area where the acetylene gas concentration exceeds the lower explosion limit of acetylene in air, i.e., the most dangerous area; the light gray area is 1/2 range of acetylene with lower explosion limit concentration in air, which is a dangerous area where acetylene can be burned, and the ratio of the light gray area to acetylene gas concentration in a safe area closest to the light gray area is the "inert gas protection flow coefficient", for example, at 25 ℃, epsilon is 1.28/1.12 and 1.15, and at 40 ℃, epsilon is 1.16/0.77 and 1.5, therefore, the inert gas protection flow coefficient is 1.15-1.5 in the range of 25-40 ℃, and in the case of considering the economic cost of an enterprise, the most preferable value of the inert gas protection flow coefficient is 1.15 in the present example.
In addition, the application also provides an inert gas flow control system for diluting the acetylene released by the calcium carbide when the calcium carbide is wet.
Fig. 6 is a block diagram of an inert gas flow control system for diluting calcium carbide to release acetylene when wet according to an embodiment of the present application. As shown in fig. 6, the system includes the following modules: acetylene emission amount acquisition module 61 and shielding gas flow control module 62. The acetylene release amount acquisition module 61 is used for introducing a certain volume of humid air with relative humidity reaching a preset value into a gas phase space of calcium carbide dust, recording reaction data of the process, specifically, recording data of the change of the relative humidity along with time, and determining the relationship between the acetylene gas release rate and the relative humidity change of the humid air (namely the acetylene gas release amount in unit time under the current relative humidity) according to a recording (testing) result; and the protective gas flow control module 62 calculates the protective inert gas inlet flow rate for diluting the concentration of the acetylene gas in the contact area between the calcium carbide dust and the humid air based on the relationship between the acetylene gas release rate and the relative humidity change of the humid air, so as to control the potential safety hazard of fire hazard caused by the release of the acetylene gas when the calcium carbide dust is wet.
The composition and function of each module will be specifically described below.
The acetylene release amount obtaining module 61 further includes: a relative humidity change characterization unit 611 and an acetylene gas release rate characterization unit 612. Specifically, after the calcium carbide dust gas reacts with the humid air to generate the acetylene gas, the relative humidity change characterization unit 611 completes a relative humidity change curve with time (refer to fig. 3), and since the amount of the acetylene gas generated gradually increases with the gradual decrease of the relative humidity, the decrease of the relative humidity of the humid air can be used to characterize the increase of the acetylene gas in the air, and a relative humidity decrease curve with time when the calcium carbide dust contacts with the humid air is drawn (refer to fig. 4); further, the relationship that the relative humidity reduction amount of the calcium carbide dust contacting the humid air is in direct proportion to the increase amount of the acetylene gas is utilized, the linear fitting is carried out on the relative humidity reduction amount in the gas phase space along with the time change curve, and then the storage and the formula (1) in the unit 611 are utilized to obtain the relative humidity reduction amount of the humid air, so that the increase amount of the acetylene gas in unit time (namely the relationship between the increase amount of the acetylene gas and the time change) is represented. Then, the acetylene gas release rate characterization unit 612 obtains each data point in the curve of the decrease amount of relative humidity in the gas phase space with time from the relative humidity change characterization unit 611, calculates the slope of each data point by combining the formula (1) stored in the unit 611, further plots the curve of the acetylene gas release rate with the change of relative humidity in humid air (refer to fig. 5), and fits the curve to obtain the fit result shown in formula (2), i.e., the relationship of the acetylene gas release rate with the change of relative humidity in humid air, and further calculates the current acetylene gas release amount per unit time.
In addition, the protection gas flow rate control module 62 includes a related parameter acquiring unit 621 and an intake air flow rate calculating unit 622. Specifically, first, the relevant parameter obtaining unit 621 stores a preset space volume parameter of the contact area between the calcium carbide dust and the humid air, and obtains the current relative humidity value of the humid air through real-time data measured by a humidity measuring device arranged in the gas phase space. Next, the intake air flow calculating unit 622 stores a relational expression (formula 3) of the acetylene gas release rate with the change of the relative humidity of the humid air, which is obtained based on the formula (2) in the acetylene gas release rate characterizing unit 612, and calculates the required amount of the inert gas to be protected under the current relative humidity of the humid air by using the formula (3) according to the current relative humidity value of the humid air and the space volume parameter obtained from the relevant parameter obtaining unit 621.
(one example)
The method is applied to Ningxia energy acetylene devices, and aiming at the potential safety hazard that calcium carbide in a calcium carbide furnace region is subjected to wet combustion and explosion, nitrogen protection is arranged in a conveying region of a dust removal belt conveyor, a dust removal ash bucket elevator and an ash storage bin.
The invention provides a method for controlling the flow of protective nitrogen for diluting calcium carbide to release acetylene when wet, which characterizes the release amount of acetylene gas generated by calcium carbide when wet air is encountered through the variation of the relative humidity of the wet air, adopts inert gas to dilute the concentration of the acetylene in a gas phase space to be below the lower explosion limit, provides a theoretical basis for fire explosion safety control of calcium carbide in a wet flammable danger area and a device, has certain requirements on enterprises engaged in calcium carbide production, and has considerable application and popularization values in the enterprises of calcium carbide production along with the gradual improvement of production safety technologies of calcium carbide related enterprises in China.
Although the embodiments of the present invention have been described above, the above descriptions are only for the convenience of understanding the present invention, and are not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
1. A flow control method of inert gas is used for diluting the concentration of acetylene gas released by calcium carbide when the calcium carbide is wet, and is characterized by comprising the following steps:
the method comprises the steps of obtaining the acetylene release amount, namely introducing a certain volume of humid air with relative humidity reaching a preset value into a gas-phase space of calcium carbide dust, recording reaction data in the process, and determining the relationship between the acetylene gas release rate and the relative humidity change of the humid air according to the recording result;
a protective gas flow control step, based on the relationship between the acetylene gas release rate and the relative humidity change of the humid air, calculating the protective inert gas inlet flow for diluting the acetylene gas concentration in the contact area of the calcium carbide dust and the humid air, thereby completing the control of fire hazard potential safety hazard caused by the fact that the acetylene is released when the calcium carbide dust is wet, wherein the protective gas flow control step comprises the following steps:
a related parameter obtaining step, namely determining the space volume of a contact area of calcium carbide dust and humid air and the current relative humidity value of the humid air in a gas phase space;
calculating the inlet gas flow, namely obtaining a calculation formula of the inlet gas flow of the inert gas by utilizing the change relation between the acetylene gas release rate and the relative humidity of the humid air, the space volume of a contact area of the calcium carbide dust and the humid air and a preset inert gas protection flow coefficient, and calculating the required quantity of the protective inert gas under the current relative humidity of the humid air based on the calculation formula, wherein the calculation formula of the inlet gas flow of the inert gas is represented by the following expression:
wherein Q represents the inert gas intake flow rate, ε represents the inert gas shielding flow coefficient,
r represents the release rate of acetylene gas,
and (3) representing the relative humidity value of the current humid air in the gas phase space, a and b representing the fitting coefficients of the curve of the acetylene gas release rate along with the change of the relative humidity of the humid air, and V representing the space volume of the contact area of the calcium carbide dust and the humid air.
2. The flow control method according to claim 1, characterized in that, in the acetylene emission amount obtaining step, further comprising,
a relative humidity change characterization step, which is to draw a curve of the relative humidity reduction amount in the gas phase space changing with time and to characterize the increase amount of the acetylene gas in unit time by using the curve;
and characterizing the acetylene gas release rate, namely acquiring the slope of each data point in a time variation curve of the relative humidity reduction amount of the gas phase space, further drawing a variation curve of the acetylene gas release rate along with the relative humidity of the humid air, and fitting the curve to obtain a variation relation of the acetylene gas release rate along with the relative humidity of the humid air.
3. The flow control method according to claim 2, wherein in the relative humidity change characterizing step, further comprising: the method comprises the following steps of utilizing the relation that the relative humidity reduction amount of calcium carbide dust contacting humid air is in direct proportion to the increase amount of acetylene gas, carrying out linear fitting on a time-dependent change curve of the relative humidity reduction amount in a gas-phase space to obtain the relative humidity reduction amount of the humid air, namely the time-dependent change relation of the increase amount of the acetylene gas, and expressing the relation by the following expression:
V'＝a0ln(t)-b0
wherein V' represents the increase of acetylene gas in humid air, t represents time, a0、b0Fitting of a curve representing the decrease in relative humidity as a function of timeAnd (4) combining the coefficients.
4. An inert gas flow control system, wherein the inert gas is used for diluting the concentration of acetylene gas released by calcium carbide when the calcium carbide is wet, the system is characterized in that the flow control system comprises:
the acetylene release amount acquisition module is used for introducing a certain volume of humid air with relative humidity reaching a preset value into a gas phase space of the calcium carbide dust, recording reaction data in the process, and determining the relationship between the acetylene gas release rate and the relative humidity change of the humid air according to a recording result;
the protective gas flow control module is used for calculating the protective inert gas inlet flow for diluting the concentration of the acetylene gas in the contact area of the calcium carbide dust and the humid air based on the relationship between the acetylene gas release rate and the relative humidity change of the humid air, so that the control of fire safety hidden danger caused by the fact that the acetylene gas is released when the calcium carbide dust is wet is completed, and the protective gas flow control module further comprises:
the relevant parameter acquisition unit is used for determining the space volume of a contact area of the calcium carbide dust and the humid air and the current relative humidity value of the humid air in the gas phase space;
the inlet gas flow calculating unit obtains a calculation formula of inlet gas flow of inert gas by using the relationship between the acetylene gas release rate and the relative humidity of humid air, the space volume of a contact area of the calcium carbide dust and the humid air and a preset inert gas protection flow coefficient, and calculates the required quantity of the inert gas under the current relative humidity of the humid air based on the calculation formula, wherein the calculation formula of the inlet gas flow of the inert gas is expressed by using the following expression in the protection gas flow control module:
wherein Q represents the inert gas intake flow rate, ε represents the inert gas shielding flow coefficient,
r represents the release rate of acetylene gas,
and (3) representing the relative humidity value of the current humid air in the gas phase space, a and b representing the fitting coefficients of the curve of the acetylene gas release rate along with the change of the relative humidity of the humid air, and V representing the space volume of the contact area of the calcium carbide dust and the humid air.
5. The flow control system according to claim 4, wherein the acetylene release amount obtaining module further comprises:
a relative humidity change characterization unit which draws a curve of the relative humidity reduction amount in the gas phase space with the change of time, and utilizes the curve to characterize the increase amount of the acetylene gas in unit time;
and the acetylene gas release rate characterization unit is used for acquiring the slope of each data point in the time variation curve of the relative humidity reduction amount of the gas phase space, further drawing a variation curve of the acetylene gas release rate along with the relative humidity of the humid air, and fitting the curve to obtain the variation relation of the acetylene gas release rate along with the relative humidity of the humid air.
6. The flow control system according to claim 5, wherein in the relative humidity change characterization unit, a relationship that the relative humidity reduction amount of the calcium carbide dust contacting the humid air is proportional to the increase amount of the acetylene gas is further utilized, a linear fitting is performed on a curve of the relative humidity reduction amount in the gas phase space along with the change of time, so as to obtain the relative humidity reduction amount of the humid air, namely the change relationship of the increase amount of the acetylene gas along with time, and the relationship is represented by the following expression:
V'＝a0ln(t)-b0
wherein V' represents the increase of acetylene gas in humid air, t represents time, a0、b0A fitting coefficient representing a curve of the decrease in relative humidity with time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810352152.6A CN110389608B (en) | 2018-04-19 | 2018-04-19 | Inert gas flow control method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810352152.6A CN110389608B (en) | 2018-04-19 | 2018-04-19 | Inert gas flow control method and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110389608A CN110389608A (en) | 2019-10-29 |
| CN110389608B true CN110389608B (en) | 2021-03-12 |
Family
ID=68283318
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810352152.6A Active CN110389608B (en) | 2018-04-19 | 2018-04-19 | Inert gas flow control method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110389608B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203255735U (en) * | 2013-05-20 | 2013-10-30 | 中国成达工程有限公司 | Closed recycle pneumatic transmission system of calcium carbide |
| CN104891062A (en) * | 2015-05-29 | 2015-09-09 | 中国石油化工股份有限公司 | Processing device and method for preventing combustible liquid and gas storage tank from mutual combustion and explosion |
| CN205948873U (en) * | 2016-07-05 | 2017-02-15 | 中国天辰工程有限公司 | Carbide feed bin nitrogen protection device |
| CN106959715A (en) * | 2017-04-14 | 2017-07-18 | 中国石油化工股份有限公司 | The control method for preventing calcium carbide dust bulk cement storage tank from exploding |
| CN106970670A (en) * | 2017-04-14 | 2017-07-21 | 中国石油化工股份有限公司 | A kind of device and method for preventing calcium carbide dust warehouse from exploding |
-
2018
- 2018-04-19 CN CN201810352152.6A patent/CN110389608B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203255735U (en) * | 2013-05-20 | 2013-10-30 | 中国成达工程有限公司 | Closed recycle pneumatic transmission system of calcium carbide |
| CN104891062A (en) * | 2015-05-29 | 2015-09-09 | 中国石油化工股份有限公司 | Processing device and method for preventing combustible liquid and gas storage tank from mutual combustion and explosion |
| CN205948873U (en) * | 2016-07-05 | 2017-02-15 | 中国天辰工程有限公司 | Carbide feed bin nitrogen protection device |
| CN106959715A (en) * | 2017-04-14 | 2017-07-18 | 中国石油化工股份有限公司 | The control method for preventing calcium carbide dust bulk cement storage tank from exploding |
| CN106970670A (en) * | 2017-04-14 | 2017-07-21 | 中国石油化工股份有限公司 | A kind of device and method for preventing calcium carbide dust warehouse from exploding |
Non-Patent Citations (1)
| Title |
|---|
| 出口电石包装桶内乙炔气产生与控制的探讨;曹家珍等;《化工标准化与质量监督》;19901127(第11期);第26-29页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110389608A (en) | 2019-10-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | Assessment of spontaneous combustion status of coal based on relationships between oxygen consumption and gaseous product emissions | |
| Zhang et al. | The graded warning method of coal spontaneous combustion in Tangjiahui Mine | |
| Guo et al. | A method for evaluating the spontaneous combustion of coal by monitoring various gases | |
| CN103952503B (en) | A kind of establishment method of pulverized coal injection into blast furna cost performance evaluation model | |
| Dupont et al. | Explosion characteristics of synthesised biogas at various temperatures | |
| Liu et al. | Influence of methane on the prediction index gases of coal spontaneous combustion: A case study in Xishan coalfield, China | |
| Lei et al. | Comparative study of single inert gas in confined space inhibiting open flame coal combustion | |
| Hosseinzadeh et al. | Minimum ignition energy of mixtures of combustible dusts | |
| Jiang et al. | Investigation on oxidative pyrolysis characteristics of bituminous coal through thermal analysis and density functional theory | |
| CN110389608B (en) | Inert gas flow control method and system | |
| Wang et al. | Laboratory study on low-temperature coal spontaneous combustion in the air of reduced oxygen and low methane concentration | |
| Lu et al. | Investigation on the suppression characteristic of deoxidization gel foam on coal spontaneous combustion | |
| Colwell et al. | A review of oxidation on steel surfaces in the context of fire investigations | |
| US9018287B2 (en) | Method and composition for preventing oxidation | |
| CN108918355B (en) | Method for evaluating explosion sensitivity parameters of low-density polyethylene powder | |
| CN103940849B (en) | The evaluation method that a kind of ambient humidity affects hydro carbons and containing oxygen derivative explosion limits thereof | |
| Santandrea et al. | Some key considerations when evaluating explosion severity of nanopowders | |
| Sommerseth et al. | Correlation between moisture and HF formation in the aluminium process | |
| KR101455031B1 (en) | Fire Monitoring System using ＣＯ Data | |
| Rath | Application of inhibitors to prevent spontaneous heating of coal | |
| Li et al. | Method for Determining Spontaneous Combustion Risk in Roof Cutting Gob‐Side Entry Retaining U+ L Ventilation Goaf for Mining Safety | |
| Gao et al. | Improved calculation model for the shortest spontaneous combustion period | |
| CN110389195B (en) | Method and system for evaluating critical relative humidity of calcium carbide burning explosion in humid air | |
| Perera et al. | Evaluation of smoke and gas sensor responses for fires of common mine combustibles | |
| Surakka et al. | PVC-smoke and hygroscopic CsI aerosol at 50 to 99% humidity |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |