Method for optimizing air-fuel ratio of lepidolite horizontal tunnel kiln

Abstract

The invention discloses a method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln. The method comprises the following steps that A, gas fuel air inflow and air inflow data of all sections of combustors on site are recorded; b, collecting multiple bags of gas fuel samples, and detecting and analyzing the data of the multiple bags of samples through equipment; c, the theoretical air demand quantity of the gas fuel is calculated according to the detected and analyzed numerical value, and then the gas inlet quantity of the gas fuel and the air inlet quantity of the air are adjusted according to the analyzed numerical value and the air demand quantity; by means of the method, sufficient combustion can be achieved, the content of industrial waste gas pollutants generated in the fuel combustion process is reduced, green, environment-friendly and healthy development is better facilitated, the intelligent air-fuel ratio adjusting valve is adopted, the air-fuel ratio is intelligently controlled, and the production efficiency is improved.

Description

Technical Field

[0001] The invention specifically relates to a method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln. Background Art

[0002] The lithium mica horizontal tunnel kiln is a high-temperature kiln equipment specially used for lithium mica (also known as a kind of lithium ore) and mineral processing. It is a continuous kiln equipment that adopts horizontal feeding and discharging methods. The raw materials enter the kiln body through a conveyor belt or other transportation system, enter from one end, and after multiple processes such as heating, reaction, cooling, etc., they are finally discharged from the other end.

[0003] The existing horizontal tunnel kiln for roasting lithium mica uses experience and some simple methods to adjust the mixing ratio of combustion air and gas fuel. When the air-fuel ratio of combustion air and gas fuel is too small, it will lead to incomplete combustion. When the ratio is too large, it will lead to excessive combustion. Excessive supplement of combustion air is required, which increases the fuel consumption. In addition, when adjusting the air-fuel ratio, manual or differential pressure proportional valve control is generally adopted, which is not convenient for automatic operation and has poor adjustment accuracy. Therefore, we propose an optimization method for the air-fuel ratio of the horizontal tunnel kiln of lithium mica. Summary of the invention

[0004] The object of the present invention is to provide a method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln, comprising the following steps:

[0006] Step A: Record the gas fuel intake and air intake data of each burner on site;

[0007] Step B: Collect multiple bags of gas fuel samples, and perform detection and analysis on the data of the multiple bags of samples through equipment;

[0008] Step C: Calculate the theoretical air demand of the gas fuel according to the detected and analyzed values, and then adjust the gas fuel intake and air intake according to the analyzed values ​​and the air demand;

[0009] Step D: Adjust the ratio of gas fuel to air entering the burner through the intelligent air-fuel ratio regulating valve.

[0010] Ensure that all burners and combustion systems are in normal working condition on site, ensure the accuracy of data collection, collect samples on site, test and analyze the samples to calculate the theoretical air demand for gas fuel and the actual amount of air required, so as to adjust the appropriate air-fuel ratio and ensure the stability and efficiency of the combustion process.

[0011] Preferably, the number of sample bags collected in step B is 2-10 bags.

[0012] It is convenient to improve the richness of sample data and reduce the loss during collection.

[0013] Preferably, the gas content of each bag collected in step B is 200-300 ml, and the material of the sample bag is polyvinyl fluoride, polyester film or polyvinyl chloride.

[0014] It is convenient to analyze multiple bags of samples, and at the same time, the convenience of carrying during sampling is improved through sampling bags made of suitable materials.

[0015] Preferably, the contents detected and analyzed in step B are: one or more of fuel composition and percentage content, Wobbe number, higher calorific value, lower calorific value, density, and relative density.

[0016] It is convenient to have a comprehensive understanding of the actual gas fuel.

[0017] Preferably, the equipment used in step B is: a gas chromatograph or a thermal conductivity gas analyzer.

[0018] It is convenient to detect gas fuel better and analyze gas fuel data.

[0019] Preferably, when making adjustments in step C, the openings of the gas fuel intake valve and the combustion air intake valve of the burner are adjusted, and the data fluctuations of the flow meter are observed until they are within the design range.

[0020] Preferably, in step C, the theoretical air demand V 需 The calculation formula is:

[0021]

[0022] H2 is hydrogen, CO is carbon dioxide, C m H n is a hydrocarbon, H2S is hydrogen sulfide;

[0023] Actual required air volume V 剩 for:

[0024] V 剩 =V 需 *α, α value range is: 1.05-1.3.

[0025] This facilitates calculation of the actual air intake required.

[0026] Preferably, the intelligent air-fuel ratio regulating valve includes an intelligent valve positioner and an MRV valve.

[0027] It is convenient to monitor the ratio of fuel to air in real time and adjust it automatically.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This patent improves the thermal energy utilization rate of fuel combustion in the lithium mica horizontal tunnel kiln through scientific calculation and adjustment of the air-fuel ratio of gas fuel and combustion-supporting air, avoiding the influence of excessive or insufficient air-fuel ratio on the combustion effect. Through the method of this patent, full combustion can be achieved, and the content of industrial waste gas pollutants generated during the fuel combustion process can be reduced, which is more conducive to green, environmental protection and healthy development. The intelligent air-fuel ratio regulating valve is used to realize intelligent control of the air-fuel ratio and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the process of the present invention.

[0031] Figure 2 It is a schematic diagram of the operating interface of the intelligent air-fuel ratio regulating valve of the present invention.

[0032] Figure 3 This is a schematic diagram of the input electrical connection of the intelligent air-fuel ratio regulating valve of the present invention.

[0033] Figure 4 This is a schematic diagram of the electrical connection of the switch output module of the present invention.

[0034] Figure 5 It is a schematic diagram of the valve position feedback connection of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] See also Figure 1 The present invention provides a technical solution: a method for optimizing the air-fuel ratio of a lithium mica horizontal tunnel kiln, comprising the following steps:

[0038] Step A: Record the gas fuel intake and air intake data of each burner on site;

[0039] Step B: Collect multiple bags of gas fuel samples, and perform detection and analysis on the data of the multiple bags of samples through equipment;

[0040] Step C: Calculate the theoretical air demand of the gas fuel according to the detected and analyzed values, and then adjust the gas fuel intake and air intake according to the analyzed values ​​and the air demand;

[0041] Step D: Adjust the ratio of gas fuel to air entering the burner through the intelligent air-fuel ratio regulating valve.

[0042] Flow meters, sensors and other equipment are used on site to measure the intake flow rate. During the test, it is ensured that each burner and combustion system is in normal working condition to ensure the accuracy of data collection. Then, by collecting samples on site, marking the sampling time, location and related environmental conditions of each bag of samples to ensure the traceability of the samples, the samples are tested and analyzed to calculate the theoretical air demand for gas fuel and the actual amount of air required, so as to adjust the appropriate air-fuel ratio and ensure the stability and efficiency of the combustion process.

[0043] Preferably, the number of sample bags collected in step B is 2-10 bags.

[0044] It is convenient to improve the richness of sample data and reduce the loss during collection. Further, each bag of samples can be analyzed repeatedly to ensure the accuracy and reliability of the data.

[0045] Preferably, the gas content of each bag collected in step B is 200-300 ml, and the material of the sample bag is polyvinyl fluoride, polyester film or polyvinyl chloride.

[0046] In the process of gas fuel sampling, it is very important to choose a suitable collection bag, because it directly affects the quality of the sample and the accuracy of the analysis results. Then, multiple bags of samples are analyzed, and the convenience of carrying during sampling is improved by using sampling bags of suitable materials.

[0047] Preferably, the contents detected and analyzed in step B are: one or more of fuel composition and percentage content, Wobbe number, higher calorific value, lower calorific value, density, and relative density.

[0048] It is convenient to fully understand the actual gas fuel in order to adjust the appropriate air intake.

[0049] Preferably, the equipment used in step B is: a gas chromatograph or a thermal conductivity gas analyzer.

[0050] Gas chromatographs use chromatography to separate different gas components, and thermal conductivity gas analyzers work based on the difference in thermal conductivity of different gases. It uses the different thermal conductivity of different gases to conduct quantitative analysis, which facilitates better detection of gas fuels and analysis of gas fuel data.

[0051] Preferably, when making adjustments in step C, the openings of the gas fuel intake valve and the combustion air intake valve of the burner are adjusted, and the data fluctuations of the flow meter are observed until they are within the design range.

[0052] Preferably, in step C, the theoretical air demand V 需 The calculation formula is:

[0053]

[0054] H2 is hydrogen, CO is carbon monoxide, C m H n is a hydrocarbon, H2S is hydrogen sulfide;

[0055] Actual required air volume V 剩 for:

[0056] V 剩 =V 需 *α, α value range is: 1.05-1.3.

[0057] Theoretical air demand is the amount of air theoretically required for complete combustion of the fuel, which can be estimated from the chemical composition of the substance. This value is crucial for optimizing energy efficiency and controlling the combustion process, and facilitates the calculation of the actual air intake required.

[0058] Preferably, the intelligent air-fuel ratio regulating valve includes an intelligent valve positioner and an MRV valve.

[0059] Working principle of intelligent air-fuel ratio regulating valve: Figure 2-Figure 5 As shown, the intelligent valve positioner, model: SVP2600, receives the 4-20mA valve position signal from the control system, and obtains the valve position setting value through A / D conversion; at the same time, the actual valve position feedback information is obtained through the position sensor; both are calculated and processed by the control software to control the action of the pneumatic actuator. The automatic cylinder model used in the present invention is: S100S07, which is used to provide power for the entire device. The intelligent valve positioner and the automatic cylinder are connected front and back through a fixed bracket. The MVR intelligent valve, the intelligent valve positioner and the automatic cylinder are connected up and down through a fixed bracket to drive the valve position to the set value. The MRV valve (gas, air linkage valve) controls the gas / air flow rate as the actuator opens, thereby realizing the output power of the burner, which is convenient for real-time monitoring of the ratio of fuel to air and automatic adjustment.

[0060] Example 2

[0061] When the lithium mica horizontal tunnel kiln is in normal roasting operation, the gas flow and combustion air flow data of the burners in the 5 groups of firing sections are collected at random. The gas pipeline specification is: DN25, and the gas flow range is: 17Nm 3 / h~20Nm 3 / h, combustion air pipeline specification: DN70, combustion air flow range: 102Nm 3 / h~300Nm 3 / h, at this time the air-fuel ratio is either too small or too large.

[0062] The 5 bags of samples were tested using a gas chromatograph. The test range included: fuel composition and percentage content, density, relative density, higher calorific value, lower calorific value, and other parameters as shown in the following table:

[0063] Table 1:

[0064] parameter Test results density <![CDATA[0.6952kg / m 3 (20℃,101.3kPa)]]> Relative density 0.5772 (20℃, 101.3kPa) High calorific value <![CDATA[36.24MJ / m 3 (20℃,101.3kPa)]]> Low calorific value <![CDATA[32.65MJ / m 3 (20℃,101.3kPa)]]>

[0065] Table 2:

[0066]

[0067]

[0068] According to the calculation formula of combustion principle, V0 is the theoretical air demand:

[0069]

[0070] Calculation shows that the theoretical air volume VO is approximately equal to: 9.53Nm 3 .

[0071] Calculate the actual required combustion air volume according to the excess air coefficient calculation formula (the value range of the excess air coefficient α of the industrial burner is: 1.05-1.3), V 剩 =V 需 *α=10~12.39Nm 3 .

[0072] The intelligent air-fuel ratio regulating valve is mainly composed of: intelligent valve positioner and MRV valve

[0073] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln, characterized in that: The following steps are involved: Step A: Record the gas fuel intake and air intake data of each burner on site; Step B: Collect multiple bags of gas fuel samples, and perform detection and analysis on the data of the multiple bags of samples through equipment; Step C: Calculate the theoretical air demand of the gas fuel according to the detected and analyzed values, and then adjust the gas fuel intake and air intake according to the analyzed values ​​and the air demand; Step D: Adjust the ratio of gas fuel to air entering the burner through the intelligent air-fuel ratio regulating valve.

2. A method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln according to claim 1, characterized in that: The number of sample bags collected in step B is 2-10 bags.

3. A method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln according to claim 2, characterized in that: The gas content of each bag collected in step B is 200-300 ml, and the material of the sample bag is polyvinyl fluoride, polyester film or polyvinyl chloride.

4. A method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln according to claim 1, characterized in that: The contents of the detection and analysis in step B are: one or more of fuel composition and percentage content, Wobbe number, higher calorific value, lower calorific value, density, and relative density.

5. A method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln according to claim 1, characterized in that: The equipment used in step B is: a gas chromatograph or a thermal conductivity gas analyzer.

6. The method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln according to claim 1, characterized in that: When making adjustments in step C, the openings of the gas fuel intake valve and the combustion air intake valve of the burner are adjusted, and the data fluctuations of the flow meter are observed at the same time until they are within the design range.

7. The method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln according to claim 1, characterized in that: In step C, the theoretical air demand V 需 The calculation formula is: H2 is hydrogen, CO is carbon monoxide, C m H n is a hydrocarbon, H2S is hydrogen sulfide; Actual required air volume V 剩 for: V 剩 =V 需 *α, α value range is: 1.05-1.

3.

8. The method for optimizing the air-fuel ratio of a lepidolite horizontal tunnel kiln according to claim 1, characterized in that: The intelligent air-fuel ratio regulating valve includes an intelligent valve positioner and an MRV valve.

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