Analysis Method of the Effect of Coal Quality Change on Boiler Combustion

Abstract

The present invention provides an analysis method for the influence of coal quality change on boiler combustion, relates to the technical field of coal quality analysis, and comprises the following steps: step one: collecting different types of coal and measuring the parameters of different types of coal; step two: selecting a plurality of boilers with the same parameters as experimental equipment; step three: screening the types of coal, and selecting the types of coal with the highest and lowest values ​​for each parameter; step four: putting different types of coal into the boiler for combustion, and using the positive balance method to respectively measure the thermal efficiency of the boiler under different types of coal; the present invention selects the types of coal with the highest and lowest values ​​according to each parameter, puts them into the boiler for combustion, thereby measuring the thermal efficiency of the boiler under different types of coal, and makes multiple combinations of different types of coal, puts them into the boiler for combustion, thereby measuring the thermal efficiency of the boiler under different types of mixed coal, and forms a bar chart based on the above data, so as to facilitate the analysis of the influence of different coal type parameters and different coal type combinations on the thermal efficiency of the boiler.

Description

Technical Field

[0001] The present invention relates to the technical field of coal quality analysis, and in particular to a method for analyzing the influence of coal quality changes on boiler combustion. Background Art

[0002] Coal is the main raw material for boiler operation. The standards for coal are different depending on the type of boiler. In order to ensure the operating efficiency of the boiler, it is necessary to strengthen the management of coal, improve the quality of coal, and ensure the stability and economy of boiler operation;

[0003] The use of mixed coal in my country is different from that in foreign countries. The burning of mixed coal includes active mixed burning and passive mixed burning, which is mainly caused by the unstable coal supply to power plant boilers. my country is rich in coal resources. Power coal includes various types of coal from bituminous coal, inferior bituminous coal, lignite to anthracite. These coals are used in thermal power plants. Due to the differences in characteristics between various types of coal, the actual range of changes in coal use has been significantly increased.

[0004] At present, the existing equipment in thermal power plants has the test conditions for blending different types of coal, the boiler operators are familiar with the precautions for boiler combustion adjustment, and the personnel are skilled in technical skills. However, the existing instrumentation and equipment are backward, the boiler fly ash and the like cannot be monitored online, and the technical means such as boiler efficiency measurement are missing. Therefore, it is of utmost importance to systematically plan and analyze the impact of different types of coal on boiler efficiency. Therefore, the present invention proposes an analysis method for the impact of coal quality changes on boiler combustion to solve the problems existing in the prior art. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for analyzing the impact of coal quality changes on boiler combustion. The method for analyzing the impact of coal quality changes on boiler combustion is convenient for analyzing the impact of different coal parameters and different coal combinations on boiler thermal efficiency.

[0006] To achieve the purpose of the present invention, the present invention is implemented by the following technical scheme: A method for analyzing the influence of coal quality change on boiler combustion comprises the following steps:

[0007] Step 1: Collect different types of coal and measure the parameters of different types of coal;

[0008] Step 2: Select multiple boilers with the same parameters as experimental equipment;

[0009] Step 3: Screen the coal types, and select the coal types with the highest and lowest values ​​for each parameter;

[0010] Step 4: Put different types of coal into the boiler for combustion, and use the positive balance method to measure the thermal efficiency of the boiler under different types of coal;

[0011] Step 5: Combine different types of coal into multiple combinations to form multiple types of mixed coal;

[0012] Step 6: Put multiple types of mixed coal into the boiler for combustion, and use the counter-balance method to measure the thermal efficiency of the boiler under different types of mixed coal;

[0013] Step 7: In step 4 and step 6, the tail gas data of boilers under different coal types and different types of mixed coal types are monitored respectively;

[0014] Step 8: Make a bar chart of the data from steps 4, 6, and 7, and conduct a comprehensive analysis to draw conclusions.

[0015] A further improvement is that in step 1, the parameters of different types of coal are measured, specifically including moisture, volatile matter, ash, sulfur content and fineness.

[0016] A further improvement is that in step 2, multiple boilers with the same parameters are selected as experimental equipment, and the parameters specifically include: furnace section heat load, furnace volume heat load, furnace flame height, burner area wall heat load, furnace volume, water-cooled wall area, and furnace cross-sectional area.

[0017] Further improvement lies in: in the step three, each parameter selects the coal type with the highest and lowest values, specifically, selects the coal type with the highest and lowest moisture content values, selects the coal type with the highest and lowest volatile matter values, selects the coal type with the highest and lowest ash content values, selects the coal type with the highest and lowest sulfur content values, and selects the finest and coarsest coal types.

[0018] A further improvement is that in step 4, the positive balance method is specifically:

[0019] Thermal efficiency = effective utilization of heat / total heat that can be released by the fuel * 100% = boiler evaporation * (steam enthalpy - feed water enthalpy) / fuel consumption * fuel low calorific value * 100%

[0020] Where:

[0021] Boiler evaporation capacity - actual measurement, kg / h;

[0022] Steam enthalpy - obtained from the surface enthalpy-entropy diagram, kJ / kg;

[0023] Feed water enthalpy - obtained from the enthalpy-entropy diagram, kJ / kg;

[0024] Fuel consumption - actual measured, kg / h;

[0025] Low calorific value of fuel - actually measured, kJ / kg.

[0026] A further improvement is that in step five, the specific method of the multiple combinations is to mix different types of coal in pairs into one type, and in pairs of three into one type until all the combinations are completed.

[0027] A further improvement is that in step 6, the counter-balancing method is specifically:

[0028] Thermal efficiency = 100% - sum of percentages of various heat losses = 100% - q2 - q3 - q4 - q5 - q6

[0029] Where:

[0030] q2——exhaust heat loss, %;

[0031] q3——heat loss due to incomplete combustion of gas, %;

[0032] q4——heat loss due to incomplete combustion of solids, %;

[0033] q5——heat dissipation loss, %;

[0034] q6——physical heat loss of ash, %.

[0035] A further improvement is that in step six, during the combustion process, flue gas waste heat recovery technology is used to reduce smoke exhaust losses.

[0036] Further improvement lies in: in the step seven, the specific process of exhaust gas data monitoring is: a fully extraction system is used to extract the flue gas from the flue through a dedicated ultra-low flue gas heating sampling probe, and after heat transmission, the flue gas is transmitted to the flue gas analysis cabinet for dust removal and water removal by a dedicated condenser. After treatment, the flue gas enters the flue gas analyzer for monitoring and analysis, and the monitoring data is transmitted to the industrial computer and the data acquisition instrument for storage and transmission. Among them, the DOAS method is adopted to utilize the narrow-band absorption characteristics of the molecules of the substance to be tested to distinguish and invert the concentration of the gas to be tested, and is not affected by other interfering gases such as water vapor.

[0037] Further improvement is: in step eight, the influence of different coal type parameters on the boiler combustion rate is analyzed according to the bar chart, the influence of different coal type combinations on the boiler combustion rate is analyzed, the changes in exhaust gas environmental protection data under different coal types and different combinations are analyzed, and the optimal coal type and combination are selected.

[0038] The beneficial effects of the present invention are:

[0039] 1. The present invention selects the coal with the highest and lowest values ​​according to various parameters, and puts them into the boiler for combustion to measure the thermal efficiency of the boiler under different coal types. Different coal types are combined in multiple ways and put into the boiler for combustion to measure the thermal efficiency of the boiler under different types of mixed coal. A bar chart is formed based on the above data to facilitate analysis of the effects of different coal type parameters and different coal type combinations on the thermal efficiency of the boiler.

[0040] 2. The present invention uses a positive balance method to measure the thermal efficiency of boilers under different types of coal, and uses a reverse balance method to measure the thermal efficiency of boilers under different types of mixed coal. The boiler efficiency is measured in multiple ways, making the measurement results more representative.

[0041] 3. The present invention monitors the exhaust data of boilers under different coal types and different types of mixed coal types, analyzes environmental protection data, and conducts diversified analysis of the impact of coal quality changes, thereby obtaining more complete data and facilitating the selection of coal types. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0043] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0044] Embodiment 1

[0045] according to Figure 1 As shown, this embodiment proposes an analysis method for the impact of coal quality changes on boiler combustion, including the following steps:

[0046] Step 1: Collect different types of coal and measure the parameters of different types of coal;

[0047] Step 2: Select multiple boilers with the same parameters as experimental equipment;

[0048] Step 3: Screen the coal types, and select the coal types with the highest and lowest values ​​for each parameter;

[0049] Step 4: Put different types of coal into the boiler for combustion, and use the positive balance method to measure the thermal efficiency of the boiler under different types of coal;

[0050] Step 5: Combine different types of coal into multiple combinations to form multiple types of mixed coal;

[0051] Step 6: Put multiple types of mixed coal into the boiler for combustion, and use the counter-balance method to measure the thermal efficiency of the boiler under different types of mixed coal;

[0052] Step 7: In step 4 and step 6, the tail gas data of boilers under different coal types and different types of mixed coal types are monitored respectively;

[0053] Step 8: Make a bar chart of the data from steps 4, 6, and 7, and conduct a comprehensive analysis to draw conclusions.

[0054] The present invention selects the coal with the highest value and the lowest value according to various parameters, and puts them into the boiler for combustion, thereby measuring the thermal efficiency of the boiler under different coal types, and makes multiple combinations of different coal types, and puts them into the boiler for combustion, thereby measuring the thermal efficiency of the boiler under different types of mixed coal. According to the above data, a bar chart is formed to facilitate the analysis of the influence of different coal type parameters and different coal type combinations on the thermal efficiency of the boiler. The thermal efficiency of the boiler under different types of coal is measured by the positive balance method, and the thermal efficiency of the boiler under different types of mixed coal is measured by the reverse balance method. The boiler efficiency is measured in multiple ways, so that the measurement results are more representative.

[0055] Embodiment 2

[0056] according to Figure 1 As shown, this embodiment proposes an analysis method for the impact of coal quality changes on boiler combustion, including the following steps:

[0057] Collect different types of coal and measure the parameters of different coal types, including moisture, volatile matter, ash, sulfur content and fineness;

[0058] Select multiple boilers with the same parameters as experimental equipment, the parameters specifically include: furnace section heat load, furnace volume heat load, furnace flame height, burner area wall heat load, furnace volume, water-cooled wall area, furnace cross-sectional area; make the boiler meet the standards;

[0059] Screen the coal types, select the coal types with the highest and lowest values ​​for each parameter, specifically, select the coal types with the highest and lowest moisture content values, select the coal types with the highest and lowest volatile content values, select the coal types with the highest and lowest ash content values, select the coal types with the highest and lowest sulfur content values, and select the finest and coarsest coal types;

[0060] Different types of coal are put into the boiler for combustion, and the thermal efficiency of the boiler under different types of coal is measured by the positive balance method. The specific positive balance method is:

[0061] Thermal efficiency = effective utilization of heat / total heat that can be released by the fuel * 100% = boiler evaporation * (steam enthalpy - feed water enthalpy) / fuel consumption * fuel low calorific value * 100%

[0062] Where:

[0063] Boiler evaporation capacity - actual measurement, kg / h;

[0064] Steam enthalpy - obtained from the surface enthalpy-entropy diagram, kJ / kg;

[0065] Feed water enthalpy - obtained from the enthalpy-entropy diagram, kJ / kg;

[0066] Fuel consumption - actual measured, kg / h;

[0067] Fuel low calorific value - actually measured, kJ / kg; the present invention selects the coal with the highest and lowest values ​​according to various parameters, and puts them into the boiler for combustion, so as to measure the thermal efficiency of the boiler under different coal types, and facilitates the analysis of the influence of different coal type parameters and different coal type combinations on the thermal efficiency of the boiler;

[0068] Combining different types of coal in various ways, specifically, mixing different types of coal in pairs into one type, mixing three types of coal into one type until all combinations are completed, forming multiple types of mixed coal;

[0069] Put multiple types of mixed coal into the boiler for combustion, and use the counter-balance method to measure the thermal efficiency of the boiler under different types of mixed coal. The counter-balance method is as follows:

[0070] Thermal efficiency = 100% - sum of percentages of various heat losses = 100% - q2 - q3 - q4 - q5 - q6

[0071] Where:

[0072] q2——exhaust heat loss, %;

[0073] q3——heat loss due to incomplete combustion of gas, %;

[0074] q4——heat loss due to incomplete combustion of solids, %;

[0075] q5——heat dissipation loss, %;

[0076] q6——ash physical heat loss, %

[0077] During the combustion process, flue gas waste heat recovery technology is used to reduce exhaust losses; the present invention combines different types of coal into multiple combinations and burns them in the boiler to measure the thermal efficiency of the boiler under different types of mixed coal, which is convenient for analyzing the effects of different coal parameters and different coal combinations on the thermal efficiency of the boiler;

[0078] The tail gas data of boilers under different types of coal and different types of mixed coal are monitored respectively. The specific process is: a fully extraction system is used to extract the flue gas from the flue through a special ultra-low flue gas heating sampling probe, and after heat transmission, the flue gas is transmitted to the flue gas analysis cabinet for dust removal and water removal by a special condenser. After treatment, the flue gas enters the flue gas analyzer for monitoring and analysis, and the monitoring data is transmitted to the industrial computer and the data acquisition instrument for storage and transmission. Among them, the DOAS method is used to distinguish and invert the concentration of the gas to be tested by using the narrow-band absorption characteristics of the molecules of the substance to be tested, which is not affected by other interfering gases such as water vapor; the present invention monitors the tail gas data of boilers under different types of coal and different types of mixed coal, analyzes environmental protection data, and analyzes the impact of coal quality changes in a diversified manner, so that the data obtained is more complete and convenient for the selection of coal types;

[0079] The above data are formulated into a bar chart, and a comprehensive analysis is performed to obtain a conclusion. According to the bar chart, the influence of different coal parameters on the boiler combustion rate is analyzed, the influence of different coal combinations on the boiler combustion rate is analyzed, and the changes in tail gas environmental protection data under different coal types and different combinations are analyzed to select the optimal coal type and combination. The present invention forms a bar chart with the measured data, which is convenient for analyzing the influence of different coal parameters and different coal combinations on the boiler thermal efficiency, and is also convenient for analyzing environmental protection data and comprehensively selecting coal types.

[0080] The present invention selects the coal with the highest and lowest values ​​according to various parameters, and puts them into the boiler for combustion, thereby measuring the thermal efficiency of the boiler under different coal types, and makes multiple combinations of different coal types, and puts them into the boiler for combustion, thereby measuring the thermal efficiency of the boiler under different types of mixed coal. According to the above data, a bar chart is formed to facilitate the analysis of the influence of different coal type parameters and different coal type combinations on the thermal efficiency of the boiler. In addition, the present invention uses the positive balance method to measure the thermal efficiency of the boiler under different coal types, and uses the reverse balance method to measure the thermal efficiency of the boiler under different types of mixed coal types, and measures the boiler efficiency in multiple ways, so that the measured results are more representative. At the same time, the present invention monitors the tail gas data of boilers under different types of coal and different types of mixed coal types, analyzes environmental protection data, and analyzes the influence of coal quality changes in a diversified manner, so that the data obtained is more complete, which is convenient for the selection of coal types.

[0081] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. The analysis method of the effect of coal quality change on boiler combustion is characterized by: The following steps are involved: Step 1: Collect different types of coal and measure the parameters of different types of coal; Step 2: Select multiple boilers with the same parameters as experimental equipment; Step 3: Screen the coal types, and select the coal types with the highest and lowest values ​​for each parameter; Step 4: Put different types of coal into the boiler for combustion, and use the positive balance method to measure the thermal efficiency of the boiler under different types of coal; Step 5: Combine different types of coal into multiple combinations to form multiple types of mixed coal; Step 6: Put multiple types of mixed coal into the boiler for combustion, and use the counter-balance method to measure the thermal efficiency of the boiler under different types of mixed coal; Step 7: In step 4 and step 6, the tail gas data of boilers under different coal types and different types of mixed coal types are monitored respectively; Step 8: Make a bar chart of the data from steps 4, 6, and 7, and conduct a comprehensive analysis to draw conclusions.

2. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 1, characterized in that: In the step 1, the parameters of different types of coal are measured, including moisture, volatile matter, ash, sulfur content and fineness.

3. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 2, characterized in that: In the step 2, multiple boilers with the same parameters are selected as experimental equipment, and the parameters specifically include: furnace cross-sectional heat load, furnace volumetric heat load, furnace flame height, burner area wall heat load, furnace volume, water-cooled wall area, and furnace cross-sectional area.

4. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 3 is characterized in that: In the step three, each parameter selects the coal type with the highest and lowest values, specifically, selects the coal type with the highest and lowest moisture content values, selects the coal type with the highest and lowest volatile matter values, selects the coal type with the highest and lowest ash content values, selects the coal type with the highest and lowest sulfur content values, and selects the finest and coarsest coal types.

5. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 4 is characterized in that: In step 4, the positive balance method is specifically as follows: Thermal efficiency = effective utilization of heat / total heat that can be released by the fuel * 100% = boiler evaporation * (steam enthalpy - feed water enthalpy) / fuel consumption * fuel low calorific value * 100% Where: Boiler evaporation capacity - actual measurement, kg / h; Steam enthalpy - obtained from the surface enthalpy-entropy diagram, kJ / kg; Feed water enthalpy - obtained from the enthalpy-entropy diagram, kJ / kg; Fuel consumption - actual measured, kg / h; Low calorific value of fuel - actually measured, kJ / kg.

6. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 5, characterized in that: In the step five, the specific method of the multiple combinations is: mixing different types of coal into one type in pairs, mixing three types of coal into one type until all the combinations are completed.

7. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 6, characterized in that: In step 6, the counter-balancing method is specifically as follows: Thermal efficiency = 100% - sum of percentages of various heat losses = 100% - q2 - q3 - q4 - q5 - q6 Where: q2——exhaust heat loss, %; q3——heat loss due to incomplete combustion of gas, %; q4——heat loss due to incomplete combustion of solids, %; q5——heat dissipation loss, %; q6——Physical heat loss of ash, %.

8. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 7, characterized in that: In step six, during the combustion process, flue gas waste heat recovery technology is used to reduce smoke exhaust losses.

9. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 8, characterized in that: In step seven, the specific process of exhaust gas data monitoring is: a fully extraction system is used to extract the flue gas from the flue through a dedicated ultra-low flue gas heating sampling probe, and after heat transmission, the flue gas is transmitted to the flue gas analysis cabinet for dust removal and water removal by a dedicated condenser. After treatment, the flue gas enters the flue gas analyzer for monitoring and analysis, and the monitoring data is transmitted to the industrial computer and the data acquisition instrument for storage and transmission. Among them, the DOAS method is used to distinguish and invert the concentration of the gas to be tested by utilizing the narrow-band absorption characteristics of the molecules of the substance to be tested, and is not affected by other interfering gases such as water vapor.

10. The method for analyzing the effect of coal quality changes on boiler combustion according to claim 9, characterized in that: In step eight, the influence of different coal type parameters on the boiler combustion rate is analyzed according to the bar chart, the influence of different coal type combinations on the boiler combustion rate is analyzed, the changes in exhaust gas environmental protection data under different coal types and different combinations are analyzed, and the optimal coal type and combination are selected.

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