Proportioning method of high-calorific-value fuel of industrial kiln

Abstract

The invention discloses an industrial kiln high-calorific-value fuel proportioning method which comprises the following steps: step A, calculating the volume quantities of fuel gas and auxiliary gas with different calorific values to determine the fuel proportioning, and then respectively controlling the fuel gas and the auxiliary gas to flow into a mixer for mixing according to the proportioning by a flow controller to form mixed gas; b, when abnormity occurs in the mixing process, an alarm is given to the outside, and fault information is displayed; c, information of the mixed gas is collected and displayed on a screen; the high-precision flow controller APU and the industrial control computer are adopted to indicate various gas flows and pressures, the amount of gas needing to be injected is calculated through matching, the content of auxiliary gas needing to be added is automatically adjusted when the gas flow changes, and the precision and stability of the gas distribution amount are controlled through the laminar flow meter and the micro differential pressure transmitter. The liquefied petroleum gas can be added into the natural gas to improve the heat value, so that the consumption of the natural gas is reduced, and the fuel cost is reduced.

Description

Technical Field

[0001] The present invention particularly relates to a method for proportioning high calorific value fuel for an industrial kiln. Background Art

[0002] Most industrial furnace industries use natural gas as the main fuel. According to relevant standards, the CH4 content in pipeline natural gas accounts for more than 95%. Since natural gas (CH4 ≥ 95%) has a lower calorific value than butane, propane, liquefied petroleum gas and other fuels, it is only about 31-32MJ / m 3 When used in a kiln, a single natural gas fuel consumes more energy and has high cost. For this reason, we propose a high calorific value fuel ratio method for industrial kilns. Summary of the Invention

[0003] The object of the present invention is to provide a method for proportioning high calorific value fuel for an industrial kiln, so as to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a method for proportioning high calorific value fuel for an industrial kiln, comprising the following steps:

[0005] Step A: Calculate the volume of fuel gas and auxiliary gas with different calorific values ​​to determine the fuel ratio. Before mixing, perform an airtightness test on the mixing system. Then, the flow controller in the mixing system controls the fuel gas and auxiliary gas to flow into the mixer according to the ratio to form a mixed gas.

[0006] Step B: When an abnormality occurs during the mixing process, an alarm is issued to the outside world and a fault message is displayed;

[0007] Step C: Collect the information of the mixed gas and display it on the screen. When the mixed gas concentration is qualified, the computer calculates the mixed gas flow rate required by the kiln and then delivers the mixed gas to the kiln;

[0008] Step D: When the mixed gas flow rate changes or the mixed gas concentration is unqualified, the amount of gas to be supplemented is calculated again, and then the laminar flow meter and micro differential pressure transmitter control the gas distribution amount to add to the mixed gas until it reaches the predetermined concentration, and then the mixed gas is delivered to the kiln.

[0009] It is convenient to adjust the ratio of fuel gas to auxiliary gas according to needs, increase the calorific value to reduce energy consumption, and avoid the low calorific value and high consumption of single natural gas.

[0010] Preferably, in step A, the fuel gas is natural gas and the secondary gas is liquefied petroleum gas.

[0011] Facilitates better calorific value and reduces the volume of natural gas consumption.

[0012] Preferably, the volume ratio in the ratio is: 87-95 parts of natural gas and 5-13 parts of liquefied petroleum gas.

[0013] It is convenient to adjust the ratio of fuel gas to auxiliary gas in the mixed gas according to the market price of natural gas and liquefied petroleum gas, so as to achieve better calorific value and lower fuel cost.

[0014] Preferably, the ratio of natural gas to liquefied petroleum gas in the mixture is any one of 87:13, 92:8 and 95:5.

[0015] Facilitates better calorific value effect to improve rapid heating of the kiln.

[0016] Preferably, in step A, the fuel gas is liquefied petroleum gas and the auxiliary gas is air.

[0017] It is convenient to reduce the consumption of liquefied petroleum gas and save energy.

[0018] Preferably, the calculation formula of the ratio is:

[0019] Where Hr represents the calorific value of r combustible components in the gas, and fr represents the volume fraction of r combustible components in the gas.

[0020] It is convenient to prepare kiln fuel with appropriate calorific value.

[0021] Preferably, the abnormal conditions in step B are the pressure occurring during the proportioning process being lower than a preset value, the proportioning concentration being too high or too low, and gas leakage.

[0022] It is convenient to ensure the safety of the mixed gas during proportioning.

[0023] Preferably, in step C, the collected information is gas flow, pressure value, ratio concentration, temperature and gas parameters.

[0024] It is convenient to judge whether the mixed gas reaches the predetermined qualified value after deployment.

[0025] Preferably, the mixed gas flow rate in step C is at least 600 Nm 3 / h.

[0026] It is convenient to add fuel to the kiln better.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention uses a high-precision flow controller APU and an industrial control computer to indicate the flow and pressure of various gases, calculates the amount of gas to be injected through proportioning, automatically adjusts the content of the auxiliary gas to be added when the gas flow changes, and controls the accuracy and stability of the gas distribution amount by a laminar flow meter and a micro-differential pressure transmitter, thereby improving the proportioning accuracy and stability of the mixed gas, ensuring that liquefied petroleum gas can be added to natural gas to increase the calorific value, thereby reducing natural gas consumption and reducing fuel costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the gas and auxiliary gas mixing device of the present invention;

[0030] Figure 2 Schematic diagram of the control interface for mixed gases of the present invention. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0032] See also Figure 1 、 Figure 2 The present invention provides a technical solution: a method for proportioning high calorific value fuel for an industrial kiln, comprising the following steps:

[0033] Step A: Calculate the volume of fuel gas and auxiliary gas with different calorific values ​​to determine the fuel ratio. Before mixing, perform an airtightness test on the mixing system. Then, the flow controller in the mixing system controls the fuel gas and auxiliary gas to flow into the mixer according to the ratio to form a mixed gas.

[0034] During the air tightness test, pressurize the gas mixture system and observe the pressure change to determine whether there is a leak. When distributing gas, the "constant flow" and "constant volume" gas distribution methods can be used. The gas distribution ratio of the corresponding gas distribution channel can be temporarily adjusted by changing the "flow setting" of each gas distribution channel. When using the "variable flow" gas distribution method, the flow setting of each gas distribution channel is the "maximum" gas distribution flow. If the "constant volume" gas distribution method is used, the gas distribution volume of each gas distribution channel can be specified by changing the "volume setting". When the volume is sufficient, the raw gas of the corresponding channel will be closed.

[0035] Step B: When an abnormality occurs during the mixing process, an alarm is issued to the outside world and a fault message is displayed;

[0036] Step C: Collect the information of the mixed gas and display it on the screen. When the mixed gas concentration is qualified, the computer calculates the mixed gas flow rate required by the kiln and then delivers the mixed gas to the kiln;

[0037] Step D: When the mixed gas flow rate changes or the mixed gas concentration is unqualified, the amount of gas to be supplemented is calculated again, and then the laminar flow meter and micro differential pressure transmitter control the gas distribution amount to add to the mixed gas until it reaches the predetermined concentration, and then the mixed gas is delivered to the kiln.

[0038] It is convenient to mix two or more gases to adjust the ratio of fuel gas to auxiliary gas according to the needs of the kiln, increase the calorific value to reduce energy consumption, and avoid the low calorific value and high consumption of a single natural gas.

[0039] Preferably, in step A, the fuel gas is natural gas and the secondary gas is liquefied petroleum gas.

[0040] It is convenient to avoid the low calorific value of natural gas and the large volume required, which leads to high energy consumption. By mixing, the calorific value can be better improved and the volume of natural gas consumption can be reduced.

[0041] Preferably, the volume ratios are: 87-95 parts of natural gas and 5-13 parts of liquefied petroleum gas.

[0042] It is convenient to adjust the amount of the two mixed gases, so as to adjust the ratio of the fuel gas and the auxiliary gas in the mixed gas according to the market price of natural gas and liquefied petroleum gas, so as to achieve better calorific value and lower fuel cost.

[0043] Preferably, the ratio of natural gas to liquefied petroleum gas in the mixture is any one of 87:13, 92:8 and 95:5.

[0044] It facilitates better calorific value effect to improve the rapid heating of the kiln, and uses a smaller volume of liquefied petroleum gas to reduce cost investment when the kiln reaches the calorific value;

[0045] When the ratio of natural gas to liquefied petroleum gas is 87:13, the calorific value of the mixed gas can be calculated:

[0046] H=0.87*34.02+0.13*95.02=41.95MJ / m 3 According to the standard lower calorific value of natural gas 34.02MJ / m 3 , the calorific value ratio after mixing is calculated as: E1=41.95:34.02=1.233.

[0047] Preferably, in step A, the fuel gas is liquefied petroleum gas and the secondary gas is air.

[0048] It is convenient to reduce the consumption of liquefied petroleum gas and save energy.

[0049] Preferably, the formula for calculating the ratio is:

[0050] Where Hr represents the calorific value of r combustible components in the gas, and fr represents the volume fraction of r combustible components in the gas.

[0051] It is convenient to prepare kiln fuel with appropriate calorific value to reduce fuel input cost after reaching the required fuel amount.

[0052] Preferably, the abnormal conditions in step B are the pressure occurring during the proportioning process being lower than a preset value, the proportioning concentration being too high or too low, and gas leakage.

[0053] It is convenient to ensure the safety of the mixed gas during proportioning.

[0054] Preferably, in step C, the collected information is gas flow, pressure value, ratio concentration, temperature and gas parameters.

[0055] It is convenient to judge whether the mixed gas reaches the predetermined qualified value after deployment and to obtain fuel information in a timely manner.

[0056] Preferably, the mixed gas flow rate in step C is at least 600 Nm 3 / h.

[0057] It is convenient to add fuel to the kiln better and ensure the stable flow rate of mixed gas input into the kiln.

[0058] The working principle and use process of the present invention:

[0059] The solutions that can be used in mixed gas include: natural gas as the main gas and liquefied petroleum gas as the auxiliary gas; natural gas mixed with liquefied petroleum gas, natural gas mixed with liquefied petroleum gas, and the natural gas and liquefied petroleum gas formula ratio is adjusted to: 8.7:1.3, 9.2:0.8, 9.5:0.5. According to the calculation formula: Where Hr represents the calorific value of the combustible component in the gas, and the unit is MJ / m 3 fr represents the volume fraction of the combustible component r in the gas, which can be calculated based on the standard lower calorific value of natural gas 34.02MJ / m 3 The standard lower calorific value of liquefied petroleum gas is 95.02MJ / m 3 The lower calorific value of the mixed gas is 37.07-41.95MJ / m 3 The calorific value it produces is about 1.089-1.233 times that of natural gas, which can greatly reduce fuel consumption costs.

[0060] The mixed gas combination can also use liquefied petroleum gas as the main gas and air as the secondary gas to replace natural gas. The specific ratios are 0.58:0.42, 0.5:0.5, and 0.4:0.6. According to the calculation formula: According to the standard lower calorific value of natural gas 34.02MJ / m 3 The standard lower calorific value of liquefied petroleum gas is 95.02MJ / m 3 The lower calorific value of the mixed gas is 38.0-55.11MJ / m 3 The calorific value it produces is about 1.117-1.619 times that of natural gas, which can greatly reduce fuel consumption costs. This solution is extremely practical for areas with a shortage of natural gas energy.

[0061] The present invention uses a high-precision flow controller APU and an industrial control computer to indicate the flow and pressure of various gases, calculates the amount of gas to be injected through proportioning, automatically adjusts the content of the auxiliary gas to be added when the main gas flow changes, and uses a laminar flow meter and a micro-differential pressure transmitter to control the accuracy and stability of the gas distribution amount, thereby improving the proportioning accuracy and stability of the mixed gas. At the same time, liquefied petroleum gas can be added to natural gas to increase the calorific value, reduce natural gas consumption, and thus reduce fuel costs.

[0062] The method of the present invention can make the mixed gas flow rate reach 600Nm 3 / h as an example: some of the achievable technical indicators are shown in the following table:

[0063]

[0064] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for proportioning high calorific value fuel for industrial kilns, characterized in that: The following steps are involved: Step A: Calculate the volume of fuel gas and auxiliary gas with different calorific values ​​to determine the fuel ratio. Before mixing, perform an airtightness test on the mixing system. Then, the flow controller in the mixing system controls the fuel gas and auxiliary gas to flow into the mixer according to the ratio to form a mixed gas. Step B: When an abnormality occurs during the mixing process, an alarm is issued to the outside world and a fault message is displayed; Step C: Collect the information of the mixed gas and display it on the screen. When the mixed gas concentration is qualified, the computer calculates the mixed gas flow rate required by the kiln and then delivers the mixed gas to the kiln; Step D: When the mixed gas flow rate changes or the mixed gas concentration is unqualified, the amount of gas to be supplemented is calculated again, and then the laminar flow meter and micro differential pressure transmitter control the gas distribution amount to add to the mixed gas until it reaches the predetermined concentration, and then the mixed gas is delivered to the kiln.

2. The method for mixing high calorific value fuel for an industrial furnace according to claim 1, characterized in that: In step A, the fuel gas is natural gas and the auxiliary gas is liquefied petroleum gas.

3. The method for mixing high calorific value fuel for an industrial kiln according to claim 2, characterized in that: The volume ratios in the above-mentioned proportions are: 87-95 parts of natural gas and 5-13 parts of liquefied petroleum gas.

4. The method for proportioning high calorific value fuel for an industrial furnace according to claim 3, characterized in that: The ratio of natural gas to liquefied petroleum gas in the mixture is any one of 87:13, 92:8 and 95:

5.

5. The method for mixing high calorific value fuel for an industrial furnace according to claim 1, characterized in that: In step A, the fuel gas is liquefied petroleum gas and the auxiliary gas is air.

6. A method for proportioning high calorific value fuel for an industrial furnace according to claim 2 or 5, characterized in that: The calculation formula of the ratio is: Where Hr represents the calorific value of r combustible components in the gas, and fr represents the volume fraction of r combustible components in the gas.

7. The method for mixing high calorific value fuel for an industrial furnace according to claim 1, characterized in that: The abnormal conditions in step B are that the pressure during the proportioning process is lower than the preset value, the proportioning concentration is too high or too low, and gas leakage occurs.

8. The method for mixing high calorific value fuel for an industrial furnace according to claim 1, characterized in that: In step C, the collected information is gas flow, pressure, ratio concentration, temperature and gas parameters.

9. The method for mixing high calorific value fuel for an industrial furnace according to claim 1, characterized in that: The mixed gas flow rate in step C is at least 600 Nm 3 / h.

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