First, the meaning is different.
1. High calorific value gas: High calorific value gas refers to the fuel gas in which the flue gas is cooled to the initial temperature after complete combustion, and the water vapor in it is discharged as condensed water. This fuel gas is called high calorific value gas.
2. Low-calorific value gas: Low-calorific value gas means that after the fuel gas is completely burned, its flue gas is cooled to the initial temperature, and the water vapor in it is still discharged in the form of steam. This fuel gas is called low calorific value gas.
Second, the combustion heat of fuels is different.
1. High calorific value gas: it is the sum of the combustion heat of fuel and the condensation heat of water vapor, that is, the total heat released when the fuel is completely burned.
2. High calorific value gas: it is only the combustion heat of fuel, that is, the difference between total heat and condensation heat.
Third, the molecular formula is different.
1, high calorific value gas: H0: high calorific value.
2. Low calorific value gas: Hn: low calorific value.
Extended data
First, there is the following relationship between high calorific value and low calorific value:
Low calorific value = high calorific value-the heat required to heat a substance when water evaporates and fuel burns.
Obviously, low calorific value is of greater significance in practical work. The transformation relationship between them is:
HN = H0[( 100-I-W)/( 100-Wl]* 5.85 W
Where: Hn: low calorific value, H0: high calorific value, I: inert substance content, W: fuel surface humidity, Wl: residual and hygroscopic humidity.
Second, strengthen the combustion measures
1、? The calorific value and composition of low calorific value gas are unstable. The combustion characteristics of combustible gases H2, CO and CH4 contained in low calorific value gas are studied, and a feasible solution is put forward, that is, when the gas turbine burns low calorific value gas fuel, a certain amount of one or more of H2, CO and CH4 can be added according to the change of combustible gas composition to make the combustion stable.
2. Literature 2 introduces the manufacturing technology and characteristics of several common low calorific value gas fuels. Through the analysis of the stable combustion conditions of gas fuel, the factors affecting the stable combustion of low calorific value gas are found out, and the measures to strengthen the stable combustion of low calorific value gas are put forward: adding oxygen, mixing high calorific value gas, local high temperature and flue gas recirculation.
Three. Patents and applications
1. The invention discloses a low calorific value gas efficient combustion boiler, which comprises a furnace body, a burner on the left side of the furnace body and an air preheater on the right side of the furnace body; The boiler body comprises a cylinder, a furnace lining located in the cylinder, a gas interface located at the lower left, a reburning chamber located at the lower right, a second reflux flue located above, a third reflux flue located above the second reflux flue, a front flue box located at the left and a rear flue box located at the right; The air preheater is connected with the boiler body through a flue.
2. Beneficial effects: The low calorific value gas is directly discharged for a long time due to the difficulty of flame stability, resulting in huge energy waste. Through the research and development of this project, it can be directly burned by boilers, saving operating costs for enterprises. The utility model provides an integrated structure of a dual-fuel nozzle and a cyclone capable of burning low calorific value gas, which comprises a fuel injection system, a gas injection system and a cyclone system, wherein an oil pipeline, an oil pad, an oil spring and an oil cyclone are connected in turn and are all installed in the outer wall of a main oil pipeline.
3. The gas pipeline is connected with the outer wall of the gas channel and installed on the outer side of the outer wall of the main oil channel. The gas pipeline, the outer wall of the gas channel and the outer wall of the main oil channel form a gas channel, the end of the gas channel is provided with a circle of cyclone blades, and a cyclone shell is arranged outside the cyclone blades. The cyclone blade has a hollow structure, the tail edge of the cyclone blade is provided with a blade tail edge injection hole, and the windward surface of the cyclone blade is provided with a blade windward surface injection hole. The dual-fuel nozzle of the utility model can use both fuel oil and low calorific value gas rich in non-combustible gas as fuel, which can strengthen the combustion effect and meet the stable combustion of gas fuel under large flow.
4. International scientific and technological cooperation specially uses low calorific value gas turbines to reduce greenhouse gas emissions. Through the cooperation with Australian Federal Research Institute, * * * Company has developed a catalytic combustion equipment for low calorific value gas turbines in coal mines. The equipment can effectively utilize 80 ~ 90% methane gas in coal mine waste gas, and realize the stable combustion of methane-air mixture with 1% concentration. Increasing energy resources while reducing pollution emissions is in line with the requirements of energy conservation and emission reduction in China's current economic development.
References:
Baidu encyclopedia-low calorific value gas