Combustion is a violent chemical reaction with both exothermic and luminous effects. Exothermia, luminescence and generation of new substances (such as carbon dioxide and water, leaving carbon and ash) are the three characteristics of combustion phenomenon. Combustion is an oxidation reaction, in which oxygen is the most common oxidant, but the oxidant is not limited to oxygen, and oxidation is not limited to combining with oxygen. The heat released by fuel combustion is still the main energy source of people, and its purpose is not to prepare products, but to obtain energy. Studying the conditions and methods of fuel full combustion is not only very important for saving energy and improving fuel utilization rate, but also of great significance for reducing the atmospheric pollution caused by harmful gases such as CO and soot produced by incomplete combustion. Generally speaking, the combustion of fuel in air is a redox reaction between fuel and oxygen in the air. In order to fully oxidize the fuel, we should ensure that there is enough air. At the same time, in order to ensure the full combustion of solid and liquid fuels, it is also an effective measure to increase the contact surface between fuel and air (solid fuel crushing, liquid fuel spraying in mist, etc.). ).

Combustion conditions: 1. Combustible (whether solid, liquid or gas, anything that can react violently with oxygen or other oxidants in the air is generally combustible, such as wood, paper, gasoline, alcohol, gas, etc. ) 2. Sufficient oxygen.

3. Reach the ignition point of matter

Basic principles and methods of fire fighting: combustion must meet three conditions at the same time, and measures should be taken to destroy at least one of them in order to put out the fire. There are three basic ways to put out a fire: (1) cold.

Solution: put out the burning substance by cooling, such as putting out the wood with water when it is on fire; (2) Asphyxiation method: the combustion-supporting substances are diluted and suffocated until they cannot be burned, such as nitrogen and carbon dioxide.

Wait for inert gas to extinguish the fire. (3) Isolation method: cut off the source of combustible gas, remove combustible substances, apply flame retardant, and cut off flame retardant substances, such as foam extinguisher for oil fire.

Common fuels in the world today: coal, oil and natural gas are the three most important fossil fuels in the world today, and they are also extremely important raw materials in the chemical industry. They are subdivided into (1) solid fuels: firewood and cigarettes.

Coal, bare coal, anthracite, charcoal, coke, pulverized coal, etc. ; (2) Liquid fuel; Gasoline, kerosene, diesel, heavy oil, etc. ; (3) Gaseous fuels: natural gas, artificial gas and liquid.

Liquefied petroleum gas and so on.

Clean fuels: liquid ammonia, alcohol, liquid hydrogen (the cleanest fuel, the combustion product is water), methanol, etc.