How flue gas is produced in steam power plant?

Air Circuit In the air preheater, the heat of the exhaust flue gases is transferred to the inlet air before it enters the furnace. In the furnace, this air supplies required oxygen for combustion. Then this air carries the generated heat and flue gases due to the combustion through the boiler tube surfaces.

How is flue gas generated?

Flue gas—the emitted material produced when fossil fuels such as coal, oil, natural gas, or wood are burned for heat or power—may contain pollutants such as particulates, sulfur dioxide, mercury, and carbon dioxide. Most flue gas, however, consists of nitrogen oxides.

How does flue gas work?

The flue is simply a piece of pipework or duct that moves gases and hot air from the combustion chamber of the boiler to outside. With condensing boilers, the flue is effectively part of the heating system, as it is the heat from the burned gases that starts warming the returning water from the system.

What are the components of flue gas?

The components of flue gas are listed below in the order of concentration in the gas.

• Nitrogen (N2) Nitrogen (N2) is the main component (79 vol.
• Carbon dioxide (CO2) Carbon dioxide is a colourless, odourless gas with a slightly sour taste.
• Water vapour (Humidity)
• Oxygen (O2)

How is flue gas cooled?

Upon exiting the ESP, it is common to cool the flue gas by evaporative cooling to a temperature close to the adiabatic saturation temperature by spraying water into the flue gas stream within a wet flue gas desulfurization (FGD) system.

Why economiser is used in boiler?

In boilers, economizers are heat exchange devices that heat fluids, usually water, up to but not normally beyond the boiling point of that fluid. They are a device fitted to a boiler which saves energy by using the exhaust gases from the boiler to preheat the cold water used to fill it (the feed water).

What is flue gas in power plant?

Flue gas (sometimes called exhaust gas or stack gas) is the gas that emanates from combustion plants and which contains the reaction products of fuel and combustion air and residual substances such as particulate matter (dust), sulfur oxides, nitrogen oxides, and carbon monoxide (Table 3.7).

Which is the major component in the flue gases produced by combustion of coal?

A typical flue gas from the combustion of fossil fuels contains very small amounts of nitrogen oxides (NOx), sulfur dioxide (SO2) and particulate matter. The nitrogen oxides are derived from the nitrogen in the ambient air as well as from any nitrogen-containing compounds in the fossil fuel.

How hot is flue gas?

The typical furnace outlet temperature of flue gases is usually around 1200 °C which will decreases gradually along the pathway of heat transfer, while the temperature of the flue gases going to stack is around 150 °C.

How do you calculate flue gas composition?

Composition of the dry flue gas from the stoichiometric combustion of 1 kg of biomass: N2 from theoretical air = 4.94 × 0.79 = 3.90 m3. N2 from biomass = 0.001 × 0.224 = 0.0002 m3. CO2 from biomass = 4.33 × 0.224 = 0.97 m3.

What is boiler flue gas?

Flue gas refers to a chemical byproduct substance that is generated as a result of a combustion reaction that has escaped through long pipes such as those in boilers, furnaces or steam generators. Flue gas may also be referred to as exhaust gas and may act as a reactor agent for atmospheric corrosion.

What is flue gas and how does it work?

Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants.

How is flue gas treated in a power plant?

At power plants, flue gas is often treated with a series of chemical processes and scrubbers, which remove pollutants. Electrostatic precipitators or fabric filters remove particulate matter and flue-gas desulfurization captures the sulfur dioxide produced by burning fossil fuels, particularly coal.

What is the source of nitrogen in flue gas?

A typical flue gas from the combustion of fossil fuels contains very small amounts of nitrogen oxides (NOx), sulfur dioxide (SO 2) and particulate matter. The nitrogen oxides are derived from the nitrogen in the ambient air as well as from any nitrogen-containing compounds in the fossil fuel.

How does SO2 transfer from flue gas to slurry?

SO2 in the flue gas is absorbed by the slurry and falls into the slurry pool at the bottom of the column. This is a complex process of heat and mass transfer accompanied by chemical reactions. This project mainly simulates the evaporation of water accompanying the heat transfer process, so the following assumptions are made: