How the flue gas temperature is used in thermal power plant?
The flue gas is used in air pre-heater to increase the temperature of the water before it reaches the boiler [5]. The heat obtained by the flue gas will be around 150ºC which will be suitable for the low pressure heater [6].
What is the temperature of 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.
What is the thermal efficiency of a coal-fired power plant?
Typical thermal efficiency for utility-scale electrical generators is around 37% for coal and oil-fired plants, and 56 – 60% (LEV) for combined-cycle gas-fired plants. Plants designed to achieve peak efficiency while operating at capacity will be less efficient when operating off-design (i.e. temperatures too low.)
Why do flue gases leave the stack at high temperature?
The combustion flue gases inside the flue gas stacks are much hotter than the ambient outside air and therefore less dense than the ambient air. That causes the bottom of the vertical column of hot flue gas to have a lower pressure than the pressure at the bottom of a corresponding column of outside air.
How do you reduce the temperature of a gas flue?
Using an integrated or downstream economiser, the flue gas temperature can be reduced to 120 – 140°C, depending on the economiser design, which reduces the flue gas loss significantly. During this process, the heat in the flue gases is transferred to the boiler feed water flowing in countercurrent.
How does flue gas desulfurization work?
How does it work? The FGD technology is based on a chemical reaction that occurs when the warm exhaust gases from the coal-fired boiler come into contact with limestone. This reaction removes 92% of the sulphur dioxide from the flue gas and converts the limestone into Calcium Sulphite.
What should my flue temp be?
A good rule of thumb is to get the temperature up to a stovepipe thermometer reading of 450 degrees F. for the first half-hour, and to keep it at an average of 300 degrees thereafter, each day that you start your stove.
How is flue temperature measured?
If the stove pipe is double-wall then a probe style thermometer is needed. The probe thermometer will read 1.5x to 2x higher than the surface temp on single wall stove pipe because the probe is directly in the flue gas stream inside the stove pipe. 350-600ºF is a common temp for a probe.
How do you calculate the efficiency of a coal power plant?
To express the efficiency of a generator or power plant as a percentage, divide the equivalent Btu content of a kWh of electricity (3,412 Btu) by the heat rate. For example, if the heat rate is 10,500 Btu, the efficiency is 33%. If the heat rate is 7,500 Btu, the efficiency is 45%.
How efficient are power stations?
The efficiency of electricity and heat production from conventional thermal power plants improved between 1990 and 2009 by 5.5 percentage points (from 45.4% in 1990 to 50.9% in 2009). Between 1990 and 2005, the improvement was even greater at 7.0 percentage points (from 45.4% in 1990 to 52.4% in 2005).
What is the desirable flue gas temperature leaving the smoke stack or chimney?
Which is the best location for sampling flue gas analysis?
Flue Gas Analysis is performed by inserting a probe into the flue of the furnace, boiler, etc., between the last heat exchanger and draft diverter or any source of make-up air that could enter the flue that did not pass through the combustion process.
What are the main components of the flue gas in pulverised coal combustion?
The main components of the flue gas in pulverised coal combustion for post- combustion capture are CO2, N2, O2and H2O, and air pollutants such as SOx, NOx, particulates, HCl, HF, mercury as well as other contaminants. The most widespread method of post-combustion capture of CO2is by solvent absorption.
What are the flue-gas changes in large power plant boilers?
In general, the flue-gas changes in large power plant boilers can affect, for example, the corrosion of the super heater area and other parts of the flue-gas system, the flue-gas cleaning systems and, finally, the emissions of power plants. These effects depend on the characteristics of aerosol generated in the combustion process.
Does pellet addition affect the flue gas particles in a boiler?
The effect of pellet addition for the flue gas particles was studied with direct sampling from the boiler super heater area.
How much sensible heat can be recovered from flue gas?
As the flue gas temperature is reduced, the amount of available sensible heat increases. The sensible heat that could be recovered from the flue gas by cooling it in a flue gas cooler (FGC) from the APH gas outlet temperature of 310F to the FGD inlet temperature of 140F is 43 to 46 Btu per pound of flue gas (depending on the coal type).
