Table of Contents
- 1 What is higher heating value and lower heating value of fuel?
- 2 What are the factors which affect the boiler performance?
- 3 Why a fuel with higher calorific value is more preferred?
- 4 Which fuel has the highest heating value?
- 5 What factors determine the efficient utilization of fuel in steam boilers?
- 6 What affects the flue gas loss in a boiler?
What is higher heating value and lower heating value of fuel?
The lower heating value (LHV) or higher heating value (HHV) of a gas is an important consideration when selecting a gas engine or CHP plant. The total amount of heat liberated during the combustion of a unit of fuel, the HHV or HCV, includes the latent heat stored in the vapourised water.
What are the factors which affect the boiler performance?
There are several factors that influence the energy performance of boilers including fuel characteristics, firing method, steam pressure, and heating capacity. The main challenge to ensure optimal operating conditions for boilers is to provide the proper excess air for the fuel combustion.
Does a higher heat of combustion for a fuel mean it is more efficient?
Heats of combustion are used as a basis for comparing the heating value of fuels, since the fuel that produces the greater amount of heat for a given cost is the more economic.
What is fuel lower heating value?
The lower heating value (also known as net calorific value) of a fuel is defined as the amount of heat released by combusting a specified quantity (initially at 25°C) and returning the temperature of the combustion products to 150°C, which assumes the latent heat of vaporization of water in the reaction products is not …
Why a fuel with higher calorific value is more preferred?
The calorific value of a fuel should be high, so that large quantities of heat can be obtained from a small quantity of coal. It should have low ash content since the presence of ash reduces the heating value of coal. Coal should have high calorific intensity.
Which fuel has the highest heating value?
hydrogen
Calorific value is nothing but the energy contained in a fuel or food, determined by measuring the heat produced by the complete combustion of a specified quantity of it. This is now usually expressed in joules per kilogram. Hence, hydrogen has the highest calorific value.
What affects the heat of combustion?
Combustion reactions require 3 things- fuel, oxygen and energy. Combustion reactions are exothermic reactions in which the reactant combines with oxygen to produce an oxide. This is an oxidation reaction. The complete combustion of hydrocarbons occurs when there is sufficient oxygen for the fuel to burn.
What is boiler efficiency and why is it important?
Boiler efficiency is a measure of how effectively chemical energy in fuel is converted into heat energy in steam going to the turbines. The largest boiler efficiency loss is sensible heat lost as hot flue gases (and ash) exit the boiler. Unburned carbon losses equate to the fraction of combustible fuel which is not burned in the boiler.
What factors determine the efficient utilization of fuel in steam boilers?
The efficient utilization of fuel in steam boilers is primarily determined by the following three factors : Complete combustion of the fuel in the furnace Deep cooling of the combustion products 2 during their passage through heating surfaces. Minimization of heat losses to the environment.
What affects the flue gas loss in a boiler?
The flue gas loss depends on the final flue gas temperature and the amount of flue gases. Thus the higher the air ratio, the higher the flue gas losses. The flue gases should leave the boiler at a temperature as low as possible to minimize the flue gas losses.
What is the heat absorbed by working fluid in boiler?
Heat absorbed by working fluid in boiler : Heat content of superheated steam from boiler Heat content of reheated steam from 3 boiler Heat content of boiler blow- down water