Output is defined as the heat that is absorbed by working fluid. Input is defined as the chemical heat of fuel plus the heat that is added to working fluid, air, gas and other fluid circuit in which the fluid circuit across thin layer.
There are several factors act as the source of heat loss combustion. These factors will be used to calculate boiler efficiency based on heat loss method. The source of heat loss can be seen as following below:
a. Heat loss due to dry flue gas
Heat loss due to dry flue gas is the heat loss which is contained in dry flue gas such as CO2, O2 and N2. These gases are one of causes of heat loss in combustion process. The high temperature of flue gas coming out from boiler affect amount of heat loss.
The weight and heat loss of dry flue gas of combustion of coal can be calculated as following formula:
Wdfg = mCO2 + mSO2 + mO2 + mN2
Eloss dfg = Wdfg x Cp x (To - Ts)
Where:
Wdfg = weight of dry flue gas (kg/kg coal)
Eloss dfg = heat loss in dry flue gas (kJ/kg)
To = temperature of dry flue gas coming out from boiler
Ts = temperature of surrounding
by Gajanan Nalegaonkar
boiler out means temperature.pressure,steam flowrate,enthapy
Purpose of the boiler drum is to collect steam from all the various tubes in a boiler, and send it to the turbine to spin the generator
boiler drum diffferential pressure level calculation explained
The term "once-through boiler" refers to a special type of water-tube boiler composed oftubes, in which water is input at the bottom, and steam is produced from the top.
A digester feed pump forces water to a boiler. It works by transferring cool water to the boiler to be heated.
boiler efficiency is how much water is converting to steam.
Boiler efficiency is calculated by determining the steam value per hour and dividing it by the amount of fuel which is consumed per hour. By doing this one can determine the efficiency of a boiler.
we can increase boiler efficiency by recovering the heat which is being carried by flue gases.by incorporating different things like Economizer, Air pre-heater , Super-heater and feed-water heater, we can there ll be notable increase in efficiency of boiler.
see results in attached link: Philips 3-drum 'Accessable' boiler
difine
The economizer is used to raise feedwater temperature up to nearly the temperature of the boiler to avoid thermal shock and improve the boiler's efficiency. Every 11 degrees Fahrenheit increase in feedwater temperature yields a 1% increase in boiler efficiency.
see results in attached link: Philips 3-drum 'Accessable' boiler
An economizer is used to heat boiler feedwater up closer to the temperature of the boiler water, using heat from the boiler exhaust gases, heat that would otherwise be wasted. The main reason is to improve the efficiency of the boiler. For every 44 degree F drop in exhaust gas temp. there is an 11 F rise in feedwater temperature and a 1% gain in boiler efficiency.
Greatest efficiency at that temperature.
The formula of efficiency is power output divided by the power input.
Pump efficiency can not be taken as given.
turndown ratio