The guaranteed heat rate, indicated on performance data table of power plant is calculated in accordance with
the following formula:
HR = (Qms x Hms - Qfw x Hfw + Qhrh x Hhrh - Qcrh x Hcrh - Qas x Has + Qmu x Hmu) x 3600 / W
HR = heat rate [kJ/kWh]
W = gross power output [kW]
Q = mass flow [kg/s]
H = enthalpy [kJ/kg]
Subscript:
ms = main steam
fw = boiler feedwater
hrh = hot reheat steam
crh = cold reheat steam
as = auxiliary steam extraction from turbine cycle for boiler users
mu = make up water at condenser
it is used balance axial thrust on turbine rotor due to admitting of high pressure steam in to turbine. it basic purpose is to save thrust bearing.
Why extractions are taken out from steam turbine.
Rankine cycle is used in steam turbine
Steam turbine nozzle clearance is the total energy content available in steam. This is through a valve.
inconsistent load will cause steam turbine hunting.
An example of an energy balance equation for a steam turbine can be expressed as: Input energy (steam flow rate x enthalpy of steam) Output energy (mechanical work done by the turbine heat losses)
Steam Rate calculation Formula for Steam Turbine
it is used balance axial thrust on turbine rotor due to admitting of high pressure steam in to turbine. it basic purpose is to save thrust bearing.
by calculating the inlet steam enthalpy-outlet steam enthalpy we will know the total kcal consumed for output mw required kcal for 1 kwh=860 now campare this with your turbine kcal for 1kwh now you came to know how much is your turbine efficiency................................................................................
The feed system cycles between boiler and turbine and enables the steam to return to the boiler as feed water. A closed feed cycles a main propulsion steam run turbine through a high pressure water tube boiler. The condenser, set to a high vacuum, will receive the steam turbine exhaust.
Why extractions are taken out from steam turbine.
Steam is redirected back into the boiler from the high-pressure turbine for reheating, but the steam from the low-pressure turbine enters into a condenser to become water again.
Efficiency formula for a steam turbine is typically derived by dividing the electrical power output by the heat energy input. The heat rate of the steam turbine represents the amount of heat energy required per unit of electrical power generated, and by rearranging the equation, we can derive the efficiency formula as the reciprocal of the heat rate.
The preventive maintenance of steam turbine mainly entails frequent servicing of the parts. This will ensure a smooth performance of the steam turbine.
manish
Rankine cycle is used in steam turbine
why we are maintain vacuum in steam turbine at steam outlet or exhaust side