IMPULSE STEAM TURBINE

-
Steam turbine is a rotating machine which converts the energy in to mechanical energy as shaft rotation.

IMPULSE TURBINE
All pressure drop of a steam occur in the nozzle.
no pressure drop through the lid passage so freezer remain constant as the steam flowing through the blood. 
So the net work output is the difference between momentum of steam at inlet of blade and momentum of Jet at exit of blade which is equal to the momentum absorbed by the wheel for reducing the shaft work.
Compounding of steambturbine 
Stage in steam turbine :- if one row of Nozzle is arranged with one row of moving blade, this is called as one stage.
So if high pressure steam is expanded to condensers pressure then high enthalpy drop on a single stage turbine so very high velocity of jet is exit from nozzle.
When this very high Velocity of jet is strike on turbine blade very high RPM are produced which is not economical. 
Which is not economical.
So turbine speed is reduced with same amount of enthalpy drop by using compounding of steam turbine.
In it several number of stages are used. Where the steam is allow to expand on a large numbers of stage.

There are two methods are used for compounding of steam turbine.
(1) Pressure compounding 
(2) Velocity compounding
(3) Pressure Velocity compounding

Single stage impulse turbine called as De-Laval turbine.

Comments

Post a Comment

Popular Posts

HPBP & LPBP

-
Image
HP Bypass Station 1:- HP/LP bypass system can handel 60% of boiler load. 2:- HPBP valve is a combined pressure reducing and desuperheating station valve 3:- Spray water is tapped from BFP discharge  and spray controled by spray control valve. 4:- HPBP dumps the depressurised and desuperheated steam with suitable parameter into CRH line. 5:-Can operate without coordinate with turbine. 6:- Allows quick raising of steam parameters at a level acceptable to turbine for rolling operqtion during start up. 7:-Oil supply unit is installed for operation of HPBP & LPBP valves  8:-Supply oil pressure is maintained at 160 kg/cm2 by the pump and accumulator unit. Modes of HP Bypass Operation 1:- Boiler start-up with TG set at stand still. 2:- Rising of steam parameters to a level acceptable to turbine for rolling. 3:- Turbine start-up and loading while steam flow gets transferred to the turbine 4:- Parallel operation with turbine on load rejection. 5:- Allowing boiler operatio
Read more

APRDS in THERMAL POWER PLANT

-
Image
OBJECTIVE Auxiliary steam is the steam that is required for various auxiliary requirements in a power plant. A part of main steam is tapped off for auxiliary steam station from MS/CRH line, after pressure reducing and de-superheating up to 16 Kg/cm 2   & 320 °C. At the HT header (16 16 Kg/cm 2    & 320⁰C) and then at the LT header (16 Kg/cm2 & 210⁰C) through desuperheater b/w the HT & LT headers. Spray water quantity required for the temperature reduction of the steam is controlled by separate spray water valve (taken from CEP discharge). TYPES OF STATIONS System consists of  two auxiliary  steam pressure reducing and desuperheating stations (APRDS). High capacity PRDS (LTPRDS)  with tapping off steam from main steam line or CRH line . Low Capacity PRDS(LTPRDS)  from HT header. APRDS SERVICES Auxiliary steam system is designed to provide steam for following systems. 1:-  Turbine  &  Turbine auxiliaries . 2:-  Boiler auxiliaries . 3:-
Read more

CONDENSATE EXTRACTION PUMP (CEP) IN A THERMAL POWER PLANT

-
Image
CONDENSATE EXTRACTION PUMP (CEP) Its Importance in Thermal Power Plant It handles water from hot well. The characteristic of that pump is that it handles water from vacuum.  Berceuse the condenser and the hot well are in vacuum bellow atmospheric pressure. No other pump has this characteristic to handle in such condition. It takes water from vacuum pressure and delivered above atmospheric pressure.   It is a vertical turbine type pump which is multi stage. It deliver water from hot well to deaerator. They may be used to pump the condensate produced from latent water vapors in any of the following mixtures: Steam condensed (exhaust from LP turbine) in condenser Make up water (dumped in condenser hot well from condensate storage tank) Flash box water LPDFT water HPDFT water Drip from ejector Drip from LPFWH   CEP for a 200 MW unit:- Each unit has been equipped with three nos. of condensate pumps installed vertically at minus four meter level in to the turbine hall.
Read more