Boiler (Steam Generator)

Boiler  (Steam Generator)

-The boiler for 1,094 t/h MCR is Single Drum Radiant Natural Circulation Boiler “ELPASO” Type which has self-drainable heating surface.  The unit is of pressurized furnace design with two regenerative air heaters, two forced draught fans and two flue gas recirculation fans. The boiler consists of the following equipment.

Steam drum

Water wall

Primary Superheater, Secondary Superheater and Tertiary Superheater

Reheater

Attemperators

Economizer

Two forced draft fans

Two gas recirculation fans

Two regenerative air heaters

Two steam coil air heaters

Ducts and flues

Gas and oil burner system

Steel structure

Piping and valves

Other auxiliary equipments

-The boiler and its auxiliaries are designed suitable for firing Natural Gas and back-up Mazout and for the following conditions:-

Economizer inlet to drum inlet :  203 bar(g)

Water wall :                                   204 bar(g)

Drum and superheater :              201 bar(g)

Reheater :                                     47 bar(g)

Superheater outlet :                   541 °C      181.1 bar(g)

Economizer inlet :                     275.8 °C    194.9 bar(g)

Reheater outlet :                       541 °C       37.6 bar(g)

Reheater inlet :                         328.6 °C    38.9 bar(g)

-Superheater outlet steam Temperature is controlled to constant within the load range from 50% turbine to 100%BMCR by spray attemperation.

-The reheater outlet temperature is controlled to constant within the load range from 50% turbine to 100% BMCR by flue gas recirculation. The reheater spray attemperation for reheat control is used only as an emergency measure during periods of load changes or of low feedwater temperature due to heater outage, or at overloads.

-The main specifications of the boiler are:-

Type of boiler                                  Babcock - Hitachi

                                                         Single Drum, Radiant, Natural Circulation Boiler

Evaporation (BMCR)                             :  1,094.4 t/h

Steam Pressure at SH outlet                : 181.1 bar(g)

Steam Temperature at SH outlet          :  541 °C

Feed water Temperature                       : 275.8 °C

Reheat Steam Flow                               : 941.4 t/h

Steam Pressure at RH outlet                : 37.6 bar(g)

Steam Temperature at RH outlet         : 541 °C

Steam Temperature at RH inlet            : 328.6 °C

Ambient Air Temperature                     : 34.8 °C

Draught system                                     : Forced draught

Fuel                                                         : N.Gas, Mazout Oil

That was a small description of the boiler from (HITACHI BABCOK Company.), Used at Thermal Power Station, the next Post I will talk about each system of the Boiler.