144 POWER PLANT ENGINEERING
superheater tubes, flow through the dust collector and then through economiser, air pre-heater and fi-
nally they are exhausted to the atmosphere through the chimney.
Steam condensing system consists of the following:
(i) Condenser
(ii) Cooling water
(iii) Cooling tower
(iv) Hot well
(v) Condenser cooling water pump
(vi) Condensate air extraction pump
(vii) Air extraction pump
(viii) Boiler feed pump
(ix) Make up water pump.4.2.1 Power Station Design
Power station design requires wide experience. A satisfactory design consists of the following
steps :
(i) Selection of site
(ii) Estimation of capacity of power station.
(iii) Selection of turbines and their auxiliaries.
(iv) Selection of boilers, and their auxiliaries.
(v) Design of fuel handling system.
(vi) Selection of condensers.
(vii) Design of cooling system.
(viii) Design of piping system to carry steam and water.
(ix) Selection of electrical generator.
(x) Design and control of instruments.
(xi) Design of layout of power station. Quality of coal used in steam power station plays an
important role in the design of power plant. The various factors to be considered while
designing the boilers and coal handling units are as follows :
(a) Slagging and erosion properties of ash.
(b) Moisture in the coal. Excessive moisture creates additional problems particularly in case
of pulverized fuel power plants.
(c) Burning characteristic of coal.
(d) Corrosive nature of ash.4.2.2 Characteristics of Steam Power Plant
The desirable characteristic for a steam power plant are as follows :
(i) Higher efficiency.
(ii) Lower cost.