Since Steam Turbine is the heart of any Thermal Power Plant, hence its performance plays an important role in enhancing the profitability. But if its performance is not monitor, it will not be possible to take appropriate action. As the size of Steam Turbine is increasing day by day from 200 MW, 250MW, 300 MW,500 MW, 660MW & 800 MW.

Steam Turbines of Capacity above 660 MW normally operates at Super Critical Parameters. For improving efficiency, very close clearances are maintained which require a very steady state of operation. But if the super critical units are operated at varied load due to Grid requirements, then some degradation is bound to take place which will reflect in deterioration in cylinder efficiency.

Since Thermal Power Plants are having various systems and sub systems. Hence we invite all to discuss possible measures for identifying and plugging the profit eaters.

Before identifying the area of concerns which are contributing for in efficiency of Steam Turbine, we have to be familiar with the various systems and sub systems of Combined Cycle Power Plants irrespective of make and capacity.

• Steam Turbine System. This system is having following sub systems
• Steam Turbine.
  • HPT Cylinder Efficiency
  • IPT Cylinder Efficiency.
  • LPT Cylinder Efficiency.
• High Energy Drain Points.
• Condenser
  • CW Flow.
  • CW Inlet Temp.
  • CW Outlet Temp.
  • CW DP.
  • Hot Well Temp.
• Cooling Tower.

Each and every system and Equipment associated with the systems are the known contributing factors for Profit Eaters.

To assess the quantum of profit eating, a thorough study has to be carried out for each and every system.

For example, suppose the Cycle Heat Rate has deteriorated by 10 Kcal/kwh.

Suppose the Plant is Firing Coal with landed Cost of 4500/Mt.

GCV of this Coal is 4,000 Kcal/Kg.

Suppose this is a 660MU Unit and assuming 90% PLF, this unit will produce :14.256 MU  of Electricity per day.

If the Cycle Heat rate is deteriorated by 15Kcal/Kwh,

Then the loss on account of increase in Heat Rate is Rs. 1.60 Lac  /Day.

Then the loss on account of increase in Heat Rate is Rs. 48.11Lac  /Month.

Then the loss on account of increase in Heat Rate is Rs. 5840  Lac  /Year.

We can see the impact of increase in Cycle Heat rate by 15 Kcal/kwh, therefore outmost care with some innovative approach has to be developed to mitigate such losses.

Normally, for Gap analysis, the operating data are compared with HMBD data. But in absence of HMBD data, certain innovative approach has to be adopted for which a set of readings are to be noted down during running of Steam  Turbine immediate after major overhauling. Then these critical parameter are used for gap Analysis. In some cases a few additional instruments may be required and these additional instruments are  to be installed for such studies.