How to calculate the specific fuel consumption of Power plant??

Specific Fuel Consumption (SFC) in Power Plants refers to the amount of fuel required to generate a unit of energy output. It is a key performance metric used to assess the efficiency of different power generation systems.

Specific fuel consumption (SFC)= Fuel consumption in kg/hr / Power generation in Kwh

Specific fuel consumption (SFC)= Specific steam consumption (SSC) / Steam to fuel ratio (SFR)

Factors affecting the Specific fuel consumption:

1-Steam consumption of the Turbine: Higher steam consumption of steam Turbine leads to more Specific fuel consumption (SFC).

2-Main steam parameters like pressure & temperature: Should be always on higher side but within design limit.

3-Boiler efficiency: High efficiency boilers consumer lesser fuel and hence Specific fuel consumption (SFC) will be on lower side.

4-Turbine efficiency: High efficiency Turbines will have higher out put on lesser input, hence Specific fuel consumption (SFC) of such Turbines is LESS

5-Fuel type & quality: High GCV fuel firing power plants will have lesser Specific fuel consumption (SFC).

6-Boiler operator competency: Efficient Operation of the Boiler, Turbine and other power plant equipment depends on the skill & competency of the operators.

7-Plant load factor: Operation of the Power plant units on higher loads or optimised loads leads to lower Specific fuel consumption (SFC) & Vice Versa, that is operation of plant on partial loads results into more fuel consumption and hence leads in more Specific fuel consumption (SFC).

8-Atmospheric conditions: Atmospheric conditions like temperature, pressure & humidity play a very vital role on achieving best efficiency of power plant equipment.

Specific fuel consumption (SFC) is also termed in terms of heat rate.

Heat rate = Energy consumed in kcal/ Power generation

It is measured in terms of kcal/kwh

Specific fuel consumption (SFC) is different for different fuels, fuels having higher heating value or calorific value will have lesser Specific fuel consumption (SFC) & fuels having lower calorific value will have higher specific fuel consumption.

It’s always recommended that Specific fuel consumption (SFC) should LESS.

Power plants having lesser Specific fuel consumption (SFC) are in more profit.

How to calculate the specific fuel consumption???

Specific steam consumption (SSC) is the amount of steam consumed by Turbine is always lesser to achieve lesser Specific fuel consumption (SFC). It’s measured in kg/kwh or MT/MW.

Similarly, Stam to fuel ratio (SFR) is the amount of steam generated on burning 1 MT or 1 Kg of fuel. It’s measured in kg/kg or MT/MT.

Examples:

1-Calculate the specific steam consumption of a 50 MW thermal power plant, which consumes around 960 MT of coal to generate 1200 MW power.

Given data,

Power generation = 1200 MW

Fuel consumed = 960 MT

Specific fuel consumption (SFC)= Fuel consumption in kg/hr / Power generation in Kwh

Specific fuel consumption (SFC)= 960/1200 =0.8 kg/kwh or 0.8 MT/MW

2-A 225 MW Thermal power plant’s steam turbines Specific steam consumption (SSC) is 3.5 MT/MW and it’s Boiler’s Steam to fuel ratio (SFR) is 4.5. Calculate the specific steam consumption of that plant

Given data,

Specific steam consumption (SSC) = 3.5

Stam to fuel ratio (SFR) = 4.5

Specific fuel consumption (SFC)= Specific steam consumption (SSC) / Steam to fuel ratio (SFR)

Specific fuel consumption (SFC)= 3.5/4.5 =0.78 Kg/kwh or 0.78 MT/MW

Indian Boiler Regulations-2024 Publication

3-A Boiler consumes 25 MT of bio mass to generate 55 MT of steam per hour at pressure 67 kg/cm2 and temperature 490 deg C, which is used to run the 12 MW condensing Turbine. What would be the specific fuel consumption of this plant?

Given data,

Fuel consumption = 25 MT

Steam generated = 50 TPH

Power generation = 12 MW

Steam to fuel ratio (SFR) = Steam generated per hour / Fuel consumed per hour

Steam to fuel ratio (SFR) = 55 / 25 =2.2

Specific steam consumption (SSC) = Steam consumption by Turbine TPH / Power generated in MW

Specific steam consumption (SSC) = 50 / 12

Specific steam consumption (SSC) = 4.16 MT/MW

Specific fuel consumption (SFC)= Specific steam consumption (SSC) / Steam to fuel ratio (SFR)

Specific fuel consumption (SFC)= 4.16 / 2.2 =1.89 MT/MW

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