Basic Biomass Power Plant Efficiency

Biomass Heating ValueFuel Moisture (%)

(AR)Lower Heating Value (kJ/kg) (AR) Higher Heating Value (kJ/kg) (AR)

Woodchip 45 8,820 1100

Rice Husk 12 13020 14500

Bagasse 55 7140 9200

EFB 60 7120 9130

* This is indicative value only. Accurate value shall be tested by certified laboratory

Ideal Rankin Cycle on T-S Diagram

P Constant

Tem

pera

ture

Entropy

(1)

(2)

(3)

(4)

P Constant

2-3 water from feed water pump is heated up temperature @ constant pressure to be rated steam condition

3-4 steam is expanded its pressure in steam turbine . Steam pressure gradually decrease in each stage of turbine blade. Super heated steam @3 become low pressure mixing steam @4

4-1 low pressure mixing steam is extracted its energy by cooling system . Then mixing steam become liquid phase “condensate water”

1-2, condensate water pressure is increased by feed water pump to boiler rated pressure (2)

Power Plant Equipment

BFWP

Condenser

Steam Turbine

Boiler

(1)

(2)

(3)

(4)

GEnergy Input (Fuel)

Work Output (Electricity)

Plant Efficiency (ɳ) =

Plant Heat Rate = kJ/kWh

Energy Input and Work OutputEnergy input is fuel fed into boiler then combust and release energy to boil water to from liquid phase to vapor phase (typically refer to super heated steam)Example: boiler consume 15 T/H of wood chip to generate steam. It is equivalent to

Work Output is electricity generated from steam turbine generator Example: from 15 T/H of woodchip, steam turbine generator produces electricity 9900 kW

Plant Efficiency is = = = 26.93%Plant Heat Rate =

Effecting parameter on plant efficiency

• Boiler Efficiency• Steam Turbine and Generator Efficiency• Condenser Efficiency• Cooling Tower Efficiency

Boiler Efficiency

Boiler Efficiency

79.5%Fuel 100%

Steam 79.5%

Loss from moisture in fuel 7 %

Loss from radiation 0.2%

Loss from CO 0.3 %

Loss from H2 in Fuel 6%

Loss from Unburn Carbon 2%

Loss in dry flue gas 5 %

Steam Turbine Efficiency

Steam Turbine

Stea

m

Adm

issio

n lo

ss

Leak

age

loss

Fric

tion

loss

Aero

dyna

mic

los

s

Leak

age

loss

Exha

ust l

oss

Condenser Efficiency

Condenser

- Less cooling water flow rate- Fouling on tube- Incondensable gas- Overheat duty

Cooling Tower Efficiency

Hot Water

Cold Water

Hot Air

Cold Air

- Evaporation loss- Drift loss - Blow down loss- Etc.

Heat and Mass Balance Diagram

Heat and Mass Balanced Diagram

• Conceptual Design• Off Design Analysis• What-if Analysis• Off-line and On-line Performance Monitoring