Steam Power Plant

Question 1

Boiler thermal efficiency

Answer 1

ηb = ms(hs - hf) / mfQh
-ms = mass of steam generated
-hs = enthalpy of steam
-hf = enthalpy of feedwater
-mf = mass of fuel
-Qh = higher heating value

Question 2

Heat release rate based on furnace volume, HRv

Answer 2

HRv = mf × HHV/V Btu/hr-ft³
-V = furnace volume

Question 3

Formula for furnace volume , V

Answer 3

V = Af × H
-Af = stoker projected area
-H = furnace height

Question 4

Dulong’s formula, used for solid fuels

Answer 4

Qh = 33,820C + 144,212( H - O/8 ) + 9,304S kJ/kg

Question 5

Rated boiler horsepower for water tube (English)

Answer 5

RBH = HS(ft²)/10 bo.hp
-HS = heating surface

Question 6

Rated boiler horsepower for water tube (SI)

Answer 6

RBH = HS(m²)/0.91

Question 7

Rated boiler horsepower for fire tube

Answer 7

HS(m²)/1.1

Question 8

Developed boiler HP

Answer 8

ms(hs-hf)
-then use boiler HP conversions

Question 9

Boiler percent rating

Answer 9

Developed boiler HP / Rated boiler HP

Question 10

ASME evaporation units

Answer 10

ms(hs-hf) kJ/hr or Btu/hr

Question 11

Factor of evaporation, FE, for SI units

Answer 11

FE = (hs - hf) / 2257

Question 12

Factor of evaporation, FE, for English units

Answer 12

FE = (hs - hf) / 970.3

Question 13

Equivalent evaporation for SI units

Answer 13

ms × FE kg/hr from and at 100°C

Question 14

Equivalent evaporation for English units

Answer 14

ms × FE lbm/hr from and at 212°F

Question 15

Equivalent specific evaporation for SI units

Answer 15

ms/mf × FE kgsteam/kgfuel from and at 100°C

Question 16

Equivalent specific evaporation for English units

Answer 16

ms/mf × FE lbsteam/lbfuel from and at 212°F