A-Boiler
1-Boiler efficiency direct method
Boiler efficiency = (Mass of steam flow X Steam enthalpy-Feed water flow at economizer inlet X Enthalpy-Attemperator water flow X Enthalpy) / (GCV of fuel X Fuel consumption)
2-Boiler efficiency by indirect method
Boiler efficiency = 100-Various losses
3-Theoretical air requirement for combustion
Theoretical air Thair = ((11.6 X C% + (34.8 X (H2-O2/8)) + (4.35 X %S))/100
Where C = % of carbon in fuel
H2 = % of Hydrogen present in fuel
S = % of sulphur present in fuel
4-Excess air requirement for combustion
%EA = O2% / (21-O2%)
Where O2 = % of oxygen present in flue gas
5-Mass of actual air supplied
AAS = (1 + EA / 100) X Theoretical air
6-Mass of flue gas
Mfg = Mass of Air + 1
6-Mass of dry flue gas
Mfg = Mass of Co2 in flue gas + Mass of Nitrogen in fuel + Mass of Nitrogen in combustion air + Mass of oxygen in flue gas + Mass of So2 in flue gas
Mfg =(Carbon % in fuel X Molecular weight of CO2 / Mol.weight of Carbon) + N2 in fuel + (Mass of actual air supplied X % of N2 in air i.e 77/100) + ((Mass of actual air – Mass of theoretical air) X 23/100) + S2 in fuel X Mol.weight of SO2 / Mol.weight of sulphur)
7-% of heat loss in dry flue gas
Heat loss = Mfg X Cp X (Tf-Ta) X 100 / GCV of fuel
Where,
Mfg = Mass of flue gas
Cp = Specific heat of flue gas in kacl/kg
Tf = Temperature of flue gas
Ta = Ambient air temperature
9-% of heat loss due to moisture in fuel
Heat loss = M X (584 + Cp X (Tf-Ta)) X 100 / GCV of fuel
Where,
M = Moisture in fuel
Cp = Specific heat of flue gas in kcal/kg
10-% of heat loss due to moisture in air
Heat loss = AAS X humidity X Cp X (Tf-Ta) X 100/ (GCV of fuel)
Where,
AAS = Actual air supplied for combustion
Cp = Specific heat of flue gas in kcal/kg
Tf = Temperature of flue gas
Ta = Ambient air temperature
11-% of Boiler water blow down
Blow down % = (Feed water TDS X % of makeup water) X 100 / (Maximum permissible TDS in Boiler water –Feed water TDS)
12-Steam velocity in line
Velocity of steam in pipe line,V = Steam flow in m3/sec / Area of pipe line (A)
Steam flow in m3/sec = (Steam flow in kg/hr / Density of steam X 3600)
Area of pipe, A = Pi X D2 / 4
Where D is pipe internal diameter
13-Condensate flash steam calculation
Flash steam % = (H1-H2) X 100 / Hfg)
Where, H1 = Sensible heat at high pressure condensate in kcal/kg
H2 = Sensible heat of steam at low pressure in kcal/kg
Hfg = Latent heat of flash steam
14-Calculation of amount of heat required to raise the water temperature
Heat required in kcal=Mw X Cp X (T2-T1)
Where, Mw = Mass of water
Cp = Specific heat of water in kcal/kg (1 kcal/kg)
T1 = Initial temperature of water in deg C
T2 = Final temperature of water in deg C
15-Calculation of heat required to raise air temperature
Heat required in kcal=Mair X Cp X (T2-T1)
Where, Mw = Mass of water
Cp = Specific heat of flue gas in kcal/kg (0.24 kcal/kg)
T1 = Initial temperature of air in deg C
T2 = Final temperature of air in deg C
16-Surface heat loss calculation
S = (10 + (Ts-Ta) / 20) X (Ts-Ta) X A
S = Surface heat loss in kcal/hr m2
Ts= Hot surface temperature in deg C
Ta = Ambient air temperature in deg C
17-Dryness fraction of steam
X = Mass of dry steam / (Mass of dry steam + Mass of water suspension in mixture)
18-Heat content in wet steam
h = hf + xhfg
h= Heat content in saturated steam
x = Dryness factor of steam
Hfg =Enthalpy of evaporation
19-Heat content in dry saturated steam
h = hf + hfg
h= Heat content in saturated steam
Hfg =Enthalpy of evaporation
20-Heat content in superheated steam
h = hf + hfg + Cps (Tsup - Ts)
h= Heat content in super heated steam
hfg =Enthalpy of evaporation
Cps = Specific heat of super heated steam
Tsup= Superheated steam temperature in deg C
Ts = Saturated temperature of steam in deg C
21-Calculation of Equivalent evaporation
Me = Ms X (h-hf) / hfg
Ms = Mass of steam
h = Steam enthalpy
hf= Feed water enthalpy
22-Factor of evaporation
Fe = (h-hf) / 539
23-Ash (Total) generation calculation
Ash generation in TPH = Fuel consumption per hour X % of ash in fuel / 100
24-Fly ash generation calculation
Fly ash generation in TPH = Fuel consumption per hour X % of ash in fuel X 80% / 100
25-Bottom ash generation calculation
Bottom ash generation in TPH = Fuel consumption per hour X % of ash in fuel X 20% / 100
26-Calculation of ash generation in ESP
Ash generation in ESP in TPH = Fuel consumption per hour X % of ash in fuel X 80% X 80% / 100
27-Boiler safety valve blow down calculation
Blow down % = (Set pressure - Re seat pressure) X 100 / Set pressure
28-Calculation of attemperator water flow
Attemperator water flow in TPH= Steam flow in TPH X (h1-h2) / (h2-h3)
h1 = Enthalpy of steam before desuper heating in kcal/kg
29-Economiser efficiency calculation
ηEco. = (Economiser outlet feed water temperature-Economizer inlet feed water temperature ) X 100 / (Economizer inlet flue gas temperature - Economizer inlet feed water temperature)
30-APH efficiency calculation
APH air side efficiency
ηAPHa = (Air outlet temp-Air inlet temp)) X 100 / (Flue gas inlet temperature -Air inlet temperature)
APH gas side efficiency
ηAPHg = (Flue gas inlet temp.-Flue gas outlet temp) X 100 / (Flue gas inlet temperature -Air inlet temperature )
31-Calculation of steam cost
Steam cost per ton = Steam enthalpy in kcal/kg X Fuel price per ton/ (Boiler efficiency % X GCV of fuel used in kcal/kg)
32-Travelling grate Boiler heating surface calculation
Boiler heating surface (Appx) = Boiler capacity in kg/hr / 18
33-AFBC Boiler heating surface calculation
Boiler heating surface (Appx) = Boiler capacity in kg/hr / 22
34-Travelling grate slop fired Boiler heating surface calculation
Boiler heating surface (Appx) = Boiler capacity in kg/hr / 12
35-AFBC slop fired Boiler (Low pressure up to 10 kg/cm2 WP) heating surface calculation
Boiler heating surface (Appx) = Boiler capacity in kg/hr / 8.2
36-Calculation of draught produced in Chimney
Hw = 353 X H (1/Ta – 1/Tg (Ma+ 1)/Ma)
H = Chimney height in meters
Ta = Atmospheric temperature in K
Tg = Flue gas temperature in K
Ma = Mass of air & Mass of flue gas = Ma+1
Also given as;
P = 176.5 X H / Ta
Hw = Chimney height in meters
Ta = Absolute atmospheric temperature in Kelvin
Hw = Draught in mmwc
37-Calculation of mass of flue gas flowing through chimney
Mg (kg/sec)= Density of gas (kg/m3) X Area of Chimney (m2) X Velocity of flue gas in Chimney (m/sec)
38-How to calculate the quantity of De-aerator venting steam?
De-aerator vent rate = 10.98 X Absolute pressure in deaerator X (D X D) Diameter of venting line orifice….Kg/hr
Note: Pressure in PSI
Diameter in inches
Or.
Steam venting flow = 24.24 X P(absolute pressure in PSI) X D X D (Size orifice in inch)........Lbs/hr
B-Turbine and Auxiliaries
1-Turbine heat rate calculation
a-Heat rate of Thermal power plant Turbine in kcal/kw =
Steam flow X (Steam enthalpy in kcal/kg-Feed water enthalpy in kcal/kg) / Power generation
b-Heat rate of Co-gen plant Turbine in kcal/kg =
Inlet steam flow X Enthalpy-(Sum of extraction steam flow X Their enthalpy + Exhaust steam X Enthalpy) / Power generation
i.e THR = ((Steam Flow x Steam Enthalpy)-(1St EXT Flow x Its Enthalpy + 2nd Ext flow x its Enthalpy + 3rd Ext flow x Its Enthalpy+ Exhaust Steam flow x its Enthalpy)) /Power Generation
Or
THR=((Steam Flow x Steam Enthalpy +Makeup Water flow x Its Enthalpy+ RC Flow x RC Enthalpy)-(Process-1 steam flow x its Enthalpy + Process-2 steam flow x Its Enthalpy+ FW Flow x FW Enthalpy)) /Power Generation
2-Turbine efficiency calculation
Efficiency = 860 X 100 / Turbine heat rate
3-Steam condenser efficiency calculation
Condenser efficiency =Difference in cooling water inlet & outlet temperatures X 100/(Vacuum temperature-condenser Inlet temperature of cooling water)
Condenser efficiency = (T2 - T1) X 100/(T3 - T1)
T2: Condenser outlet cooling water temperature,
T1: Condenser inlet cooling water temperature,
T3: Temperature corresponding to the vacuum or absolute pressure in the condenser.
4-Vacuum efficiency calculation
Vacuum efficiency = (Actual vacuum in condenser X 100)/Max. Obtainable vacuum.
I.e
Vacuum efficiency in % =Actual vacuum X 100 / (Atmospheric pressure or barometric pressure-Absolute pressure)
5-Cooling tower range
Range = Cooling tower outlet water temperature-Cooling tower inlet water temperature
6-Cooling tower approach
Approach = Cooling tower outlet cold water temperature - Wet bulb temperature
7-Cooling efficiency calculation
Efficiency = Range X 100 / (Range + Approach)
8-Heat rejected or heat load of cooling towers
Heat load =Mass of circulating water X Specific heat of water Cp X Range
9-Cooling tower evaporation loss calculation
Evaporation loss in m3/hr = 0.00085 X 1.8 X Water circulation rate m3/hr X Range
Evaporation loss in % = Evaporation loss X 100 / Water circulation rate m3/hr
10-Cooling tower blow down loss calculation
Blow down loss in % = Evaporation loss X 100 / (COC-1)
Where COC: Cycles of concentration
Its generally calculated as;
COC = Conductivity in circulation water / Conductivity in makeup water
OR
COC = Chloride in circulation water / Chloride in makeup water
11-Calculation of mass of cooling water required to condenser steam in surface condensers
Mw = (Ms X (hfg X dryness fraction(x) + Cpw (T3 - Tc)))/(Cpw X (T2 - T1))
Mw = Mass of cooling water required in TPH
Ms = Mass of exhaust steam to condenser in TPH
Hfg = Enthalpy of evaporation at exhaust pressure in kcal/kg
Cpw = Specific heat of cooling water in kcal/kg
T3= Temperature at exhaust pressure in deg C
Tc= Temperature of condensate in deg C
T1=Cooling water temperature entering condenser in deg C
T2 = Cooling water temperature leaving condenser in deg C
12-Steam turbine wheel chamber pressure calculation (Appx)
Turbine wheel chamber pressure (kg/cm2 ) = (Turbine inlet pressure (kg/cm2 ) X Turbine operating load (MW) X 0.6) / Turbine rated capacity (MW).
13-Calculation of power generation in steam Turbine
Power generation in MW= Turbine inlet steam flow in TPH X (Inlet steam enthalpy in kcal/kg- Exhaust steam enthalpy in kcal/kg) / 860
14-Power generation calculation in multi stage Turbines
Power generation in MW= Steam flow from 1st stage X (Inlet steam enthalpy in kcal/kg- 1st stage extraction steam enthalpy in kcal/kg) + Steam flow from 2nd stage X (Inlet steam enthalpy in kcal/kg- 2nd stage extraction steam enthalpy in kcal/kg) + Exhaust steam flow to condenser X (Inlet steam enthalpy in kcal/kg- Exhaust steam enthalpy in kcal/kg) / 860
15-Calculation of work done per kg of steam in Turbine
Work done/kg of steam = Inlet steam enthalpy in kcal/kg-Exhaust steam enthalpy in kcal/kg
16-Calculation of steam required per per KWH
Steam required per KWH = 860 / (Work done per kg of steam)
Or
Steam required per KWH =860/(Inlet steam enthalpy in kcal/kg-Exhaust steam enthalpy in kcal/kg)
17-Thermal power plant efficiency calculation
Efficiency = 860 X Power generation / Heat input
Efficiency = 860 X PG X 100 / (Fuel consumption X Fuel GCV)
18-Co gen-plant efficiency calculation
Efficiency = 860 X Power generation X 100 / (Fuel consumption X GCV + Make up water X Make up water enthalpy + Return condensate water X Enthalpy-Process steam flow X Enthalpy)
19-HP heater steam consumption calculation
Steam flow in TPH = FW flow in TPH X (HP heater outlet FW temperature-HP heater inlet FW temperature) /(Steam enthalpy in kcal/kg-HP heater outlet condensate water enthalpy in kcal/kg)
Where, FW = Feed water
20-Deaerator steam consumption
Mass of steam in TPH = (Deaeraor outlet Feed water flow in TPH X Enthalpy –CEP flow X Enthalpy-Makeup water X Enthalpy) / (Enthalpy of steam-Enthalpy of deaerator outlet water)
Note: Enthalpy in kcal/kg
Feed water, CEP water & Make up water flow in TPH
C-Pumps fans and air compressors
1-Centrifugal pumps hydraulic power consumption
Hydraulic power in Kwh = Flow (M3/sec) X Total head (m) X Fluid density (kg/m3) X g (m/s2) / 1000
2-Pump shaft power calculation
Pumps shaft power Ps = Hydraulic power / Pump efficiency
3-Pump electrical power calculation
Electrical power = Pump shaft power / Motor efficiency
4-Pump affinity laws
a-Q1/Q2 = N1/N2
Q1 & Q2 are pump flow at different RPM
N1 & N2 are pump speed
b-H1 / H2 = (N1)2 / (N2)2
Where H1 & H2 are pump head at different RPM
N1 & N2 are pump speed
c-P1 / P2 = (N1)3 / (N2)3
P1 & P2 are pump flow at different RPM
N1 & N2 are pump speed
5-Relation between head,flow ,power and impeller diameter
Q = D (Flow is directly proportional to impeller diameter)
H = D2 (Head is directly proportional to square root of impeller diameter)
P =D3 (Power is directly proportional to impeller diameter)
6-Relation between NPSHR, flow and speed
NPSHR = N2 (NPSHR is directly proportional to square root of speed)
That is as the flow and speed increase, pump need more NPSH
7-Fans volumetric flow calculation
Flow (m3/sec) = Velocity of fluid (m/sec) X Area of duct (m2)
8-Fans Mechanical efficiency calculation
Mechanical efficiency % = Flow (m3/sec) X Total pressure (mmwc) X 100 / (102 X power input to fan shift in KW)
9-Fans Technical efficiency calculation
Static efficiency % = Flow (m3/sec) X Static pressure (mmwc) X 100 / (102 X power input to fan shift in KW)
11-Fans affinity laws
a-Q1/Q2 = N1/N2
Q1 & Q2 are fans flow in m3/sec at different RPM
N1 & N2 are fans speed
b-SP1 / SP2 = (N1)2 / (N2)2
Where SP1 & SP2 are static pressure in mmwc of fan at different RPM
N1 & N2 are pump speed
c-P1 / P2 = (N1)3 / (N2)3
P1 & P2 are flow flow at different RPM
N1 & N2 are pump speed
11-Isothermal power of reciprocating compressors
P = P1 X Q X loge r/36.7
Where, P = Isothermal power
Q = Free air delivered by compressor in m3/hr
R = P2/P1
P1 & P2 are absolute inlet & deliver pressure respectively
10-Isothermal efficiency of reciprocating compressors
Isothermal efficiency = Isothermal power X 100 / Actual measured input power
11-Isothermal efficiency of reciprocating compressors
Isothermal efficiency = Free air delivered (m3/min) X 1007 / Compressor displacement (m3/min)
12-Compressor displacement = 3.142 X D2 X L X S X n X N
Where, D = Cylinder bore in meter
L = Cylinder stroke in meter
S = Compressor speed in rpm
n= 1 for single acting & 2 for double acting cylinders
N=No.of cylinders
13-Compressed air leakage calculation
% of leakage = T X 100 / (T+t)
Or air leakage in m3/min = T X Compressor capacity (m3/min) / (T+t)
T = Loading time in minutes, t = Unloading time in minutes
14-Calculation of intermediate pressure of reciprocating air compressors
P2 =SQRT ( P1 X P3)
Where P1,P2 & P3 are suction pressure, intermediate pressure and discharge absolute pressure respectively
D-Fuel handling
1-Minimum length of belt conveyor take up
Total belt length X 1.5%
2-Conveyor belt speed calculation
Belt speed (m/sec) = 3.142 X D X N / 60
Where, D= Head pulley diameter in meter
N = Head pulley speed in RPM
Head pulley speed = Moto RPM / Gear box reduction ratio
3-Conveyor start up tension calculation
T (N/mm)= P X 3.2 / (V X W)
Where,P = Power consumption of conveyor
V = Belt speed in m/sec
W = Belt width in mm
4-Tensile strength of belt
Initial tension of the belt X 5.4 / Belt splicing efficiency
E-Mechanical Maintenance
1-V pulley speed calculation
N1/N2 = D2/D1
N1 & N2 are speed in RPM of drive and non drive end pulleys
D1 & D2 are diameter (inch or mm) of drive and non drive end pulleys
2-Gear box output speed calculation
Gear box out put shaft speed = Motor RPM / Reduction ratio
3-Speed of pulley calculation
Pulley speed (m/sec) = 3.142 X D X N / 60
Where, D = Diameter of pulley in meter
N = Pulley rotary speed in RPM
4-V belt length calculation
L =∏ (R1+R2) + 2C + (R2+R1)2/C
Where, R1 & R2 are radius of DE & NDE pulleys
5-C is centre distance between two pulleys
6-Torque developed on a shaft
T = P X 60 / (2 X ∏ X N)
Where, P = Power consumption, N is speed of the shaft
7-Calculation of hub diameter of a shaft
Hub diameter = 2 X Shaft diameter
8-Bearing lubrication quantity calculation
Bearing lubrication quantity in grams = Bearing OD (D) X Width (B) X 0.05
9-Safe working load of steel wire rope of size D (inches)
SWL = 8D2
10-Safe working load of Chain block having Load link diameter D in mm
Safe working load of chain block = 80 X 0.4 X D2
Where 80 is the grade of chain block steel material
D is the link diameter in mm
12-Safe working load of Nylon lifting rope of diameter D in mm
Safe working load of chain block = D2
13-Calculation of weight of steel plate
Weight in kg = Plate length (m) X width (M) X Thickness (m) X density of steel (kg/m3)
14-Calculation of weight of round steel plate
Weight in kg = (∏D2/4) X plate thickness in meter
D is diameter of plate in meter
15-Calculation of weight of hollow cylinder
Weight in kg = (∏R22X h- ∏R21X h) X steel density in kg/m3
Where, R1 & R2 are outer radius & inner radius of tank in meter
H is height of tank in meter
F-Electrical and Instrumentation
1-Single phase power consumption calculation
P = VI Cos θ
Where,Cos θ P is power consumption in Watts, V&I are Voltage in volts and current in Amps receptively
Cos θ is power factor
2-Three phase power consumption calculation
P = √3VI Cos θ
3-Apparent power = V X I (Voltage X Current)
4-Real power = √3VI Cos θ
5-Reactive power of 3-phase power =√3VI Sin θ
Reactive power of single-phase power =VI Sin θ
6-Resistance of a conductor
R = ƍ X L/A
R = Resistance in Ohm-meter or Ohm-cm
L & A are Length and area of conductor measured in meter & m2
7-Voltage, current and resistance relation
Voltage = Current X Resistance, i.e. V = IR
8-Resistance of a conductor at temperature t °C is given by
Rt = R0 (1 + α t) Where α is temperature coefficient at t °C.
8-Electrical Power calculation
Power= Work done watt-sec./Time in second
P = VI X t/t i.e. VI Watts
P = I2R… Watts
9-Power factor calculation
Power factor (cosՓ) = Active power (KW) / Apparent power (KVA)
10-Synchronous speed calculation
Synchronous speed/RPM = (120 X frequency)/No. of poles.
11-Absolute Pressure = Gauge Pressure + Atmospheric Pressure
12-Relation between flow and differential pressure (DP). Flow (Q) = √(DP
Q1/Q2 = (√∆P1/∆P2)
13-Compensated flow calculation
Compensated flow= Raw value from flow meter X Sqrt ((Absolute Design temperature/Absolute Operating temperature) X (Absolute operating pressure/Absolute design pressure))
Atmospheric pressure goes on decreasing as altitude goes on increases.
It is 1.033 kg/cm2 at sea level & goes on decreasing at higher elevation from sea level.
It is calculated as below;
Formula for calculation of atmospheric pressure at height more than sea level
Atmospheric pressure at particular elevation = Atmospheric pressure at sea level X (1–2.255 X (10^-5) X Elevation in meter)^5.25585
Note: Pressure is in Kg/cm2
Elevation is in meters.
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