Boiler Feed Water Design Calculations
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Boiler Feed water design calculations 1. P & T Pressure & Temperature of steam h 1 = From steam tables at P & T h 2 = at P C pw = 4.186 KJ/Kg-K h 3 = h f = at P 2. Surface Area: a. Desuperheating Zone: To find t x M s (h 1 -h 2 ) = M w C pw (t wo -t x ) Take U = 350 -450 Kcal/hr m K KW/m 2 -K Heat Load Q = W s (h 1 -h 2 ) Area A 1 = Q/U Length of zone Baffle Spacing B = 0.2 * L b. Condensing Zone: To find T y M s (h 2 -h 3 ) = M w C pw (t x -t y ) Film Temp. t f = t s – 0.8 * If t f > 250 , take t f = 250 F
Transcript of Boiler Feed Water Design Calculations
Boiler Feed water design calculations
1. P & T Pressure & Temperature of steamh1= From steam tables at P & Th2= at PCpw= 4.186 KJ/Kg-Kh3= hf = at P
2. Surface Area: a. Desuperheating Zone:
To find tx
Ms(h1-h2) = MwCpw(two-tx)
Take U = 350 -450 Kcal/hr m K
KW/m2-K
Heat Load Q = Ws(h1-h2)Area A1= Q/U
Length of zone
Baffle Spacing B = 0.2 * L
b. Condensing Zone:
To find Ty
Ms(h2-h3) = MwCpw(tx-ty)
Film Temp. tf = ts – 0.8 * If tf > 250 , take tf = 250 F
Assume Velocity of feed water such that V < 8 fpsAt V = ________ at tf form Fig. 5.20 U = __________ Btu/hr F ft2
= _______ KW/m2-K
Taking Tube OD = 15.875mm, BWG = _____, & Material:________Multiplication Factor = ________ from Table T 5.19U1 = U * Multiplication Factor
Heat Load Q = Mw Cpw (tx-ty)Area A2= Q/U1
Length of zone
Baffle Spacing B = 0.4 * L
c. Drain sub-cooling Zone:Form Experimental data Td = ____oC
Take U = 2000 -2500 Kcal/hr m K
= _____KW/m2-K
Heat Load Q = Mw Cpw (ty-twi)Area A3= Q/U
Length of zone
Baffle Spacing B = 0.4 * L
Total Surface Area of Feed Water heater = A1+A2+A3 =
Theoretical calculation
Actual provided by at Power Plant
Remarks
Total surface areaLength of tube
HPH6 Feed water design calculations
1. P & T Pressure & Temperature of steamh1= From steam tables at P & Th2= at PCpw= 4.186 KJ/Kg-Kh3= hf = at P
2. Surface Area: a. Desuperheating Zone:
To find tx
Ms(h1-h2) = MwCpw(two-tx)
Take U = 350 -450 Kcal/hr m K
KW/m2-K
Heat Load Q = Ws(h1-h2)Area A1= Q/U
Length of zone
Baffle Spacing B = 0.2 * L
b. Condensing Zone:
To find Ty
Ms(h2-h3) = MwCpw(tx-ty)
Film Temp. tf = ts – 0.8 * If tf > 250 , take tf = 250 F
Assume Velocity of feed water such that V < 8 fpsAt V = ________ at tf form Fig. 5.20 U = __________ Btu/hr F ft2
= _______ KW/m2-K
Taking Tube OD = 15.875mm, BWG = _____, & Material:________Multiplication Factor = ________ from Table T 5.19U1 = U * Multiplication Factor Heat Load Q = Mw Cpw (tx-ty)
Area A2= Q/U1
Length of zone
Baffle Spacing B = 0.4 * L
c. Drain sub-cooling Zone:Form Experimental data Td = ____oC
Take U = 2000 -2500 Kcal/hr m K
= _____KW/m2-K
Heat Load Q = Mw Cpw (ty-twi)Area A3= Q/U
Length of zone
Baffle Spacing B = 0.4 * L
Total Surface Area of Feed Water heater = A1+A2+A3 =
