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//Variable declaration:
h1 = 800 //Heat transfer coefficient for steam condensing inside coil (Btu/h.ft^2. F)
h2 = 40 //Heat transfer coefficient for oil outside coil (Btu/h.ft^2. F)
h3 = 40 //Heat transfer coefficient for oil inside tank wal (Btu/h.ft^2. F)
h4 = 2 //Heat transfer coefficient for outer tank wall to ambient air (Btu/h.ft^2. F)
k1 = 0.039 //Thermal conductivity of insulation layer (Btu/h.ft. F)
l1 = 2/12 //Thickness of insulation layer (ft)
D = 10 //Diameter of tank (ft)
H = 30 //Height of tank (ft)
k2 = 224 //Thermal conductivity of copper tube (Btu/h.ft. F)
l2 = (3/4)/12 //Thickness of insulation layer (ft)
T1 = 120 //Temperature of tank ( F)
T2 = 5 //Outdoor temperature ( F)
//Calculation:
Uo1 = 1/(1/h3+(l1/k1)+1/h4) //Overall heat transfer coefficient for tank (Btu/h.ft^2. F)
At = %pi*(D+2*l1)*H //Surface area of tank (ft^2)
Q = Uo1*At*(T1-T2) //Heat transfer rate lost from the tank (Btu/h)
//From table 6.3:
l2 = 0.049/12 //Thickness of coil (ft)
A = 0.1963 //Area of 18 guage, 3/4-inch copper tube (ft^2/ft)
Uo2 = 1/(1/h2+(l2/k2)+1/h1) //Overall heat transfer coefficient for coil (Btu/h.ft^2. F)
//From steam tables:
Tst = 240 //Temperature for 10 psia (24.7 psia) steam ( F)
Ac = Q/(Uo2*(Tst-T1)) //Area of tube (ft^2)
L = Ac/A //Lengt of tube (ft)
//Result:
printf("The length ofcopper tubing required is : %.1f ft",L)
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