As promised in my earlier blog entry "Cost Estimation Of Fixed Roof (Cone) Carbon Steel Storage Tanks", today's blog entry relates to cost estimation of S&T heat exchangers. The equations are empirical and the reference is the same i.e.:

"Estimate Costs of Heat Exchangers and Storage Tanks via Correlations" by Armando B. Corripio, Katherine S. Chrien, and Lawrence B. Evans, Chemical Engineering magazine January 25, 1982.

There is a bunch of equations and it took some time to program it in excel but ultimately it was done.

Let us get down to the equations:

**Base Cost for CS Floating-Head, 700 kPag (100 psig) exchanger**

**SI Units**

C

_{B}= EXP(8.202 + 0.01506*lnA + 0.06811*(lnA)

^{2})

where:

C

_{B}= Base Cost of the HE, USD

A = Heat Transfer Area in m

^{2}

Lower Limit: 14 m

^{2}; Upper Limit: 1100 m

^{2}

**Exchanger-type cost factor, F**_{D}*Fixed Head*:

F

_{D}= EXP(-0.9003 + 0.0906*lnA)

*Kettle Reboiler*:

F

_{D}= 1.35

*U-Tube*:

F

_{D}= EXP(-0.7844 + 0.0830*lnA)

where:

F

_{D}= Exchanger-type cost factor

**Design-pressure cost factor, F**_{P}*700-2100 kPag*:

F

_{P}= 0.8955 + 0.04981*lnA

*2100-4200 kPag*:

F

_{P}= 1.2002 + 0.07140*lnA

*4200-6200 kPag*:

F

_{P}= 1.4272 + 0.12088*lnA

where:

F

_{P}= Design-pressure cost factor

**Material-of-Construction Cost Factor, F**_{M}*SS316*:

F

_{M}=1.4144 + 0.23296*lnA

*SS304*:

F

_{M}=1.1991 + 0.15984*lnA

*SS347*:

F

_{M}=1.1388 + 0.22186*lnA

*Nickel 200*:

F

_{M}=2.9553 + 0.60859*lnA

*Monel 400*:

F

_{M}=2.3296 + 0.43377*lnA

*Inconel 600*:

F

_{M}=2.4103 + 0.50764*lnA

*Incoloy 825*:

F

_{M}=2.3665 + 0.49706*lnA

*Titanium*:

F

_{M}=2.5617 + 0.42913*lnA

*Hastelloy*:

F

_{M}=3.7614 + 1.51774*lnA

where:

F

_{M}= Material-of-construction cost factor

**Heat-Exchanger Cost , C**

_{E}C

_{E}= C

_{B}*F

_{B}*F

_{D}*F

_{M}

where:

C

_{E}= Heat Exchanger Cost, USD

**USC Units**

C

_{B}= EXP(8.551 - 0.30863*lnA + 0.06811*(lnA)

^{2})

where:

C

_{B}= Base Cost of the HE, USD

A = Heat Transfer Area in ft

^{2}

Lower Limit: 150 ft

^{2}; Upper Limit: 12000 ft

^{2}

**Exchanger-type cost factor, F**_{D}*Fixed Head*:

F

_{D}= EXP(-1.1156 + 0.0906*lnA)

*Kettle Reboiler*:

F

_{D}= 1.35

*U-Tube*:

F

_{D}= EXP(-0.9816 + 0.0830*lnA)

where:

F

_{D}= Exchanger-type cost factor

**Design-pressure cost factor, F**_{P}*100-300 psig*:

F

_{P}= 0.7771 + 0.04981*lnA

*300-600 psig*:

F

_{P}= 1.0305 + 0.07140*lnA

*600-900 psig*:

F

_{P}= 1.14 + 0.12088*lnA

where:

F

_{P}= Design-pressure cost factor

**Material-of-Construction Cost Factor, F**_{M}*SS316*:

F

_{M}=0.8608 + 0.23296*lnA

*SS304*:

F

_{M}=0.8193 + 0.15984*lnA

*SS347*:

F

_{M}=0.6116 + 0.22186*lnA

*Nickel 200*:

F

_{M}=1.5092 + 0.60859*lnA

*Monel 400*:

F

_{M}=1.2989 + 0.43377*lnA

*Inconel 600*:

F

_{M}=1.2040 + 0.50764*lnA

*Incoloy 825*:

F

_{M}=1.1854 + 0.49706*lnA

*Titanium*:

F

_{M}=1.5420 + 0.42913*lnA

*Hastelloy*:

F

_{M}=0.1549 + 1.51774*lnA

where:

F

_{M}= Material-of-construction cost factor

**Heat-Exchanger Cost , C**

_{E}C

_{E}= C

_{B}*F

_{B}*F

_{D}*F

_{M}

where:

C

_{E}= Heat Exchanger Cost, USD

**Updated Heat Exchanger Cost**

C

_{E(updated)}= (CI

_{(calculation yr)}/ CI

_{(base yr)}) * CE

where:

CI

_{(calculation yr)}= cost Index for the calculation year &

CI

_{(base yr)}= cost index for the base year

Notes:

1. As an example, if you are trying to calculate the cost of the exchanger for the year 2010, the most probable updated cost would be based on a ratio of the cost index for the year 2010 to the cost index for a base year of 2005. It is not recommended to use a base cost index more than 5 years older than the cost index for the calculated year.

2. The cost index ratio is subjective in nature and readers are exercised caution in determining the "Cost Index Ratio" for calculating the updated equipment cost.

Readers and Members of "Cheresources", this is it for today's blog entry. Would welcome comments from all of you on the subject matter.

Regards,

Ankur.