Targets capital cost

To predict the capital cost of a network, it must first be assumed that a single heat exchanger with surface area A can be costed according to a simple relationship such as 

If the problem is dominated by equipment with a single specification (i.e., a single material of construction, equipment type, and pressure rating), then the capital cost target can be calculated from Eq. (7.21) with the appropriate cost coefficients. However, if there is a mix of specifications, such as different streams requiring different materials of construction, then the approach must be modified. 

Heat exchanger cost data usually can be manipulated such that the fixed costs, represented by the coefficient a in Eq. (7.20), do not vary with exchanger specification. If this is done, then Eq. (7.6), as derived in App. F, can be modified to  

Heat exchanger cost laws often can be adjusted with little loss of accuracy such that the coefficient c is constant for different specifications, i.e.. Cl = Ca = c. In this case, Eq. (7.23) simplifies to  

to calculate the capital cost target for a network comprising 

When cost targeting, the distribution of the targeted area between network exchangers is unknown. Thus, to cost a network using Equation 17.10, some area distribution must be assumed, the simplest being that all exchangers have the same area  

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There is a tradeoff between energy and capital cost i.e., there is an economic degree of energy recovery. Chapter 7 explains how this tradeoff can be carried out using energy and capital cost targets. 

Calculate the capital cost target for the mixed specification heat exchanger network from Eq. (7.21) using the cost law coefficients for the reference specification. 

These small positive and negative errors partially cancel each other. The result is that capital cost targets predicted by the methods described in this chapter are usually within 5 percent of the final design, providing heat transfer coefficients vary by less than one order of magnitude. If heat transfer coefficients vary by more than one order of magnitude, then a more sophisticated approach can sometimes be justified. ... 

Overall, the accuracy of the capital cost targets is more than good enough for the purposes for which they are used ... 

Figure 7.12 Energy emd capital cost targets can be combing to optimize prior to design. (From Smith and Linnhoff, Trans. IChemE, ChERD, 66 195,...

Hall, S. G., Ahmad, S., and Smith, R., Capital Cost Target for Heat Exchanger Networks Comprising Mixed Materials of Construction, Pressure Ratings and Exchanger Types, Computers Chem. Eng., 14 319, 1990. 

Algorithm for Heat Exchanger Capital Cost Target... 

Thus, to calculate the capital cost target for a network comprising mixed exchanger specifications, the procedure is as follows. 

Figure 17.8 Energy and capital cost targets can be combined to optimize prior to design (From Smith R and Linnhoff B, 1988, ChERD,66 195 reproduced by permission of the Institution of Chemical Engineers.).

Algorithm for Heat Exchanger Network Capital Cost Targets... 

The initial evaluation showed that utilizing fiber-reinforced polymer (FRP) for pipelines is a feasible alternative to steel pipelines with regard to performance and cost [35]. From the cost analysis, an FRP pipe is quite attractive, especially in the regional or distributed service. Currently, spoolable piping manufacturers could install a composite pipeline for serving a 100,000 population for a cost of 250,000-500,000/mi. (does not include the cost for right-of-way), which is well below the DOE s capital cost target in 2017 of 800,000/mi. [35]. From this estimate and cost analyses, it is seen that FRP pipe economics is very attractive, especially for the distribution service. 

Jegede, F. O. and G. T. Polley. Capital Cost Targets for Networks with Non-Uniform Heat Transfer Specifications. Comput Chem Eng 16 All (1992). 

R. D. Colberg and M. Morari. Area and capital cost targets for heat exchanger network synthesis with constrained matches and unequal heat transfer coefficients. Comp. Chem. Eng., 14 1,1990. 

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