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2 months ago

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Six years ago, an 80-kW diesel electric set cost $160,000. The cost index for this class of equipment six years ago was 187 and

is now 194. The cost-capacity factor is 0.6. The plant engineering staff is considering a 120-kW unit of the same general design to to power a small isolated plant. Assume we want to add a pre-compressor, which (when isolated and estimated separately) currently costs $18,000. Determine the total cost of the 120-kW unit.
b. Estimate the cost of a 40-kW unit of the same general design. Include the cost of the $18,000 precompressor.

1 answer:

grin007 [323]2 months ago

7 0

Answer:

total expense for the new boiler = $229706.825

total expense for new boiler = $127512

Explanation:

provided information

initial power p1 = 80 kW

price C = $160000

cost index CI 1 = 187

cost index CI 2= 194

capacity factor f = 0.6

subsequent power p2 = 120 kW

present cost = $18000

to determine

total expense and cost for 40 kW

solution

we evaluate CN cost for the new boiler and CO cost for the existing boiler

where x represents the capacity of the new boiler

first we compute the current cost of the old boiler which is

current cost CO = C × $\frac{CI 1 }{CI 2 }$ .............1

substituting the value here

current cost = 160000 × $\frac{194 }{187 }$

updated current cost = $165989.304

and

employing power sizing strategy for 124 kW

CN/CO = $(\frac{p2}{p1} )^{f}$ ...............2

insert value and calculate CN

CN/CO = $(\frac{p2}{p1} )^{f}$

CN / 165989.304 = $(\frac{120}{80} )^{0.6}$

CN = 211706.825

therefore the new expense = $211706.825

hence

total expense for the new boiler amounts to

total expense = new expense + current cost

total exp = 211706.825 + 18000

boiler expense total = $229706.825

and

concerning a 40 kW unit, the calculated new cost will be

applying equation 2

CN/CO = $(\frac{p2}{p1} )^{f}$

CN / 165989.304 = $(\frac{40}{80} )^{0.6}$

CN = 109512

thus the new cost is $109512

therefore

total expense for the new boiler is

total exp = new cost + current cost

total expense = 109512 + 18000

total cost for the new boiler = $127512

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A liquid food containing 12% total solids is heated via steam injection at a pressure of 232.1 kPa (see Fig. E3.3). The product starts at a temperature of 50°C and has a flow rate of 100 kg/min, being elevated to a temperature of 120°C. The specific heat of the product varies with its composition as follows:

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Product total solids out ( $X_{B}$ ) = 0.1

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Steam pressure = 232.1 kPa at ( $T_{S}$ ) = 125°C

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$m_{A}C_{PA}(T_{A}-0)+m_{s}H_{s}=m_{B}C_{PB}(T_{B}-0)$

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