WSP10809 - Laserfiche WebLink

Home Browse Search

N 6 S 14 00 FCR l: C' . + I l: C' . + l: C' . \"\ tv C l r l l Ul pw = i=l i=7 i=9 ...'..,..... (45) .~,~ 3.65x10-4 " C x Uf x , . ~"( P 6 S 14 FCR l: C' , + I l: C' . + l: C' . Cs l r l l = i=l i=7 i=9 ................ (46) -4 Cb x Cbo x Uf x 3.65xlO in which, C = pw C = s C! = l C = P Cb - Cbo - FCR = I = r Uf - unit cost of product water, $/m3; unit cost of brine salts, $/metric ton; total annual cost for element i, $/year (feedwater + plant + brine) (Ci = construction cost, C'2 = steam generation, C'3 = site development, C'4 = interest during construction, C'5 = start-up costs, C'6 owner's general expense, C'7 = land, C'S = working capital, C'9 = labor and materials, C'10 = chemicals, C'll = fuel, C'12 = electrical, C'13 = steam generation 0 & M, and, C'14 = replacement.) product water volume, m3/day; brine volume, m3/day; TDS concentration in brine, mg/~; fixed charge rate; interest rate; and use factor - fraction of total time in actual operation, The r~sults from the desalting cost model indicate that unit costs as described in Eqs. 45 and 46 for either water or salt production are highly affected by plant capacity (scale effects). For example, a hypothetical reverse osmosis system desalting feedwater at 4000 mg/~ to produce product water at 500 mg/~ would have cost characteristics as illustrated in Figure 2. These data are based on feedwater wells approximately one kilo- meter from the plant site and brine injection wells at the site. Interest, fuel, and electrical costs are those used by U. S. Department of the Interior (1972). 27 "j ': "4 "\ ; j if , ;0 ~~ j