INTEGRATED ENERGY SYSTEM FOR INDUSTRIAL-COMPLEXES .1. A LINEAR-PROGRAMMING APPROACH

A personal-computer based model of an Integrated Energy System for Ind ustrial Estates (IESIE) has been developed as a pre-feasibility tool: it addresses the total energy concept by combining a set of CHP plant( s), boilers, vapor-compression and absorption chillers, national grid and utility transportation system. The core of the general model is th e linear programming (LP) model which takes into account the changing demand-pattern of various loads and their tariffs, standby charge of e lectricity, unit fuel price, equipment costs, land cost, depreciation, 0 & M expenses, interest rate, taxes, etc. The output of the LP model yields the minimum total operating cost, optimal sizes of the equipme nt and their respective operational schedules. The hot utility and col d utility transportation model estimates the economic-minimum pipe siz e, considering installation cost, heat loss/gain cost and pumping cost . The heat balance model finds the thermal cycle equipment sizes as we ll as the variation of the heat- to-power ratio with load. Finally the economic model does the cash-flow analysis to determing whether the p roject will yield ay required rate-of-return to be economically viable . Simulations have been done using the model considering a number of s ample load patterns with the prevailing cost factors in India. An afte r tax IRR of 20% was found for sites having load factors greater than 0.6, and up to 10 km utility transportation distance.