AN ANALYTICAL APPROACH TO COGENERATION UNITS ECONOMIC SIZING, THAT TAKES INTO ACCOUNT THE EVOLUTION OF VARIABLE PARAMETERS OVER LIFETIME

Abstract

In this paper the problem of getting formulas for calculating the optimal share of cogeneration within a heat supply system for a consumption zone / node is considered. Optimization criterion – the minimum of the total discounted cost during the study period, related to the considered sources of energy (cogeneration units and hot water boilers). The consumption regime is presented by the annual classified heat load curve, described analytically by Sochinsky-Rossander equation. The applied mathematical model takes into account the evolution over time of a series of parameters such as the selling price of the electricity produced, the purchase price of fuel and other factors. In addition, several approaches to the problem are considered – for different operating regimes of energy sources. The obtained analytical expressions to determine the optimal share of cogeneration were tested, demonstrating a coincidence of the results with those got by applying the method of evaluation and comparison of variants.