Methodology and Continuous Time Mathematical Model to Select Optimum Power of Gas Turbine Set for Dual-Fuel Gas-Steam Combined Heat and Power Plant in Parallel System

Ryszard Bartnik,Aleksandra Otawa,Zbigniew Buryn,Waldemar Skomudek,Anna Hnydiuk-Stefan

doi:10.3390/en11071784

Abstract

This paper contains the results of a study in which a novel approach using continuous time notation was applied in the search for the optimum capacity of a gas turbine designed for a dual-fuel gas-steam combined heat and power plant in a parallel system. As a result of the application of mathematical models of any functions that account for variations in time of all integrand quantities, for example prices of energy carriers, the model that was developed provides a way to analyze complex dependencies. The results of calculations obtained as a result of using this notation provide a rational selection of technologies and equipment designed for the energy industry. The results are based on an analysis involving a combined heat and power plant with an extraction-condensing steam turbine and extraction backpressure steam turbine for a wide range of the variability in energy prices and environmental charges corresponding to the current prices and environmental charges. All the curves were obtained using innovative methodology and mathematical model in which the total, discounted profit is calculated at the given moment and expressed as NPV achieved from the operation of dual-fuel gas-steam combined heat and power (CHP) plant.

Highlights

Coal resources in the world, and in Poland, are huge and we can forecast that energy sector can use it for many years to come
They are presented for two alternatives: for a combined heat and power plant with an extraction-condensing turbine, and for the case of an extraction-backpressure turbine
They are presented for the alternatives comprising a combined heat and power plant with an extraction-condensing steam turbine and an extraction backpressure steam turbine for a wide range of the variability in energy prices and environmental charges and, for current prices and environmental fees

Summary

Introduction

Coal resources in the world, and in Poland, are huge and we can forecast that energy sector can use it for many years to come. To use the resources in a rational way from the point of view of technology, the combustion of coal should apply so-called clean technology. When coal combustion in dual-fuel gas-steam systems takes place with the simultaneous production of electricity and useful heat, for example to cater meet the demands of municipal heating, this will lead to a significant reduction in global coal consumption resulting in a decrease of the emission of harmful combustion products into the environment. It is necessary to conduct a technical and economic analysis of the combined production of electricity and heat in dual-fuel gas-steam systems to determine the economic feasibility of using them. It should be noted that the parallel system offers a rational way to modernize existing coal-fired power stations (and power plants) for Energies 2018, 11, 1784; doi:10.3390/en11071784 www.mdpi.com/journal/energies

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Conclusion