FEATURES OF SELECTING TECHNICAL AND ECONOMIC INDICATORS OF COGENERATION AND COGENERATION-HEAT PUMP PLANTS

Abstract

Cogeneration or combined production of electrical and thermal energy has gained significant popularity and development in both large and small energy sectors around the world. Such installations are of particular importance and significance in the case of energy autonomy in the absence of centralized energy systems or in the event of their disruption, in the event of force majeure circumstances. Such autonomy of the energy sector leads to the need to consider a large number of options for cogeneration plants (CGU), the choice of their optimal thermal schemes, as well as the main energy equipment. To solve these problems, it is necessary to have a simple, but sufficiently reliable and universal calculation methodology.

One of the most important parameters characterizing the energy efficiency of a CHP is the amount of fuel consumed for energy generation. Therefore, the purpose of this work is to conduct an initial comparative analysis of thermal schemes of cogeneration plants and assess the prospects for their implementation to increase the energy efficiency of using the energy potential of fuel, while producing the same amount of electrical and thermal energy by the plants.

The article considers the methodology for comparative calculation of consumption characteristics of various thermal schemes of CHP using the main energy parameters of installations – electrical and thermal efficiency coefficients (EFC) of engines and installations, thermal efficiency of boilers and boilers – waste heat exchangers, heat transformation coefficient of heat pumps. When selecting these parameters, traditionally, the engine data is used, which are usually design data. However, when forming a CHP, the characteristics of the power equipment may differ from the design ones, or may be unknown altogether.

For such cases, as well as to accelerate and simplify the comparative analysis, it is proposed to use statistical data on the values ​​of electrical and thermal efficiency of piston engines and gas turbine plants of more than 50 foreign and domestic companies. Based on these data, a graphical dependence of thermal efficiency on electrical efficiency is constructed, which is approximated by an analytical dependence used for comparative analysis. For example, two thermal schemes are considered - a cogeneration plant with a boiler and a power plant and a cogeneration plant with a heat pump and a boiler, in the heat-only mode.