Efficiency of a Lithium Bromide Absorption Thermotransformer with Two-Stage Absorption in the Structure of Gasified Power Plants

Abstract

Abstract It is possible to increase the efficiency of using fossil fuels and to reduce thermal emissions into the environment and the emission of hazardous greenhouse gases by using thermotransformers (TTs) that utilize low-potential waste heat originating from man-caused sources to heat water for heating and hot water supply (HWS). As the main sources of low-grade waste heat, we have considered water circulation systems in heat power and industry as well as waste smoke fumes in boiler houses. The utilization of smoke fume heat (including latent) is the most relevant type of energy saving and of primary fuel saving, which additionally includes environmental benefits implemented by means of reducing nitrogen oxide emission. This paper proposes a scheme for the profound utilization of the heat obtained from combustion products of gas boilers using a condensation heat exchanger-utilizer and a lithium bromide absorption heat pump (LBAHP) with two-stage absorption. The analysis of the efficiency of this technology is carried out and the prospects for its implementation in gas boiler houses in Russia are considered. Studies have shown the feasibility of using LBAHP with two-stage absorption at existing large power facilities (thermal power from 116.3 MW and greater) and at small autonomous gas boiler houses (thermal power lower than 116.3 MW). The theoretical transformation ratio of LBAHP with profound utilization of smoke fumes amounts up to 1.71, whereas the saving of primary fuel in LBAHP amounts to 40% as to compared to a hot-water gas boiler. The economic effect of LBAHP significantly increases if it is used in the mode of a chilling machine for technological cooling and air conditioning in the warm season.