Advanced exergetic analysis of a heat pump providing space heating in built environment

Abstract

In addition to conventional exergy-based methods, advanced exergetic analyses consider the interactions among components of the energy-conversion system and the real potential for improving each system component.The paper demonstrates the results of application of a detailed advanced exergetic analysis to a wastewater source heat pump providing space heating in the built environment. In order to determine thermodynamic parameters of the refrigeration vapour compression cycle in different operating modes, the simulation model has been used. The analysis includes splitting the exergy destruction within each component of a heat pump into unavoidable, avoidable, endogenous and exogenous parts as well as detailed splitting of the avoidable exogenous exergy destruction. Besides, variabilities of heating demands of a building within both the chosen heating season and also from year to year are taken into account. Distribution of the split exergy destructions during different periods of time is also presented for the analysed cases of the heat pump and built environment. It is shown that in the investigated system only about 50% of the total annual destruction in components of the heat pump can be avoided. About 30…40% of this avoidable thermodynamic inefficiency is caused by interactions among components. Based on the applied advanced exergetic analysis it is possible to receive more precise and useful information for better understanding and improving the design and operation of the analysed energy-conversion system.

Advanced exergy-based performance enhancement of heat pump space heating system

“…This means that the exergy destruction within this component can be reduced through changes in the remaining components (evaporator, condenser and compressor) or in the structure of the overall system. This conclusion completely coincides with the data provided in [3,12,13]. According to the results presented in Fig.…”

“…The avoidable parts of exogenous exergy destruction within the evaporator and the throttling valve and caused by compressor are also negative and equal respectively to -13 kWh and -16 kWh. The similar information concerning negative values of exogenous exergy destruction is obtained in a series of works: [3] for a vapour-compression refrigeration machine with R407C, [10] for an absorption refrigeration machine, [13] for a water source heat pump providing space heating, [23,24] for geothermal district heating systems, [25] for a combined cycle power plant. Negative values of exogenous exergy destruction provides negative values of costs and environmental impact due to exergy destruction.…”

“…For exergetic, exergoeconomic and exergoenvironmental assesment of the heat pump providing space heating it is proposed to consider annual (seasonal) values of parameters [13,18]. For different operational modes ambient temperature can be referred in a different manner to temperatures of working fluids of the heat pump.…”

Conventional and Advanced Exergy-Based Analysis of Hybrid Geothermal–Solar Power Plant Based on ORC Cycle

“…The relationship between Avoidable and Unavoidable Irreversibility for each stream, Wang et al [22], Sert and Balkan [23], Voloshchuk [54].…”

Advanced exergy analysis of a novel air source heat pump system coupled with the liquid receiver and gas-liquid separator

“…After improvement, the system exergy loss was decreased by 30.2%, and the exergy efficiency was increased from 6.9% to 9.5%. Voloshchuk [6] found that 63% and 20% of the avoidable endogenous exergy loss came from the inefficient work of the evaporator and condenser by using advanced exergy ways. An advanced exergy study model of the new ASHP is constructed in this article, and the avoidable exergy loss and exergy efficiency of the components and system are studied.…”