Modeling and Analysis of Ground-Source Heat Pump System on Low GWP Refrigerants for Domestic Applications

DOI: 10.18462/iir.compr.2017.0222

Session: Technologies. Chaired by Hermann Halozan, Dariusz Bytrymowicz, Michael Khmelniuk

Accept state: Submission accepted

Authors

Abstract

The increasing demand of energy sources for urban, household and industrial facilities requires strategies development for seeking new energy sources. In recent years an important problem is to have energy storage, energy production and energy consumption which fulfill the environment friendly expectations. At a few meters below the earth’s surface the underground maintains a constant temperature in an approximation through the year allowing to withdraw heat in winter for heating needs and to surrender heat during summer for air-conditioning purposes. Ground-Source heat pumps have been proved to be one of the most efficient systems for heating and domestic hot water (DHW) production in buildings. A lot of attention is devoted to alternative energy sources and one of the most attracting among them is energy production form geothermal sources because the amount of energy used for heating and DHW is very high and will keep increasing. Using ground as a heat source, heat exchange is carried out with heat pumps compound to vertical ground heat exchanger tubes that allows the heating and cooling of the buildings utilizing a single unit installation. Heat pump unit provides a high degree of productivity with moderate electric power consumption.
In this paper a theoretical performance study of a vapor compression heat pump system with various natural and synthetic refrigerants (HFCs) is presented. Operation mode of the heat pump unit was chosen according to European Standard EN14511-2:2011. An influence of discharge temperature on system performance was evaluated at different boiling temperatures. The comparison of mass flow rate and coefficient of performance for considered refrigerants at constant cooling capacity and condensation temperature was performed. Although, for specifying the possibilities for thermodynamic improvement, in many cases energy analysis is not enough and exergy analysis is more appropriate. In this study an exergy assessment of a geothermal heat pump system is provided. The exergy losses in each of the components of the overall system are determined. Exergy efficiencies of the system components are determined to assess their performances, environmental impact lowering and to demonstrate the potential energy saving for further improvement.

Keywords

Ground-Source Heat Pump, Exergy Analysis, Energy Efficiency, Low GWP Refrigerants.