Development of geothermal heat pumps by using environment friendly refrigerants

Today, energy consumption and demand together with global warming are one of the most important challenges of human life. From the environmental point of view, the Heating Ventilation and Air Conditioning industry and current refrigerants are one of the important factors of global warming which need to be resolved. In terms of energy consumption, the main way is the development and use of renewable energy technologies which not only increases the efficiency of these systems but also generates diversification in energy resources. Among the various renewable energy systems, geothermal heat pumps offer significant potential to reduce energy consumption and also carbon dioxide emissions. The main purpose of this research is to select environmentally friendly refrigerants with the best performances. To assess the thermodynamic performance of organic refrigerants in geothermal heat pumps, this system is modeled using Engineering Equation Solver software. In this research, the results are compared with the results of the thermodynamic behavior of conventional refrigerants R22 and R134a for geothermal heat pumps with horizontal and vertical closed loop ground heat exchangers and also open-loop systems. Finally, R152a, R600, and R717 were introduced as substitute refrigerants to replace with synthetic refrigerants in the above-mentioned geothermal heat pump systems, resulted in an increase in 2.97–5.8 percent coefficient of performance in the cooling mode which means reducing the operating cost of the system compared to conventional artificial refrigerants.