Calculation of the heat pump cycle with various sources of low-grade heat in the conditions of the Arctic of the Republic of Sakha (yakutia)

To date, there is a growing trend in the world to introduce heat pumps into heat supply systems. Due to the ability to use low-potential heat as a source, the heat pump has high energy efficiency parameters. In this regard, the calculation of the heat pump cycle with various sources of low-potential heat is an important task in assessing the feasibility of introducing a heat pump into isolated power supply systems in the Arctic territories of the Republic of Sakha (Yakutia). The paper considers three sources: soil; pond and air with temperatures of -5 °C, 2 °C, 5 °C, respectively. The use of a heat pump circuit with an intermediate heat exchanger is proposed for an additional increase in efficiency. Freon of the R134a brand, which is part of the ozone-safe group, was selected as the working medium. Calculations of thermodynamic parameters of the cycle of operation of a heat pump with an intermediate heat exchanger are carried out. From the obtained calculation data, graphs of the freon cycle in the p,h –diagram are constructed. A graph of the dependence of the electric power transformation coefficient (COP) on the temperature of a low-potential heat source is constructed. It is revealed that for various sources of low-potential heat, the value of the electric power transformation coefficient (COP) remains greater than 1, which corresponds to the effective mode of operation. Also, the maximum value of the electric power transformation coefficient (COP) equal to 2.5 is achieved when using low-potential air heat with a temperature of +5 ° C as a source. Based on the calculations, the dependence of the electric power transformation coefficient (COP) on the temperature of low-potential heat is observed. This is due to the costs of compression operation in the compressor, namely the energy costs of the electric drive. The technical feasibility of introducing a heat pump into isolated power supply systems of the Arctic regions of Yakutia is shown.

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