Abstract
The article presents a study of a refrigeration unit operating in two modes – heating and cooling. The study is aimed at evaluating the effectiveness of the system for each mode.In the process of efficiency analysis, heat flows passing through key components of the installation, such as a condenser and an evaporator, were taken into account.The analytical dependences of the heat load on the evaporator and the compressor power, the refrigeration coefficient and the transformation coefficient relative to the temperature of the coolant at the inlet to the heat exchanger are given, comparative cycles of a heat pump with an intermediate heat exchanger for steady-state cooling and heating modes were constructed, and their nodal points were analyzed.The results showed differences in characteristics depending on the operating mode of the system, which made it possible to identify optimal conditions for increasing the overall efficiency of the installation.The balance points for the heating and cooling mode were identified, where the thermal load on the evaporator is equalized with the compressor power.Analytical dependences of the installation characteristics for both the cooling and heating modes were obtained.The accuracy of the approximation of all the obtained lines was more than 0,95.As a result of the conducted research, it was found that the refrigeration system works more efficiently in heating mode, and the optimal temperature of the coolant for cooling and heating modes was 5,5°С и 9°С respectively.