Improving a water treatment and a heating performance of the water-to-water heat pump: misallocation and available solutionsThe Authors thank the Government of the Russian Federation for its financial support of the Decree No. 860 August, 29 2017

The object of our experimental investigation is a heat pump system operating at low temperatures of a low-grade heat source. The purpose of experimental research of the heat pump installation is to increase the efficiency and reliability of heat pump unit by adjusting compressor performance. To carry out the experiment we connected the reciprocating compressor with Variable Frequency Drive of AC 0..650 Hz, designed for rated capacity of 2.2 kW, as well as electricity meter. The dependence of heat load of pump condenser on the speed (rpm) is approximated by the formula and will be used to design a heat pump unit. The proposed experimental unit allowed us to determine the correlation between basic characteristics and the compressor shaft speed and determine the possible range of its regulation (50..180%). The obtained results allow us to design the water treatment plant with using heat pump unit with quality regulation systems as well.