Minimizing Electricity Consumption by Electric Drives of the Outdoor Air and Water Supply Units in a Heat Pump Used for Heating Multistorey Buildings

This paper focuses on control systems for hybrid heat pumps that utilize the heat from return heating water and outdoor air, designed to operate in district heating systems based on central heating plants. The aim of the research is to develop control systems for heat pumps that operate based on qualitative, quantitative, and quantitative-qualitative thermal regime control laws. The established objective is achieved by introducing two controlled heat exchangers: one of the "water-refrigerant" type, installed after the evaporator, and the other of the "air-refrigerant" type, installed after the gas cooler. The most important results are the hydraulic diagram of the heat pump, the control system for the gas superheater after the evaporator, and the gas superheater after the gas cooler. The significance of the results lies in the development of a technical solution that ensures the heat pump operates under various heating modes. Equations describing the heat pump system were derived, highlighting the influence of flow rate and working fluid temperature on the heat pump's operating mode. The derived thermal equilibrium equations enabled the development of control system architectures for the heat exchangers, compressors, and control valves of the hybrid heat pump. The scheme developed for the heat pump's air duct allowed for the use of a minimum amount of heat from the district heating network's return water in the heat pump.