The issue of energy efficiency and energy saving is particularly pressing for Ukrainians, especially in heating and air conditioning systems. Most of these systems use inefficient or expensive in use heating systems, heat pumps of foreign manufacture, having a high unit cost of installed capacity (about 1000 euros per 1 kW of power). The efficiency coefficient of such systems for the conditions in Ukraine is 3-3.5. Today, it is necessary to develop new technologies with higher energy efficiency indicators immediately. The introduction of a new economically efficient and efficient heating system will solve one of the most important domestic problems of every Ukrainian. Therefore, the project "Superenergy-efficient heat supply system of buildings using psychometric energy of the environment" aroused general interest at the Festival of Innovative Projects "Sikorsky Challenge 2017" and was named among its winners.
Energy-efficient heat supply system of buildings, proposed by scientists of the Institute of Technical Thermophysics of the NAS of Ukraine (ITTP) and the Institute of Physics and Technology of the Igor Sikorsky KPI, is an economical air heating system, the efficiency of which is ensured by a synergistic combination of the Maisotsenko and Rankine cycles in one installation. The Maisotsenko cycle makes it possible to use psychrometric energy of the environment, which is in the air in unlimited quantities. The using of phase transitions in the heat transfer system, such as condensation and evaporation, allows to obtain energy from the environment more efficiently and to provide almost complete utilization of exhaust heat. The efficiency coefficient of the cycle is 3-3.5. The Rankine cycle is a thermodynamic cycle through which most refrigerating machines, heat pumps and air conditioners operate. The combination of these cycles gives a synergistic effect.
The combination of two cycles is used for the first time, based on the sequential placement of the heat and mass transfer device in the Maisotsenko cycle and the traditional heat pump. This allows not only to use the psychrometric temperature difference effectively, but also to increase the efficiency of the heat pump in the Rankine cycle by effectively cooling the condenser. Experimental studies of a pilot sample with a thermal power of 20 kW have shown high thermal efficiency at the level of 8-10, which is twice as high as all known heating systems based on heat pumps in the Rankine cycle. The prime cost of thermal energy gigacalorie is about 150 UAH, and the payback period is up to two years.
Nowadays, the heat supply system of buildings based on the Maisotsenko and Rankine cycles has a lower capital cost and higher efficiency indicators compared to existing ones. The authors of the project – an academician of NAS of Ukraine, a doctor of technical sciences, a professor A.A. Khalatov – the head of the High-Temperature Thermogasdynamics Department at the Institute of Technical Thermophysics of the NAS of Ukraine, the head of the Power Systems Physics Department of the IPT; a graduate student O.S. Stupak.