Energy-saving individual heating systems based on liquid-vapor ejector

Abstract

The problem of increasing the efficiency of individual heating systems is solved by using heat pumps based on a liquid-vapor ejector with the working fluid R718 (water). The research object was the working process of the liquid-vapor ejector, based on the principle of jet thermal compression. It involves the generation of vapor in the nozzle of the motive flow of the liquid-vapor ejector and does not require its supply from an external source. Schemes and descriptions of the traditional system and the proposed scheme were given. Their difference from the traditional ones was indicated according to the schematic solution and working cycle. The article compared the proposed schemes’ thermodynamic calculation with the working flow R718 and traditional heat pump systems with carried-out refrigerants R134a, R410a, and R32. As a result, the values of the thermodynamic parameters of all system components were obtained. The coefficients of performance (COP) for the traditional and proposed cycles were determined. Applying the new scheme made it possible to increase the COP by an average of 40 %. An exergy analysis assessed the expediency of implementing vacuum units based on liquid-vapor ejectors in individual heating systems. This made it possible to compare systems that use several types of energy (e.g., electrical, thermal) and to determine their efficiency with high accuracy. As a result of the exergy analysis, the value of the proposed scheme’s exergy efficiency was obtained.