Comparison of working (operating) efficiency of electric and gas heat pump regarding to renewable heat source

Abstract

Rational use and managing with energy is basic presumption of sustainable development. Economy with energy today is directed to using and promotion of pure technologies, with high energetic efficiency and using of renewable sources, and all in purpose of environmental protection. During the last decade heat pump technology has attracted increasing attention as one of the most promising technologies to save energy. Exactly, heat compressor pumps represent technology with high energetic efficiency. Heat pump is a device for moving heat from a low temperature heat source to a higher temperature heat sink using the power for compressor running. In most cases, electric engine runs the compressor. The efficiency of electric heat pump is defined with Coefficient Of Performance (COP – heating factor). It is defined as the ratio of heat delivered by the heat pump and the electric power for compressor running and auxiliaries. But, COP is not observed from primary energy source, it is observed after fuel energy transformation into electric energy (after primary energy transformation). In this article the electric heat pump running will be compared with the gas heat pump running from primary energy source (PER- primary energy ratio). PER is ratio between useful heating energy and primary energy. Gas heat pump uses a primary energy source without energy transformation and has got a lower CO2 emission. In this article, the major advantage of gas heat pump, the utilization of exhausted heat from gas engine (from cooling water and exhausted gases) will be described. Also, it will be described the two renewable heat sources: air and sea water with advantages and disadvantages.