I.C. Engine Driven Heat Pumps with a heat power up to 20 kW

Abstract

Fichtel & Sachs AG has developed I.C. engine driven fuel oil and natural gas heat pumps with a heating power of 20 kW. The engine compressor unit is a special development of Fichtel & Sachs, also the microprocessor control equipment. As demonstration constructions 40 heat pumps (27 fuel oil, 13 natural gas) were installed in residential houses in the Schweinfurt region. The houses have a theoretical heat demand between 20 and 60 kW. The installations were realized by handicraft companies — under inspection of employees of Fichtel & Sachs. Each of the heat pumps was supplied with measuring instruments for data processing. The first heat pump was put into operation in December 1981, the last in September 1982. On an average the heat pumps have worked 2 503 h/a; the longest operation hours came to more than 6 000 h until June 1983. All heat purrps are working bivalent-alternatively. The PER (Primary Energy Ratio) of the fuel oil heat purrps amount to 1.32 in the yearly average, the natural gas heat pumps have 1.25 in average; the coefficients of the burner-/boiler system comes to below 70 %. The noise problems were settled satisfactorily; waste gas emissions must be futher improved. The quality of some components gives trouble for they are not always suitable for applications in I.C. engine driven heat pumps. Regarding the present fuel oil and natural gas prices, pay back periods below 5 years are possible, when the saving potential is higher than 4 000 1/a in bivalent-alternative/parallel-installations.