Open AccessEfficiencies and emissions of a 192 kW el Otto engine CHP‐unit running on biogas at the research station “Unterer Lindenhof”
Author(s) -
Thomas Bernd,
Wyndorps Agnes
Publication year - 2012
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201100070
Subject(s) - biogas , waste management , environmental science , thermal efficiency , unit (ring theory) , gas engine , engineering , automotive engineering , chemistry , combustion , mathematics education , mathematics , organic chemistry
An Otto engine CHP‐unit running on biogas has been under investigation for more than two years. Within this time data regarding temperatures, energy flows, biogas composition, emissions etc. were collected, and this paper presents some of the results. In detail, electric and thermal output are discussed for one full year. From these data the monthly electric availability of the unit can be calculated, which ranges from 84.0 to 96.4%. In addition, the utilization of the heat produced by the CHP‐unit during one year is displayed. It was found that 18.2% of the heat was needed for heating purposes within the biogas plant, and 64.5% of the heat could be supplied to the district heating system. Hence, 17.3% of the useful heat had to be released to the ambient air by an additional cooler. Regarding emissions, a strong impact of the excess air ratio on emissions of NO X has been observed. Moreover, the effect on electric efficiency is outlined in this paper. As known from theory, the experimental results revealed that an increase in the excess air ratio helps to lower NO X ‐emissions, while electric efficiency is reduced by this means.