Reduction of Cold-Start Emissions for a Micro Combined Heat and Power Plant

Abstract

Decentralized power generation by combined heat and power plants becomes increasingly popular as a measure to advance the energy transition. In this context, a substantial advantage of small combined heat and power plants is based on the relatively low pollutant emissions. However, a large proportion of the pollutant emissions is produced during a cold-start. This fact is not reflected in governmental and institutional emission guidelines, as these strongly focus on the emission levels under steady-state conditions. This study analyzes the spark advance, the reference air/fuel ratio and an electrically heated catalyst in terms of their potential to reduce the cold-start emissions of a micro combined heat and power plant which uses a natural gas fueled reciprocating internal combustion engine as prime mover and a three-way catalytic converter as aftertreatment system. Based on these measures, control approaches were developed that account for the specific operating conditions of the class of small combined heat and power plants, e.g., full-load operation and flexible, demand-driven runtimes. The experimental data demonstrates that even solutions with marginal adaptation/integration effort can reduce cold-start emissions to a great extent.

Applications of Electric Heating Technology in Vehicle Exhaust Pollution Control

“…Electric heating is often combined with engine management technology to improve pollution-cleaning performance and fuel efficiency. The efficiency of electric heating in conjunction with the air/fuel ratio and spark advance is validated by Zobel T. et al [52] The findings indicate that NOx emissions may rise as electric heating time increases when utilized only with the air/fuel ratio adjustment method. On the other hand, when employed alone or in conjunction with changing the air-fuel ratio and ignition advance, good NOx cleanup outcomes can be produced.…”

Energy-efficient heating strategies of diesel oxidation catalyst for low emissions vehicles

“…Similarly, Zobel et al [30] proved the significant improvement in cold-start emissions reduction up to 91% with the combined effect of spark advance, air/fuel ratio and EHC in a power plant that uses natural gas-fuelled IC engines as a power generator and TWC as aftertreatment system.…”

Influence of the Thermal State of Vehicle Combustion Engines on the Results of the National Inventory of Pollutant Emissions

“…There is a comprehensive literature available on the subject of pollutant emissions from internal combustion engines during warm-up, e.g., [1,[9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”

“…In [11], the emission of pollutants from spark-ignition engines (both multipoint-and direct-injection) was examined under temperatures from −7 • C to 30 • C. A higher sensitivity of pollutant emissions to ambient temperature was found for multipoint-injection engines. In [22], pollutant emissions were examined during the cold-start of a spark-ignition engine used in small heat and power generating plants.…”