Homogeneous Charge Compression Ignition (HCCI) Using Isooctane, Ethanol and Natural Gas - A Comparison with Spark Ignition Operation
972874
10/01/1997
- Event
- Content
- The Homogeneous Charge Compression Ignition (HCCI) is the third alternative for combustion in the Internal Combustion (IC) engines. Here, a homogeneous charge is used as in a spark ignited engine but the charge is compressed to auto-ignition as in a diesel. The characteristics of HCCI were compared to SI using a 1.6 liter single cylinder engine with compression ratio 21:1 in HCCI mode and 12:1 in SI mode. Three different fuels were used; isooctane, ethanol and natural gas.Some remarkable results were noted in the experiments: The indicated efficiency of HCCI was much better than for SI operation. Very little NOx was generated with HCCI, eliminating the need for a LeanNOx catalyst. However, HCCI generated more HC and CO than SI operation. Stable and efficient operation with HCCI could be obtained with λ=3 to λ=9 using isooctane or ethanol. Natural gas, with a higher octane number, required a richer mixture to run in HCCI mode.
- Pages
- 13
- Citation
- Christensen, M., Johansson, B., and Einewall, P., "Homogeneous Charge Compression Ignition (HCCI) Using Isooctane, Ethanol and Natural Gas - A Comparison with Spark Ignition Operation," SAE Technical Paper 972874, 1997, https://doi.org/10.4271/972874.