Optimizing the ignition timing of a converted CNG mono-gas engine
Governmental policies on renewable energy and environmental act are aggressively being enforced to mitigate recent climate change. Natural gas is not renewable but it is the most abundant and has the lowest Lifecycle CO2 emission among fossil fuel. Realizing such promising alternative, many logistic...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Published: |
Trans Tech Publications Inc
2014
|
| Subjects: | |
| Online Access: | http://www.dx.doi.org/10.4028/www.scientific.net/AMM.554.474 http://www.dx.doi.org/10.4028/www.scientific.net/AMM.554.474 http://eprints.uthm.edu.my/8236/1/abd_fathul_hakim2.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Governmental policies on renewable energy and environmental act are aggressively
being enforced to mitigate recent climate change. Natural gas is not renewable but it is the most
abundant and has the lowest Lifecycle CO2 emission among fossil fuel. Realizing such promising
alternative, many logistics and transportation companies are converting their existing diesel-fueled
vehicle to CNG-fueled. Researchers have shown that CNG engines offer advantages compared to
diesel and gasoline engines such as high efficiency and low emissions. Prior to this work, a 4.3L 4-
cylinder diesel engine was modified and retrofitted with a CNG mono gas system. However, it was
observed that the engine, CNG-fueled combustion is not stable especially at idling speed. The
purpose of this study is to optimize the ignition timing best suited for idling both in normal
operating mode (700-850 rpm) and in cold start mode (1000-2000 rpm). The ignition timings tested
were 20oBTDC and 25oBTDC. The measurements were made at engine speeds from 700 to 2500
rpm. Some irregularities were found in the result, but overall, the ignition timing 25oBTDC is better
than 20oBTDC in terms of fuel consumption and exhaust gas emissions. For this particular system,
the results recommend that the idling engine speed should be at 700-800 rpm and 1500 rpm during
the normal mode and cold start mode respectively. The use of engine speed of 1000 to 1300 rpm
should be minimized to reduce overall exhaust gas emissions. |
|---|