|
NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR) >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Engineering and Materials Sciences (IJEMS) >
IJEMS Vol.17 [2010] >
IJEMS Vol.17(1) [February 2010] >
| Title: | Improvement in part-load performance of a manifold injected spark ignition engine – an experimental investigation |
| Authors: | Purushothama, H R
Mallikarjuna, J M
Ganesan, V |
| Keywords: | Extended expansion engine
Manifold injection
Spark-ignition engine
Part-load performance |
| Issue Date: | Feb-2010 |
| Publisher: | CSIR |
| Abstract: | This paper deals with the
experimental investigations carried out on a single-cylinder, four-stroke,
manifold injected spark ignition engine to improve the part-load performance
and emission characteristics by modulating the inlet valve closure timing
(IVCT) and clearance volume (CV). The IVCT is delayed in order to reduce the
volumetric efficiency of the engine with full throttle operation which in turn
reduces the brake power output so that engine can be operated at part-load. In
addition, the CV is also reduced with respect to IVCT to maintain the effective
compression ratio (ECR) of the engine. These things change the geometric
expansion ratio (GER) and ECR of the engine along with reduced pumping losses
to increase the brake thermal efficiency and reduce the exhaust emissions at
part-loads. In order to vary the part-load brake power output, a suitable
combination of the IVCT and CV is used which in turn vary the GER/ECR ratio of
the engine. In this study, experiments are carried out for the different
GER/ECR ratios varying from 1.25 to 2 with two ECRs of 7 and 8 at a constant
engine speed of 1500 rev/min. From the results, it is found that for GER/ECR
ratio of 1.5 with ECR of 8 and 7, the improvement in brake thermal efficiency
is about 3.5 and 6.6%, the reduction in unburned hydrocarbon emissions is about
25 and 22.5% and the reduction in nitric oxides emissions is about 51 and 52%
respectively compared to conventional engine at the corresponding brake power
outputs. |
| Page(s): | 7-12 |
| ISSN: | 0975-1017 (Online); 0971-4588 (Print) |
| Source: | IJEMS Vol.17(1) [February 2010]
|
|
