Exergy analysis of natural gas/diesel combustion in homogenous charge compression ignition engines (HCCI) using multi-dimensional model. (2015)

• Record Type: Journal Article
• Authors: Jafarmadar, Samad
• Is Part Of: International journal of exergy. Volume 17:Number 4(2015)
• Page Start: 475
• Page End: 491
• Publication Date: 2015
• Subjects: exergy analysis -- dual fuel blends -- diesel fuel -- natural gas -- multidimensional modelling -- homogenous charge compression ignition engines -- HCCI combustion engines -- combustion timing -- energy analysis -- CFD -- computational fluid dynamics -- combustion modelling -- irreversibility; Exergy -- Periodicals; 621.402105
• Languages: English
• ISSNs: 1742-8297

Abstract

One of the major problems in application of HCCI combustion engines is lack of direct control for combustion timing. A suggested solution for combustion timing control is using a binary fuel blend in which two fuels with different auto-ignition characteristics are blended at various ratios. The aim of this research is to investigate the energy and exergy analysis of HCCI combustion when a blended fuel, which consists of diesel fuel and natural gas, is used. In order to accomplish this task, the extended coherent flame model-three zone model (ECFM-3Z) has been used, which performs combustion computations using a CFD model. For the exergy analysis, an in-house computational code is developed, which uses the results of the energy analysis and combustion modelling at various cases. With crank position at different gas fuel-air ratios, various rate and cumulative exergy components are identified and calculated separately. It is found that as gas fuel-air ratio increases from 0.3 to 0.8, the exergy efficiency decreases 46.2% to 37.9%. Furthermore, the value of irreversibility decreases from 24% to 21.4% of the mixture fuels chemical exergies.