Increasing thermal efficiency of biogass application with more-expansion cycle and direct-injection stratified combustion

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420149
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Thermal engineering
• Research Institution: Gunma University
• Principal Investigator: Shiga Seiichi 群馬大学, 大学院理工学府, 教授 (00154188)
• Co-Investigator(Kenkyū-buntansha): ARAKI Mikiya 群馬大学, 大学院理工学府, 准教授 (70344926) ; GONZALEZ P JUAN 群馬大学, 大学院理工学府, 助教 (30720362)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: バイオマス / 熱効率 / 成層燃焼 / 超過膨張サイクル / ガス機関 / 蓄電 / 実バイオガス / 充放電効率

Outline of Final Research Achievements

Bio-gas produced through low and high temperature gasification was applied to a spark-ignition engines. A diesel based engine with higher turbulence and higher compression ratio gave the indicated thermal efficiency of about 40%. Actual bio-gas was also used to a gas engine. It gave the maximum brake thermal efficiency of 30% in the case of low-temperature gasification, while in high-temperature gasification, it goes down to 22 %. Over-expansion effect in a homogeneous compression ignition mode was also examined and gave the maximum indicated efficiency of 45% with no NOx emission. Direct-injection of gaseous fuelwas experimentally examined by using a rapid compression machine where engine-like condition was safely reproduced. A model was successfully established on the basis of comparison between emissions data obtained by completely uniform mixture combustion. The non-uniformity was reasonably expressed by the mean equivalence ratio and the dispersion of Gaussian distribution.

Free Research Field

熱工学