Effects of Engine Operating Parameters on Lean Combustion Limit of Hydrogen Enhanced Natural Gas Engine

2011 ◽  
Vol 383-390 ◽  
pp. 6116-6121
Author(s):  
Xin Wang ◽  
Hong Guang Zhang ◽  
Yan Lei ◽  
Xiao Lei Bai ◽  
Xiao Na Sun ◽  
...  
Keyword(s):  
Experimental Study ◽  
Natural Gas ◽  
Engine Speed ◽  
Operating Parameters ◽  
Ignition Timing ◽  
Compressed Natural Gas ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Lean Combustion ◽  
Combustion Limit

An experimental study was conducted on a S.I. engine fueled by compressed natural gas and hydrogen blends (HCNG), in order to test different engine operating parameters that affect lean combustion limit (L.C.L) of HCNG engine. Firstly, constant ignition timing and ignition timing under maximum L.C.L (L.L.T) conditions were compared, then L.L.T conditions were adopted in this paper. The results indicated that for each condition, neither over-retarded nor over-advanced ignition timing are advised in order to achieve leaner combustion. L.C.L increases with hydrogen fraction in the blends, and slightly increases with throttle opening, while decreases when the engine speed is raised

Impacts of Ignition and Jet Timing on Natural Gas Engine Start Process

2014 ◽  
Vol 1070-1072 ◽  
pp. 1748-1751
Author(s):  
Bo Wen Zou ◽  
Jing Bo Li ◽  
Jun Gang Liu
Keyword(s):  
Natural Gas ◽  
Engine Speed ◽  
Direct Injection ◽  
Ignition Timing ◽  
Gas Engine ◽  
Idle Speed ◽  
Natural Gas Engine ◽  
Hc Emissions ◽  
Start Process ◽  
Engine Start

Based on modified natural gas direct injection engine, we studied the impacts of ignition timing and jet timing on natural gas engine start process in this paper. The results shows that: when the first jet ignition occurs in the first compression stroke, the engine reaches idle speed 400rpm fastest; as the jet timing is delayed, emissions during engine start is gradually reduced, but when the jet late, HC surge occurs, the emissions deteriorates; with the ignition advance angle increasing, the engine speed growth accelerates, the peak moves forward; with the ignition advance angle increasing, HC emissions peak increases, the peak moves forward.

Experimental study on factors affecting lean combustion limit of S.I engine fueled with compressed natural gas and hydrogen blends

Energy ◽  
2012 ◽  
Vol 38 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Xin Wang ◽  
Hongguang Zhang ◽  
Baofeng Yao ◽  
Yan Lei ◽  
Xiaona Sun ◽  
...  
Keyword(s):  
Experimental Study ◽  
Natural Gas ◽  
Compressed Natural Gas ◽  
Factors Affecting ◽  
Lean Combustion ◽  
Combustion Limit

Experimental study of combustion strategy for jet ignition on a natural gas engine

2020 ◽  
pp. 146808742097775
Author(s):  
Ziqing Zhao ◽  
Zhi Wang ◽  
Yunliang Qi ◽  
Kaiyuan Cai ◽  
Fubai Li
Keyword(s):  
Experimental Study ◽  
Natural Gas ◽  
Efficient Points ◽  
Lean Burn ◽  
Gas Engine ◽  
Absolute Value ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Excess Air ◽  
Lean Limit

To explore a suitable combustion strategy for natural gas engines using jet ignition, lean burn with air dilution, stoichiometric burn with EGR dilution and lean burn with EGR dilution were investigated in a single-cylinder natural gas engine, and the performances of two kinds of jet ignition technology, passive jet ignition (PJI) and active jet ignition (AJI), were compared. In the study of lean burn with air dilution strategy, the results showed that AJI could extend the lean limit of excess air ratio (λ) to 2.1, which was significantly higher than PJI’s 1.6. In addition, the highest indicated thermal efficiency (ITE) of AJI was shown 2% (in absolute value) more than that of PJI. Although a decrease of NOx emission was observed with increasing λ in the air dilution strategy, THC and CO emissions increased. Stoichiometric burn with EGR was proved to be less effective, which can only be applied in a limited operation range and had less flexibility. However, in contrast to the strategy of stoichiometric burn with EGR, the strategy of lean burn with EGR showed a much better applicability, and the highest ITE could achieve 45%, which was even higher than that of lean burn with air dilution. Compared with the most efficient points of lean burn with pure air dilution, the lean burn with EGR dilution could reduce 78% THC under IMEP = 1.2 MPa and 12% CO under IMEP = 0.4 MPa. From an overall view of the combustion and emission performances under both low and high loads, the optimum λ would be from 1.4 to 1.6 for the strategy of lean burn with EGR dilution.

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