Prechamber Plug Research Articles

Evaluation of Engine Performance and Combustion in Natural Gas Engine with Pre-Chamber Plug under Lean Burn Conditions

Evaluation of Engine Performance and Combustion in Natural Gas Engine with Pre-Chamber Plug under Lean Burn Conditions

On Comparative Performance Testing of Prechamber and Open Chamber Laser Ignition

Laser ignition is a potential ignition technology to achieve reliable lean burn ignition in high brake mean effective pressure (BMEP) internal combustion engines. The technology has the potential to increase brake thermal efficiency and reduce exhaust emissions. This submission reports on engine testing of a Caterpillar G3516C stationary natural gas fueled engine with three types of ignition approaches: (i) nonfueled electric prechamber plug with electrodes at the base of the prechamber, (ii) nonfueled laser prechamber plug with laser spark in the middle of the prechamber, and (iii) open chamber plug with laser spark in the main chamber. In the second configuration, a stock nonfueled prechamber plug was modified to incorporate a sapphire window and a focusing lens to form a laser prechamber plug. A 1064 nm Q-switched Nd:YAG laser was used to create laser sparks. For these tests, a single cylinder of the engine was retrofitted with the laser plug while the remaining cylinders were run with conventional electric ignition system at baseline ignition timing of 24 deg before top dead center (BTDC). The performances of the three plugs were compared in terms of indicated mean effective pressures (IMEP), mass burn fraction duration and coefficient of variation (COV) of IMEP, and COV of peak pressure location. Test data show comparable performance between electric and laser prechamber plugs, albeit with a lower degree of variability in engine’s performance for electric prechamber plug compared to the laser prechamber plug. The open chamber plug exhibited poorer variability in engine performance. All results are discussed in the context of prechamber and engine fluid mechanics.

B109 天然ガスエンジン用プレチャンバープラグの開発(OS3 省エネルギー・コジェネ技術),動力エネルギーシステム部門20周年,次の20年への新展開)

As the interest in environmental issues increases, the cogeneration system has recently been attracting much attention. Particularly, the use of gas engines for cogeneration systems with low emission and high thermal efficiency is now expected to become widespread. For improving thermal efficiency, it is necessary to extend the lean limit and accelerate combustion. In this study, attention was focused on "Pre-chamber Spark Plug", which has a pre-chamber at the tip of the standard plug. We studied the effects of using a pre-chamber spark plug for 300kW to 2MW gas engines with a single-cylinder test engine. By the pre-chamber plug, the lean limit was extended and the thermal efficiency was improved.