OPERATING COMPANY EXPERIENCE WITH ELECTRONIC PRE-COMBUSTION CHAMBER CHECK VALVES: A CASE STUDY
Since pre-combustion chambers have been offered with large-bore gas engines, operators have had problems with check valves that tend to malfunction, mainly on start-up after the engine has been shut down for whatever reason. This sticking causes the pre-combustion chamber to either be over- or under-fueled, leading to poor combustion or no combustion in the pre-chamber and thus in the main chamber. This has led to onerous maintenance practices, such as changing all check valves prior to every start. This problem has been solved with an electronic precombustion chamber check valve, and this paper gives one companys experience with this new technology. Large-bore gas internal combustion engines utilized in the gas pipeline industry have a long history of reliable service. Starting in the 1970s, engine manufacturers began to offer engines that produced lower levels of undesirable emission, mainly NOx and unburned hydrocarbons. In order to accomplish this goal, larger turbochargers were employed to produce air in excess of the air needed for combustion. The excess air served as a heat sink to keep combustion temperatures down, thus lowering NOx. However, this excess air led to unstable combustion and in order to restore stable combustion, pre-combustion chambers were employed.