Development of a thermally-efficient, durable, and low emission natural gas-fueled electric power generator

Etalim Inc.是一家加拿大能源相关公司，开发小型（1-5千瓦时）发电机。这些发电机通过几种热流体过程（包括燃烧）将天然气的化学能转化为电能。当前版本的Etalim燃烧器通过将其转移到天然气/空气流中，在排气之前回收部分燃烧产品的内能。目前Etalim燃烧器的运行方式是预混燃烧，即天然气和空气在反应前充分混合。不幸的是，由于自燃问题，这种操作模式不能最大限度地回收燃烧产物的热量。具体来说，超过850 K，天然气和空气混合物在到达燃烧室之前就自发反应。这被称为自动点火，是不希望预混燃烧系统。为了解决这个问题，首先，将使用湍流产生装置对Etalim燃烧器的运行进行表征和优化，用于预混运行模式和反应物温度低于850 K。然后，将设计一个旋流器并与燃烧器集成，允许产生部分预混火焰。与预混火焰相比，自燃稳定了部分预混火焰，是人们所希望的。对于这种类型的火焰，旋流器的几何特征，如叶片角度，将被修改，旨在最大限度地提高自燃发生频率。这将促进稳定和热效率高的Etalim燃烧器的发展。虽然部分预混的火焰结构可以使燃烧器热效率最大化，但它会导致燃烧室中的热声（热释放率和压力）振荡，从而导致燃烧器机械疲劳。将设计四分之一波管（一种阻尼装置）并与Etalim燃烧器集成，旨在减轻热声振荡。最后，所有与完全预混和部分预混运行模式相关的设计参数都将进行调整，以最大限度地减少燃烧污染物的排放。开发的Etalim燃烧器将服务于加拿大约290个需要独立发电装置的偏远地区。

Etalim Inc. is a Canadian energy-related company that develops small-scale (1-5 kWatt) power generators. These generators convert chemical energy of natural gas to electricity through several thermo-fluid processes, including combustion. Current version of the Etalim burner recovers part of combustion products internal energy prior to exhaust by transferring it to natural gas/air flow. Current Etalim burner mode of operation is premixed combustion, meaning that natural gas and air are fully-mixed before reaction. Unfortunately, this mode of operation does not allow for maximized heat recovery from combustion products due to auto-ignition issue. Specifically, beyond 850 K, the natural gas and air mixture reacts spontaneously before reaching the combustion chamber. This is referred to as auto-ignition and is undesired for premixed combustion systems. In order to address this issue, first, the operation of the Etalim burner will be characterized and optimized using turbulence generating apparatus for premixed mode of operation and for reactants temperatures below 850 K. Then, a swirler will be designed and integrated with the burner, allowing to produce partially-premixed flames. Compared to premixed flames, auto-ignition stabilizes partially-premixed flames and is desired. For this type of flames, the swirler geometrical features, e.g. vane angles, will be modified, aiming to maximize auto-ignition occurrence frequency. This will facilitate development of stable and thermally-efficient Etalim burners. Although the partially-premixed flame configuration may allow for maximized burner thermal-efficiency, it leads to thermoacoustic (heat release rate and pressure) oscillations in the combustion chamber which causes burner mechanical fatigue. Quarter-wave tubes (a damping device), will be designed and integrated with the Etalim burner, aiming to mitigate the thermoacoustic oscillations. Finally, all design parameters related to both fully- and partially- premixed modes of operation will be tuned aiming to minimize combustion pollutants emission. The developed Etalim burner will serve about 290 remote areas in Canada that require stand-alone power generation units.