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)发电机。这些发电机通过包括燃烧在内的几个热-流体过程将天然气的化学能转化为电力。当前版本的Etalim燃烧器通过将燃烧产物转化为天然气/空气流动，在排放之前回收部分燃烧产物的内能。目前Etalim燃烧器的运行模式是预混燃烧，这意味着在反应之前天然气和空气完全混合。不幸的是，由于自燃问题，这种操作模式不允许最大限度地从燃烧产物中回收热。具体地说，在850K以上，天然气和空气混合物在到达燃烧室之前会自发反应。这被称为自动点火，对于预混燃烧系统是不受欢迎的。为了解决这个问题，首先，对于预混操作模式和低于850K的反应物温度，将使用湍流发生装置来表征和优化Etalim燃烧器的操作。然后，将设计一个旋流器并将其与燃烧器集成在一起，以允许产生部分预混火焰。与预混火焰相比，自动点火稳定了部分预混火焰，是理想的点火方式。对于这种类型的火焰，旋流器的几何特征，如叶片角度，将进行修改，旨在最大限度地提高自燃发生的频率。这将促进稳定和热效率高的标准具燃烧器的开发。虽然部分预混火焰结构可以最大限度地提高燃烧器的热效率，但它会导致燃烧室中的热声(热释放速率和压力)振荡，从而导致燃烧器机械疲劳。四分之一波管(一种减振装置)将被设计并与标准具燃烧器集成，旨在缓解热声振荡。最后，将调整与完全和部分预混运行模式有关的所有设计参数，以将燃烧污染物排放降至最低。开发的Etalim燃烧器将为加拿大约290个需要独立发电机组的偏远地区提供服务。********

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. ********