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多种热流体过程将天然气的化学能转化为电能。目前版本的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物内部能量。目前Etalim燃烧器的操作模式是预混燃烧，这意味着天然气和空气在反应前充分混合。不幸的是，由于自燃问题，这种操作模式不允许从燃烧产物中最大化地回收热量。具体地，超过850 K，天然气和空气混合物在到达燃烧室之前自发反应。这被称为自动点火并且对于预混合燃烧系统是不期望的。为了解决这个问题，首先，Etalim燃烧器的操作将使用湍流产生装置进行表征和优化，用于预混合操作模式和低于850 K的反应物温度。然后，旋流器将被设计并与燃烧器集成，允许产生部分预混火焰。与预混火焰相比，自动点火使部分预混火焰稳定并且是期望的。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。这将有助于开发稳定和热效率高的Etalim燃烧器。尽管部分预混火焰构造可允许最大化燃烧器热效率，但其导致燃烧室中的热声（热释放速率和压力）振荡，这导致燃烧器机械疲劳。四分之一波管（阻尼装置），将设计和集成的Etalim燃烧器，旨在减轻热声振荡。最后，将调整与完全预混和部分预混操作模式相关的所有设计参数，以最大限度地减少燃烧污染物排放。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.