Miniature Combustor with Liquid-Fuel Film

摘要CTS-0212163 W。Sirignano和D.标题：具有液体燃料膜的微型燃烧室一种新的概念是先进的，用于直接喷射液体燃料燃烧室的小型化，其中燃料在壁膜中流动，以减少热损失，优化蒸发速率，并抑制淬火。高表面/体积燃烧室的新的替代方案是在燃烧室表面上以薄膜形式输送液体燃料。 这种输送同时冷却燃烧室壁并暴露燃料以进行蒸发。 一个简单的分析表明，如果燃烧室是微型发动机的一部分，那么在燃烧室体积从几百立方毫米变化到几立方厘米，燃料流速从大约每秒一毫克变化到每秒一克的情况下，可以实现从十瓦到十千瓦的功率水平。 液膜燃烧的概念超出了紧凑型动力装置的范围，适用于要求或需要高表面体积比的任何燃烧室。 研究分析thebustor在一系列层流和湍流条件下使用实验和计算方法。 目标是最大化燃烧室效率和稳定性，同时最小化尺寸和排放。 虽然概念验证研究是有希望的，但需要大量的研究来提出薄膜燃烧策略。 这包括与膜表面相互作用的旋流、在这些条件下的热传递和蒸发、燃烧室中的燃料/空气混合以及最小化反应时间有关的基本问题。 还研究了一系列技术问题，包括燃料成膜方法（例如，多孔气缸或壁喷雾）、向高压条件移动、火焰稳定性、点火策略和不同燃料类型的容限。 小型燃烧室对运行条件非常敏感，因此系统的控制可能很重要。燃料和空气流率的控制、通过壁冷却的热通量控制以及涡流控制是维持最佳燃烧室性能所需的潜在重要系统输入的示例。蜂窝电话和膝上型计算机）到能够安全地探索潜在危险环境的小型移动的侦察机器人。 这些轻型设备中的许多需要数十瓦的功率，持续时间大约为数十小时，从而将电源考虑推向具有最高能量密度的那些。由于内燃机具有同时提供高功率密度和高能量密度的潜力，因此探索这种发电方法是很自然的。微型燃气涡轮机（燃烧室容积0.04 cc）、微型（排量0.078 cc）和微型（排量0.0017 cc）转子发动机、微型火箭（0.1 cc燃烧室）和微型瑞士滚燃器就是这种探索的例子。这些设备的效率还不能使它们与最好的电池竞争，但它们已经证明了内燃机作为个人电源的可行性。

AbstractCTS-0212163W. Sirignano and D. Dunn-Rankin, University of California-IrvineTitle: Miniature Combustor with Liquid-Fuel FilmA new concept is advanced for the miniaturization of direct-injection liquid-fueled combustors wherein the fuel is flowed in a wall film that reduces heat losses, optimizes vaporization rate, and inhibits quenching. The new alternative for high surface/volume combustors is the delivery of the liquid fuel as a film on the combustor surfaces. This delivery simultaneously cools the combustor walls and exposes the fuel for vaporization. A simple analysis indicates that if the combustor were part of a miniature engine, power levels from ten watts to ten kilowatts would be achievable with combustor volumes varying from a few hundred cubic millimeters to a few cubic centimeters and fuel flow rates varying from about a milligram per second to a gram per second. The liquid-film burning concept extends beyond compact power devices and applies to any combustor where high surface-to-volume ratio is imposed or desired. Studies analyze thecombustor over a range of laminar and turbulent conditions using both experimental and computational methods. The goals are to maximize the combustor efficiency and stability while minimizing size and emissions. Although proof-of-concept studies are promising, a substantial amount of research is needed to bring the film-combustion strategy forward. This includes fundamental issues regarding swirl flows interacting with filming surfaces, heat transfer and vaporization under these conditions, fuel/air mixing in the chamber, and minimizing reaction times. A range of technical issues are also examined, including fuel filming approaches (e.g., porous cylinders or wall sprays), moving to high pressure conditions, flame stability, ignition strategies, and tolerance of different fuel types. Small combustors are quite sensitive to operating conditions, so it is likely that control of the system will be important. Control of the fuel and air flow rates, heat flux control through wall cooling, and swirl control are examples of potentially important system inputs needed to maintain optimal combustor performance.The growing market of ideas that require personal power ranges from electronic and telecommunication equipment (e.g., cellular telephones and laptop computers) to small, mobile reconnaissance robots that can safely explore potentially hazardous environments. Many of these lightweight devices demand tens of watts of power for durations on the order of tens of hours, thereby driving the power source considerations towards those with highest energy density. Because internal combustion has the potential to simultaneously provide high power density and high energy density, it is natural to explore this method of power generation. The micro-gas turbine (combustor volume 0.04cc), the mini (0.078 cc displacement) and micro (0.0017 cc displacement) rotary engine , the microrocket (0.1 cc combustion chamber) , and the micro Swiss rollburner are examples of such exploration. These devices are not yet performing at efficiencies that make them competitive with the best available batteries, but they have demonstrated the plausibility of internal combustion as a personal power source.