LAir Dearman Engine for Power and Cooling in Confined Spaces

该项目将通过采用尖端的Dearman发动机(DE)来提供具有成本效益的零排放系统，用于有限空间的电力和冷却。Dearman发动机是一种朗肯循环膨胀机，目前由液氮(LN2)提供动力，以利用液态空气。使用LAIR而不是LN2为Dearman提供了非常有吸引力的建议，因为它的可用性、更简单的生产工艺，但最重要的是其安全特性，将Dearman发动机的使用扩展到仓库、矿山和大型建筑等新应用中。然而，当空气被液化时，它会分离出其元素O2和N2，这预计会影响Dearman发动机的运行和性能，但最重要的是引发了健康和安全问题，因为纯O2和纯N2可能会对人类造成致命影响。了解和控制LAIR在整个输送系统(坦克到发动机)中的行为对于实现安全和高效的LAIR发动机至关重要。伯明翰大学将与迪尔曼合作开发一种老巢驱动的迪尔曼发动机，并将其性能与老巢的组成和从储存到排气的特性相关联。伯明翰大学将领导与LAIR输送系统的开发和发动机性能评估相关的一揽子工作。这项工作包括：1-开发由液氮、氧气和LAIR储罐、泵、热交换器和阀门/管道系统组成的LAIR测试设施。这样的试验台将在每个主要部件之间的中间阶段配备温度和压力传感器、流量计和成分传感器。2-进行广泛的CFD模拟和实验，以开发工具来预测从储罐到发动机进气口的整个LAIR输送系统的沸腾和富氧率。3-通过模拟和实验研究通过热交换器(发动机外部)的液态空气蒸发过程，以表征进入Dearman发动机之前的成分、温度和压力的出口条件。工作还包括评估HEF流体的热性能对热交换器性能的影响。4-调查LAIR组成对发动机性能的影响以及发动机排气中混合物的组成。将根据发动机输出功率、耐用性和稳定性(即IMEP和峰值压力的变异系数)确定最佳的氮气/氧气混合气。这项工作还将评估LAIR和HEF的经济性，以及将突出在一系列速度负载条件下可能出现的任何发动机操作问题。

The project will deliver a cost-effective zero emission system for power and cooling in confined spaces, by adapting the cutting-edge Dearman Engine (DE), a Rankine-cycle expander currently powered by liquid nitrogen (LN2) to utilize liquid air. The use of LAir instead of LN2 provides very attractive proposition for Dearman given its availability, simpler productionprocess but most importantly its safety features that will expand the use of Dearman engine into new applications like warehouses, mines and large buildings. However, when Air is liquefied it separates to its elements, O2 and N2, this is expected to affect the Dearman engine operation and performance, but most importantly raises health and safety concernsas pure O2 and pure N2 can be deadly to humans. The ability to understand and control the behavior of LAir throughout the delivery system (tank to engine) is of paramount importance to achieve safe and efficient LAir engine. The University of Birmingham in collaboration with Dearman will develop a LAir driven Dearman engine and correlate its performance with LAir composition and properties from storage to exhaust. The University of Birmingham will lead the work packages associated with the development of the LAir delivery system and assessment of the engine performance. This work involves:1- Develop LAir test facility consisting of LN2, LO2 and LAir storage tanks, pump, heat exchanger and the valves/piping system. Such test rig will be instrumented with temperature and pressure sensors, flow meter and composition sensors at intermediate stages between each major component.2- Carry out extensive CFD simulation and experiments to develop tools to predict boil off and oxygen enrichment rates throughout the LAir delivery system from the storage tank to the engine inlet.3- Investigate through simulation and experimentation the Liquid air vaporization process through the heat exchanger (external to the engine) to characterize the exit conditions in terms of constituents, temperature, pressure before entering the Dearman engine. Work also includes assessing the effect of HEF fluid thermal properties on the heat exchanger performance.4- Investigate the effect of the LAir composition on the engine performance and the composition of the mixture at the engine exhaust. The optimum N2/O2 mixtures, based on engine power outputs, durability and stability (i.e. coefficient of variations of IMEP and peak pressure), will be identified. This work will also assess the LAir and HEF economy and as wellas will highlight any engine operability problems that may arise, over a range of speed-load conditions.