LAir Dearman Engine for Power and Cooling in Confined Spaces

该项目将采用先进的Dearman发动机（DE），为密闭空间的动力和冷却提供经济高效的零排放系统，这是一种目前由液氮（LN2）驱动的朗肯循环膨胀器，利用液态空气。使用LAir代替LN2为Dearman提供了非常有吸引力的提议，因为它的可用性，更简单的生产过程，但最重要的是它的安全特性，将扩大Dearman发动机在仓库，矿山和大型建筑物等新应用中的使用。然而，当空气液化时，它会分离成它的元素O2和N2，这预计会影响Dearman发动机的运行和性能，但最重要的是引起健康和安全问题，因为纯O2和纯N2对人类来说是致命的。在整个输送系统（油箱到发动机）中理解和控制LAir行为的能力对于实现安全高效的LAir发动机至关重要。伯明翰大学将与Dearman合作开发一款LAir驱动的Dearman发动机，并将其性能与LAir成分和从储存到排气的性能相关联。伯明翰大学将领导与LAir交付系统开发和发动机性能评估相关的工作包。这项工作包括：1-开发LAir测试设备，包括LN2， LO2和LAir储罐，泵，热交换器和阀门/管道系统。这种试验台将在每个主要部件之间的中间阶段安装温度和压力传感器、流量计和成分传感器。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入口的整个LAir输送系统的沸腾和氧气富集率。通过模拟和实验研究通过热交换器（发动机外部）的液体空气蒸发过程，以表征进入迪尔曼发动机之前的成分，温度，压力等出口条件。工作还包括评估HEF流体热特性对热交换器性能的影响。4-研究LAir成分对发动机性能和发动机排气处混合气成分的影响。将根据发动机功率输出、耐久性和稳定性（即IMEP和峰值压力的变化系数）确定最佳的N2/O2混合物。这项工作还将评估LAir和HEF的经济性，并强调在一系列速度负载条件下可能出现的任何发动机可操作性问题。

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.