Model Based Experimental Study on Next Generation Hybrid Environmental Control Systems (HECS)

下一代混合环境控制系统（HECS）基于模型的实验研究

• 批准号: 1785530
• 金额: --
• 依托单位: Loughborough University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1785530
• 关键词: Model; Based; Experimental; Study; Next

The environmental temperature range of the avionics is specified at between -31degreesC and +70degreesC. Operation outside the range leads to exponentially increases in failure rate. Controlling to the lower limit of the range requires the Environmental Control System (ECS) to supply surplus conditioned air. The generation of the surplus requires increased use of bleed and ram air, demands extra engine power and reduces aircraft aerodynamic performance. Controlling to the upper limit of the range significantly reduces the amount of the conditioned cold air, increases engine power output, improves fuel efficiencies, and improves aircraft performance. Conventional - bleed air ECS uses engine bleed air and external ram air. It is a proven and reliable technology but largely inefficient. It demands extra engine power, reduces aircraft aerodynamic performance, and results in an enormous of thermal power penalty over the engine in addition to other maintenance problems due to overheating on ground and during ascent/descent (when ram air flow must be forced with a fan, the engine fan or a dedicated one, for example).Electric ECS uses dedicated electric compressor(s) that feed on ram air to produce the conditioned air. It eliminates engine bleed, offers potentials such as: (1) improve airframe systems utilization and implement more efficient power units, (2) reduce engine core size, overall pressure ratio and the turbine inlet temperature, thus improving engine performance which lead to more efficient aircraft, and (3) eliminate bleed air systems lead to overall aircraft mass reduction. However, the increases in high avionics and radar heat loads demand excessive cooling power. The current electric system is relatively immature to satisfy the high demands. A potential solution of optimisation can be achieved through a hybrid environmental control system (HECS) concept by adding a small-scale electric ECS to the conventional bleed air system. In doing so, the bleed air ECS is reduced to only provide the conditioned air to maintain the avionics at the upper operating temperature range. The add-on electric ECS will be a start-stop design, which only supply the excessive conditioned air when it is needed. The HECS therefore provides an energy efficient yet low risk solution. It keeps the demand of engine bleed air to minimum, therefore significantly increases engine power output, improves fuel efficiencies, and improves aircraft performance. It is an intermediate step towards realisation of electric ECS for future aircrafts. The aim of this project is to develop the HECS concept into a proof-of-concept demonstration unit based on our current research outputs on avionic thermal demands, ECS modelling studies and experimental ECS evaluations. The HECS concept developed from this project will offer the potential of improving the ECS efficiency while maintaining a low failure rate. In addition, the optimised HECS can improve the aircraft performance and increase the engine power.

航空电子设备的环境温度范围规定在-31°c到+70°c之间。超出范围的操作导致故障率成倍增加。控制到范围的下限需要环境控制系统（ECS）提供多余的空调空气。产生多余的空气需要增加引气和冲压空气的使用，需要额外的发动机功率，并降低飞机的空气动力学性能。控制到范围的上限可以显著减少调节冷空气的数量，增加发动机功率输出，提高燃油效率，并改善飞机性能。传统的引气ECS使用发动机引气和外部冲压空气。这是一种经过验证的可靠技术，但在很大程度上效率低下。它需要额外的发动机功率，降低飞机的空气动力学性能，除了在地面和上升/下降过程中由于过热而导致的其他维护问题（当冲压空气流动必须用风扇，发动机风扇或专用风扇，例如）之外，还会导致发动机的巨大热功率损失。电动ECS使用专用的电动压缩机，以冲压空气为原料产生调节空气。它消除了发动机引气，提供了以下潜力：(1)提高机体系统利用率，实现更高效的动力单元；(2)减小发动机核心尺寸、总压比和涡轮入口温度，从而提高发动机性能，从而提高飞机效率；(3)消除引气系统，从而降低飞机整体质量。然而，高航空电子设备和雷达热负荷的增加需要过多的冷却功率。目前的电力系统相对不成熟，无法满足高需求。一种潜在的优化方案可以通过混合环境控制系统（HECS）概念来实现，即在传统的引气系统中添加小型电动ECS。在这样做的过程中，引气ECS减少到只提供调节空气，以维持航空电子设备在较高的工作温度范围内。附加的电动ECS将是一个启停设计，只在需要时提供多余的空调空气。因此，HECS提供了一种节能且低风险的解决方案。它使发动机引气需求降至最低，因此显著增加发动机功率输出，提高燃油效率，改善飞机性能。这是实现未来飞机电动ECS的中间步骤。该项目的目的是根据我们目前在航空电子热需求、ECS建模研究和实验ECS评估方面的研究成果，将HECS概念发展为概念验证演示单元。该项目开发的HECS概念将提供提高ECS效率的潜力，同时保持低故障率。此外，优化后的HECS可以改善飞机性能，增加发动机功率。