The potential of balloon engines to convert the low grade heat in warm, saturated air to electrical energy
The potential of balloon engines to convert the low grade heat in warm, saturated air to electrical energy
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DOI：
10.1016/j.solener.2011.01.012
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发表时间：
2011-05
期刊：
影响因子：
6.7
通讯作者：
I. Edmonds
中科院分区：
文献类型：
--
作者：
I. Edmonds
本文概述了发动机的概念，理论和性能，用于将温暖，饱和空气中的热量转换为电能。该发动机包括驱动气球和支撑气球，两者都通过绳索连接到发电机。来自太阳能池或发电站冷却塔的温暖、饱和的空气被用来为较大的驱动气球充电。两个气球在发电机上工作时上升了几公里。在某个最大高度，较大的驱动气球将其所有空气排放到寒冷的高层大气中，并且较小的气球为较大的气球气囊提供支撑，通过将发电机切换到电动机操作，将两个气球拖回地面。在上升期间由系统对发电机所做的功超过在下降期间由电动机对系统所做的功，从而导致正的功输出。驱动气球中的水蒸气的冷凝保持内部饱和空气温度高于环境温度，并提供随高度增加的升力。回收冷凝物增加了发动机的功输出并节约了水。发动机的理想热效率接近15%，对应于对流层10km高度内的大温差。发动机功率与驱动气球直径的立方成比例。从市售球囊的直径放大四倍，提供MW范围内的功率输出。
This article outlines the concept, theory and performance of an engine for converting the heat in warm, saturated air to electrical energy. The engine comprises a drive balloon and a support balloon both connected to an electric generator by a rope. Warm, saturated air from a source such as a solar pond or the cooling tower of a power station is used to charge the larger drive balloon. The two balloons ascend several kilometers while performing work on the electric generator. At some maximum height the larger drive balloon discharges all its air into the cold upper atmosphere and, with the smaller balloon providing support for the larger balloon envelope, the two balloons are hauled back to ground by switching the electric generator to electric motor operation. The work done by the system on the electric generator during ascent exceeds the work done on the system by the electric motor during descent resulting in a positive work output. Condensation of water vapor in the drive balloon maintains the internal saturated air temperature above ambient temperature and provides an increasing lift force with height. Recycling the condensate adds to the work output of the engine and conserves water. The ideal thermal efficiency of the engine approaches 15%, corresponding to the large temperature difference available within the 10km height of the troposphere. The engine power scales as the cube of the drive balloon diameter. Scaling by a factor of four up from the diameter of commercially available balloons provides power outputs in the MW range.