ABSTRACT The studies of nested helical coil heat exchangers for an absorption heat transformer are very limited, although this arrangement has a greater heat transfer area in a smaller volume. The heat exchangers are vertically placed to develop the desorption, condensation, evaporation and absorption processes by falling film mode. The usage of energy from point of qualitative view in these times is mandatory, due to the fossil fuels reduction and pollution. This experimental study analyses the behavior the nested helical coils heat exchangers through the first and second law of thermodynamics. The physical and chemical exergy for the main components and whole system is calculated by using the conventional method. All the experimental tests are carried out by varying the source temperature from 343.15 to 358.15 K with heating mass flow rate in the generator between 0.07 and 0.13 kg/s. For this study, the condensation and absorption processes reach the highest exergy destruction at high temperatures, while the solution heat exchanger presents the lowest irreversibility. The exergy coefficient of performance always improves when the supplied heat in the generator increases owing to the heating mass flow rate and temperature, however there is an increment considerably of total irreversibility at 349.15 K.

中文翻译：

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用于吸收式热变压器的嵌套螺旋盘管换热器的实验评估

摘要 用于吸收式换热器的嵌套螺旋盘管换热器的研究非常有限，尽管这种布置在较小的体积中具有较大的传热面积。换热器垂直放置，通过降膜模式进行解吸、冷凝、蒸发和吸收过程。由于化石燃料的减少和污染，这些时代从定性的角度来看能源的使用是强制性的。本实验研究通过热力学第一定律和第二定律分析嵌套螺旋盘管换热器的行为。主要部件和整个系统的物理和化学火用使用常规方法计算。所有的实验测试都是通过将源温度从 343.15 变化到 358 来进行的。15 K，发生器中的加热质量流量在 0.07 和 0.13 kg/s 之间。在本研究中，冷凝和吸收过程在高温下达到最高的火用破坏，而溶液换热器的不可逆性最低。由于加热质量流量和温度，当发电机中供应的热量增加时，性能的火用系数总是会提高，但是在 349.15 K 处总不可逆性有相当大的增加。