【作者】 黄超；

【导师】 何国庚；

【作者基本信息】 华中科技大学 ， 制冷及低温工程， 2009， 硕士

【摘要】 对一种太阳能热源驱动的小型增压式、绝热吸收的吸收式制冷循环进行了理论研究和模拟。基于传热传质分离强化的理论在循环中使用了绝热吸收、循环冷却的填料吸收器。系统的冷凝器、蒸发器和吸收器的散热器均采用蒸发式换热器。由于发生压力较低,在发生器和冷凝器之间带有罗茨真空泵作为增压机。该系统设计在80℃热水驱动下工作,其热力学计算结果表明这种新型吸收式制冷循环能够很好地提升系统性能。由于吸收器是吸收式循环中最重要的部件之一,如何提高吸收器的吸收效率和减小吸收器的体积也是小型太阳能吸收式制冷的难题之一,因此本文利用Aspen Plus的非平衡级模型RateFrac对吸收器中的吸收过程进行了模拟分析。该模拟对于这种LiBr电解质水溶液吸收水蒸汽的过程采用了ELECNRTL性质方法。通过对不同尺寸和类型的填料模拟得到的吸收度进行比较,能够实现对吸收器设计参数的优化。在吸收过程模拟的基础上运用Aspen Plus对系统流程进行了模拟分析,并将模拟结果与热力学编程计算的结果进行了比较。结果进一步表明该制冷循环在太阳能热源驱动下具有较好的系统性能。通过对Aspen Plus的电解质物性方法得出的LiBr溶液热力学参数与饱和LiBr溶液焓浓图中的数据进行对比,分析了模拟误差产生的来源,并提出了进一步改进的措施。更多还原

【Abstract】 Studies and simulation is done on a small solar-powered adiabatic absorption refrigeration cycle. Based on the theory of the separation and respective aggrandizement on the heat and mass transfer, uses an absorber of adiabatic absorption with packing inside and circular cooling in the cycle. Evaporative exchangers are applied in the system as the condenser, evaporator and the radiator of the absorber. Because of the low pressure in the generator, a roots vacuum pump is used as a compressor between the generator and condenser. The system is powered by the hot water of 80℃. Results of the simulation have showed this novel absorption refrigeration cycle brings an improvement in the system performance.As the absorber is one of the most important components, how to improve the efficiency and reduce the volume of the absorber is also one of the difficulties of small solar-powered absorption refrigeration system, simulates and analyses the process of the absorption in Aspen Plus with a non-equilibrium stage model of RateFrac. This simulation adopts a method of ELECNRTL in simulating the process of LiBr electrolytical aqueous solution absorbs water vapor. With the results of the simulation on the packing with different sizes and types, a parameter optimization of the absorber could be done.Simulates the system process with Aspen Plus based on the simulation of absorption, and compares the results obtained from the simulation and thermodynamic calculation program. It further shows this solar-powered refrigeration cycle has a better performance. By the comparison between the thermodynamic parameters of LiBr solution obtained respectively from the electrolytical property method in Aspen Plus and the enthalpy- concentration map of LiBr saturated solution, analyses the source of deviation in the simulation, and proposes measures to further improvement.更多还原