内燃机尾气驱动的化学吸附式制冷系统仿真研究

发布时间：2018-07-08 20:07

本文选题：化学吸附 + 吸附制冷　；参考：《中南大学》2014年硕士论文

【摘要】：摘要：内燃机尾气是一种可以充分利用的高温余热资源,其带出的热量相当于内燃机所用燃油发热值的30%左右,对其进行余热回收利用具有极大的社会经济意义。吸附式制冷是一种环境友好的、可利用低品位能源的绿色制冷技术,非常符合运载工具内燃机尾气余热的回收利用场合。本文采用吸附式制冷方式应用于内燃机尾气的余热回收,应用数值模拟的方法对吸附式制冷系统的运行特性进行分析。首先,根据吸附工质对的性能和吸附式制冷系统的循环方式特点确定了适合内燃机尾气余热利用的吸附工质对(氯化钙—氨)和循环方式(三床连续循环),并提出提高系统效率的回热、回质循环。其次,在平衡吸附的前提下,从热力学角度对三床吸附式制冷系统理想循环中的各个过程进行了能量分析,并根据氯化钙—氨的吸附特性分析了处于不同温度范围、不同蒸发温度、不同冷凝温度和采用回热、回质循环的系统循环性能的特点。再次,基于非平衡吸附特性,建立了吸附床的传热传质数学模型,并利用fluent软件对其进行求解分析,讨论了吸附床内温度分布规律与运行过程中的温度变化规律,并对影响床内温度分布的参数与吸附量的关系进行了分析。最后,研究了内燃机尾气驱动的氯化钙—氨化学吸附式制冷系统的动态运行特性。通过建立热力学动态数学模型,仿真得到吸附床温度、蒸发温度、冷凝温度、蒸发器与冷凝器出口温度在系统运行时的变化,总结了在变蒸发温度或冷凝温度下系统性能参数的变化规律,并对采用回热、回质循环对系统性能影响进行了初步分析。本文的结论可以为今后有关化学吸附式制冷系统各部件的匹配性和优化系统性能的进一步研究提供参考。
[Abstract]:Abstract: the exhaust gas of internal combustion engine is a kind of high temperature waste heat resource which can be fully utilized. The heat produced by it is about 30% of the heating value of the fuel used in the internal combustion engine. It is of great social and economic significance to recycle the waste heat from the exhaust gas of the internal combustion engine. Adsorption refrigeration is an environment-friendly, low-grade energy green refrigeration technology, which is very suitable for the recovery and utilization of exhaust heat from internal combustion engine. In this paper, adsorption refrigeration method is used to recover waste heat from exhaust gas of internal combustion engine, and the operation characteristics of adsorption refrigeration system are analyzed by numerical simulation method. First According to the properties of adsorptive working pairs and the characteristics of the cycle mode of adsorption refrigeration system, the adsorption working pairs (calcium chloride ammonia) and the cycle mode (three-bed continuous cycle) suitable for the utilization of residual heat from tail gas of internal combustion engine were determined, and the improvement was proposed. The recovery of system efficiency, Return cycle. Secondly, on the premise of equilibrium adsorption, the energy analysis of each process in the ideal cycle of three-bed adsorption refrigeration system is carried out from the viewpoint of thermodynamics, and the adsorption characteristics of calcium chloride and ammonia are analyzed in different temperature range according to the adsorption characteristics of calcium chloride and ammonia. The characteristics of the system with different evaporation temperature, different condensing temperature and using regenerative and regenerative cycle. Thirdly, based on the characteristics of non-equilibrium adsorption, the mathematical model of heat and mass transfer of adsorption bed is established, and the temperature distribution in the adsorption bed and the temperature variation during operation are discussed by using fluent software. The relationship between the parameters affecting the temperature distribution in the bed and the adsorption capacity was analyzed. Finally, the dynamic operation characteristics of calcium chloride-ammonia chemisorption refrigeration system driven by internal combustion engine exhaust gas are studied. By establishing a thermodynamic dynamic mathematical model, the variations of adsorption bed temperature, evaporation temperature, condensation temperature and outlet temperature of evaporator and condenser during the operation of the system are obtained by simulation. The variation law of system performance parameters at variable evaporation temperature or condensing temperature is summarized, and the effect of regenerative and regenerative cycle on system performance is analyzed preliminarily. The conclusion of this paper can be used as a reference for further research on the matching of various components of chemisorption refrigeration system and the optimization of system performance.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB657

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