【作者】 郑宋平；

【导师】 郑丹星；

【作者基本信息】 北京化工大学 ， 化学工程， 2004， 硕士

【摘要】 本文以氨水吸收式制冷循环为对象,对循环理论和氨水吸收式制冷实验开展了系统的研究。分析了循环的操作温度、压力和浓度变化范围,探讨了热泵的能量转换目标及不可逆性。并通过系统 T-S 图分析了三个热源热泵子循环与热机子循环耦合关系,进而根据耦合关系探讨了热源温度对系统性能的影响情况。借助 Aspen 模拟软件,对氨水吸收式制冷循环主要设备中的精馏塔、吸收塔,以及全流程进行了模拟计算。研究了循环的冷凝温度、蒸发温度、精馏温度、循环倍率对性能系数的影响;分析了精馏操作加热温度与循环倍率、放气范围之间的关系;分析了回流比对分离效果的影响;讨论了吸收塔冷凝水进口温度对于冷凝负荷的影响,以及稀溶液的进口浓度对吸收过程传热、传质的影响情况。在分析原有实验现象的基础上,经过实验装置的改进,提高了系统的稳定性。经过改进操作条件及方式,在塔釜加热温度 TGEN为 71.8℃情况下,系统制冷性能系数为 0.278。初步实验证明了系统的制冷性能。实验表明高效填料有利于提高精馏塔的分离效果,同时表明板式换热器与降膜吸收塔的有效性。基于对可再生能源利用的考虑和热泵热源温差的协调配置的研究,建立了一种太阳能与地热结合利用的氨水吸收式制冷与供热新系统,并对其进行了计算机模拟。在本研究提出的基本操作参数下,组 II<WP=5>北京化工大学硕士研究生毕业论文合热源热泵系统的制冷工况COPR为 0.583,供暖工况COPHP为 1.509。分别高于常规热源形式的热泵系统 12.0%和 16.2%。表明本研究建立的组合热源热泵系统是可行的。更多还原

【Abstract】 Focusing on ammonia-water absorption refrigeration cycle, this paperstudies the theory and experiments of the cycle. In the paper, the operationtemperatures, pressures and the changes of concentration were analyzed.The target to energy conversion of heat pump and the irreversiblecharacteristics were discussed. According to the analysis of T-S diagrams,the coupling relationship between the heat-pump subcycle and theheat-engine subcycle was proposed. Furthermore, the influences ofheat-source temperature to system performance were evaluated. With software Aspen Plus, the characteristics of rectifier, absorber andwhole process were simulated. The influences of condensation-temperature,evaporation temperature, generation temperature and circular ratio to thecoefficient of performance were studied. The relationship betweengeneration temperature and circular ratio was analyzed. And therelationship between reflux ratio and separation effect was analyzed. Theinfluence of cooling water temperature at absorber entrance tocondensation load was discussed. The influence of weak solution IV<WP=7>北京化工大学硕士研究生毕业论文concentration to heat transfer and mass transfer were discussed too. After have analyzed former experiment result, the experimental deviceconfiguration was rebuilt. And the process stability was improved. By theimprovements for operation conditions and procedures, the COP reached0.278 when the temperature at rectifier bottom is 71.8℃. Pilot studyprovesthat the experimental device possess refrigeration performance. It comes tothe conclusion that the efficient-packing is helpful to improve theseparation effect of rectifier, moreover, the plate heat-exchanger andfalling-film absorber are appropriate, respectively. Based on researches on the utilization of renewable energy and thematching of heat source temperatures of heat pump, this work proposes anammonia absorption cycle system for refrigeration and heat-supply, whichis a the heat pump combined heat sources. While combing solar energy andgeothermal heat and based on the operation parameters proposed in thework, the system achieves COPR of 0.583 at refrigeration condition andCOPHP of 1.509 at heat-supply condition, that are higher than conventionalsystem by 12.0% and 16.2%, respectively. It shows that is reasonable toadopt the heat pump combined heat sources.更多还原