【作者】 洪大良；

【导师】 陈光明； 唐黎明； 何一坚；

【作者基本信息】 浙江大学 ， 制冷及低温工程， 2013， 博士

【摘要】 随着经济的发展和人们生活质量的提高,制冷与采暖消耗的能源占全社会能耗的比例越来越大；另一方面,大量的工业余热、废热没有加以利用,造成严重浪费。因此,研究余热驱动且对环境友好的吸收式制冷系统受到人们越来越多的关注。为了提高吸收式制冷系统的竞争力,需要提高其性能。采用新型吸收式制冷循环是提高吸收式制冷系统性能的一种主要方式。传统上,构建新型制冷循环主要依赖研究人员的灵感,循环构建过程漫长而低效。考虑到制冷过程本身的特点,本文提出了制冷能力分析方法,并将其用于吸收式制冷循环性能的分析及新循环的构建。针对中低温变温余热利用不充分的技术难题,本文通过制冷能力理论分析,发现传统单效吸收式制冷循环吸收器出口溶液具有潜在扩散制冷能力,并发现可以通过改变传统单效吸收式制冷循环吸收器出口溶液的理论终态温度,以实现将潜在制冷能力转化为现实扩散制冷能力。在上述研究思路突破的基础上,构建了一种结构形式简单、能高效利用该类热源的新型吸收式制冷循环,并进行了详细的理论研究。理论研究结果显示,在所研究的工况范围内,新循环单位质量热源流体的制冷量比传统单效循环高20%以上。针对低温余热难以高效利用的技术难题,本文以制冷能力分析方法为基础,通过合理利用或者改变溶液的现实扩散制冷能力,根据不同工况的需求,分别构建了两个新型O.x效吸收式制冷循环。理论研究表明：新构建的循环比传统循环具有更高的效率,这对于低温热源的高效利用具有重要的意义。针对中温余热难以高效利用的技术难题,本文以制冷能力分析方法为基础,分别通过改变吸收器进口溶液的制冷剂质量分数和吸收器出口溶液理论终态温度以改变溶液现实扩散制冷能力的方式,构建了两个1.x效吸收式制冷循环。理论研究表明,在所研究工况范围内,新提出的1.x效吸收式制冷循环的COP比传统单效循环可以提高20%左右。为了验证所提出的新循环及其所采用的理论模型,本文设计并搭建了1.x效喷射吸收复合制冷循环实验装置。实验研究表明,理论模拟结果与实验结果符合较好。当蒸发温度为5℃、吸收温度和冷凝温度为40℃、发生温度为135.3℃的时候,新循环的COP比传统单效循环的COP提高24%左右,当发生温度为127℃、冷凝温度和吸收温度为40℃、蒸发温度为10℃时,新循环的COP能达到1,比传统单效循环COP高30%左右,从而在实验上验证了新循环具有比传统循环更高的效率。更多还原

【Abstract】 With economic development and improvement of people’s life quality, the energy consumed by the refrigeration and heating makes up a growing percentage of the total energy consumed by the whole society; On the other hand, a lot of industrial waste heat has not been utilized. This leads to the researches on absorption refrigeration systems which can be driven by waste heat and are friendly to environment have attracted more and more attentions.The competitive power of absorption refrigeration systems can be improved by improving their performance. Using the novel absorption refrigeration cycles is one of the most important methods to improve their performance. Conventionally, constructing the novel absorption refrigeration cycles mainly depends on the talent of the researchers. It would take a long time and be not efficient. Considering the characteristic of the process of the cooling, this paper proposes a new method named as cooling availability and uses it to analyze the absorption refrigeration cycles and construct novel absorption refrigeration cycles.For the technical problem of that variable-temperature waste heat at medium-low temperature are not made full use, this paper finds that there are potential diffusion cooling availability which belong to the solution out from the absorber of conventional single effect cycle. The potential diffusion cooling availability can be converted to real diffusion cooling availability by decreasing the equivalent surrounding temperature of the solution. Based on the above breakthrough of research approach, a new novel absorption refrigeration cycle with simple structure is constructed in this paper. This cycle can make efficient use of the variable-temperature waste heat. Then the detail theoretical analysis on the new cycle is presented. Simulation results show that the cooling per unit mass of the heating fluid of the new cycle is always20%higher than that of conventional single effect cycle at all simulated working conditions.For the technical problem of that it is difficult to make efficient use of the waste heat at low temperature, this paper constructs two new novel0.x effect absorption refrigeration cycles based on cooling availability analysis method by making rational use of the real diffusion cooling availability of the solution or changing the real diffusion cooling availability to match different working conditions. The simulation results show that the performance of the new cycles are better than that of conventional cycles at most simulated working conditions. This is very important to make efficient use of the waste heat at low temperature.For the technical problem of that it is difficult to make efficient use of the waste heat at medium temperature, this paper constructs two novel1.x effect absorption refrigeration cycles based on cooling availability analysis method by changing the real diffusion cooling availability of the solution by changing the concentration of the solution into absorber or ideal absorption temperature of the solution out from absorber respectively. The simulation results show that the COP of the1.x effect absorption refrigeration cycles is20%higher than that of conventional single effect cycle at some simulated working conditions.To validate the performance of the proposed new cycles and theory model used in this paper, an experimental system of the ejector-absorption combined refrigeration cycle based on conventional double effect absorption refrigeration cyccle is designed and built.The ejector-absorption combined refrigeration cycle is one type of1.x effect absorption refrigeration cycle proposed in this paper. The experimental research shows that the experimental results coincide well with the simulation results. What is more, when evaporation temperature is5℃, absorption temperature and condensation temperature are40℃, if the generation temperature reaches to135.3℃, the COP of the new cycle is about0.9and24%higher than that of conventional single effect cycle, when generation temperature is127℃, absorption temperature and condensation temperature are40℃, if the evaporation temperature reaches to10℃, the COP of the ejector-absorption combined refrigeration system is about1and30%higher than that of conventional single effect cycle. Then the performance of the constructed new cycles being better than that of conventional cycle is proved by experiment.更多还原