【作者】 郑慧凡；

【导师】 李安桂； 范晓伟；

【作者基本信息】 西安建筑科技大学 ， 供热、供燃气、通风及空调工程， 2009， 博士

【摘要】 随着能源危机的日益加剧,太阳能作为一种环保清洁能源越来越受到人们的重视,在太阳能利用技术中,太阳能喷射制冷系统以其结构简单,运动部件少,成本低等优点在空调制冷领域的应用越来越广泛。本文提出了一种多功能的太阳能喷射/电压缩联合制冷系统,对其系统特性进行了分析和实验研究,建立了太阳能喷射制冷系统的性能仿真模型：.提出了基于室外温度和太阳辐射分区的控制发生温度的系统运行控制策略,主要研究工作如下：1、太阳能喷射制冷受气候条件的制约,单一的太阳能喷射制冷系统难以实现全天侯、稳定的供冷和供热,针对此,提出了一种新型太阳能喷射/电压缩联合制冷系统,解决了单纯依靠常规太阳能喷射制冷系统所难以实现的制冷量与空调负荷间的供需平衡问题。2、基于太阳能喷射制冷系统工作原理,编制了喷射系数计算程序,建立了太阳能喷射制冷系统热力性能计算模型。利用上述计算模型,进行了7种制冷剂在太阳能喷射制冷系统中的应用分析,指出在相同条件下,系统COP由大到小的顺序依次为R407c、R290、R152a、R134a、R600a、R141b和R123,最终从环保和安全两方面考虑选择了R134a作为系统用制冷剂；并结合郑州地区的一栋典型建筑分析了太阳能喷射/电压缩联合制冷系统在该建筑中的应用,指出整个制冷季节,太阳能喷射制冷系统可以提供该建筑物8：00-16：00时刻所需冷负荷的42%左右。3、针对本文所建立的太阳能喷射制冷系统实验装置,建立了蒸发器、冷凝器、发生器、喷射器和太阳能集热系统等主要部件的稳态计算模型,在各部件模型基础上,建立了R134a太阳能喷射制冷系统的稳态仿真模型,计算和分析了发生器热水进口温度和流量、太阳辐射值变化时的系统性能。模型计算结果与实验结果的变化趋势相同,吻合较好。4、设计并搭建了太阳能喷射/电压缩联合制冷系统性能测试实验平台。以R134a为工质,通过实验揭示了相关因素对系统COP、喷射系数和制冷量等的影响。实验研究了太阳能喷射制冷系统的逐时性能；实验研究了太阳能喷射/电压缩两级串联制冷时的系统性能。实验研究表明,当发生温度、蒸发温度和临界冷凝温度分别介于350K-358.5K之间、280K-285K之间和305K-311K之间时,系统的COP在0.14-0.24之间波动,系统平均EER可达3.0以上,系统可以提供5℃-15℃的冷冻水,给出了系统临界冷凝温度的计算关联式。研究指出,系统在不同蒸发温度和冷凝温度范围内工作时,存在一个最佳发生热量工作区；两级串联制冷实验研究表明,当发生温度为353K,蒸发温度为283K时,室外温度在299K-304K之间时,与电压缩单独制冷相比,EER平均提高11.8%,最大提高14.62%。5、提出了基于室外温度和太阳辐射分区的控制发生温度的太阳能喷射/电压缩联合运行控制策略,给出了控制运行流程图。研究表明,相同太阳辐射和集热面积情况下,控制策略下运行时,太阳能喷射制冷系统的平均COP依次增加10.82%、33.38%和14.42%；制冷量依次增加25.36%、39.21%和13.63%；太阳能喷射/电压缩联合制冷系统与电压缩系统单独工作时的系统性能对比表明,联合制冷系统可以明显降低系统的一次能源消耗量,平均EER依次增加14.23%、28.44%和15.7%。更多还原

【Abstract】 With the growing of energy crisis, as a kind of green energy, solar energy has attracted more and more attention. In the utilization of solar energy technology, the solar-driven ejector refrigeration system has been used popular for its simple structure, fewer moving parts and low cost. In this dissertation, a solar-driven ejector/electric co-compression refrigeration has been studied experimentally, a mathematical model has been established for the simulation of the solar ejector refrigeration system, and the control strategies of the solar-driven ejector/electric co-compression refrigeration system has been presented. The works of this dissertation are as following.The efficiency of the solar ejector refrigeration is restricted by climate conditions, and it is very difficult for a single solar ejector refrigeration system to cool and heat efficiently all day. So, a new type of solar-driven ejector/electric compression combined refrigeration system is proposed to overcome the shortcoming that the conventional solar ejector refrigeration system can’t realize the cooling capacity and air-conditioning load balance between the supply and demand.Based on the principle of the solar ejector refrigeration system, the mathematical model of the entrainment ratio is formulated, and a computing model about the solar ejector refrigeration system is set up. Based on the Zhengzhou climate characteristics for the first time, a selection calculation of the refrigerant solar-driven ejector refrigeration system is made using the above calculation model, and choose the R134a as the refrigerant finally. The applications of the solar-driven ejector refrigeration system combining with a villa construction in Zhengzhou region is analyzed, and it is found that solar energy can provide about 42% cooling load for the villa.Based on a detailed analysis of the solar ejector refrigeration system, a steady-state simulation model is established for the experimental components of solar ejector refrigeration system, including the evaporator, condenser, generator, ejector and solar collector system etc. The simulation model about the R134a the solar ejector refrigeration system has been developed with regard to energy and refrigerant inventory conservations among all the above components finally. The influence about the hot inlet temperature, quantity of hot water and the solar radiation on the system performance are analysed. The calculation results of the model agree well with the experimental values.A experimental bench is set up for the solar ejector/electric compression refrigeration system using R134a as refrigerant, the affection of relevant factors to the system COP, ejector coefficient and cooling capacity are studied experimentally, the hourly performance of the solar ejector refrigeration system is studied experimentally, and the performance of the solar ejector/electric co-compression refrigeration system is studied experimentally.The results from the experiments indicate that when the generator temperature is between 350K and 358.5K, the evaporator temperature between 280K and 285K, and the critical condenser temperature is between 305K and 311K, the system COP fluctuated between 0.14 and 0.24, the system average EER could get up to 3.0, the system could provide the chilled water with between 5℃and 15℃, and the correlation is obtained by regression analysis to calculate the critical condenser temperature. In addition, the research indicates that the COP is directly affected by the ambient temperature and solar radiation values. When the system circle under the condition of the different evaporator temperature and condenser temperature, there is an optimum range about generator heat, and when the evaporator temperature is 283K, the condenser temperature is equal to 306K, the generator temperature is 355.5K, and the system chilled water outlet temperature is 15℃, the system EER could get up to 5.0 or so. Two stage series refrigeration experimental results show that when the generator temperature is 353K, the evaporator temperature is 283K, and the ambient temperature is between 299K and 304K, the EER can be increased averagely 11.8% compared with the electric compression refrigeration alone and the biggest increase can reach 14.62%.The solar ejector/compression combined operation control strategy of control generator temperature based on the ambient temperature and solar radiation is proposed for the first time, the control operation flow chart is given. Studies have shown that the system COP and cooling capacity has been improved significantly when the system run on the same solar radiation and collector area,, and the average COP of the solar ejector/electric co-compression refrigeration system increased by 10.82%,33.38%, 14.42%, and the cooling capacity increased by 25.36%,39.21%,13.63%, respectively. The comparison between the solar ejector/electric compression combined refrigeration system and the electric compression system shows that:using the solar ejector/electric compression combined refrigeration system cooling can significantly lower the system’s primary energy consumption, the average EER increase about 14.23% on June 19, about 28.44% on July 26, and about 15.7% on August 18.更多还原