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DOI: 10.11817/j.issn.1672-7207.2018.03.030 水平微肋管内有机工质R245fa的沸腾换热性能 王志奇1,刘力文1,贺妮1,夏小霞1, 2,彭德其1,张建平1,明镇洋1 (1. 湘潭大学 机械工程学院,湖南 湘潭,411005; 2. 中南大学 能源科学与工程学院,湖南 长沙,410083) 摘要:为增强有机朗肯循环发电系统中蒸发器的传热能力,对水平微肋管内新型有机工质R245fa的沸腾换热性能进行实验研究.研究结果表明:R245fa沸腾换热系数随质量流速增大而提高,随饱和温度和热流密度增大而减小;随着干度增大,沸腾换热系数先增大后降低,存在1个临界干度;在实验条件下,临界干度约为0.4,并与实验工况有关;超过临界干度时,质量流速对R245fa沸腾换热系数的强化作用增大,而饱和温度对沸腾换热的抑制作用增大;在4种常用关联式中,KANDLIKAR关联式......
J. Cent. South Univ. (2019) 26: 3200-3212 DOI: https://doi.org/10.1007/s11771-019-4246-9 Experimental investigation on boiling heat transfer and pressure drop of R245fa in a horizontal micro-fin... heat transfer and frictional pressure drop of R245fa in a 7 mm horizontal micro-fin tube was performed. The results show that in terms of flow boiling heat transfer characteristics, boiling heat......
was deduced. According to the formula derived, the thermal efficiency of four organic working fluids (R134a, R123, R245fa and R227ea) for the small ORC system were calculated under the same condition...系统成败的关键因素.Lakew等[1]通过分析各种蒸发压力下系统的循环净功和换热器的面积,对R134a,R227ea,R123和R245fa等6种工质进行比较;Papadopoulos[2]提出一种新的观点:通过系统的设计来优化选择循环工质.顾伟等[3]研究了不同工质下系统工作参数对ORC系统性能的影响规律. 工质的选择首先应该满足小型ORC系统对工质的热物性的基本要求,如工质的临界温度,膨胀比......
一种低温太阳能热发电循环系统的理论分析宋建忠1, 2,张小松1, 2(1. 东南大学 能源与环境学院,江苏 南京,210096; 2. 常熟市东南应用技术研究院,江苏 常熟,215500)摘 要:提出一种可以有效利用太阳能来生产电力同时也提供一定热能或热水的动力系统.该系统基于有机朗肯循环,采用低沸点工质作为循环工质.选用R245fa(五氟丙烷)为工质,针对该系统在理想循环与实际循环下的性能进... and co-provide certain amount of domestic hot water, and it employs the fluid with low boiling point as the working fluid. In this work, R245fa was selected as the working fluid. The cycle performance......
R11,R141b,R113和R123的热力性能略优于其他有机工质,而R245fa 和R245ca是最有利于环保的有机工质.KASKA[10]运用实际工厂运行结果对有机朗肯循环过程的能量和火用进行分析,发现蒸发压力对能量效率和火用效率都有很大影响,并采用节点分析法研究了蒸发器内热交换过程对净输出功的影响.谢飞博等[12]通过实验研究了冷却水温度对有机朗肯循环系统性能的影响,发现当热源温度不变时,随着冷却水温度升高,冷凝器和蒸发器的负荷减小,系统的输出电功和热效率降低.在实验工况范围内,冷却水温度每升高1 ℃,系统输出电功降低0.041 1 kW,降低幅度达1.74%.PANG等[15]采用R245fa和R123以及这两者混合的有机介质,通过实验研究了工质质量流量和膨胀机进口工质的过热度对系统净输出电量的影响.结果表明,当热源温度为110 ℃时,纯R245fa工质能产生的最大净电量为1.56 kW......
铝电解槽低温烟气余热发电系统热力分析王志奇1,2,周乃君1,罗亮1,郭静11. 中南大学能源科学与工程学院2. 湘潭大学机械工程学院摘 要:采用R245fa为循环工质,以某铝业公司一个净化系统的低温烟气为研究对象,对该烟气余热发电系统进行热力分析.该净化系统的烟气流量为5.0×105m3.h-1,温度为150℃.结果表明:当传热窄点一定时,系统存在一个最佳蒸发压力,此时系统的输出净功最大.针对所研究的烟气,系统的最佳蒸发压力为1.0MPa,此时该净化系统的最大输出净功为1055kW,相当于吨铝能耗降低1.6%.最佳蒸发压力下,系统的热效率和效率分别为10.3%和40.5%.系统各部件中,蒸发器的损失最大.为增加系统的最大输出功率,应重点降低蒸发器的损失.当烟气温度从100℃增加到180℃时,系统的输出......
低能耗石灰回转窑废气余热发电有机郎肯循环工质选择王新建1,2,黄高泉1,2,彭岩1,2,郝景周1,21. 洛阳矿山机械工程设计研究院有限责任公司2. 矿山重型装备国家重点实验室(中信重工机械股份有限公司)摘 要:石灰窑竖式预热器出口的烟气温度约为250℃,采用水蒸汽郎肯循环回收烟气余热,存在发电功率低,热效率低及项目投资回收期长等缺点;而采用有机工质郎肯循环(Organic Rankine Cycle,ORC)对烟气余热加以回收,可有效提高系统热效率及发电量.但有机工质的选择对系统影响很大,笔者采用热水和有......
power and heat recovery efficiency into account, a multi-objective mathematical model was developed for organic Rankine cycle (ORC). Working fluids considered were R123, R134a, R141b, R227ea and R245fa... boiling substances in sub-critical processes with n-butane. LAKEW and BOLLAND [4] found that R227ea gave the highest power for heat source temperature range of 80-160 ℃ and R245fa produced the highest......
was developed and a parametric study was conducted. The energy efficiency and exergy efficiency of the EHW-driven ORC system were modeled with R245fa, R113 and R123 as the working fluids. The results demonstrate... fluids perform better. BARAL et al [21] investigated 15 organic fluids to evaluate their fitness and performance as working fluids in an ORC system. In the investigated application, R134a and R245fa......
of the plate heat exchanger, with a variation of flowrate of R245fa. The influence of working fluid flowrate on a 500W ORC system was investigated. Adjusting the working fluid flowrate to an optimal... fluids in terms of the performance of the whole systems. HUANG et al [5], Wang et al [6] and Wang et al [7] analyzed the effects of working fluids on ORCs and R245fa was proven to be one of the best......