制冷剂水合物相平衡和形成过程实验研究

发布时间：2018-03-01 18:18

本文关键词： 水合物制冷剂相平衡诱导时间　出处：《苏州科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着经济的发展,空调使用越来越广泛,空调负荷加剧了高峰用电负荷。为了减少空调在用电高峰的负荷,蓄冷空调应运而生。蓄冷空调能够充分利用低谷电力,从而实现电力的“移峰填谷”。制冷剂水合物作为蓄冷介质,具有相变潜热大和相变温度高的优点,但同时也有诱导时间长和形成压力高等缺点,解决这些缺点是制冷剂水合物蓄冷走向应用的关键。利用定容逐步加热的方法测量了二氧化碳+水+四氢呋喃/HCFC141b/环戊烷体系水合物相平衡条件。实验结果表明,在给定温度下,二氧化碳+水+四氢呋喃/HCFC141b/环戊烷水合物相平衡压力均低于纯水中二氧化碳水合物相平衡压力。实验结果同时也表明,随着四氢呋喃水溶液质量分数的增加,二氧化碳水合物相平衡压力降低越明显。当四氢呋喃水溶液质量分数大于19.05%的时候,过量的四氢呋喃并不能进一步有效降低二氧化碳水合物相平衡压力。当温度小于288K,HCFC141b比环戊烷更能降低二氧化碳水合物的相平衡压力,但是在高温的时候,环戊烷和HCFC141b对二氧化碳水合物相平衡压力的影响相类似。利用水合物相平衡数据计算了水合物的相变潜热,二氧化碳、二氧化碳+四氢呋喃(四氢呋喃质量浓度分别为0.0726、0.1024和0.1905)、二氧化碳+HCFC141b和二氧化碳-环戊烷水合物的相变潜热分别为68.22 kJ/mol、(155.15 kJ/mol、156.73 kJ/mol、171.98 kJ/mol)、232.93 kJ/mol和248.27 kJ/mol。实验研究了HCFC141b及HCFC141b+表面活性剂SDS对二氧化碳气体水合物的生成过程的影响。与纯二氧化碳气体水合物进行相比,添加HCFC141b和表面活性剂SDS可促进二氧化碳气体水合物生成和缩短诱导时间。实验结果表明,在初始压力为0.4MPa,水浴温度为277.15K时,诱导时间仅需142min左右。利用泡沫铜大比表面积和传热性能好的特点,实验研究了泡沫铜对水合物形成过程的影响。泡沫铜可促进四氢呋喃水合物生成,诱导时间缩短至50min左右。
[Abstract]:With the development of economy, air conditioning is used more and more widely, and the load of air conditioning intensifies the peak power load. In order to reduce the load of air conditioning in the peak of electricity consumption, the storage air conditioning emerges as the times require. The refrigerant hydrate, as a cold storage medium, has the advantages of large latent heat of phase change and high temperature of phase transformation, but also has the disadvantages of long induction time and high formation pressure. To solve these shortcomings is the key to the application of refrigerant hydrate cold storage trend. The phase equilibrium conditions of hydrates in the system of tetrahydrofuran / HCFC141b / cyclopentane in carbon dioxide water have been measured by means of constant volume step by step heating. The experimental results show that, at a given temperature, The phase equilibrium pressure of tetrahydrofuran / HCFC141b / cyclopentane hydrate in carbon dioxide water is lower than that in pure water. The lower the phase equilibrium pressure of carbon dioxide hydrate is, the more obvious it is when the mass fraction of tetrahydrofuran aqueous solution is greater than 19.05%, Excess tetrahydrofuran can not further reduce the phase equilibrium pressure of carbon dioxide hydrate. When the temperature is less than 288kg HCFC141b, it can lower the phase equilibrium pressure of carbon dioxide hydrate more than cyclopentane, but at high temperature, The effect of cyclopentane and HCFC141b on the phase equilibrium pressure of carbon dioxide hydrate is similar. The latent heat of phase transition of carbon dioxide HCFC141b and carbon-cyclopentane hydrate was 68.22 kJ / mol ~ (-1) 155.15 kJ / mol ~ (-1) 156.73 kJ / mol / L ~ 171.98 kJ / mol ~ (-1) kJ/mol and 248.27 kJ 路mol ~ (-1) mol respectively. The surface activity of HCFC141b and HCFC141b was studied experimentally. The effect of SDS on the formation of carbon dioxide hydrate. The addition of HCFC141b and surfactant SDS can promote the formation of carbon dioxide hydrate and shorten the induction time. The experimental results show that when the initial pressure is 0.4 MPA, the water bath temperature is 277.15 K. The induction time is only about 142 minutes. The effect of copper foam on the formation of hydrates has been experimentally studied by using the characteristics of large specific surface area and good heat transfer performance of copper foam. The copper foam can promote the formation of tetrahydrofuran hydrate, and the induction time is shortened to about 50 minutes.
【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU831

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