【作者】 任晶；

【导师】 赵宗昌；

【作者基本信息】 大连理工大学 ， 化学工程， 2010， 硕士

【摘要】 吸收热泵是一种能够将低品位热源的热量从低温位传送到高温位的有效节能装置,在工业废热回收方面起到提高能源利用率、降低温室气体排放量作用,具有节能降耗和清洁生产的双重特性。吸收式热泵的性能很大程度上取决于所用的工质对理化性质。现有的吸收式热泵工质存在着腐蚀性、结晶、工作压力高和毒性等问题。因此,对热泵新工质的研究成为人们关注的热点。离子液体是一种在室温或室温附近温度下呈液态的由离子构成的物质,它具有很多独特的性质,如：良好的热稳定性和化学稳定性,较宽的液态范围,较低的蒸汽压等。本文提出将离子液体1-乙基-3-甲基咪唑磷酸二甲酯[EMIM][DMP]为热泵工质的吸收剂,以水、甲醇、乙醇为制冷剂。在实验室内一步法合成了离子液体[EMIM][DMP],并对其进行了表征。采用泡点法测定了离子液体[EMIM][DMP]和水、甲醇、乙醇组成的三个二元体系在不同温度,不同浓度下的气液平衡数据,采用了NRTL模型进行关联。实验值和计算值之间平均相对误差分别为1.44%,1.96%,1.54%。实验发现三个二元体系均对Roualt定律呈负偏差。测定了在298.15K时,[EMIM][DMP]分别和水、甲醇、乙醇之间的二元混合热,以及[EMIM][DMP]和水、甲醇三元体系的混合热,并采用了RK模型进行关联。其平均相对误差为0.71%,3.41%,0.64%,1.57%。实验发现三个二元体系和三元体系的混合过程均是放热过程,符合热泵工质对的要求。测定了298.15K—323.15K下,上述三个二元体系在不同离子液体浓度下的比热,并采用经验关系式进行了关联,实验值和计算值平均相对误差分别为0.47%,1.05%,和0.82%。实验发现在298.15K—323.15K范围内上述三个二元溶液的比热和温度呈直线关系,随着离子液体浓度的升高,溶液的比热减小。更多还原

【Abstract】 Heat pump is an effective energy-saving device use low-grade heat source to transfer heat from low temperature to high one. In the industrial waste heat recovery, heat pump improves energy efficiency and reduces greenhouse gas emissions. The application of absorption heat pump in the industry depends largely on the thermodynamic property of working pair.Current working pair of absorption heat pump has corrosion, crystallization, high work pressure and toxicity issues. Therefore, new woking pair has been the focus.Ionic liquid is the liquid composed of the ion at or near room temperature. Ionic liquid has many special properties, such as good thermal stability and chemical stability, wide liquid range, low vapor pressure, etc.In this paper, the solution containing ionic liquid is suggested to be working pair, which ionic liquid 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM][DMP]) as an absorbent to water, methanol, and ethanol as the refrigerant.One-step synthesis and characterization of the ionic liquid [EMIM][DMP] were in the laboratory.Vapor pressures for the three binary systems ([EMIM][DMP]+H2O/C2H5OH/CH3OH respectively) with different concentration of [EMIM][DMP] were measured at different temperatures. The vapor pressure were correlated by NRTL model. The result showed that the average relative error between experimental and calculated values are 1.44%,1.96%,1.54% respectively and the binary system are negative deviation to Raoult’s law.Excess enthalpies at the temperature of 298.15K and the pressure of 1atm for these binary systems and ternary system were measured and corrected by RK model. The average relative errors between experimental and calculated values are 0.71%,3.41%,0.64% and 1.57% respectively. The results indicate that the mixing process of [EMIM][DMP] with water, ethanol and methanol is an exothermic process, which is a very important characteristic for working pair used in absorption heat pumps or in absorption refrigerators.The specific heat capacity of binary system were measured at different temperature and different concentrations and correlated well by the empirical polynomial. The average relative errors between experimental and calculated values are 0.47%,1.05% and 0.82% respectively. The result shows that the specific heat capacity of binary system in line with temperature, and specific heat capacity decreases with the ionic liquid concentration.更多还原