研究建立空调系统实际工况模型并离散求解，提出取代现行单一标准工况、科学评价不同替代物系统性能的基准工况组及其权重体系；探索引入不同实际因素对循环性能的影响、允许不同工质有合理而不同的内循环参数改进现有理论制冷循环分析和系统模拟方法；筛选碳氢化合物混合工质，进行热物性和替代HCFC22的循环性能研究。具有学术、节能与环保意义。

Performances of hydrocarbons(HCs) and hydrocarbon mixtures in ir-conditioning cycles as replacements for HCFC22 were theoretically and experimentally investigated, which shown that HC1270, HC290, HC1270/HC290, HC1270/600a, HC290/HC600a have close thermodynamic properties and theoretical performances to HCFC22, and HC1270, HC290 and HC1270/HC290 exhibit much better practical performances than HCFC22 in a drop-in experimental air-conditioning system. It was also found that the relative order in air-conditioning cycle performances among different substances didn't change with the changes in condensing temperature when the evaporating temperatures were fixed.To enhance the safe application of HCs, selected environment friendly fire suppressants were introduced to form HC/Fire-suppressant mixtures with 0 ODP, low GWP and promising performances. As a result, CO2/HC1270/R13I1, CO2/HC1270/HFC134a, CO2/HC290/R13I1 and CO2/HC290/HFC134a were found potential substitutes to HCFC22 in air-conditioning systems..The PVTx experimental apparatus was adapted with new temperature and pressure measuring instruments, and the PVTx behaviors of HC1270/HC600a, HC1270/HFC227ea, HC290/HFC227ea and HC170/HFC227ea were experimentally investigated in the temperature range of 252K-363K. The impact of the uncertainties in the P-T equation of state and the mixing rules on the calculations of the thermodynamic property and the air-conditioning cycle performance was analyzed. It was found that the cycle performances were not as sensitive as the VLE properties to the uncertainties in the binary interaction coefficients. Binary interaction coefficients for 4 binary HC-mixtures were correlated base on available experimental data.Issues on fairly assessing the performances of different working fluids and the safety of HCs in application were discussed. The performances of HC600 and HC600a as working fluids in moderate/high condensing temperature heat pumps were also analyzed. .