Propane (R290) as a natural refrigerant has attracted much interest in the refrigeration and air conditioning fields. To increase the solubility-database for R290 in oils and better understand the oil presence effect on evaporator performance, solubilities of R290 in two polyol ester oils (RL 32H and RL 68H) were measured from 253.15 to 343.15 K. The nonrandom two-liquid model was used to correlate the measured data. R290 is more soluble in RL 68H than in RL 32H. New pressure–enthalpy–vapor quality diagrams were plotted for pure R290 and R290/oil blends at different circulating oil mass fractions. A demarcation point was found along the isotherms of the R290 and R290/oil blend, that is mainly dependent on the solubility and circulating oil mass fraction. The lower is the demarcation point, the greater is the contribution of the sensible heat, which is unfavorable to the heat transfer. The enthalpy changes through an evaporator with and without the presence of oil were analyzed, indicating that the enthalpy change ratio increases as the superheat rises and the mass fraction of the circulating oil decreases.

中文翻译：

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油的存在对使用 R290 的蒸发器的热力学性能的影响

丙烷（R290）作为一种天然制冷剂，引起了制冷和空调领域的极大兴趣。为了增加 R290 在油中的溶解度数据库并更好地了解油的存在对蒸发器性能的影响，R290 在两种多元醇酯油（RL 32H 和 RL 68H）中的溶解度从 253.15 到 343.15 K 测量。非随机两液模型用于关联测量数据。R290 在 RL 68H 中比在 RL 32H 中更易溶解。为不同循环油质量分数的纯 R290 和 R290/油混合物绘制了新的压力-焓-蒸汽质量图。沿着 R290 和 R290/油混合物的等温线发现了一个分界点，这主要取决于溶解度和循环油的质量分数。分界点越低，显热的贡献越大，这对传热不利。分析了在有油和无油的情况下通过蒸发器的焓变，表明焓变比随着过热度的升高和循环油的质量分数的降低而增加。