华中科技大学硕士学位论文
摘要
R134a是目前应用最广泛的中低温制冷剂，但使用普通R134a热泵装置制取中高温热水时，存在着冷凝压力过高、系统效率低及不环保等问题。故本文旨在研制出冷凝温度在70-90℃，高效环保、可直接充灌R134a热泵装置的新型混合工质。
本文通过对比分析多种状态方程和混合规则的计算精度及适用范围，研究了基于R134a的三元混合工质的状态方程和混合规则。着重对vdW混合规则的相互作用k和PR方程的压缩因子z进行编程计算研究。建立利用PR状态方程和vd混系数
ij
合规则的三元混合工质气液相平衡和热力学模型。采用相对误差分析法，对比计算了0~90℃范围内混合工质的气液相平衡和热力学特性参数。根据工质优势互补原则，提出三种三元混合工质M1、M2和M3，并将其与R134a和已研制出的三元混合工质C1、C2进行变工况对比分析。
提出了计算vdW混合规则相互作用系数和PR状态方程的方法，相对误差均在6%以下。对三元混合工质气液相平衡和热力学模型进行验证，气液相组分的平均误差为3.13%、1.61%，焓、熵值的平均误差分
别为3.27%、3.49%，模型具有很高的精度。通过变冷凝温度工况分析，M1的COP最高且变化平稳，在4.0左右。M2的压缩机排气温度最低，在78~98℃之间。M3的压缩比最低，在2.6~2.9之间。M1、M2和M3分别具有高COP、低排气温度和低压缩比的特点。通过变循环温升工况分析，M3的压缩比最低，循环温升为75℃时，压缩比为6.6。M1和M2适用于循环温升为65℃的工况，M3可用于循环温升为75℃的工况，且较R134a、C1和C2在单位容积制热量、COP及循环压缩比上有更优越的性质。
佳能a700通过多种工况计算分析表明，三元混合工质M1、M2和M3的环境性能优良，热力性能与R134a非常接近，可直接充灌R134a热泵装置，适用于低热源温度、高供热温度的实际应用情况。
关键词：混合工质；中高温热泵；R134a；气液相平衡；循环性能
华中科技大学硕士学位论文
Abstract
R134a is the most widely ud low temperature refrigerant. To solve the problems in R134a heat pump such as high condensing pressure, low system efficiency, not environment-friendly, etc., this paper aimed at finding out new refrigerant mixture ud under heat pump working condition of condensing temperature at 70-90 o C.
The equation of state(EoS) and mixing rule of the ternary refrigerant mixture bad on R134a heat pump were analyzed by comparing the calculation accuracy and the application range of various EoS and mixing rules. Interaction parameters of vdW mixing rule and Peng-Robinson(PR) EoS were studied. Ba on PR EoS and vdW mixng rule, the vapor liquid equilibrium(VLE) and thermodynamics model of ternary refrigerant mixture was established. VLE and thermodynamics data were calculated in 0-90o C by relative error analysis method. Three ternary refrigerant mixtures M1, M2 and M3 were propod according to the principle of complementary advantages. The cycle performance was compared with R134a, C1 and C2 under variable working conditions.
The method of calculating refrigerant mixture interaction parameters of vdW mixing rule and the compressibility factor of PR EoS were propod. The relative error is below 6%. The VLE and thermodynamics model of ternary refrigerant mixture was validated. The average error of vapor and liquid mole component is 3.13% and 1.61%, respectively. The average error of enthalpy and entropy is 3.27% and 3.49% respectively. The model has high accuracy. Under the working condition of variable condensing temperature, the COP of M1 is the highest and varies steady, about 4.0. The discharge temperature of M2 is lowest, among 78~98 o C. The compression rate of M3 is lowest, among 2.6~2.9. M1, M2 and M3 have the high COP, low discharge temperature and low compressio
因数和倍数n rate, respectively. Under the working condition of variable temperature ri, the compression rate of M3 is lowest. When temperature ri is 75 o C, compression rate is 6.6. M1 and M2 are fit under heat pump working condition of cycle temperature ri below 65 o C, while M3 is fit under heat pump working condition of cycle temperature ri below 75 o C. The propod mixture has a better cycle performance compared to the contrast mixtures.
华中科技大学硕士学位论文
According to the study of variable working condition, M1, M2 and M3 are environment-friendly, thermal performance are clo to R134a, and can be directly replace in R134a heat pump system. M1, M2 and M3 are fit for practical application of the low heat resource temperature and high heating temperature condition.
好困怎么办Keywords：refrigerant mixture, moderate and high temperature heat pump, R134a, VLE, cycle performance
华中科技大学硕士学位论文
目录
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摘要 ................................................................................................................................... I Abstract ................................................................................................................................ I I 1 绪论 (1)
1.1 研究背景与意义 (1)
假声男高音1.2 国内外研究概况 (2)
开窗放入大江来1.3 本文的主要研究内容 (7)
2 基于R134a的三元混合工质状态方程与混合规则 (9)
2.1 三元混合工质状态方程对比分析 (9)
2.2 基于R134a的三元混合工质混合规则研究 (13)
2.3 基于R134a的三元混合工质相互作用系数求解 (14)
2.4 基于R134a的三元混合工质压缩因子求解 (17)
2.5 本章小结 (22)
3 基于R134a的三元混合工质的气液相平衡与热力性质计算 (23)
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3.1 三元混合工质气液相平衡 (23)
3.2 基于R134a的三元混合工质气液相平衡数学模型 (25)
3.3 基于R134a的三元混合工质气液相平衡研究 (26)
3.4 基于R134a的三元混合工质热力性质计算 (33)
3.5 本章小结 (37)
4 基于R134a的三元混合工质热泵循环特性分析 (38)
4.1 基于R134a装置的三元混合工质组分筛选原则 (38)
4.2 纯工质理论循环计算及分析 (39)
4.3 混合工质循环性能计算及对比分析 (43)
4.4 本章小结 (48)
5 总结和展望 (49)
华中科技大学硕士学位论文
赏樱花
5.1 总结 (49)
5.2 展望 (50)
致谢 (51)
参考文献 (52)
附录1 攻读学位期间发表论文 (57)
附录2 攻读学位期间参与科研项目 (58)
