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分析了气相声速与理想气体比定压热容的热力学关系,用超声变程干涉仪测定了1,1,1,2,3,3,3-七氟丙烷(HFC-227ea)的 72组气相声速值,温度范围 273-333 K,压力范围 26-315 kPa,测量不确定度小于 0.05%。根据这些实验数据,确定了HFC-227ea的理想气体比定压热容和声速第二维里系数,并分别拟合得到了与温度的函数,理想气体比定压热容的不确定度小于 0.5%.使用方阱势能模型导出了 HFC-227ea的第二维里系数,并与文献值进行了比较。 相似文献
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新型环保制冷剂氟化醚类物质的热力学分析 总被引:7,自引:1,他引:6
本文筛选了可能作为替代制冷剂的氟化醚类(HFEs)纯物质和混合物,然后对这些工质的制冷循环性能进行了热力学分析。分析结果表明:在醚类纯质及混合物中 c-HFE216、 HFE143a、 c-E2-216、 c-HFE216/HFE143a和c-HFE216/c-E2-216适合替代 CFC12和 HFC134a ; HFE125适合替代 CFC115; HFE134、 HFE245cb β和 HFE143/HFE31-10适合替代 CFC114 ; HFE338mf、 HFE245fa、 HFE143、 HPE263fb、 HFE236ea/HPE245fa和 HFE236ea/HFE143有望成为CFC11的替代物。 相似文献
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1前言声速是重要的物性参数,由声速测量还可以得到理想气体热容、第二维里系数等重要物性.清华大学热能系从1987年开始进行声学法测量理想气体热容的研究山,设计了一套变程声速干涉仪,并成功地用于HFC-134a的声速和理想气体热容研究问。HFC-32与其它HFC类物质的混合物被认为是HCFC-22最有希望的替代物,CF3I的ODP为0,GWP也很低,是一种重要的各选工质.迄今为止国际上只有一套HFC-32的气相声速数据问,而CF。I尚无可用数据.作者实测了这两种工质的气相声速,并确定了其理想气体热容、声速第二维里系数及第二维里系数… 相似文献
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高温高密度条件下CH4气体分子间的排斥势函数与二级维里系数的… 总被引:1,自引:0,他引:1
张中明 《原子与分子物理学报》1993,10(4):2960-2966
本文采用文献(1)所给出的关于甲烷分子的单中心对称类氖波函数,从理上计算了CH4-CH4分子间的排斥函数和高温度高密度条件下CH4气体的二级维里系数。 相似文献
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本文报道了6种取代苯胺基亚胺二茂铁类化合物R-N=CH-Fe(-Fe为二茂铁基,R为-C6H4X,(X=H,4-Br,4-OH,2-CH3,4-COOH)及4-NHC6H4NO2)的Mossbauer谱数据,其化学位移分别为(mm.s^-1):0.323,0.332,0.338,0.324,0.315和0.310。其四极矩分裂值分别为(mm.s^-1):2.263,2.285,2.287,2.21 相似文献
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氟原子与氯溴代甲烷反应的光谱及动力学研究 总被引:1,自引:0,他引:1
本文报导了氯原子与三种含氢氯溴代甲烷(CH2BrCl,CHBrCl2,CHBr2Cl)反应的光谱及动力学研究结果,观察了这些反应的可见化学发光(300-900nm)和染料R6G波段(565-610nm)的激光诱导荧光,观测到HF基电子态振动泛频跃迁和Br2(A,B),BrF(B)分子电子激发态跃迁的发射谱以及BrF(X),CHF(X)的基电子态的激发谱,计算机模拟光谱求出了Br2(B),BrF(X 相似文献
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HFC混合物表面张力的预估方程 总被引:1,自引:1,他引:0
表面张力是有沸腾和凝结换热计算必不可少的物性参数,目前国际上已商业化使用或提出的潜在的环保工质,大多数为氢氟烃(HFC)混合物,尤其是R22和R502的替代物、本文应用对比态原理和重正化群理论,提出了一种新的HFC类物质混合物表面张力的预估方程,并与国际上现有的预估式进行了比较分析。新预估式可以在广阔的温度范围内较高精度地再现实验数据,计算精度可以满足工程应用的需要. 相似文献
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适用于整个区域的HFC-227ea状态方程 总被引:7,自引:0,他引:7
基于现有的pvT和导出性质实验数据,拟合了一个HFC-227ea的35项专用状态方程。本方程适用于HFC-227ea压力从零至65MPa,密度从零至1730 kg.m_-3,温度从204至423 K整个流体区域的热力学性质计算。通过与实验结果比较,检验了对HFC-227ea各种热力学性质的计算精度,包括pvT性质、比定压热容、声速、焦汤系数、饱和蒸气压等,结果表明本方程具有很高的精度。 相似文献
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析了气相声速与理想气体比定压热容的热力学关系,用超声变程干涉仪测定了1,1,1,2,3,3,3-七氟丙烷(HFC-227ea)的72组气相声速值,温度范围273-333 K,压力范围26-315 kPa,测量不确定度小于0.05%。根据这些实验数据,确定了HFC-227ea的理想气体比定压热容和声速第二维里系数,并分别拟合得到了与温度的函数,理想气体比定压热容的不确定度小于0.5%。使用方阱势能模型导出了HFC-227ea的第二维里系数,并与文献值进行了比较。 相似文献
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制冷剂替代物相平衡性质的分子动力学模拟 总被引:1,自引:0,他引:1
本文利用分子动力学模拟算法研究制冷剂替代物的气液相平衡性质。通过将制冷剂替代物作为极性的2CLJ流体处理,建立了针对它们的 2CLJD 势能模型。利用 NPT+Test Particle 算法对五种制冷剂替代物 (HFC-152a,HFC-143a,HFC-134a,HCFC-142b和HFC-227ea)的气液相平衡性质进行了计算,同时验证了计算结果的热力学一致性。模拟结果与 NIST 的 REFPROP 数据库的最大相对偏差在2%以内。 相似文献
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The saturation pressure, pressure and density of superheated vapor of 1,1,1,2,3,3-hexafluoropropane (HFC-236ea, R-236ea) were
studied by an isochoric piezometer within the temperature range of 294–423 K up to the pressure of 4.0 MPa. The uncertainties
of temperature, pressure, and density measurements were estimated as ±20 mK, ±1.5 kPa, ±(0.1–0.2) %, and ±(0.1–0.2) %, correspondingly.
The purity of studied samples was 99.68 mass %. The obtained experimental data are shown as tables and analytical equations.
Coefficients of the virial state equation were calculated for R-236ea on the basis of these data.
The work was financially supported by the Russian Foundation for Basic Research (Grant No. 04-02-16355). 相似文献
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HFC—32的热力学性质 总被引:5,自引:0,他引:5
1前言HFC-32和其它HFC类物质的混合物被认为是HCFC-22的最有希望的替代物,因此,需要HFC-32的热物理性质。本文提供了一个适用于整个区域的HFC-32状态方程,结合理想气体比热关系式,给出了HFC-32各种热力性质,如:PVT(压力-比容-温度),内能,Helmholtz函数,Gibbs函数,焓,熵,等容比热,等压比热,声速等的计算式。另外,还给出了单独的饱和蒸气压和饱和液密度关联式。2蒸气压方程与饱和液密度方程至今已有多位学者测量过HFC-32的饱和蒸气压,提供了从180K至临界温度的蒸气压测量数据,根据实验中使用的样品纯度… 相似文献
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空调制冷工质R143a/R227ea、R125/R227ea的理论与实验研究 总被引:3,自引:0,他引:3
1前言制冷剂R22的替代迫在眉睫,还未有一致的意见。但一般认为,R22的替代,无纯质可寻,只能采用混合工质。本文将从理论和实验两方面,探讨混合工质R143a/R227ea、R125/R227ea做为空调制冷系统,尤其是变浓度容量调节系统的循环工质的可行性。2R143a/R227ea、R125/R227ea的热力性质分析考虑到国内外对丙烷、丁烷衍生物制冷工质的研究较少,二元混合工质的组成纯质将不仅从甲烷、乙烷系列中筛选,还将考虑采用丙烷、丁烷衍生物中的一些热物性和物理化学性质研究较充分的物质。从组成纯质及变浓度等几个角度加以筛选,本文推荐采… 相似文献
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Densities ρ, viscosities η, and refractive indices nD, of the binary and ternary mixtures formed by cyclohexanone + N,N-dimethylacetamide + N,N-diethylethanolamine were measured at (298.15, 308.15, and 318.15) K for the liquid region and at ambient pressure for the whole composition ranges. The excess molar volumes VmE, viscosity deviations Δη, and refractive index deviations ΔnD, were calculated from experimental densities and refractive indices. The excess molar volumes are positive over the mole fraction range for binary mixtures of cyclohexanone(1) + N,N-dimethylacetamide (2) and N,N-dimethylactamide (2) + N,N-diethylethanolamine (3) and increase with increasing temperatures from (298.15 to 318.15) K. The excess molar volumes of cyclohexanone (1) + N,N-diethylethanolamine (3) are S-shaped dependence on composition with negative values in the N,N-diethylethanolamine rich-region and positive values at the opposite extreme and increase with increasing temperatures from (298.15 to 318.15) K. The excess molar volumes are positive over the whole mole fraction ranges for the ternary mixtures at all temperatures. Viscosity deviations are negative over the mole fraction range for all binary and ternary mixtures and decrease with increasing temperatures from (298.15 to 318.15) K. Refractive index deviations are negative over the mole fraction range for all binary and ternary mixtures and increase with increasing temperatures from (298.15 to 318.15) K. The experimental data of constitute were correlated as a function of the mole fraction by using the Redlich–Kister equation for binary and , Cibulka, Jasinski and Malanowski , Singe et al., Pintos et al., Calvo et al., Kohler, and Jacob–Fitzner for ternary mixture, respectively. McAllister's three body, Hind, and Nissan–Grunberg models were used for correlating the kinematic and dynamic viscosity of binary mixtures. The experimental data of the constitute binaries are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures. 相似文献
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The PVT properties of sulfur hexafluoride in the critical region have been measured by using a combination of the Burnett and the isochoric methods. The measurement of one reference PV-isotherm at about 333 K was performed by the Burnett method of repeated expansions; the measurement of a large number of PT quasi-isochores between 313 and 333 K relied on the so-called isochoric method. An important feature of the data analysis is the application of several consistency criteria to the least-squares analysis for polynomial representation which made it possible to determine reliable values of the Burnett constants and the virial coefficients. The reference isotherm with 105 data points covers a pressure range between 1 and 100 bar and a density range up to 1.2 g cm?3. The 21 isochoric runs with densities between 0.1 and 1.2 g cm?3 contain 220 data points. Except for the region very close to the critical point, the accuracy of the measurements is estimated to be better than 0.01% in the pressure, 0.02% in the density and 1 mK in the temperature. 相似文献