A PROPERTY OF THE SATURATED VAPOR PRESSURE: RESULTS FROM EQUATIONS OF STATE

2009 ◽  
Vol 23 (26) ◽  
pp. 3091-3096 ◽  
Author(s):  
JIANXIANG TIAN ◽  
HUA JIANG ◽  
YI XU
Keyword(s):  
Critical Temperature ◽  
Equation Of State ◽  
Vapor Pressure ◽  
Hard Sphere ◽  
Critical Pressure ◽  
Equations Of State ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Maximum Point ◽  
Critical Amplitudes

Experimentally, a maximum point in the curve of the saturated property ψ=(1-Tr)Pr versus the saturated temperature was postulated (High Temp.-High Press.26 (1994) 427). Here, Tr is the saturated temperature reduced by the critical temperature and Pr is the saturated pressure reduced by the critical pressure. Later, this behavior was applied to assure the saturated vapor pressure critical amplitudes (Appl. Phys. Lett.90 (2007) 141905). In this paper, we indicate that theory of equation of state (EOS) can predict this maximum point. The EOSs we study are the combinations of the hard sphere repulsions and some normally used attractions such as the Redlich–Kwong attraction. We find the EOSs with Redlich–Kwong attractive terms give out the results in the experimental range.

scholarly journals Investigation of applicability of Peng–Robinson and GERG-2008 equations of state of real gas for calculating properties of Freons for refrigeration machines and compressors

2021 ◽  
Vol 5 (1) ◽  
pp. 34-43
Author(s):  
M. I. Sokolov ◽  
◽  
Yu. V. Kozhukhov ◽  
Keyword(s):  
Experimental Data ◽  
Vapor Pressure ◽  
Mathematical Modelling ◽  
Equations Of State ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Saturation Pressure ◽  
State Equations ◽  
Real Gas ◽  
Enthalpy And Entropy

A study of real gas state equations Peng–Robinson and GERG-2008 with respect to calculation of Freons R404A, R408A and R410A has been carried out. Four Freon parameters are calculated during the study: saturated vapor pressure at the saturation line at some Freon temperature, Freon density at saturation pressure and some temperature, enthalpy and entropy at the same pressures and temperature. The data obtained from the calculation of Freon by the above equations are compared with the experimental data for each of the above Freons. As a result of this work, data have been obtained to evaluate the accuracy of the Peng–Robinson and GERG-2008 equations of state for each of the three CFCs, to evaluate the effectiveness of these equations, and to provide recommendations for the calculation and application of these equations in the design and mathematical modelling of refrigeration machines

scholarly journals Effects of nanoparticles on hydraulic cavitation

2018 ◽  
Vol 240 ◽  
pp. 03004
Author(s):  
Min-rui Chen ◽  
Jin-yuan Qian ◽  
Zan Wu ◽  
Chen Yang ◽  
Zhi-jiang Jin ◽  
...  
Keyword(s):  
Vapor Pressure ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Geometric Model ◽  
Pressure Ratio ◽  
Perforated Plate ◽  
Significant Parameter ◽  
Operation Conditions ◽  
Small Bubbles ◽  
Crucial Condition

When liquids flowing through a throttling element, such as a perforated plate, the velocity increases and the pressure decreases. If the pressure is below the saturated vapor pressure, the liquid will vaporize into small bubbles, which is called hydraulic cavitation. In fact, vaporization nucleus is another crucial condition for vaporizing. The nanoparticles contained in the nanofluids play a significant role in vaporization of liquids. In this paper, the effects of the nanoparticles on hydraulic cavitation are investigated. Firstly, a geometric model of a pipe channel equipped with a perforated plate is established. Then with different nanoparticle volume fractions and diameters, the nanofluids flowing through the channel is numerically simulated based on a validated numerical method. The operation conditions, such as the temperature and the pressure ratio of inlet to outlet, are the considered variables. As a significant parameter, cavitation numbers under different operation conditions are achieved to investigate the effects of nanoparticles on hydraulic cavitation. Meanwhile, the contours are extracted to research the distribution of bubbles for further investigation. This study is of interests for researchers working on hydraulic cavitation or nanofluids.

Porous Hydroxyapatite with Tailored Crystal Surface Prepared by Hydrothermal Method

2005 ◽  
Vol 284-286 ◽  
pp. 353-356 ◽  
Author(s):  
Koji Ioku ◽  
Giichiro Kawachi ◽  
Nakamichi Yamasaki ◽  
Hirotaka Fujimori ◽  
Seishi Goto
Keyword(s):  
Aspect Ratio ◽  
Vapor Pressure ◽  
Hydrothermal Method ◽  
Saturated Vapor Pressure ◽  
Crystal Surface ◽  
Saturated Vapor ◽  
Pure Water ◽  
Porous Hydroxyapatite ◽  
Exposure Method ◽  
The Mean

Porous plates of hydroxyapatite (Ca10(PO4)6(OH)2; HA) with about 0.5 to 5 mm in thickness and porous HA granules of about 40 µm to 1 mm in size with tailored crystal surface were prepared by the hydrothermal vapor exposure method at the temperatures above 105 °C under saturated vapor pressure of pure water. Porous HA plates with about 75 % porosity prepared at 120 °C were composed of rod-shaped crystals of about 20 µm in length. Porous HA granules prepared at 160 °C were also composed of rod-shaped crystals of about 20 µm in length with the mean aspect ratio of 30. These crystals were elongated along the c-axis. Rod-shaped HA crystals were locked together to make micro-pores of about 0.1 to 0.5 µm in size. Both of materials were nonstoichiometric HA with calcium deficient composition. These materials must have the advantage of adsorptive activity, because they had large specific crystal surface and much micro-pores.

scholarly journals Application of a Micro-Flow Regulating Valve in Saturated Vapor Pressure Measurements

Daxue Huaxue ◽  
2021 ◽  
Vol 0 (0) ◽  
pp. 2107062-0
Author(s):  
Shuai Zhang ◽  
Jian Zhang ◽  
Shaowei Bian ◽  
Yaping Zhao ◽  
Li Shen ◽  
...  
Keyword(s):  
Vapor Pressure ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Pressure Measurements ◽  
Micro Flow ◽  
Vapor Pressure Measurements

IMPROVING THE DESIGN OF THE FILM DEODORIZER

2019 ◽  
Author(s):  
О.И. НИКОНОВ ◽  
Н.Н. БЕЛИНА ◽  
А.В. ГУКАСЯН
Keyword(s):  
Vapor Pressure ◽  
Thin Layer ◽  
Saturated Vapor Pressure ◽  
Saturated Vapor ◽  
Live Steam ◽  
Deodorization Temperature ◽  
Improved Design

Приведены характеристики содержащихся в масле одорирующих веществ. Проведен анализ конструкции существующих дезодораторов. Рассчитаны параметры, влияющие на процесс дезодорации в тонком слое. Получена зависимость давления насыщенных паров от температуры дезодорации. На основе проведенных расчетов предложены способы интенсификации процесса дезодорации. Предложена усовершенствованная конструкция дезодоратора, позволяющая интенсифицировать процесс дезодорации: сократить время и уменьшить расход острого пара. The characteristics of the odorizing substances contained in the oil are given. An analysis of the design of already existing deodorizers is given. The parameters affecting the deodorization process in a thin layer are calculated. The dependence of the saturated vapor pressure on the deodorization temperature was obtained. On the basis of the calculations performed, methods for intensifying the deodorization process have been proposed. The proposed improved design of the deodorizer, which allows intensify the deodorization process: to reduce the time and reduce the consumption of live steam.

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