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Is there any place where I can look up the Pratt numbers of commonly used gases and liquids? I have also seen calculation formulas, but what I calculated always feels wrong. Can any classmate help me calculate the Pratt number of saturated water vapor at 160 degrees! ! ! ! ! ! ! ! ! ! ! ! I calculated that it's only 0.0. Thank you :handshake :'( Urgent
Volume 1 of "Principles of Chemical Engineering" published by Chen Minheng of East China University of Science and Technology, P360 has the physical properties of water and water vapor, among which P361 has the Prandtl number of water at 160 degrees Celsius, 1.10
oh. . . Thank you, Floor 2, but I checked other data. The properties of saturated water vapor at 160 degrees and water at 160 degrees are different. The specific heat capacity, viscosity, and thermal conductivity are different.
Replying to the above, you found that the physical properties of saturated water vapor and water are different. It is normal because steam is a gaseous state and water is a liquid state. The physical properties of the two will be very different. Generally, the density and viscosity of gases will be much smaller than that of liquids. The enthalpy value of steam will be greater than that of water because the phase change of liquid water into gaseous steam requires a lot of heat. Regarding water vapor and water, you can also refer to the content of engineering thermodynamics. * .
I found the reason. The unit was wrong. Specific heat capacity is generally measured as KJ. It should be converted into J.
Just look for a book on Principles of Chemical Engineering and you’ll find it in the appendix at the back of the book! There are many units and conversion relationships between units! Plant number http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE015.GIF = http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE017.GIF v---Momentum diffusion coefficient α---Thermal diffusion coefficient This formula reflects the relationship between thermal diffusion and momentum diffusion and reflects the relative thickness of the flow boundary layer thickness and the thermal boundary layer thickness. http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE019.GIF http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE021.GIF http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE023.GIF http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE025.GIF http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE027.GIF http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE029.GIF http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE031.GIF http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE033.GIF http://ww2.sjzc.edu.cn/hxx/Software/Dl/no4/CH4X4X2/IMAGE035.GIF