Thermodynamic properties of compressed liquids

In summary, the conversation discusses the difficulty of finding thermodynamic properties for compressed liquids, specifically water, at pressures smaller than 5MPa. The conversation mentions various resources and equations that can assist in finding these properties. However, the person responding is not familiar with the equations mentioned.
  • #1
guideonl
58
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TL;DR Summary
required properties for compressed liquids
Hi All,
I have review my thermodynamic notes (~35 year ago..), and I could not able to restore how to get thermodynamic properties (u,h,s,v ..) for compressed liquids. I have found properties tables for compressed liquids ( for water..) but unfortunately the data starts at 5MPa. What if I look for properties of compressed liquids (let say water) at pressures smaller than 5MPa? let say 0.5MPa?
 
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  • #4
Thank you,
It was helpfull
 
  • #5
Equations that might be helpful to you are
$$\left(\frac{\partial u}{\partial P}\right)_T=(P\beta-T\alpha)v$$
$$\left(\frac{\partial h}{\partial P}\right)_T=(1-T\alpha)v$$
$$\left(\frac{\partial s}{\partial P}\right)_T=-\alpha v$$where v is the specific volume, ##\alpha## is the volumetric coefficient of thermal expansion, and ##\beta## is the bulk compliance:$$\alpha=\left(\frac{\partial \ln{v}}{\partial T}\right)_P$$and $$\beta=-\left(\frac{\partial \ln{v}}{\partial P}\right)_T$$In these equations, away from the critical point, you can treat the specific volume as constant, and values of the coefficient of thermal expansion and bulk compliance (or its reciprocal, the bulk modulus) are in tables.
 
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Likes Lnewqban
  • #6
Sorry,
I'm not femiliar with latest formulas you noted above..
Thanks any way
 

1. What are compressed liquids?

Compressed liquids are substances that are in a liquid state at a pressure higher than their vapor pressure at a given temperature. This means that they are in a compressed state and have a higher density than normal liquids.

2. What are some examples of compressed liquids?

Some common examples of compressed liquids include carbon dioxide, propane, and refrigerants such as Freon. These substances are often used in industrial processes, refrigeration systems, and as propellants in aerosol cans.

3. How do the thermodynamic properties of compressed liquids differ from those of normal liquids?

The thermodynamic properties of compressed liquids, such as specific heat capacity, thermal conductivity, and viscosity, are significantly affected by the high pressure they are under. This can result in changes in their physical and chemical properties, making them behave differently than normal liquids.

4. What is the relationship between temperature, pressure, and the thermodynamic properties of compressed liquids?

The relationship between temperature, pressure, and the thermodynamic properties of compressed liquids is described by the laws of thermodynamics. Generally, as pressure increases, the temperature of a compressed liquid also increases, leading to changes in its properties. However, this relationship can vary depending on the specific substance and its phase diagram.

5. How are the thermodynamic properties of compressed liquids measured and calculated?

The thermodynamic properties of compressed liquids can be measured using various experimental techniques, such as calorimetry and viscosity measurements. They can also be calculated using thermodynamic equations and models, which take into account factors such as pressure, temperature, and the specific properties of the substance being studied.

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