Compressed liquid tables

Definition

Compressed liquid tables are reference tables that provide thermodynamic properties of substances in their liquid state, specifically when they are below their saturation temperature at a given pressure. These tables are essential tools in engineering and science, as they help in determining the properties of liquids when they are not boiling and are instead in a compressed state, often used in various thermodynamic calculations and analyses.

5 Must Know Facts For Your Next Test

1. Compressed liquid tables are typically utilized for substances like water and refrigerants, where the properties of the liquid phase need to be understood under different pressures.
2. These tables include values for properties such as specific volume, internal energy, enthalpy, and entropy at various temperatures and pressures.
3. In compressed liquid conditions, the liquid density is significantly higher than that of vapor, making it important for engineers to use these tables to calculate system behavior accurately.
4. The data in compressed liquid tables is crucial for designing systems like heat exchangers, boilers, and refrigeration units where precise control over liquid properties is necessary.
5. When using compressed liquid tables, it is vital to ensure that the substance being analyzed is indeed in the compressed liquid state and not transitioning to vapor.

Review Questions

• How do compressed liquid tables assist engineers in thermodynamic calculations?
  • Compressed liquid tables provide critical thermodynamic properties that engineers need to understand how liquids behave under different pressures and temperatures. By referencing these tables, engineers can accurately determine specific volume, enthalpy, and other properties necessary for designing and analyzing systems such as boilers or heat exchangers. This ensures that designs meet efficiency and safety standards by accounting for the actual conditions under which the liquids operate.
• What factors must be considered when using compressed liquid tables to ensure accurate data is obtained?
  • When using compressed liquid tables, it's essential to confirm that the substance is indeed in the compressed liquid state and not approaching saturation or vaporization. Engineers must also consider the pressure and temperature conditions to ensure they reference the correct section of the table. Using incorrect states or conditions can lead to significant errors in calculations and affect the performance of thermodynamic systems.
• Evaluate the implications of incorrect usage of compressed liquid tables on system design and operation.
  • Using compressed liquid tables incorrectly can lead to serious design flaws and operational inefficiencies in thermodynamic systems. If an engineer misinterprets the state of a fluid, such as assuming it is still a compressed liquid when it has started vaporizing, it could result in inadequate cooling or heating performance. This may cause system failures or safety hazards, emphasizing the importance of accurate data retrieval from these tables to maintain reliability and efficiency in engineering applications.

Related terms

Saturation Temperature:

The temperature at which a liquid and its vapor can coexist in equilibrium at a given pressure.

Specific Volume:

The volume occupied by a unit mass of a substance, typically measured in cubic meters per kilogram (m³/kg).

Phase Change:

The transition of a substance from one state of matter to another, such as from liquid to vapor, which is crucial for understanding thermodynamic processes.