1. What is the Compressed Water Equation?

The compressed water equation estimates the specific volume of water under pressure using the saturated volume, compressibility, and pressure difference from saturation. This approximation is useful for thermodynamic calculations involving compressed liquids.

2. How Does the Calculator Work?

The calculator uses the compressed water equation:

Where:

• \( v \) — Specific volume (m³/kg)
• \( v_f \) — Saturated volume (m³/kg)
• \( \beta \) — Compressibility (1/Pa)
• \( p \) — Pressure (Pa)
• \( p_{sat} \) — Saturation pressure (Pa)

Explanation: The equation accounts for the small volume change of water when compressed above its saturation pressure.

3. Importance of Specific Volume Calculation

Details: Accurate specific volume calculation is crucial for thermodynamic analysis, pump sizing, and system design in power plants and industrial processes.

4. Using the Calculator

Tips: Enter all values in SI units. Saturated volume and compressibility are temperature-dependent properties typically found in steam tables.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this approximation?
A: It's reasonably accurate for small pressure differences from saturation but becomes less accurate at very high pressures.

Q2: Where can I find β values for water?
A: Compressibility values can be found in thermodynamic property tables or engineering handbooks, typically ranging from 4.4×10⁻¹⁰ to 5.0×10⁻¹⁰ 1/Pa for liquid water.

Q3: What's the typical range for v_f?
A: For liquid water at common temperatures, v_f ranges from about 0.001000 to 0.001043 m³/kg.

Q4: When is this equation not applicable?
A: Not suitable for large pressure differences, near the critical point, or for supercritical conditions.

Q5: What are common applications?
A: Used in power plant cycle analysis, hydraulic system design, and process engineering calculations.