1. What is Feed Water Enthalpy?

Feed water enthalpy represents the total heat content of water per unit mass, calculated as the product of specific heat capacity and temperature. It's a crucial parameter in thermodynamics and energy systems.

2. How Does the Calculator Work?

The calculator uses the enthalpy equation:

Where:

• \( h \) — Enthalpy (kJ/kg)
• \( c_p \) — Specific heat capacity (kJ/kg·K)
• \( T \) — Temperature (°C)

Explanation: This simplified equation provides an approximate calculation of water enthalpy, assuming constant specific heat capacity.

3. Importance of Enthalpy Calculation

Details: Accurate enthalpy calculation is essential for designing and analyzing thermal systems, including boilers, heat exchangers, and power plants, where it helps determine energy requirements and efficiency.

4. Using the Calculator

Tips: Enter specific heat capacity in kJ/kg·K and temperature in °C. For water, the specific heat capacity is approximately 4.18 kJ/kg·K at standard conditions.

5. Frequently Asked Questions (FAQ)

Q1: Why is this an approximate calculation?
A: This calculation assumes constant specific heat capacity, while in reality, c_p varies slightly with temperature and pressure.

Q2: What is the typical specific heat of water?
A: At standard conditions (20°C, 1 atm), water has a specific heat capacity of approximately 4.18 kJ/kg·K.

Q3: Can this calculation be used for steam?
A: No, this simplified formula is only appropriate for liquid water. Steam enthalpy calculations require more complex equations that account for phase change.

Q4: How does pressure affect enthalpy?
A: This simplified calculation doesn't account for pressure effects. For precise calculations, especially at high pressures, more comprehensive equations or steam tables should be used.

Q5: What are typical enthalpy values for feed water?
A: Enthalpy values depend on temperature. For example, water at 20°C has approximately 83.6 kJ/kg enthalpy, while at 100°C it's approximately 418 kJ/kg.