Heat Exchanger Calculation Tool

Heat Transfer Equation:

\[ Q = U \times A \times \Delta T_{lm} \]

Overall Heat Transfer Coefficient (U):

W/m²K

Area (A):

m²

Log Mean Temperature Difference (ΔT_lm):

Heat Transfer Rate (Q):

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1. What is the Heat Exchanger Calculation?

The heat exchanger calculation determines the heat transfer rate (Q) using the fundamental equation Q = U × A × ΔT_lm, where U is the overall heat transfer coefficient, A is the heat transfer area, and ΔT_lm is the log mean temperature difference.

2. How Does the Calculator Work?

The calculator uses the heat transfer equation:

\[ Q = U \times A \times \Delta T_{lm} \]

Where:

\( Q \) — Heat transfer rate (W or BTU/h)
\( U \) — Overall heat transfer coefficient (W/m²K or BTU/h ft²°F)
\( A \) — Heat transfer area (m² or ft²)
\( \Delta T_{lm} \) — Log mean temperature difference (K or °F)

Explanation: This equation calculates the rate of heat transfer through a heat exchanger surface based on the temperature difference and material properties.

3. Importance of Heat Transfer Calculation

Details: Accurate heat transfer calculations are crucial for designing efficient heat exchangers, optimizing energy consumption, and ensuring proper thermal performance in various industrial applications.

4. Using the Calculator

Tips: Enter the overall heat transfer coefficient in W/m²K, area in m², and log mean temperature difference in K. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is log mean temperature difference (ΔT_lm)?
A: ΔT_lm is the logarithmic average of the temperature difference between the hot and cold fluids at each end of the heat exchanger.

Q2: How is U value determined?
A: The overall heat transfer coefficient depends on the materials, fluid properties, flow arrangement, and fouling factors.

Q3: What are typical U values for different heat exchangers?
A: U values range from 10-1000 W/m²K depending on the fluids and exchanger type (water-to-water: 800-1500, gas-to-gas: 10-50, etc.).

Q4: Can this calculator handle different units?
A: This calculator uses SI units (W/m²K, m², K). For imperial units, convert values before calculation.

Q5: What are the limitations of this calculation?
A: This assumes constant U value and proper counterflow arrangement. Complex flow patterns may require correction factors.