1. What is a Flat Plate Heat Exchanger Sizing Calculator?

Definition: This calculator determines the required heat transfer area for a flat plate heat exchanger based on thermal parameters.

Purpose: It helps engineers and designers properly size plate heat exchangers for various industrial and HVAC applications.

2. How Does the Calculator Work?

The calculator uses the fundamental heat exchanger equation:

Where:

• \( A \) — Heat transfer area (m²)
• \( Q \) — Heat duty (W)
• \( U \) — Overall heat transfer coefficient (W/m² K)
• \( LMTD \) — Log Mean Temperature Difference (K)

Explanation: The heat duty is divided by the product of the overall coefficient and temperature difference to determine the required surface area.

3. Importance of Proper Heat Exchanger Sizing

Details: Correct sizing ensures efficient heat transfer, proper equipment selection, and optimal system performance while avoiding oversizing costs.

4. Using the Calculator

Tips: Enter the heat duty in watts, overall coefficient (default 500 W/m² K), and LMTD (default 10 K). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical U value for plate heat exchangers?
A: For water-water systems, U typically ranges from 3000-7000 W/m² K. The default 500 is conservative for general calculations.

Q2: How do I calculate LMTD?
A: LMTD = [(ΔT1 - ΔT2)/ln(ΔT1/ΔT2)] where ΔT1 and ΔT2 are temperature differences at each end.

Q3: What affects the overall heat transfer coefficient?
A: Fluid properties, flow rates, plate material, fouling factors, and flow arrangement all influence U.

Q4: Should I include fouling factors?
A: Yes, for practical designs reduce the clean U value by 10-25% to account for fouling.

Q5: How does plate count relate to area?
A: Each plate provides a certain area (typically 0.1-1 m²). Total area ÷ single plate area ≈ number of plates needed.