Reynolds Number For Condensate Film Outside Vertical Tubes In Heat Exchanger Calculator

Reynolds Number Formula:

\[ Re = \frac{4 \times M_{flow}}{\pi \times D_{outer} \times N_{tubes} \times \mu_{fluid}} \]

Mass Flowrate (M_flow):

kg/s

Pipe Outer Diameter (D_outer):

Number of Tubes (N_tubes):

Fluid Viscosity at Bulk Temperature (μ_fluid):

Pa·s

Reynolds Number (Re):

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1. What is Reynolds Number for Condensate Film?

The Reynolds Number for condensate film outside vertical tubes in heat exchangers is a dimensionless quantity that characterizes the flow regime of the condensate film. It helps determine whether the flow is laminar or turbulent, which affects heat transfer coefficients and overall heat exchanger performance.

2. How Does the Calculator Work?

The calculator uses the Reynolds Number formula:

\[ Re = \frac{4 \times M_{flow}}{\pi \times D_{outer} \times N_{tubes} \times \mu_{fluid}} \]

Where:

\( M_{flow} \) — Mass flowrate (kg/s)
\( D_{outer} \) — Pipe outer diameter (m)
\( N_{tubes} \) — Number of tubes
\( \mu_{fluid} \) — Fluid viscosity at bulk temperature (Pa·s)
\( \pi \) — Archimedes' constant (approximately 3.1416)

Explanation: The formula calculates the ratio of inertial forces to viscous forces for condensate film flow outside vertical tubes in heat exchangers.

3. Importance of Reynolds Number Calculation

Details: Accurate Reynolds Number calculation is crucial for predicting flow behavior, determining heat transfer coefficients, and optimizing heat exchanger design for condensate films on vertical tube surfaces.

4. Using the Calculator

Tips: Enter mass flowrate in kg/s, pipe outer diameter in meters, number of tubes, and fluid viscosity in Pa·s. All values must be positive and valid for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of Reynolds Number in condensate flow?
A: Reynolds Number helps determine the flow regime (laminar, transitional, or turbulent) of the condensate film, which directly affects heat transfer rates and pressure drops.

Q2: What are typical Reynolds Number ranges for condensate films?
A: For condensate films outside vertical tubes, Reynolds Numbers typically range from 30-1800, with laminar flow below Re=30 and turbulent flow above Re=1800.

Q3: How does tube arrangement affect Reynolds Number calculation?
A: The number of tubes and their arrangement affects the flow distribution and thus the Reynolds Number calculation for the condensate film.

Q4: Why is viscosity measured at bulk temperature?
A: Fluid viscosity varies with temperature, so using the viscosity at bulk temperature provides the most accurate representation of fluid properties during heat exchange.

Q5: Can this calculator be used for horizontal tubes?
A: This specific formula is designed for vertical tubes. Horizontal tube condensate flow may require different correlations and formulas.