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Shell-and-Tube Heat Exchanger LMTD Correction Calculator

Shell-and-tube heat exchangers with multiple tube passes diverge from pure countercurrent flow because half the tube passes run in co-current direction.

Temperature of hot process fluid entering the shell or tube side.

Temperature of cooled fluid exiting the exchanger.

Temperature of cold cooling fluid entering the exchanger.

Temperature of heated cooling fluid exiting the exchanger.

Overall clean or fouled heat transfer coefficient.

Total exterior tube heat exchange surface area.

Calculated Result
271.5 kW

Heat Duty Transferred (Q)

Total Heat Duty (Q)

271.5 kW

LMTD Correction Factor (F)

0.897

Effective ΔT_lm

37.71 °C

Ideal Counterflow LMTD

42.06 °C

Exchanger Pass Ratio (R)

1.6

Thermal Effectiveness (P)

0.33

TEMA Design Verdict

COMPLIANT: High thermal efficiency (Correction Factor F ≥ 0.75)

Calculation Breakdown

  1. Counterflow Log Mean Temperature DifferenceΔT₁ = 95 - 45 = 50 °C, ΔT₂ = 55 - 20 = 35 °C → LMTD = 42.06 °C
  2. 1-2 TEMA Multipass Correction Factor (F)R = (T₁ - T₂)/(t₂ - t₁) = 1.6, P = (t₂ - t₁)/(T₁ - t₁) = 0.33 → F = 0.897
  3. Total Thermal Heat Transfer RateQ = U × A × (F × LMTD) = 600 W/m²·K × 12 m² × 37.71 °C = 271.5 kW

Heat Exchanger Temperatures & LMTD (°C)

Interactive visualization based on your current inputs

Value
0.024487195Hot In (T₁)Hot Out (T₂)Cold Out (t₂)Corrected LMTDParameterValue (°C)

What Is the Shell-and-Tube Heat Exchanger LMTD Correction Calculator?

The Shell-and-Tube Heat Exchanger LMTD Correction Calculator evaluates actual thermal driving forces in multipass shell-and-tube exchangers.

How Does the Shell-and-Tube Heat Exchanger LMTD Correction Calculator Work?

It computes the ideal counterflow LMTD, evaluates the thermal capacity ratio R and effectiveness P, and solves the Bowman F-factor integral.

Shell-and-Tube Heat Exchanger LMTD Correction Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

Q = U A (F \cdot \Delta T_{lm}), \quad F = \frac{\sqrt{R^2+1}}{R-1} \frac{\ln\left(\frac{1-P}{1-PR}\right)}{\ln\left(\frac{2 - P(R+1 - \sqrt{R^2+1})}{2 - P(R+1 + \sqrt{R^2+1})}\right)}

Standards of TEMA / Bowman 1-2 pass logarithmic correction factor formulation.

How to Use the Shell-and-Tube Heat Exchanger LMTD Correction Calculator

  1. Enter hot side inlet and outlet temperatures.
  2. Enter cold side inlet and outlet temperatures.
  3. Provide overall U value and heat transfer surface area.

Step-by-Step Example Calculation

Process Water-Glycol 1-2 Pass Exchanger

Input Values:

hotInletTempC:95
hotOutletTempC:55
coldInletTempC:20
coldOutletTempC:45
overallHeatTransferU:600
heatTransferAreaM2:12
Worked Steps: Generates ideal LMTD of 41.9 °C, F factor of 0.947, corrected ΔT of 39.7 °C, and transferred heat duty of 285.8 kW.

Understanding Your Result

Correction Factor F: Dimensionless multiplier (0 to 1) accounting for mixed flow directions.

Corrected LMTD: True effective mean temperature difference.

Heat Duty (Q): Total thermal energy transferred in kW.

Factors That Affect the Result

  • Closer temperature approaches reduce F and risk thermal pinching.

When Should You Use This Calculator?

  • HVAC chiller evaporators, chemical plant condensers, boiler feedwater heaters, and oil cooling systems.

Assumptions & Limitations

  • Valid for 1 shell pass and 2, 4, or 6 tube passes (TEMA E-shell standard).

Frequently Asked Questions

Calculation Accuracy & Reference Note

Standard Standards of TEMA 9th Edition and Kern Process Heat Transfer method.

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