Enter stream temperatures and flows — get duty, LMTD, correction factor and the required heat-transfer area.
Open the calculator →Given the hot and cold streams you want to exchange heat between, EnggiBasis computes the duty, the effective temperature driving force, and the surface area you need — then, in Rate/Design mode, uses the Bell-Delaware method for a realistic shell-side coefficient and an honest % overdesign number.
Q = m · Cp · ΔT — the heat transferred, from the mass flow, specific heat and temperature change of one stream.
LMTD = (ΔT₁ − ΔT₂) / ln(ΔT₁/ΔT₂)
where ΔT₁ and ΔT₂ are the hot-minus-cold temperature differences at each end. A correction factor F (from the Bowman charts) accounts for multi-pass, non-counter-current arrangements.
A = Q / (U · LMTD · F)
with U the overall heat-transfer coefficient. EnggiBasis builds U from film coefficients (Gnielinski tube side, Bell-Delaware shell side) plus fouling — not a single guessed number.
Honest positioning: EnggiBasis implements publicly documented methods (TEMA, Bell-Delaware, Gnielinski) for single-phase service and study-grade mechanical estimates. For rigorous two-phase and proprietary correlations, dedicated tools like HTRI still lead — and we say so on the page.
| Input | Value |
|---|---|
| Duty | 1500 kW |
| Overall U | 500 W/m²·K |
| LMTD | 50 °C |
| Correction factor F | 0.90 |
Result: required area A = 1,500,000 / (500 × 50 × 0.90) ≈ 66.7 m². Try it with your own streams →
A = Q / (U · LMTD · F) — duty over the product of U, the log-mean ΔT and the correction factor.
LMTD = (ΔT₁ − ΔT₂)/ln(ΔT₁/ΔT₂), the log-mean of the end temperature differences.
Heat exchanger sizing is part of EnggiBasis Pro (₹99/month). Open the app free to explore.
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