Size vaporizers with clear, auditable heat duty. Compare ideal, required, and margin-adjusted loads instantly here. Download CSV and PDF summaries for project submittals fast.
| Case | Flow | Tin (°C) | Tsat (°C) | Tout (°C) | Cp(liq) | Latent | Cp(gas) | Eff | Margin | Design duty (kW) |
|---|---|---|---|---|---|---|---|---|---|---|
| Typical sizing check | 1000 kg/h | -160 | -130 | 5 | 3.5 | 510 | 2.3 | 95% | 10% | ~ 607 |
Numbers are illustrative; use project-specific properties and operating pressure.
Vaporizer duty is the heat rate needed to warm LNG, change phase, and deliver the required outlet temperature. This calculator reports ideal duty in kW from mass flow and specific energy, then applies efficiency and margin to reach a design duty. For construction packages, this supports equipment sizing, utility loads, and basis-of-design notes. Consistent units and an auditable trail reduce review cycles.
Mass flow sets scale; doubling flow doubles duty. Temperature spans set sensible loads: max(0, Tsat − Tin) for liquid warm-up and max(0, Tout − Tsat) for superheat. Latent heat often dominates, so excluding it can understate duty. Cp values should match composition and temperature range because small Cp shifts accumulate at high throughput. Record the pressure basis that influences Tsat.
The model uses q = CpL·ΔTliq + Hvap + CpG·ΔTgas to produce kJ/kg. It then multiplies by ṁ in kg/s to obtain kW because kJ/s equals kW. Flow units such as kg/h, t/h, and lb/h are converted internally to kg/s. This is practical for early sizing when enthalpy tables are not fixed. For final design, confirm properties against a database.
Efficiency captures heat-transfer losses, fouling allowance, approach limits, and non-ideal operation. Required duty equals ideal duty divided by (Eff/100). A margin is then applied for variability, startup transients, and procurement conservatism. Example: 95% efficiency and 10% margin increases ideal duty by about 15.8%. Keeping margin separate from efficiency makes the basis easier to review.
Use design duty in kW and MW on data sheets, load summaries, and interfaces with heat sources such as seawater, glycol, steam, or electric heaters. Cross-check that Tout aligns with downstream fuel gas requirements and that Tsat reflects operating pressure. Export CSV or PDF to capture inputs, assumptions, and flags. If warnings appear, confirm temperatures, units, and whether latent heat should be included.
Design duty is the required heat rate after applying efficiency losses and a margin. It is the value typically carried into specifications, utilities, and vendor sizing to provide conservative capacity.
Use the unit you have available and select it in the list. The calculator converts kg/h, kg/s, t/h, or lb/h into kg/s internally so the duty calculation remains consistent.
Most LNG duty is spent on phase change. Excluding latent heat can significantly understate duty and lead to undersized equipment. Only disable it for special sensitivity checks with clear documentation.
Pick a saturation temperature consistent with your operating pressure and LNG composition basis. If pressure is not finalized, use a conservative Tsat and update the calculation when the pressure basis is set.
Yes. Uncheck the superheat option to set the gas sensible term to zero. This is useful when the outlet is near saturation or when downstream heating is handled elsewhere.
Recheck temperatures, units, and whether any values drive ΔT terms to zero. Confirm that Cp and latent values match your property source. If the control case is unusual, document assumptions in Notes and rerun.
Engineering note: This is a sizing aid, not a final design. Confirm properties, pressure effects, and heat-transfer limits with vendor data and project standards.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.