Equipment Sizing Overview
Jasper sizes equipment automatically after every converged simulation. Sizing is a deterministic post-processing pass: it reads the standardized simulation result (streams, duties, work, stage counts) and produces a size for every cost-bearing unit — no extra solver iterations, no engine-specific code paths.
How it works
Simulation (Quick / Rigorous / Optimize)
│ streams (T, P, flow, density, vapor fraction, composition)
│ unit results (duty, work, stages, reflux ratio)
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Sizing pass (per unit, closed-form correlations)
│ size + derived geometry + every assumption recorded
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Equipment sizes (shown per node, feed the economics engine)
Because the pass runs on the standardized result format, the same correlations produce the same sizes regardless of which engine solved the flowsheet. Identical inputs always produce identical sizes.
Sizing basis by unit type
Every unit type declares one sizing basis, which is also the size variable the economics engine costs against:
| Basis | Unit types | Output |
|---|---|---|
| Power | Pump, Compressor, Expander | kW (from simulated work) |
| Heat duty | Heater | kW (from simulated duty) |
| Area | Cooler, HeatExchanger | m² (LMTD method) |
| Volume | Flash, Separator, ThreePhaseSeparator, columns, all reactors | m³ (+ diameter, height) |
| Delegate | CustomUnit | inherits its base type, or an agent-defined formula |
| None | Feed, Sink, Mixer, Splitter, Valve, PipeSegment | not sized |
See Sizing Methods for the correlations behind each basis and Reactor Sizing for reactors in depth.
Honesty rules
- Every assumption is recorded. Each size carries the list of assumptions used to produce it (U value, residence time, flooding fraction, …), visible in the node's Sizing panel.
- Missing inputs are flagged, never fabricated. A pump with no simulated work is reported as unsized, with the reason.
- Defaults are conservative and overridable. The weakest defaults (e.g. reactor residence time) are explicitly marked "OVERRIDE per reaction" in the recorded assumptions.
Units
Sizing computes in SI (m², m³, kW) and displays in SI or US units (ft², ft³, hp, MMBTU/hr) with a single toggle. Conversion happens at display time only — stored sizes are always SI.
Where sizes show up
- Node sidebar → Sizing section — size, derived geometry, method, and assumptions per unit.
- Economics — sizes are the inputs to capital cost estimation; see Economics Overview.