Cooling-water utility circuit — treatment, dosing, consumers, blowdown

A whole cooling-water utility rather than a single tower: raw water is filtered, dosed, and joins a circulating header that a pump pushes through three consumers with different duties — a reactor jacket, a condenser and a compressor intercooler — before the warmed return goes to the tower and a blowdown draw-off leaves for effluent treatment.

The number worth checking is the consistency between the two halves. The tower computes the blowdown it needs to hold 4 cycles of concentration (32.1 mol/s) and the makeup that implies (128.3 mol/s); the drawn blowdown split and the sized raw-water intake match those to under 1.5%. A circuit whose blowdown valve and cycles disagree is the commonest way a real plant silently runs at a different concentration than its water chemistry was designed for, and the flowsheet is arranged so you can see them agree.

Solved: 300 m3/h circulating at 301.15 K, split 45/35/20 across the three exchangers, returning mixed at 312 K for an 11.0 K tower range at a 4.0 K approach.

What is drawn but not modelled, stated plainly. The biocide, scale-inhibitor and corrosion-inhibitor streams are real streams carrying real flow, and their chemistry is not simulated — no inhibitor efficacy, no biological control, no corrosion rate exists in this tool. They are here because a utility flowsheet without them misrepresents the plant, not because dosing more of them will change a number. The scale risk that IS quantified comes from the tower's saturation indices against the makeup analysis, and on this water it says calcite saturates at 2.2 cycles — below the 4 being held.

Blowdown leaves to a product labelled for effluent treatment; the treatment train itself is not modelled, because carrying dissolved hardness as flowsheet components requires an electrolyte package and would change the thermodynamics of the entire water loop. And there is no basin: steady state has no inventory, so a sump level and its controller belong to the dynamic engine.