Performance curves: reading a test back to water flow

Cold-water temperature against flow, one curve per wet bulb, and the inverse solve back to flow.

Cold-water temperature against water flow, one curve per entering wet bulb at a fixed range, and the inverse solve from a measured cold-water temperature back to the flow the curve predicts.

Reference conditions: test flow 200 kg/s, entering wet bulb 27 °C, range 10 K, measured cold water 32.80 °C — a predicted 32.50 °C at 200 kg/s and, inverted, 210 kg/s at 32.80 °C, a capability of 95.2 %.

Formula: CWTgrid(WB, range, qpredicted) − CWTtest = 0 solved for the flow, then Capability % = 100 × qtest, adjusted / qpredicted and ΔTc = Tctest − Tcpredicted.

Cooling tower performance-curve family: cold-water temperature against flow for wet bulbs 25.5, 27 and 28.5 °C at a 10 K range, with the inverse solve from a measured 32.8 °C back to 210 kg/s (illustrative)Illustrative performance-curve family for a cooling tower: cold-water temperature against water flow, one curve per entering wet bulb (25.5, 27.0, 28.5 °C) at a 10 K cooling range, with the fill characteristic KaV/L = 1.9 (L/G)^−0.6 and the air mass flow fixed at the test point. The family is the Merkel model anchored to the grid points the post states, so at 200 kg/s the 27 °C curve reads 32.50 °C and at 32.80 °C it reads 210 kg/s. Reference condition: test flow 200 kg/s, wet bulb 27 °C, range 10 K; measured cold water 32.80 °C. Capability = 100 × 200 ÷ 210 = 95.2 %. The leaving-water deviation is 32.80 − 32.50 = +0.30 K, about 5 % of flow capability at this duty. Values are computed from the formulas, not measured; the curve is anchored to the post's stated grid points. (chart-performance)Performance curves — Illustrative — not a measurementCold-water temperature against flow15017520022525029303132333435Water flow (kg/s)Cold-water temperature (°C)grid 32.50measured 32.8021025.5 °C wb27.0 °C wb28.5 °C wbCurves: wet bulb 25.5 / 27 / 28.5 °C · range 10 K · fill KaV/L = 1.9 (L/G)^−0.6Model anchored to the post's grid: 200 kg/s → 32.5 °C, 32.8 °C → 210 kg/s(× 0.9632, + 1.609 K)grid CWT at 200 kg/s (°C)32.50measured CWT (°C)32.80inverse solve → flow (kg/s)210capability 100 × 200 ÷ 21095.2 %Computed from the formula — not field data.
Illustrative, computed from the tower model — not a measurement. Each curve is the cold-water temperature at which the fill’s characteristic equals the Merkel demand over the stated range at the wet bulb named, with the measured point and the inverted flow marked.

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