A novel fouling measurement system: Part II. Commissioning

Abstract

The Fouling Measurement System (FMS) supports research on the relationships between fouling deposit and operation condition involving water velocity, water quality and tube geometry by measuring variation of fouling resistance on a heat transfer tube during long-term running. Part I of this series provides the description and design evaluation of the newly developed FMS. Part II of this series describes FMS commissioning and documents the entire system performance and primary fouling test with nine same type enhanced tubes. Results of system commissioning demonstrated that the FMS would take 128min to reach steady-state. Water velocity could be controlled at three velocities of ∼0.9m/s, ∼1.6m/s and ∼2.4m/s respectively to satisfy the experiment requirement. Saturation temperature can be adjusted in the range of ∼34.0–35.5°C at water velocity of 0.99m/s, as a result, the heat flux varied from ∼20.1kW/m2 to 26.5kW/m2 correspondingly. The rising rate of electrical conductivity (EC) was 130μs/cm per day. All the parameters of the cooling water were controlled at the required range, except calcium hardness, which is 480–860ppm and much higher than the upper limit of 391ppm. The fouling resistances increased to 0.3865–0.5078m2K/kW after 60days at an amplitude of 12.48% around the averaged value of 0.4864m2K/kW. The water-side pressure drop decreased from 4.34–4.62kPa at clean condition to 2.90–3.10kPa at fouled condition after 60-day continuous running at ∼0.99m/s.