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Parameters optimization of the PI controller was investigated for the header flux control of Ultra-fast cooling. Taking the measured curve, Ultra-fast cooling (UFC) header flux under different open rate of valve, as the input parameters, a simulation model was developed. Based on the coupling control of proportion(P) and integration(I), the parameters with minimum root-mean-square-error of header flux was considered as the best. The simulation results showed that the optimal integration time was 600ms under industrial conditions. Furthermore, the correction equations for the P and I controller were established by the newly developed simulation model. The results from the on-site implementation indicated that the flux deviation between target and measured values was less than ±l.0m3/h during the constant operation of the UFC header, and the overshoot value was within 3.0m3/h of the apparent interference.

Trough collectors are laid out in rows in a field withrow spacing. Wind and sandstorm loads on the collectors will be influenced by surrounding collectors. This paper presents analyzed results from a combined wind tunnel and sandstorm tunnel study on a trough collector field with seven rows and five spans. In wind tunneltests, the measured model with pressure taps was installed in the field to measure wind pressures on the surfaces. Mean and fluctuating pressures on the model were measured by the synchronous multi-pressure sensing system under typical boundary layer wind flow field. In sandstorm tunneltests,a isolated trough collector model was measured by the high-frequency force balance technique under wind-blown sand flow field.