Margin slow released full cycle optimization due to slow time-varying fouling characteristics of multi-effect evaporation desalination system

Abstract

The slow time-varying fouling accumulation is the biggest obstacle to the full-cycle operation of the multi-effect evaporation with thermal vapor compression (MEE-TVC) desalination system. In order to avoid the impact of increased fouling resistance in fresh water production, the heat transfer area is generally oversized during design, but the utilization of redundant heat transfer area is unreasonable. The analysis has found that the reduction of feed seawater flow rate in the MEE-TVC system will increase the required heat transfer area for normal production, but will also reduce the external motive steam consumption. Based on this, a margin slow released full-cycle optimization method is proposed. This method continuously adjusts the operating conditions to adapt to the state changes of the MEE-TVC system, which not only makes full use of the redundant heat transfer area, but also reduces the full-cycle energy consumption. Furthermore, it also avoids the rapid exhaustion of the motive steam margin, so that the operating performance of the system is always better than that under the design condition during the full cycle.