Dirt Monitoring System Design Of Ship Plate Heat Exchanger

Long-running of ship plate heat exchanger leads to fouling phenomenon, which poses a threat to the safety of the ship. And now traditional method relying on the experience evaluating dirty state of heat exchangers is difficult to meet the requirements of intelligent automation. In this paper, an important parameter measuring the impact of fouling on heat exchanger-fouling resistance is used in the completion of the dirt monitoring algorithm and related systems design.Firstly, the Online fouling monitoring algorithm is designed. Ships central cooling system is a variable-flow-control system. According to this feature, Based on the thermal resistance equation and through the analysis of the thermal resistance equation parameters, obtain of fouling resistance is converted to getting the real-time overall heat transfer coefficient and high and low temperature coefficient of convective heat transfer. The mathematical model of heat exchanger plate is established on heat transfer relationship. On the basis of model estimation algorithm using Extended Kalman Filter, the identification of the heat transfer coefficient is completed. The method applied to the plate heat exchanger and easy to operate-flow rate method is detailed to get coefficients.Secondly, build bench, and verify the fouling monitoring algorithm through experiments. The equal flow rate method is used to design experiments, and to obtain a high/low temperature convection heat transfer rule equation respectively. Further, under cleaning and different fouling resistances, the monitoring results are compared with the theoretical value to verify the feasibility of monitoring algorithm.Finally, based on the monitoring algorithm and combined with the plate heat exchanger management needs on the real ship, the monitoring system is designed. This system not only achieves the automatic intelligent management, but also improves the safety of ship operations.