Water Level Process Research Articles

Intelligence-based hybrid control for power plant boiler

A hybrid classical/fuzzy control methodology is presented to integrate low-level machine control and high-level supervision for the steam temperature and water level processes of the power plant boiler. The coupling between two spraying systems can be reduced using hybrid coarse-fine intelligent control with qualitative decoupling strategy. A hierarchical fuzzy system is used for the water level control, instead of the human operator or the proportional integral derivative (PID) control. Industrial applications show the superiority of the proposed intelligent control over the traditional methods.

Simulation modeling of nuclear steam generator water level process — a case study

Simulation modeling of the nuclear steam generator (SG) water level process in Qinshan Nuclear Power Plant (QNPP) is described in this paper. A practical methodology was adopted so that the model is both simple and accurate for control engineering implementation. The structure of the model is in the form of a transfer function, which was determined based on first-principles analysis and expert experience. The parameters of the model were obtained by taking advantage of the recorded historical response curves under the existing closed-loop control system. The results of process dimensional data verification and experimental tests demonstrate that the simulation model depicts the main dynamic characteristics of the SG water level process and is in accordance with the field recorded response curves. The model has been successfully applied to the design and test of an advanced digital feedwater control system in QNPP.

Water Level Controls for a Drum-Type Boiler System using Fuzzy Logic Approach

The major downfall of conventional self-tuning controller has been the requirements of an accurate or a good model of the process, and the inability to set meaningful goals for the adaptive mechanism. The fuzzy logic theory based approach circumvents the shortcomings by deploying a set of heuristic rules and procedures derived from the “deep knowledge” obtained from experienced skilful control engineers' and plant operators' knowledge of the-plant operations and plant behaviours and other plant operational records. In this paper, we describe a method of implementing a selftuning Pill controllers using fuzzy logic approach. Fuzzy inference mechanism is used to adaptively tune the settings of a PID controller. The controller is then applied to control the drum water level process of a boiler for electric power generating plant

The Impact of Large Water Engineering Projects on Geomorphic Processes in Stream Valleys

AbstractLarge storage reservoirs have a significant effect on the landscape of river valleys. A rise of the base level, caused by dam construction, together with the resulting changes in the stream regime set off a sequence of interrelated geomorphic processes. Upstream from the edge of the backwater produced by the dam, regressive aggradation gradually spreads upriver, resulting both in a rise in the valley floor and a rise in water level. Within the reservoir itself, waves, longshore currents, seasonal changes in water level and gravitational processes on shoreline slopes combine to produce a distinctive shoreline relief, characterized by large areas of recurrent inundation, lagoon closed off by baymouth bars, and high cliffs retreating under the impact of wave abrasion. Downstream from the dam, heavy downcutting of the river channel gives rise to a stream terrace, whose relative height declines from the vicinity of the dam toward the mouth. Downcutting of the channel in the main stream in turn tends to...