A Study On Method And Device Of The Cooling Water Fouling Countermeasures Evaluating And Predicting

Fouling is a poor heat conductor. It is not only the result of energy waste of heat exchanger and fluid machinery and environmental pollution, but also is great harm on the equipment operation and the major incentives of reducing equipment utilization and causing heavy economic losses. Therefore fouling has become the main objectives of energy saving and emission reduction in industry. In view of the fouling mechanism complexity and the dissatisfaction with researching fouling, the meaning of the research in fouling monitoring technique and equipment is great. This work was supported by a grant from the Major State Basic Research Development Program of China (973 Program) (No.2007CB206904). The main studying contents include:In consideration of the deficiency of the traditional bubble test and manual conductometric titration, this study developed a new integrated intelligent instrument for rapid evaluation of the scale inhibitor efficiency based of the conductometric titration. It brought about automatically evaluation of the scale inhibitor efficiency with microcomputer. This paper analyzes the factors affecting detection results and optimizes experiment conditions based on a new integrated intelligent instrument for evaluating rapidly scale inhibitor performance. The instrument is high precision, good repeatability, quick-evaluation and easy-operation. It could meet the needs of the enterprises which exploit or utilize the scale inhibitor by means of the precision and rapid evaluating the scale inhibitor efficiency. This instrument may become the alternative suggestion of bubble test device.This study puts forward a new method evaluating rapidly the scale inhibitor efficiency by titration solution volume of the corresponding inflection point based on measuring transmittance as sodium carbonate titrating calcium chloride. A new integrated transmittance intelligent instrument is developed, including: photoelectric detector, automatic titration controller, temperature controller and computer. The optimal evaluating conditions are accompanied with analysing and optimizing influencing factors.Based on the comparative analysis of the essential characteristic of conductimetric titration curve with the calcium carbonate fouling process dynamic, this study proposed a precise definition for the calcium carbonate fouling induction period. The fouling induction period, Ca²⁺ and CO₃^2- concentration, nucleation rate, crystals growth rate and reaction order are determined by real time measuring titration conductivity. The results show that: the definition of the calcium carbonate fouling induction period is exact and easy detecting, the experimental unit for real-time monitoring fouling induction period and all above-mentioned parameters is convenient and feasible.In consideration of the feature predicting the cooling water fouling, this paper is designed to an dynamic experimental system simulating shell-and-tube heat exchanger. It can be used for monitoring water parameters, working conditions parameters and fouling characteristics parameters in the specified conditions. The quantitative relation of these monitoring parameters is established in the artificial intelligence algorithms. The typical industrial cooling water is continuously measured for more than a year in order to test the repeatability and precision of prediction model and the equipment, such as the water of songhua river in Jilin City. This mothed and equipment can be used for predicting or monitoring fouling thermal resistance of other geographical cooling water for the water cooler designing, accurately calculating the resistance of pipeline, pump selection and evaluating the scale inhibitor and corrosion. Due to the system unfinished a complete cycle, this paper only describes predicting method and testing system design.