Research On Intelligent Detection Methods Of Odor Online Monitoring System

With the rapid development of Chinese economic construction,more and more odorous pollution incidents have occurred.It is a serious threat to human health and damage to the living environment.Therefore,it is imperative to develop an automatic monitoring and warning system.Although there are many gas detection equipment on the market to detect some odor,there are other deficiencies such as low detection accuracy,high prices,shortage of online analysis and so on.Therefore,it is both theoretically important significance and practical that we research intelligent detection method of Odor Online Monitoring System.First of all,this thesis summarizes the domestic and abroad research results and development direction of Odor Online Monitoring System.Afterwards,it is introduced that the developed Odor Online Monitoring System's working principle and system structure.For the software,a set of Intelligent Detection Software System has been developed,through the use of Expert Systems and Fuzzy Control Principle.For the hardware,we developed a set of Gas Concentration Equipment,which can improve the detection limit.From the overall system is concerned,detecting gas simples can process chromatographic data and offer substances and concentrations.Odor Online Monitoring System achieves gas samples injection and analyzes chromatographic data through the Intelligent Detection Software System.Based on the design concept of intelligent detection method such as Expert System and Fuzzy Control,the intelligent identification algorithm of chromatographic peak pattern is studied and verified by experiment.This thesis discussed the noise source of the instrument and analyzed the filtering effect of three different filtering methods.Based on the different filtering characteristics,different filtering algorithms are proposed for different chromatographic regions.In order to improve the detection limit of Odor Online Monitoring System,the peak pattern recognition algorithm is improved in the software,the detection threshold of the peak feature points are reduced,and the small peaks are identified by Increasing Tangent Search and verified by experiment.Meanwhile,we developed a set of Gas Concentration Instrument,which concentrated the low concentration sample gas before it tested,and realized the intelligent automatic switching of high and low concentration gas detection.The Dimethyl sulfide was used as an example to verify the experiment and obtain the third party test certificate.According to analyzing a large amount of experimental data,this thesis analyzed the influence of flow rate and temperature on the response value of single gas simple and the separation degree of the mixture,and obtained an optimal working range for flow rate and temperature,to realize the rapid and efficient detection of odor.Odor Online Monitoring System applies absolute retention value and standard curve method to calibration method,which was compared with the commercialized GCRAE1000 Portable Gas Chromatograph.According to the repeatability and stability experiments,it proved that the system has good repeatability(0.54 SD)and stability(less than 1.356% RSD),and meet the requirements of the instrument repeatability(less than 10% RSD).