Design Of Multipurpose Liquid Flow Standard Device Based On Standard Meter Method

at present,in the flowmeter verification and calibration market,the most commonly used off-line methods are weighing method,volume method and standard meter method.Although the accuracy of weighing method and volume method is high,the single verification takes a long time,which has become more and more difficult to meet the heavy measurement tasks.In the aspect of on-line calibration,its low calibration accuracy is an urgent problem to be solved.Based on this situation,this paper designs and builds a new dual-purpose liquid flow standard device based on the working way of the standard meter method,and analyzes its stability,uncertainty and other performance indicators as well as its performance in the process of practical application.The main contents completed during the period are as follows:(1)Based on the analysis of the working modes of off-line verification,calibration and on-line calibration,the overall design scheme of the multifunctional liquid flow standard device is put forward,and the technical indexes,structural composition and working principle of the device are determined.According to the actual working conditions,the pipeline structure of the device is designed,and the hydraulic loss of the pipeline is technically analyzed.At the same time,AMCA flow straightener is used to ensure the stability of flow field,and its effect is evaluated by simulation.(2)The overall construction of the flow standard device is completed.Combined with the technical indexes and pipeline design of the device,the selection analysis of main hardware equipment such as water pump,regulating valve,standard flowmeter,pressure stabilizing device and controller is carried out.In order to realize the online calibration function,the connection structure of the standard flowmeter is optimized,and the field calibration component of the removable mobile standard meter is realized..The verification management software of the device is designed,which has the functions of human-computer interaction,verification mode selection,report query and printing,data storage and so on.(3)The stability,uncertainty and other important performance indexes of the device as well as the flow response time and other reference indexes are evaluated.The results show that the stability of the device is 0.26% and the uncertainty is better than 0.22%.The overall performance of off-line verification,calibration and on-line calibration of the device was tested by 0.5-level electromagnetic flow meters with different diameters such as DN100,DN80,DN65 and DN50.All the results were less than 0.5%,which met the requirements of 0.5-level flow meters.The application effect of the device reached the expected requirements.