Design Of Measurement And Control System For Hydrostatic Test Of CNG Cylinders Based On MCGS

Hydrostatic test is one of the most effective means to check the gas cylinders.In this paper,the gap between domestic hydrostatic test devices and foreign ones are analyzed.Based on the realistic need of hydrostatic test,a computer measurement and control device for steel cylinder test using direct expansion method is designed.The main contents of this paper are as follows:1. Developing a computer control device of direct expansion method based on data and signal acquisition.Besides,the work also includes choosing appropriate specification and type of related hardwares.2. A set of data acquisition and control software is developed with MCGS on the Windows XP platform.It can not only realize the acquisition,display,processing and storage of analog signals such as pressure ,temperature and water amount,but also generate hydrostatic test report according with industry-standard requirement.3. Developing an automatic control system of hoisting equipment.It realized the automatic conveyance of gas cylinder from weighing area to hydrostatic test area.The computer control divice has the following characteristics:(1) High control precision.While hydrotatic test is carried out,the computer sends control signal to actuators according to the predetermined precedure and conditions.So the parameters such as test pressure and time can be controled accurately.(2) High degree of automation.The system realizes automatic start-stop of hydraulic pump and open-close of electromagnetic valves.Steel cylinders can be conveyed from weighing area to hydrostatic test area automatically.(3) Strong safety.In addition to real-time monitoring of the test process,the device provides alarm functions including leak,overpressure and unqualified result alarming.(4) More reliable inspection results.The water compression coefficient is valued according to real-time testing temperature to calculate cylinder's total deformation.Besides this,for datas are storaged in the computer,the potential mistakes causing by original manual input are avoided.Due to the above,the reliability of inspection results is greatly increased.(5) The report can be printed conveniently.The inspection datas are automatically storaged in database,which is good for related research.Hydrostatic test report can be printed as needed.