The Study Of Intellectualization Of Pneumatic Valve

The pneumatic actuator is indispensable control product in automation system. It is consist of pneumatic valve and electropneumatic converter. At present all the products made in our country based on mechanics balanced principle and analogue electronic technology. With the development of intelligent technology, network technology, communication technology and controlling /management comprehensive automatic technology, available pneumatic valve can not meet the demands of industrial field control. All the intelligent products applied in the market are provided by foreign companies. Intelligent actuator receives the output signal from the regulator and compares it with valve position feedback signal and obtains output signal which is directly proportional to the output signal of regulator according to the deviation between the signals and then control the pneumatic actuator. It is a non-fungible terminal product in dangerous inflammable site in petrochemical industry as it is superior to electrical actuator in terms of performance of explosion-proof. The article put forward the general plan to realize intelligent pneumatic actuator and studied and analyzed on some of key technical questions: low power-consumption electrical-pneumatic converting unit and low power-consumption control circuit solution which is based on piezo ceramic principle and meet the requirements of intrinsically safe explosion-proof (iBⅡCT5) ; general software solution which realizes the goal of intelligence and HART communication function ; reliability design solution which answers the purpose of MTBF≥16000 hours and regard electrocircuit, machine unit and software as main parts. Main research result: 1.To succeed in researching miniature pressure modulator, realizes integretion of electropneumatic conversion, high importation resistance, low power consumption , bear vibration and miniaturization by making use of physics/ electricity characteristic design of piezo ceramics; 2. To succeed in design control circuit based on C51 series single-slice computor with two line system, low power consumption and strong function according to the requirements of intrinsically safe explosion-proof (iBⅡCT5 ); 3. Software design realizes functions of flow characteristic correction, automatic zero setting, span setting, alarm, fault diagnosis and field display; 4. The item is up to MTBF25000 hours by means of reliability design, invalidity analysis, reliability allotment and adopting the dependable the measure,It is proved through experiment and application that the solution is reasonable and is realizable technologically. It meets the requirements of design target and is worth spreading and is of the potential of industrialization and marketability.