Study On Key Technique Of Multi-parameter Automatic Tank Gauging System Based On Magnetostriction Effect

Automatic Tank Gauging System is one of the most significant equipments in gas station, oil product pier and petrochemical industry. At the present time, there are totally 3 kinds of automatic tank gauging system — ATG based on principle of liquid level measurement, HTG based on theory of static pressure measurement, and HTMS(hybrid tank measurement system). All the three systems have their own advantages and disadvantages, and cannot fully meet the requirements of actual measurement. In addition, all the automatic tank gauging system that used domestically have the problems such as low automation, low measuring precision, single measuring data, and conflicting measurement unit. In order to increase the automatic standard and minimize the loss occurring in trade of oil product, especially during international trade, there is an urgent need to develop new type automatic tank gauging system which can adapt to our country's actual measuring circumstances. Research of automatic tank gauging system is a multi-field and cross-subject thesis which involves in sensor technology, material technology, signal processing technology, and digital communication technology. This paper researched technology of automatic tank gauging in detail, and the main work accomplished can be summed up as the following:1. The principle, advantages and disadvantages of current tank measuring detection methods are researched, and finally theory of magnetostriction measurement which can change displacement information into time signal, is selected as the foundation of a new type multi-parameter automatic tank gauging system. 2. Operating principle and measuring precision of conventional liquidometer based on magnetostriction is researched, and measuring theory of a new type of elastic wire magnetostrictive liquidometer is brought forward.3. Temperature influence on measuring precision of magnetostrictive liquidometer is researched and a magnetostrictive liquidometer sensor with function of self-calibration and removing temperature deviation is designed. 4. "Multi-floater relative displacement" method is brought forward, and on-line measurement of liquid density based on Magnetostriction Effect is realized with high precision. Measuring precision of density sensor based on Magnetostriction Effect is verified through theoretical analysis and experiments. 5. Influence of oil density change on measuring precision of magnetostrictive liquidometer sensor is researched and a method of correcting liquid level measuring error taking account of measuring value of density is put forward. 6. A new algorithm of calculating oil product volume precisely taking account of tank table, measuring value of liquid level and interface is brought forward.7. Temperature gradient distribution in tank, principle of tank temperature measurement, and temperature compensation algorithm are researched.8. Tank leakage detection method founded on small mass change is achieved taking advantage of ANN technology. 9. An intelligent digital multi-parameter sensor for automatic tank gauging is developed taking advantage of SCM, Embedded Internet, and digital communication technique. Together with superior management software which is newly programmed, the new type automatic tank gauging system is built up.