Research And Development Of A Double Bottom Storage Tank Based On Monitoring On Line

Chinese national strategic petroleum reserve plan is carried out and thus a lot of large tanks for oil storage are needed. However, bottom leakage caused by corrosion offen happens to traditional vertical tanks with only one single bottom. A new double bottom tank structure based on leakage monitoring on line was given in the paper after studying the interrelation between the bottom structure and on-line monitoring device. Its test device was developed successfully and relatated leakage tests were also done. Besides, the thickness calculation formula of the upper bottom was gotten by means of theoretical derivation and numerical simulation. The work is of engineering practical significance.(1) A new double bottom tank structure was developed after researching the items of double bottom tanks in the foreign standards. Structure design of the two bottoms and center plate support was done.(2) The test device of double bottome tank based on leakage monitoring on line was successfully developed. The test tank’s thickness was calculated referring to the related specification of shell and bottom in GB50341-2003. Finite element model based on contact was established to calculate the test tank’s stress and deflection. The test tank’s strength was checked by stress classification to provide a design method for maximization application research.(3) Gasoline leakage test and ammonia leakage test on the test device were carried out. The tests showed that the double bottom structure worked efficiently and the on-line monitoring device met the design requirement.(4) The thickness calculation formula was derived by plate theory. At first, the maximum deflection calculation method of rectangular thin plates under hydrostatic pressure and respectively with simply support and completed clamped support on the four sides was analyzed and extended to the upper bottom. Thus, the general formula of the upper bottom’s maximum deflection was gotten. And then the general formula’s coefficients of pareallel support and cross support were obtained by finite element simulation and numerical fitting. Finally the upper bottom thickness calculation formulas were derived by combining the maximum deflection formula with stiffness limit conditions.