Tank Fill Level Research Articles

Flammability Of Alcohol-gasoline Blends In Fuel Tanks

This paper examines the relative flammability hazard presented by the fuel tank headspace vapours of various alcohol-gasoline blends, including methanol (MlOO), ethanol (ElOO), winter gasoline, summer gasoline and winter and summer blends of M85, E85 and E10. Ignition tests were conducted to establish flammability limits for each of the fuels. Measured limits were compared to those predicted by the RMC multicomponent fuel volatility model and conclusions were drawn as to the comparative hazards of the fuels studied. The model was also used to examine the effect of fuel tank fill level on the flammability limits of the respective blends. The results show the tendency of the flammability limits both to broaden and shift to warmer temperatures with decreasing fill level or increasing alcohol content.

Rollover Threshold of Partially Filled Tank Vehicles with Arbitrary Tank Geometry

Rollover threshold limits of partially filled tank vehicles equipped with tanks of arbitrary cross-sections are estimated using a simple methodology. Overturning moment caused by the lateral liquid shift within a partially filled arbitrary tank geometry is obtained as a function of the tank shape, fill level and the gradient of the free surface of liquid. The liquid load shift computed using a set of closed-form equations, developed based on the tank shape and fill level, is compared to those obtained from a comprehensive software developed based on a numerical technique. The static rollover threshold of the tank vehicles with arbitrary tank shapes are estimated by balancing the total overturning moment against the restoring moment. The results are compared to those obtained from a kineto-static analysis of tank vehicles.

Fire engulement of LPG tanks: heatup, a predictive model

A predictive model of the behaviour of horizontal pressurised LPG vessels engulfed by fire is described. Complete fire engulfment is treated with a heat flux distribution that is both variable in the vertical direction and time dependent. Heat flow through the tank walls, convective and radiative exchange to the fluid and heat and mass transfer between the liquid and vapour are incorporated. The liquid and vapour zones are each assumed to be separately well mixed. The operation of different designs of pressure relief valves is simulated. Model validation was against extensive measurements on 0.25, 1 and 5 tonne LPG tanks filled to a range of levels and engulfed in kerosine pool fires. HEATUP successfully predicted pressure relief valve opening times, discharge rates, pressure histories and average liquid and vapour temperatures for the different tank sizes and fill levels. Predicted mean wall temperatures in both liquid and vapour zones also agreed with measurements.