The analysis on calculation model of heat-wave velocity during the process of crude oil storage tank fire
The formation mechanism of boilover fire in crude oil storage tank is very complex and harmful. Heat-wave velocity is an important research topic in the boilover fire. After introducing boilover mechanism, the models of heat transfer and heat-wave velocity was built by heat transfer analysis for oil layer. Comparing the calculation results of model with the experimental data, this heat-wave speed calculation model is reasonable. Through the research, several conclusions were found: the main factors that impact heat-wave rate are the viscosity and component of oil, heat of heat-wave comes mainly from thermal radiation of flame; Emulsified water in the oil will not trigger boilover fire normally. Only the heat-wave encountered bottom water cushion at the bottom of the tank, did boilover fire take place. In practice, the heat-wave moving speed can be valued 1m/h to estimate the occurrence time of boilover. The results of this study are important for control and security of boilover fire accident.
A study on large-scale boilover using crude oil containing emulsified water
In order to elucidate the effect of emulsified water on boilover, an experimental study on large scale boilover was conducted using Sarukawa crude oil, which is produced in Japan and contains about 0.3 vol.% water. A 1.9 m diameter pan was used in the experiments, and initial fuel depth was set at three different levels of 100, 200 and 400 mm. Radiation from the fires to outside targets, temperatures of fuel and flame, and fuel burning rate were measured, and direct and thermal images of flames were recorded. Boilover occurred after a period of long burning as expected, but the periods from ignition to boilover observed in the present study were shorter than those predicted on the basis of results of previous studies. This result was inferred to be due to emulsified water in the fuel.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.