PUBLICATIONS AND VIDEOS

SUMMARY

A programme of jet fire tests was undertaken by British Gas over a two-month period, between May and June 1995, under contract to the Steel Construction Institute as part of the industry sponsored ‘Blast and Fire Engineering Project for Topside Structures’. An overview report has been prepared which describes the measurement techniques and equipment used. The overview report also contains a summary of the data from each of the tests. In addition, an individual data report has been prepared for each test. This data report contains the detailed results of measurements taken during Test 7.

Test 7 was specified to be an impacting flame experiment, fuelled by 5 kg/s crude oil released horizontally from a circular hole at an absolute static pressure of 20 bar, and impacting normally on a horizontal 0.9 m diameter instrumented pipe target located such that its axis was a distance of 9 m from the release hole. Preferred weather conditions were dry, with a nominally co-flowing wind (i.e. blowing from behind the release, within 30° either side) and a horizontal wind speed in the range 3 to 8 m/s.

The conditions during Test 7 were within the preferred conditions specified. The crude oil release hole diameter required to achieve the pressure and flow rate specified was identified prior to the test, and was 14.0 mm. The crude oil flow rate achieved in the test was 5.1 kg/s, released at an absolute static pressure of 20.2 bar. Weather conditions were dry, with a time-averaged wind speed (measured 41 m nominally cross-stream of the crude oil release axis, at a height of 6.9 m above the crude oil release point) of 4.4 m/s, from a time-averaged direction 21° off the crude oil release axis. The flame impacted approximately 0.3 m off centre on the horizontal 0.9 m diameter pipe target, engulfing approximately 4.5 m of the 16 m length of the pipe target.

In the test, a natural gas pilot was used to stabilise the crude oil flame close to the release point. The flame generated large quantities of thick, black smoke which partially obscured the tail of the flame. That part of the flame which was visible extended approximately 16 m in a horizontal direction. There was significant interaction between the flame and the ground, within a 5 m distance downstream of the pipe target, and a small amount of fuel was observed to bum on the ground in this area during the test. Some liquid and soot deposits were observed on the surface of the pipe target following the test. The flame was luminous and radiative, with a time-averaged maximum flame surface emissive power of 264 kW/m². The time-averaged total heat fluxes measured by instruments located on the surface of the pipe target and maintained at nominally 60°C were generally in excess of 150 kW/m² for most of the instruments located in the central section of the pipe target, and exceeded 200 kW/m² at several central locations. The time-averaged radiative heat fluxes measured at a central location on the front of the pipe target were approximately 33% of the total heat fluxes measured 0.05 m away. However, the time-averaged radiative heat fluxes measured at central locations on the top and back of the pipe target were approximately 63% and 75% respectively of the total heat fluxes measured 0.05 m away, consistent with a greater radiative contribution from the tail of the flame.