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The technology Technological foundations |
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The technology Propane burners |
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IMPROVING THE SYSTEMS EFFICIENCY |
The task of the experts assigned by Breitling aimed to improve the balloon's efficiency and consequently its flight autonomy. The Industrial Energy Laboratory of Lausanne's Federal School of Technology (EPFL) gave top priority to the study of the envelope. The main problem observed during the Breitling Orbiter 2 flight was the large consumption of kerosene, as the burners were brought into use at night to maintain altitude. Initially, their work involved evaluating new insulating materials for the envelope which have already been studied by NASA for satellite applications. |
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Nonetheless, the most significant development towards mitigating thermal differences on the helium mass involved the actual shape of the balloon. Laboratory simulations of temperature variations enabled them to clearly determine that, although the initial shape of the balloon was fundamentally correct, slight modifications would make it possible to significantly improve efficiency. The total volume of the helium cell now stands at 18,500 cu.m. (650,000 cu.ft), meaning 15% more than that of Breitling Orbiter 2. It has been reinforced - but without being made heavier - and the "tent" which insulates the peak has also been enlarged to diminish the effect of solar radiation. |
The size of the cone of the envelope has been proportionately reduced, compared with the envelopes previously used, in order to diminish the volume of air to be heated - meaning less need of propane gas - and secondarily to avoid needless accumulation of solar radiation by day and lessen heat loss at night. Another modification is that the appendices serving to evacuate surplus helium, which formerly hung down the sides, are now held tightly against the envelope, while a larger area of the lower part of the cone is now fireproofed. |
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Technological foundations The technology |
Contents |
Propane burners The technology |
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