Sulphur hexafluoride (SF6), the holy grail of the power industry, circulates in electricity substations sealed in circuit breakers. It is non-toxic, non-flammable and has perfect insulating properties, thus being capable of interrupting electric current, for example when a switch is flipped. Physicists have spoken of it only in superlatives since it came into use in the first half of the 20th century. Unfortunately, it also comes with negatives. It is unrivalled among greenhouse gases in terms of its harmfulness and it significantly damages the environment. Therefore, scientists, including electrical engineers from the BUT, decided to find a more environmentally friendly replacement.
Petr Kloc welcomes me to his office at the Faculty of Electrical Engineering and Communication. A wave of heat immediately hits my face, even though there are people in coats outside the window and the radiators are off. It raises a question in my mind: is somebody mining Bitcoin here? “They are running the calculations for our project,” laughs the physicist, who is involved in a European project led by the international corporation General Electric.
How can a computer running non-stop help the environment? “Before anything is tested in real life, for example in our case the insulating gas in the circuit breaker, it is tested using numerical models. The better the input data, the more precise the models" describes the role of BUT in the project Petr Kloc, who, in addition to the Department of Power Electrical and Electronic Engineering, works at the CVOOZE workplace at the FEEC BUT. The office machines are tasked with calculating how the Novec g3 gas, which was intended to replace the environmentally unfriendly SF6, behaves at certain temperatures and pressures, the researcher continues: “It seems like it could be a great candidate. It is non-toxic, non-flammable, has better insulation properties than SF6 and is approximately twelve times less environmentally damaging."
The columns show alternating values of pressure, temperature and various chemical elements. It is not possible for a human to calculate all the possibilities and it is not an easy task for computers either, as there are over five million combinations and each one takes five to ten minutes to calculate. An average computer would take about fifty years to finish the task.
“We have two computer rooms with sixty new machines and in the summer, when there were no classes, I took them all and ran calculations on them. However, it happened to me once that an entire classroom was shut down by an under voltage protective device over the weekend. Fourteen days of calculations on thirty computers were gone. I then had to write a programme that monitored the calculations and if needed forwarded the logs to another computer, thus effectively involving the unused devices at our faculty,” concludes Petr Kloc, adding that although General Electric has already presented the first prototype of the g3 gas-filled substation, the calculations will still run for some time at the FEC to create a complete picture of its properties.
(tk)