Engineers use the summer break to launch new heat recovery system
This summer, when millions of Europeans were departing for their first holidays since the start of the pandemic, also Prof. Hussam Jouhara packed his bags and left his labs at Brunel University London. But his destination was not a beach at the Mediterranean Sea, but SIJ Metal Ravne, one of Europe’s largest tool and special steel producers in the Slovenian mountains.
»For SIJ Metal Ravne, the first two weeks of August is a maintenance break, when many of our furnaces are shut down«, explains Kristijan Plesnik, Head of Investments at the company. So, when this maintenance window was nearly over, Professor Jouhara arrived to supervise the launch of the ETEKINA heat pipe heat exchangers (HPHE) he had designed for one of the furnaces. The unit is a fully functional and full scale prototype intended for energy-intensive industries, such as a steel producer, but the technology can also be adapted for other industries with high energy and heat requirements.
Fouad Al-Mansour from the Jožef Stefan Institute in Ljubljana, the capital of Slovenia, has supported the process of the installation of the HPHE and explains the concept: »The system for utilization of excess heat in Metal Ravne consists of two connected sections. The first section is raises the temperature of the combustion air in the furnace itself while the second section heats water that is intended for space heating and sanitary water of the office buildings nearby.«
The calculations made by Fouad Al-Mansour and Hussam Jouhara predicted a heat recovery rate of 47%, but would this also be achieved when the system is running? The first measuements right after the unit was commissioned are very promissing indeed. »We recovered, through the unit, nearly 60% of the total waste heat in the exhaust stream«, says Prof. Jouhara, and this is not the only good news: »The installed system does not interfere with the process, which is paramount in any waste heat recovery installation, so we should all be proud of this joint achievement.«
Fouad Al-Mansour and the engineers from SIJ Metal Ravne will now collect more data in the upcoming months to see how the seasonal effects may affect the recovery rate. But already today, this installation can be seen as a successful innovation project and a first step to make similar industrial processes more energy efficient. »The installation of this first ETEKINA system opens up possibilities for the adapting the technology in other processes, either for Metal Ravne or in other companies,» says Fouad Al-Mansour and is supported by Alojz Buhvald, Executive Director for Steel Processing at the steel company: »Indeed. Together with our partners from the Brunel University London and the Jožef Štefan Institute, we will soon examine other currently untapped potentials of resources in our production.« With a total of 70 furnaces currently in operation at the company, the heat recovery concept of ETEKINA has the potential of huge energy savings and at the same time a significant reduction in greenhouse gas emissions for SIJ Metal Ravne or anyone adapting this technology at a larger scale.
Bakartxo Egilegor Ezenarro
Energy, Storage and Management
P° J.M. Arizmendiarrieta
20500 Arrasate-Mondrágon (Gipuzkoa), Spain
Project Technical Co-ordinator:
Professor Hussam Jouhara
Heat Pipe and Thermal Management Research Group
Brunel University London, UB8 3PH, UK