The University’s Department of Industrial and Manufacturing Engineering is playing a role in improving the sustainability of industrial and manufacturing sector by identifying applications where energy is wasted.
One such application is the use of compressed air systems which are critical for manufacturing companies. With an increase in awareness related to sustainability and carbon footprints, local industries and companies are becoming increasingly aware of the financial and environmental penalties linked with inefficient compressed air systems.
Details of an ongoing research study that started in 2017 by Paul Refalo and Emmanuel Francalanza in collaboration with AIM Enterprises Ltd were published in two papers in the scientific journal Procedia CIRP earlier this year. These were entitled ‘Design and implementation of an energy monitoring cyber physical system in pneumatic automation’, and ‘Utilisation of a compressed air test bed to assess the effects of pneumatic parameters on energy consumption’.
It has also led to the postgraduate research study of Kyle Abela that involved identifying and testing advanced monitoring techniques in industrial pneumatic applications. With the financial backing of the Tertiary Education Scholarship Scheme (TESS) of 2018, Abela worked on an initial version of a customised compressed air system in the form of a test bed, and upgraded it to include the latest sensors, communication protocols and control equipment in pneumatics and compressed air.
The equipment was set up such that a data monitoring system could detect and quantify losses from equipment on the demand side of a compressed air system. Due to the scale and complexity typically associated with compressed air systems, monitoring equipment is usually installed close to the compressor at the supply side. However, literature studies show that 50 to 70 per cent of all improvement opportunities in these systems are attributable to demand side waste, which ultimately amalgamate in the form of increased maintenance costs and electrical bills.
Using high-end sensors, the study showed the operational changes in compressed air systems are governed by variances in the fluid dynamic behaviour of the compressed air. The results were generated in the form of diagnostics according to each test condition which allowed the research team to identify and locate leaks at the demand side.
Leaks are the most common form of waste in compressed air systems and very often aggravate and develop into other issues such as artificial demand or breakdowns. The highly configurable testbed was set up such that flow rate and pressure drop data was logged across different leakages of known diameters.
The literature showed that due to the lack of data monitoring available in compressed air systems, losses such as leaks easily spiral out of control. Furthermore, through the study’s fluid dynamic diagnostics it was concluded that in large industrial compressed air systems, common compressed air parameters and key performance indicators, such as pressure, drops, and flow rate changes are increasingly unreliable. This is because sensors are selected in accordance with the consumption of each system where high consuming systems require sensors with a subpar sensor accuracy. For this reason, minute losses may easily go unnoticed and are only corrected when the cumulative and unsustainable effects of multiple leaks are observed in a system.
This study has paved the way to using compressed air data to identify and locate misused energy sources. Future research is set to elaborate further on the way in which compressed air information is gathered, interpreted and presented.