Aliaxis Group is a global leader in the manufacturing and distribution of advanced plastic piping systems. Headquartered in Belgium, it has a presence in over 40 countries around the world.
The process of manufacturing plastics is very energy-intensive, and electricity costs can be a significant overhead as a result, especially for a business with small margins. CoolPlanet was tasked with increasing the efficiency of the extrusion process and the refrigeration system used in the cooling process of plastic pipe manufacturing.
Summary of Actions
- Remove 2 out of 3 existing chillers, keep one in place and install a new increased efficiency chiller.
- Remove 2 cooling towers and replace them with 1 more efficient.
- Remove 2 DC-driven extrusion motors & replace them with AC, inverter-driven motors & VSDs.
- Deploy CoolPlanetOS controls on the main energy users e.g. Efficient Boiler, Heating, LTHW Controls, Compressed Air & Production Line Ancillary Controls.
High monthly electricity bills were proving to be a major cost drain for Aliaxis. With rising utility prices, the company stakeholders at HQ were under pressure to take actions to address the escalating costs whilst still maintaining focus on its core business. To add to this challenge, there was also the issue that the site had no visibility of exactly where the energy was being consumed or whether there were any real opportunities to actually save money.
CoolPlanet was engaged to work with the site to solve the issue. The first step on this journey was to undertake a detailed investment-grade energy efficiency audit on-site. As part of this, temporary metering of the large identified energy users was carried out to measure energy consumption. Using this data and CoolPlanet’s extensive industry knowledge and experience, they were able to break down how the energy was consumed and propose a number of energy-efficient solutions for the client.
Install CoolPlanetOS EMS
Once the project commenced, the first step in the process was to install CoolPlanet’s energy management software (CoolPlanetOS), which provided accurate data and real-time visibility of consumption. This enabled the large energy users to be identified, consumption recorded accurately and solutions to be implemented to reduce the electrical and oil utilization on site.
The existing system for cooling the process machines consisted of three chillers and two cooling towers with two chillers operating continuously with no efficient controls in place. Two of the chillers plus two of the cooling towers were replaced with one new chiller and one new cooling tower. When the project was commissioned, the new cooling tower was providing all of the cooling load and a control logic set up and deployed so that the new chiller will only operate when the cooling tower cannot keep the chilled water temperature below +15°C. Variable speed drives together with controls instrumentation were also fitted to the cooling tower fans, chilled water pumps, and main process pump in order to optimise their consumption based on varying wet bulb temperature and process cooling demand. Through the CoolPlanetOS energy management system, it is now possible to measure, monitor, and maintain the optimum Coefficient of Performance (COP) for the chilling system.
On two of the Extrusion machines, the motors were operating with a mechanical belt and pulley system on a direct current (DC) which is old technology and inefficient by current standards. New energy-efficient direct-drive motors, which attach directly to the load of the machine were installed delivering significant energy savings. These motors also had variable speed controls, which meant that the consumption ramped up and down with the load, leading to additional energy savings at certain times during the process.
Space Heating and Boiler
Through the CoolPlanetOS EMS platform, a number of issues around space heating in the factory were identified, leading to excess oil consumption on the boiler. A control panel was installed to integrate ambient temperature conditions into the boiler controls, and the space heaters were controlled based on the return water temperature to the boiler. These heaters were also cleaned as part of the project to maximise the heat output. The controls were also interlocked with the factory door, so that the boiler was not operating when the door was open, leading to high levels of awareness and a step-change in behaviour amongst staff. Finally, the low-temperature hot water pump controls were automated ensuring that they were not continuously running.
Air Compressors and Dryer
In order to reduce the energy consumption of the compressed air system, a full air leak survey was conducted. With this information, work was then carried out to repair each of these leaks to reduce the demand for air. This allowed airflow supply to be reduced at the machine, which in turn reduced the electrical consumption. To monitor this on a continuous basis an alert was activated on the CoolPlanetOS EMS to indicate when energy consumption increases over time. This indicates to the maintenance team that more air leak repairs need to be fixed.
Ongoing CoolPlanetOS Monitoring
As part of the project, an out-of-hours energy audit was conducted to identify energy users that were operating when not required. With this information, alerts were set up on CoolPlanetOS to notify the site maintenance and engineering of deviations and unnecessary energy consumption. It also highlighted issues with certain equipment which were then repaired to run more efficiently.
CoolPlanet’s holistic approach to energy consumption on the site meant that all energy consumers were identified and assessed for potential savings opportunities. Those identified projects were then further distilled down to the ones that could deliver a significant impact on the site's electrical and oil consumption whilst ensuring a short payback on the CapEx investment by the client.
The project successfully stopped the issue of the costly monthly drain on the client’s finances. The CoolPlanetOS controls deployed on-site not only managed the current energy consumption but also ensured robust controls were put in place to give the client full visibility of the plant’s energy usage and facilitated the optimising of their energy consumption into the future.
CoolPlanet reduced the electricity spend at the client’s Spanish site by 24%, achieving annual energy savings of €207,097.