The unit was installed in the basement of Aarhus Maskinmesterskole in late 2019 and put into operation shortly afterwards with a view to making it much easier for students to connect the theoretical lessons taking place in the classroom with practical engineering.
“The facility is built for students to see and understand how things are connected. At the same time, they now get the possibility to work with a CO2 unit of highest quality. That’s also very helpful for the teaching,” said Lars Astrup, marine engineer and teacher at Aarhus Maskinmesterskole. He is one of the teachers who will introduce students to the control, operation and troubleshooting of the CO2 system.
For the application, Bitzer has delivered three Ecoline ME reciprocating compressors for subcritical applications as well as three Ecoline+ reciprocating compressors for transcritical applications that are equipped with line start permanent magnet motor, Varistep capacity regulation and IQ module.
The Bitzer IQ module is an advanced protection module that monitors the condition of the compressors. It gives teachers and students the possibility to quickly view and analyse historical as well as direct operational data.The IQ module optimises the system by gathering and monitoring temperature, pressure and oil system data. With the collected data, students can monitor the unit and its energy consumption and, subsequently, give suggestions for its optimisation.
The unit itself can be monitored via the Bitzer electronics service tool (BEST), which is free of charge and can be accessed via smartphone, tablet and computer.
Supply and demand
The CO2 system is financed by the Danish foundation Den Danske Maritime Fond (The Danish Maritime Fund) and all the companies involved have offered the individual components at a minimum price. This way, the unit has been built based on the market's leading technologies, giving the students the opportunity to work with a CO2 system of sublime quality.
The rack was built and installed by the company JF Køleteknik whose specialists designed the unit together with Per Skærbæk, consultant at Aarhus Maskinmesterskole and owner of the consultancy agency Cool Partners.
JF Køleteknik has previously worked on building and constructing refrigeration systems for teaching purposes. Since 2009, they have built 130 CO2 refrigeration units – all with Bitzer ?compressors. Morten Hansen, owner of JF Køleteknik, said: “We have a lot of experience in this area. When all partners meet and share experience as we did with the Aarhus Maskinmesterskole project, I always walk out the door wiser than when I came in.”
H Jessen Jürgensen sold the Bitzer ?components to JF Køleteknik and supported the project with an extra discount and technical support. Both JF Køleteknik and H Jessen Jürgensen find it difficult to recruit new employees with an interest in refrigeration technology, so they have an extra interest in supporting the project - they depend on eventually finding qualified staff with knowledge of CO2.
“We are always looking for engineers who have good knowledge about refrigeration and CO2 systems. When we support such a facility for educational use, we hope that more young engineers will catch interest for refrigeration. In this way, we can recruit more qualified workers in the long run,” said Kim Kirkegaard, regional manager at H Jessen Jürgensen.
The fishing industry has a need for more knowledge about larger CO2 industrial refrigeration systems for maritime use. “This interest is very important for Aarhus Maskinmesterskole. In the long term, we must deliver the competencies that the market demands, including applied research,” said Søren Skøtt Andreasen, head of research at Aarhus Maskinmesterskole.
Aarhus Maskinmesterskole wants to enable their students to handle the refrigeration of the future – and there is no way around CO2: all future students at Aarhus Maskinmesterskole will get in touch with the CO2 unit. New European legislation also points towards CO2 as a refrigerant, since the legislation requires a step-down regulation of HFC and HCFC refrigerants with high GWP values. Teacher Lars Astrup often meets students with a special interest in a sustainable future that focuses on natural refrigerants such as CO2, propane and ammonia. “With the new CO2 unit, I can also focus my teaching on how we work to create a sustainable cooling industry – here, the unit is an optimised and more climate-conscious solution,” he states.