A system where the containers themselves can predict whether they will need to be repaired – even before they break down – has been developed by Rasmus Lundgaard Christensen, Department of Electronic Systems, Aalborg University, in conjunction with the company Lodam in Sønderborg that provides control units for refrigeration containers.
Goodbye to food waste and unusable medicine
When perishable goods have to be transported around the world, it is crucial that this is done in refrigeration containers that can maintain the same low temperature throughout the entire trip. A broken refrigeration system often results in several tons of rotten fruit, spoiled meat or – even worse – an entire batch of life-saving medicines that are no longer usable.
So all modern refrigeration containers are equipped with a SIM card and a system that can sound the alarm if an error occurs.
The problem is that it is often impossible to repair a refrigeration container that is already on its way on a ship, so a defective container almost always means damaged cargo. The new system can remedy this.
Container with a crystal ball
– All newer containers already have a lot of monitoring equipment keeping an eye on the different components of the cooling system. We’re using this data in a new way to predict when there is a high risk of a breakdown, says Rasmus Lundgaard Christensen.
As part of his Industrial PhD, he analyzed data from the refrigeration system in containers that have broken down and found a number of factors that can indicate whether the refrigeration system is getting worn down or is in need of new parts.
– For example, there may be a compressor that is starting to compress liquid instead of gas. The system can register something like that immediately. We know that if a compressor is doing that, it's only a matter of time before it breaks down. When we have that knowledge, we can repair the container the next time it’s in port, before it breaks down, and thus avoid valuable cargo being destroyed, he explains.
Expensive testing can be avoided
Today, all refrigeration containers are put through a Pre-Trip Inspection (PTI) between each journey or if they have been through a repair.
This is a thorough inspection that checks that the system is working, but the process is both time consuming and costly. The shipping industry uses over DKK three billion annually on PTI testing.
If the containers were equipped with an intelligent system that could predict errors this test would in most cases be superfluous.
– If the container itself can predict which components need to be replaced and indicate this in advance, there’s no need to spend time and money testing the entire system over and over again. It’s a bottleneck you can skip, says Rasmus Lundgaard Christensen.
Rasmus Lundgaard Christensen's main challenges in designing the new system have not been the data collection or mathematical algorithms to predict a breakdown, but rather the skepticism of his colleagues in the container industry.
– It’s no secret that there is a certain kind of conservatism when it comes to containers. The design of the refrigeration system in containers has virtually not changed in the past 50 years, and now we come along with a system that almost gives the containers artificial intelligence – or at least an advanced form of machine learning. There are a lot of people in the industry who just need a little time to get used to that, he says.
95 percent certainty
Rasmus Lundgaard Christensen emphasizes that the system – although smart – will not be able to predict and prevent all breakdowns.
– We work with mechanical parts, pumps, gases and fluids that are flowing. It’s not predictable in the same way that a digital system is, but we’ll probably be able to predict 95 percent of all breakdowns, he estimates.
Despite a five percent margin of error and widespread skepticism in the industry over technologies, Rasmus Lundgaard Christensen expects that system will find its way into modern refrigeration containers.
– This will mean really big savings for shipping companies: Cargo will not be destroyed, they will not have to use energy sailing around with worthless cargo, and their containers will always be in order and ready to go.
Each year the world’s 1.5 million refrigeration containers transport products with a total value of more than DKK 21 trillion.
Exactly how often refrigeration containers break down and how many items each year go to waste, shipping companies do not publicize, but a cargo of bananas for example is valued at approximately DKK 250,000.
Rasmus Lundgaard Christensen, Industrial PhD, Department of Electronic Systems, AAU, firstname.lastname@example.org, 24 22 67 08
Nelly Sander, press contact AAU, email@example.com, tlf. 99 40 20 18