First heat exchangers for the ITER Liquid Nitrogen plant and auxiliary systems ready

One way of describing the ITER Cryoplant in simple terms is like a massive fridge that will produce and distribute cooling temperatures in the machine through different networks. Air Liquide, gas technology global leader, technologies and services for industry and health, has been entrusted with the manufacturing of the components that will perform this task. The most advanced cryogenic technologies will be deployed to generate the extremely low temperatures needed for the ITER magnets, thermal shields and cryopumps. The magnets will be cooled with super critical helium to reach a superconducting state at 4.5 K, close to absolute zero, in order to confine the hot plasma that will reach 150 million ˚ C.

Europe will provide the Liquid Nitrogen (LN2) Plant and the auxiliary systems that will cool down, process, store, transfer and recover the cryogenic fluids of the machine. Two nitrogen refrigerators will be manufactured along with two 80 K helium loop boxes, warm and cold helium storage tanks, dryers, heaters and the helium purification system.

F4E, ITER International Organization and Air Liquide are celebrating an important milestone with the successful factory acceptance testing of the first two heat exchangers for the 80 K loop boxes, which represent the first manufactured equipment for a contract signed in December 2013. These exchangers are aluminium plate fin type, brazed under vacuum in order to achieve high leak tightness internally and externally. They have been manufactured in Amagasaki, Japan by Sumitomo Precision Products and they are on their way to Europe.

Six additional heat exchangers are being produced by the same company. Four of them, which are roughly 5 m long and with a cross section of 1.5 m by 1 m, will ensure the main cycle exchanges for the LN2 Plants as well as the 80 K Helium loops. The two remaining ones, 3.1 m long with a cross section of 1.3 m by 1.1 m, will provide  subcooling for the LN2 Plants. All six are expected to be delivered by the end of the year to be integrated into their respective cold boxes.Following the go-ahead that was received at the Preliminary Design Review of the Cryoplant in September 2014, the purchase orders for the heat exchangers were issued and manufacturing started a few months later.

The heat exchangers reflect the high performance requirements and strict quality and safety standards for the sophisticated operational system of the ITER machine. They are considered as “key components” due to the fact that are essential for the refrigeration of the cryogenic system. They have been designed and manufactured with the highest classification concerning quality requirements. The components have to comply with stringent leak tightness requirements, given the fact that once inserted into the perlite cold boxes they will no longer be accessible.