Compressor replacement at PSI in Villigen

New technology offers great potential for energy saving

Paul Scherrer Institute PSI was able to reduce its energy needs by 133.000 kWh/year, which corresponds with energy savings by 22%, thanks to the modification of their compressor system.

In 2011, PSI commissioned a study with the aim to reduce operating expenses of the already existing helium refrigeration plant . PSI collaborated with Linde Kryotechnik to elaborate a new concept for the modification of the compressor system. Placing of the cornerstone. The project was completed in 2018.

Customer feedback

«We are extremely satisfied. The most important issues like plant function and better energy efficiency have been considered. From the very beginning, Linde aimed to meet all our needs, e.g. by a scope split. It is normal that things sometimes go wrong when working on such a huge modification project. Therefore, it is essential to work with a strong partner. At this point, I would like to underline that problems were solved efficiently, fast and with a great deal of commitment on part of Linde Kryotechnik. Our high expectations, especially regarding delivery time, were met accordingly.”, says project manager Christian  Geiselhart (head of department refrigeration plants at PSI). “The deadline for the shutdown at PSI required a delivery before Christmas Eve. And exactly like Linde Kryotechnik promised, the goods arrived at our site on December 22nd. We are aware that Linde Kryotechnik pulled out all the stops to meet the extremely tight schedule. This was just great!”

What are the main reasons for such a great success?

The financial resources for the entire modification project come to approximately 30% from the Swiss initiative “Prokilowatt”. The aim of “Prokilowatt” is to achieve a better energy efficiency not only in the industry sector but also in private households. In order to spend subsidies efficiently, PSI and Linde Kryotechnik agreed on a scope split.

Linde Krotechnik’s scope included specifications, construction and delivery of the compressors, oil adsorbers and gas management panel whereas PSI was responsible for the overall project management, piping, flow measurement, system integration and structural adjustments. Linde Kryotechnik had the lead for the full integration of the compressor system into PSI’s already existing control system. Additional customer requirements such as usability, operational flexibility and maintainability were considered in the design of the compressor stations and their auxiliary units.

Current status and outlook

The refrigeration plants for the large-scale facilities of the Swiss Spallation Neutron Source SINQ and some associated experiments of HIPA (High Intensity Proton Accelerator) were handed over in 2018.

  • they have been in operation without failure ever since
  • nowadays, all compressors are identical
  • thanks to the identical maintenance concept, maintenance in general has been simplified and plant availability increased

The compressors are equipped with components enabling heat recovery. In a next step for PSI will integrate the compressors into the hot water system to become an even more energy-efficient plant.

Based on the positive experiences gained from this project, PSI is planning the modification of further plants in the future.