CORDIS - Forschungsergebnisse der EU

Vacuum insulation (VACI)

Final Report Summary - VACI (Vacuum Insulation)

Flat evacuated insulation elements are an established product. They also may be bent to a cylindrical form. However, without the possibility to fit such vacuum insulations to curved pipes and other doubly curvilinear plant components, little advantage accrues from the use of these extremely insulating elements. Therefore, the general objective of the project was the development and refinement of methods, processes and machinery to manufacture and maintain complex vacuum insulation panels in a way that would facilitate their use in industrial applications, preferably for cold service equipment. This implies the development of methods that allow manufacturing of segments of doubly curved shape and also methods of on-site repair or exchange of damaged segments. Furthermore, a major task of the research was the minimizing of heat losses at gaps and joints and especially the limitation of performance deterioration during service time.

To optimise the thermal performance of vacuum insulated pipe systems, Finite element (FE) calculations on thermal and mechanical properties were performed. The mechanical and gas barrier properties of high barrier films - also as function of temperature - were investigated intensively. As a consequence, the gas and water vapour barrier of metallised films could be improved by using a special technique. Several core materials for the vacuum panels were examined for their usability and the most advantageous materials selected.

Manufacturing facilities for producing cylindrical vacuum insulations were established. Furthermore, procedures for repairing damaged panels on construction site were established.

An experimental equipment was conceived and built on which the vacuum insulation could be installed and tested under near-reality conditions.

A wide range of methods were employed during the project, such as theoretical finite element calculations, measurements of temperature dependent mechanical properties of foils and seams, measurements of thermal conductivity and gas pressure increase and test of operational heat fluxes and temperatures. Furthermore, new manufacturing techniques for three-dimensional shaped vacuum insulations were established.

The results of the project had a considerable impact on other application fields like insulations of freezers, buildings and temperature controlled transport boxes. Especially, when it comes to the improved methods for quality monitoring of high barrier films and vacuum panels. Improved production methods for vacuum panels were also found. By lowering production costs these new methods could be used for a wide range of applications and open many new market areas.