From Concept to Implementation: Hands on the pipe test bench at District Lab in Kassel

Abstract

The transformation of district heating networks (DHN) towards lower operating temperatures and more dynamic operating conditions provides an occasion to examine the mechanical and thermal behaviour of buried pre-insulated bonded pipes under these new conditions in detail. This paper presents the development and implementation of a full-scale pipe test bench (PTB) at the District Lab research facility in Kassel, Germany, established within the UrbanTurn research project. The PTB consists of a buried pipe loop with high- and low-temperature circuits and two test fields with different bedding materials, enabling an experimental investigation of pipe–soil interaction. A comprehensive measurement concept was implemented, comprising 54 local sensors and a distributed fibre-optic temperature monitoring system along the test section. The paper documents the iterative design process, the alignment of investigation objectives with the technical infrastructure, and the practical implementation under real construction conditions. The results highlight key challenges in integrating measurement technology into civil engineering works and underline the importance of detailed as-built documentation for experimental infrastructure.