Low Grade Heat

In the majority of manufacturing plants, low grade heat is generated and discarded because of the difficulty in using it. This heat can be in gas or vapour but is more often in water. The heat sources are defined as low grade because the difference between their temperature and ambient temperature can be as low as 10 degC but is more often in the range 30 to 50 degC. Typical sources of such heat include chilling circuits, compressors, cooling towers and CIP systems.

The capital investment required to recover the energy from these streams using traditional heat transfer technology makes it an uneconomic proposition but increases in energy costs over recent years suggest that it is timely to re-investigate the possibility of recovering this wasted energy. The aim of this research project is to investigate ways of recovering useable energy from factory waste heat and low heat sources (including compressor waste heat boiler stack heat etc.) via

  • the development of efficiency review techniques for systems
  • techniques to reduce pre-defined critical emission levels