Energy efficiency improvement through technology optimisation and low grade heat recovery

The undertaken project is a case study, focusing primarily on the energy efficiency improvement of an industrial partner in the food processing industry through the recovery of low grade waste heat. An analysis of the energy efficiency (enthalpy and exergy) of the plant was carried out and consequently the installation of standard heat recovery devices have been recommended (plate heat exchangers, reboiler etc.) for the improvement of energy efficiency. Additionally, a novel heat recovery technology is discussed which allows for the recovery of low grade waste heat from boiler flue gases with a complementary reduction in NOx gas emissions through combustion air prehumidification. As part of this project, experiments have been carried out to investigate the impact of boiler combustion air prehumidification on the NOx gas emissions of a liquid fuel burning boiler. Previously, no such experiments had been carried out on liquid fuel burning boilers.