Simplified techniques for low grade heat energy management -industrial application

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Reducing industrial low grade heat generation and waste leads to improved energy efficiency, decreased environmental emissions and reduced fuel costs. However it is an area that is recognised as being underexploited. Many studies have been carried out developing methodologies and techniques for the reduction and reuse of the waste heat. However the techniques are typically specific to a process or industry platform. Additionally success levels can be heavily dependent on the prior knowledge and experience of the practitioner. This paper shows the development of a new methodology called GALGEM (General Approach to Low Grade Energy Management), which combines existing Process Integration techniques with second law of Thermodynamics analysis and heuristic rules to give a general guideline for energy management. The specific focus is on low grade waste heat. GALGEM is a simplified technique, based on the solid foundation of existing techniques and best practice. It guides practitioners through the decision making process to exclude the less effective solutions, thus reducing reliance on tacit knowledge and expertise for the predetermination of success. GALGEM is designed to be applicable across all sectors and industrial processes. The success of the technique is demonstrated in an industrial case study, a large international semiconductor manufacturing plant, highlighting direct, indirect and combined heat exchange opportunities for waste heat recovery