Case Study of Integration of Energy Systems for Low Grade Waste Heat Utilization Based on Pinch Method

摘要

Efficient integration of energy systems is important for low grade waste heat utilization to achieve high energyefficiency. This paper presents a thermodynamic method for integration of energy systems, including ORC,heat pump, refrigeration and thermal storage systems by using the pinch method. The integration analysis isconducted through temperature matching between the waste heat source and the energy systems according tothe practical energy demands. The heat input and output processes of the energy systems are processed to beappropriate for valid heat matching. A case study is introduced to demonstrate how to use this method andhow to obtain the optimal integration directly. Moreover, the optimal heat exchanger network can be modifiedby a posterior check, and thus a more practical integration can be obtained. This method is applied to a practicalproject where the pressurized water, originally used to preheat processing water, is optimized to be used forproducing cooling effect by an absorption chiller and achieving the preheating of the processing water. Theenergy efficiency of the optimized system is improved by 42.3% compared to the existing system.