Synthesis of energy efficient chilled and cooling water network by integrating waste heat recovery refrigeration system

Abstract

Abstract Vapor compression refrigeration system (VCRS) is the conventional technology that uses electricity to generate chilled water for process cooling and air conditioning. On the other hand, there are various alternative green technologies that use waste heat to drive refrigeration system. In current industrial practices, abundant amounts of waste heat in the form of steam, hot water and flue gas remain untapped and are wasted. Absorption refrigeration system (ARS) is the alternative green technology that could recover those waste heats to produce cooling utility. In previous works, the integration of chilled and cooling water network within an Eco-Industrial Park (EIP) has been proven to be more cost effective than individual plant. However, the network is configured with VCRS which is an energy intensive technology. In this paper, ARS is integrated with VCRS to synthesize an energy efficient chilled and cooling water network using superstructure optimization approach. To further enhance energy efficiency, secondary waste heat recovery is proposed. Results shown the proposed ARS-VCRS integrated network has reduced the CO2 emission and the overall costs by 53% and 21% compared to VCRS alone. The minimum cooling duty and waste heat in the EIP for ARS-VCRS installation are determined through sensitivity analysis.