Modelling Investigation of Optimum Operating Conditions for Circulating Water Waste Heat Recovery

Abstract

This study is dedicated to present a reliable numerical methodology based on Aspen Plus simulation to assess the performance of energy-saving for circulating cooling water waste heat and water resource recovery system. Heat-pump is used in the system to assist or replace cooling towers to recover the waste heat of low-grade industrial circulating cooling water and convert the waste heat into high grade heat, such as hot water at 90 °C or low-pressure saturated steam, to meet the specific cooling and heat requirements of industrial process. The design schemes are simulated using Aspen Plus V10.0 to explore the effects of critical operating parameters, such as working medium temperature and pressure (water, steam, refrigerant), energy efficiency, economic and reliability analysis. The operating conditions of each design scheme are adjusted and optimized to achieve the best energy efficiency and economy. Results proves that it is feasible to use absorption heat pump to recover the waste heat of circulating cooling water and water resource, which provides theoretical guide and reference for the utilization of low-grade waste heat using heat pump.