Analysis And Design Of The Ammonia Absorption Refrigeration System Driven By Waste Heat In Refineries

Energy and environment are two major issues facing the world today.Economic and social development relies heavily on energy,however,energy consumption may have a tremendous negative impact on the environment.Therefore,energy conservation and emission reduction are the inevitable requirements for major enterprises,especially chemical enterprises,to fulfill their social responsibilities and achieve high-quality development.Based on current situation of insufficient utilization of the refinery waste heat resources,and in view of high energy consumption resulted from ammonia compression refrigeration of the refrigeration system in Ketone Benzene Unit,this paper presents an upgrading design of ammonia absorption refrigeration driven by waste heat,which can not only make full use of the waste heat resources produced in the refinery,but also reduce the consumption of high quality power in refrigeration process,thus cutting cooling costs significantly and achieving certain management and social benefit in terms of improving the intrinsic safety of the unit operation,stabilizing processing load of Ketone Benzene Unit and reducing noise pollution,etc.Taking the refrigeration system of the Ketone Benzene De-waxing Unit as the object to be upgraded,on the basis of meeting the demand for actual refrigeration capacity,refrigeration temperature needed and the temperature of cooling medium while guaranteeing the processing capacity of the unit,an analytical model of the ammonia absorption refrigeration circulation system was established and corresponding calculations were made,and the coefficient of performance of cooling(COP)of the upgraded system can reach 0.621.Comparison analysis on the absorption pattern of the absorber,a key equipment unit of the ammonia absorption refrigeration system was made and the optimal design was selected.And the circulation process and performance of the system were verified through pilot-plant test.This article also makes technical and economic analysis for the upgraded design of the refrigeration system in respect of investment,operational profit,management and environmental benefits,etc.The upgraded system may reduce the cost of power consumption by 14 million yuan,and the payback period is only 1.46 year with quick recovery cost,it is expected to bring huge environmental and social benefits apart from economic benefit.The research of this paper conforms to the trend of energy conservation and emission reduction,and is in line with the actual demand of production and operation of the enterprise.In-depth study,analysis and design have been made for the technical innovation of the refrigeration system of the Ketone Benzene Unit,which has practical significance to some extent.