Prediction on Performance of Cascading Cogeneration System with ORC and Adsorption Technology

摘要

Renewable energy,featured by environmental benign,is gathering the momentum in recent years.Adsorption refrigeration technology draws more and more attention because it is driven by the low grade heat and utilizes green refrigerant that has zero ODP and GWP.The successful development of small silica-gel adsorption refrigerators has enjoyed reasonable performance.However,it cannot satisfy the requirements for the places both electricity and refrigeration needed.Combined with silica gel adsorption refrigeration cycle,a cascading cycle was proposed and discussed in this paper,where an Organic Rankine Cycle(ORC)and an adsorption refrigeration cycle were utilized as the first and the second stage energy conversion cycle,respectively.Four different fluid such as R245fa,R134a,R407c,R22 was analyzed for the ORC by engineer equation solver(EES),and silica-gel-water working pair was calculated for adsorption cycle under the condition of cooling water inlet is 27-32oC,chilled water outlet of 12-16 oC,and heating temperature of 85-100 oC.Energy efficiency as well as exergy efficiency of the cascading cycle for electrical generation and refrigeration is analyzed.The results show that 1kW electricity and 4.74kW refrigeration can be obtained under the condition of about 25kW heating power.The electricity generation efficiency is 5.86％-6.78％,while the refrigeration coefficient of performance is approximately 0.42.The exergy efficiency was found to be 0.3-0.35 and 0.28-0.33 for single ORC and single adsorption cycle,respectively.The total exergy efficiency is 0.33-0.40 for the cogeneration of electricity and refrigeration.