基于医疗垃圾等离子气化的零碳高效热电联产系统性能分析

Performance Assessment of a Zero-carbon Emission Waste-to-energy CHP Hybrid System Based on Plasma Gasification

为降低医疗垃圾回收与运输环节的成本与风险,实现清洁高效的就地资源化利用,提出一类基于医疗垃圾等离子气化的燃料电池-燃气轮机热电联产系统。根据碳排放需求,创新系统分为常规方案和零碳方案。零碳方案在常规方案的基础上增加了碳捕集子系统,相应地余热利用系统中增加了部分换热设备。以300kg/h等离子气化炉为研究对象,对创新系统的常规方案和零碳方案进行了力学和经济学分析。计算结果表明,常规方案的净发电效率和热电联产效率分别为52.06%和84.34%,零碳方案的净发电效率降低了3.22%,热电联产效率下降了3.22%。等离子气化炉和换热器组是创新系统2种方案最主要的?损来源,约占系统总?损的50%以上。根据经济性分析结果,全生命周期内创新系统常规方案和零碳方案的净现值分别为5737.59万元和4832.46万元,动态回收周期分别为4.62年和5.46年。

To enhance the overall performance of the waste-to-energy(WTE)process,an advanced WTE hybrid system consisting of with plasma gasifier,solid oxide fuel cells(SOFC),gas turbine(GT)and waste heat recovery subsystem was proposed for power and heat cogeneration(CHP).Two schemes of the new design,named conventional plan and zero-carbon emission plan,were proposed based on the requirement of carbon emission.A carbon capture and storage subsystem was equipped to the conventional scheme,and the waste heat utilization subsystem in the zero-carbon emission plan has been changed accordingly.A tech-economic evaluation was conducted to examine the benefits based on a 300kg/h plasma gasifier.The results show that the net electricity efficiency and CHP efficiency of the conventional scheme are 52.06%and 84.34%.In the zero-carbon emission plan,the net electricity efficiency and CHP efficiency are only reduced by 3.22%and 0.89%for carbon capture.The main source of irreversibility can be traced to two components,plasma gasifier and heat exchanger units,nearly accounting for half of the total exergy destruction.Only 4.62 years is required to recover the initial investment of the conventional scheme and a net present value of 57.38 million yuan can be attained by the WTE project during its lifespan.After carbon capture,the dynamic payback period is extended to 5.46 years with a NPV of 48.32 million yuan.