生物质化学链气化（BCLG）是具有发展前景的生物质利用和碳捕集技术，有机朗肯循环（ORC）是可提高能源品位的能源转化技术。为实现生物质能源高值化利用，提出了一种生物质化学链气化联合燃气轮机（GT）并耦合有机朗肯循环（ORC）的新型发电系统。该系统通过子系统间物质/能源交换实现了不同品位能源的梯级利用。采用Aspen Plus软件进行模拟，研究以玉米秸秆、稻秆及麦秆为气化燃料时，氧与生物质比（λ）和压气机压比（PR）等对BCLG-GT系统发电效率的影响。模拟结果表明，麦秆是3种生物质中应用于BCLG-GT系统的最优气化燃料，最佳模拟工况为：λ=0.05，PR=13。在BCLG-GT子系统运行最佳工况基础上耦合ORC子系统，研究了4种不同有机流体工质（R245fa、R134a、HCFC-123和R-404A）和有无回热装置对ORC子系统发电效率的影响。结果表明：R245fa具有更高的实用价值与较好的环境友好性，相较其他3种有机流体工质具有明显优势；另外，加装回热装置后，ORC系统的净输出功率提高了13.37%，新型具有回热装置的BCLG-GT-ORC发电系统的净能量效率达35.48%。本研究为工业规模的生物质化学链气化装置的设计和优化提供思路和理论指导。

Biomass chemical looping gasification (BCLG) is a promising biomass utilization and carbon capture technology, while Organic Rankine Cycle (ORC) is an energy conversion technology that can achieve a higher energy grade. A new type of power system of BCLG coupled with the gas turbine (GT) and ORC was proposed to achieve the high-value utilization of biomass energy. This system achieved the graded utilization of different grades of energy through the material/energy exchange between subsystems. Aspen Plus software was used to simulate the effect of oxygen/biomass ratio (λ) and compressor pressure ratio (PR) on the power generation efficiency of the BCLG-GT system when corn straw, rice straw, and wheat straw were used as gasification fuels, respectively. The simulation results show that straw is the optimal gasification fuel for the BCLG-GT system among the three types of biomass, and the optimal simulation conditions are λ= 0.05 and PR=13. Based on the optimal operating conditions of the BCLG-GT subsystem, coupled with the ORC subsystem, the effects of the four organic fluids (R245fa, R134a, HCFC-123, and R-404A) and regenerative devices on the ORC system were further studied. The simulation results reveal that R245fa has higher practical value and better environmental friendliness, compared with R134a, HCFC-123, and R-404A. The net power output of the ORC system is increased by 13.37% after adding the regenerative device, and the net energy efficiency of the new BCLG-GT-ORC power system with the regenerative device reachs 35.48%. This study provids ideas and theoretical guidance for the design and optimization of BCLG units on an industrial scale.

0 引言

1 系统描述

   1.1 模拟工艺流程

   1.2 系统模拟与假设

   1.3 系统评价准则

2 结果和讨论

   2.1 模型验证

   2.2 灵敏度分析

   2.3 ORC工质种类及有无回热装置的影响

3 结论