煤炭在相当长一段时间内仍将是我国的主要能源，提高其利用效率对减碳具有重要意义；固体氧化物燃料电池(SOFC)是最高效的能量转化装置，二者结合将实现煤炭资源的最大化利用，助力新老能源的平稳过渡。但传统煤炭气化工厂产出的煤气中灰分、硫等杂质含量高，不能直接作为SOFC燃料，针对煤炭气化和净化过程以及燃料电池发电和热回收系统进行设计与模拟。使用Aspen Plus软件建立煤炭裂解、煤炭气化、煤炭净化、煤气冷却热回收、SOFC发电、尾气燃烧、蒸汽轮机发电、热水供应模块，使用软件内置Fortran模块对煤炭气化和SOFC发电的电化学过程进行建模，最终得到一种适合固体氧化物燃料电池的煤炭气化模块，气化效率为70.1%，该煤气主要含58% CO、32% H2，可直接通入燃料电池进行发电。模拟结果显示，该系统在拟定工作条件下，SOFC净发电效率可达37.54%，热水效率为35.11%，系统总体能量利用率可达78.58%。经灵敏度分析发现，采用适当的燃料利用率和燃料流量可有效降低系统运行成本，空气过量比在可选择范围内尽量选大。可实现煤炭的绿色、清洁高效应用。对煤炭气化燃料电池发电技术热电联供系统(IGFC-CHP)的全部过程进行了模型搭建，对IGFC-CHP的实现具有借鉴意义。

Coal is still the main energy resources in our country before the realization of the "carbon peak and carbon neutrality targets". Therefore, it is vital to improve the efficiency of energy utilization. Solid oxide fuel cell (SOFC) is a kind of highly efficient energy conversion device. Coal based SOFC would make the maximum utilization of coal resources and contribute to the smooth transition of energy from fossil to the renewable ones. However, the coal produced by the traditional gasification plant contains ash, sulfur and other impurities, which can not be used as the fuel of SOFC directly. This work designs and simulates the gasification and purification process of coal which is suitable to supply to SOFC, as well as the fuel cell power generation and exhaust heat recovery system. The modules of coal cracking, coal gasification, coal purification, gas cooling and heat recovery, SOFC power generation, tail gas combustion, and hot water supplying are modeled by Aspen Plus software. The electrochemical processes of SOFC power generation and gasification processes are simulated by the Fortran module of software. As results, a suitable gas gasification module with 70.1% gasification efficiency is obtained which can be directly connected to SOFC for power generation . The gas mainly contains 58% CO and 32% H2. It is found that the overall energy utilization ratio of the simulation system can reach 78.58% with 37.54% net power generation efficiency of SOFC and 35.11% hot water efficiency under the proposed working conditions. Through sensitivity analysis, it is found that the use of appropriate fuel utilization rate and fuel flow can effectively reduce the operating cost of the system, and the air excess ratio is as big as possible within the selectable range. The whole process of combined heat and power supply system (IGFC-CHP) based on coal gas SOFC power generation technology is modeled and studied in this work, which is significant to the realization of IGFC-CHP technology.

0 引言

1 系统设计

   1.1 煤炭气化系统搭建

   1.2 燃料电池与尾气燃烧模型系统

2 数值建模

   2.1 电化学数值建模

   2.2 供热水数值建模

   2.3 燃气轮机发电数值建模

   2.4 性能评估标准

3 流程组件选择

   3.1 煤炭气化炉

   3.2 阳极

   3.3 阴极

   3.4 燃烧器

   3.5 热交换器

   3.6 除渣除灰

   3.7 脱硫器

   3.8 压力变送装置

   3.9 蒸汽轮机发电

4 模型假设

5 SOFC模型验证

6 结果与讨论

   6.1 输出结果讨论

   6.2 灵敏度分析

7 结论