超临界CO2燃煤火力发电系统构建及分析

Coal-fired power generation is an important guarantee for China's power supply. It plays a key role in achieving the goal of energy saving priority and solving the environmental problems caused by the coal combustion. It is urgent to develop efficient and clean coal-fired power systems with low emission of pollutants and CO2 and high efficiency through theoretical innovation. Supercritical CO2 cycle is a promising alternative to steam based Rankine cycle for coal-fired power plant. S-CO2 cycle has a series of advantages such as high efficiency and low cost at low pressure, which may be a breakthrough of the design theory for conventional coal-fired power systems. This project mainly focuses on the design and thermodynamic optimization of a highly efficient supercritical CO2 coal-fired power plant. To realize optimal temperature and pressure matching for key components of S-CO2 coal-fired power system, energy conversion and transfer mechanism of key components, flow and heat transfer characteristics in the heat regenerator and CO2-cooler, and the effects of heat transfer path on the irreversible loss of regenerator are studied. A comprehensive simulation platform of the S-CO2 coal-fired power plant is developed and the distribution of material flow, energy flow and exergy flow between components is obtained to put forward the optimal matching criterion of available energy loss between components. Comparative analysis of supercritical CO2 Brayton cycle, Rankine cycle and combined cycle is conducted to put forward an innovative supercritical CO2 thermodynamic cycle. A low-carbon and efficient S-CO2 coal fired power system based on CCS is set up to realize near zero emission. The feasibility, economy and safety of S-CO2 power system based on CCS are also analyzed. The research will provide theoretical and project guide for developing efficient and clean S-CO2 coal-fired power systems.

燃煤发电是我国电力供应的重要保障，对实现节能优先的目标具有决定性作用，也是解决环境问题的关键。寻求基于原理性的根本创新从而降低污染物，提高发电效率，实现燃煤发电系统高效清洁利用，面临重大的理论和技术创新需求。本项目拟将煤炭清洁高效利用与超临界CO2（S-CO2）动力循环相结合，发挥S-CO2具有在较低压力下的高效率和低成本等一系列优势，突破传统燃煤火力发电系统设计理论，开展S-CO2燃煤火力发电系统构建及优化分析。研究关键部件能量转换及传递机理，实现关键部件的最优温压匹配；开发高效S-CO2火力发电系统模拟平台，获得物质流、能量流、火用流在部件间的分布，寻求可用能损失在部件间的优化匹配准则；对比分析不同S-CO2动力循环，提出创新热力学循环；构建低碳高效基于CCS的S-CO2燃煤火力发电系统，实现S-CO2发电系统的近零排放。为发展高效低污染S-CO2燃煤火力发电系统提供理论、工程指导。

燃煤发电是我国电力供应的重要保障，对实现节能优先的目标具有决定性作用，也是解决环境问题的关键。寻求基于原理性的根本创新从而降低污染物，提高发电效率，实现燃煤发电系统高效清洁利用，面临重大的理论和技术创新需求。本项目将煤炭清洁高效利用与超临界CO2（S-CO2）动力循环相结合，发挥S-CO2具有在较低压力下的高效率和低成本等一系列优势，突破传统燃煤火力发电系统设计理论，开展S-CO2燃煤火力发电系统构建及优化分析。.按照预定研究计划执行，进展顺利，未进行大的调整，已初步完成全部研究内容。提出了S-CO2燃煤火力发电系统与蒸汽朗肯循环、S-CO2与布雷顿循环新型复合循环系统，利用底循环吸收烟气余热，实现了锅炉烟气热量梯级利用及烟气热量全温区吸收；建立了对流、热传导、辐射多场耦合的S-CO2燃煤火力发电系统冷却壁物理模型，获得了S-CO2燃煤火力发电系统冷却壁温度分布及关键运行参数对换热部件影响规律，并对系统关键部件进行火用分析，为系统进一步优化设计指明方向；并与以水蒸气为传热工质的冷却壁性能进行了对比分析，由于物性参数差异，以二氧化碳为传热工质的冷却壁的工质温升、冷却壁管壁最高温度远远高于以水蒸气为传热工质的冷却壁的工质温升、冷却壁管壁最高温度，为S-CO2燃煤火力发电系统热力学循环安全性运行奠定了基础； 实验室搭建了全周和半周加热的超临界CO2流动传热实验平台，该实验台运行参数范围广，仪器仪表测量精确。最高运行压力达25MPa，温度500oC。初步获得了全周加热条件下二氧化碳在垂直上升管中的实验数据。为发展高效低污染S-CO2燃煤火力发电系统提供理论、工程指导。.依托本项目资助，发表高水平SCI期刊论文4篇，培养研究生3名，顺利毕业2名；协助完成了由华北电力大学能动学院举办的第一届International Conference on Supercritical CO2 Power System国际会议；项目负责人也顺利从青年教师评为副教授职称。