Selective exhaust gas recirculation in combined cycle gas turbine power plants with post-combustion CO2 capture
Selective exhaust gas recirculation in combined cycle gas turbine power plants with post-combustion CO2 capture
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DOI：
10.1016/j.ijggc.2018.01.017
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发表时间：
2018-04
影响因子：
3.9
通讯作者：
L. Herraiz;E. S. Fernández;E. Palfi;M. Lucquiaud
中科院分区：
文献类型：
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作者：
L. Herraiz;E. S. Fernández;E. Palfi;M. Lucquiaud
在燃烧后碳捕集（PCC）的过程强化的背景下，天然气联合循环（NGCC）电厂中的选择性废气再循环（SEGR），一个概念，其中CO2选择性地回收，以增加浓度和降低烟气流量，进行了分析。与下游PCC系统并联或串联运行的SEGR使CO2浓度增加到14 vol%以上，并将燃烧室中的氧气水平保持在约19 vol%，远高于非选择性废气再循环（EGR）报告的16 vol%限值。过程建模表明，当前等级的燃气涡轮机发动机可以在压缩机和涡轮机性能没有显著偏差的情况下运行。压气机进口温度和工质中CO2浓度是影响燃气涡轮机净功率输出和效率的两个关键参数。较高的涡轮机排气温度允许在余热锅炉中产生额外的蒸汽。对于SEGR并联和SEGR串联的研究配置，这导致净功率输出分别增加约42 MW（5.2%）和18 MW（2.3%），净热效率分别增加0.55%和0.83%。SEGR采用30 wt%的含水单乙醇胺洗涤技术，可实现操作和成本效益。与具有PCC的空气基燃烧CCGT相比，与70%再循环、97%选择性CO2转移效率和96%PCC效率并行的SEGR导致填充体积减少46%和比再沸器负荷减少5%，并且与35%EGR相比，填充体积减少10%和比再沸器负荷减少2%。SEGR在95%的选择性CO2转移效率和32%PCC效率下串联运行，与具有PCC的空气基CCGT相比，填充体积减少64%，比再沸器负荷减少7%，与35%EGR相比，填充体积减少40%，比再沸器负荷减少4%。在选择SEGR应用技术时，CO2选择性、压降和传热流速是对SEGR发电厂性能影响较大的操作参数。重要的是使从空气到烟道气中的氧气泄漏最小化，使热传递最小化，否则热传递会增加压缩机入口处的富CO2空气温度，并使压降最小化，例如，1 kPa压降导致燃气涡轮机降额2 MW（0.7%）。
In the context of the process intensification of Post-combustion Carbon Capture (PCC), Selective Exhaust Gas Recirculation (SEGR) in Natural Gas-fired Combined Cycle (NGCC) plants, a concept where CO2is selectively recycled to increase concentration and reduce flow rates of the flue gas, is analysed. SEGR operated either in parallel or in series with a downstream PCC system increases CO2concentration beyond 14 vol% and maintains oxygen levels in the combustor to approximately 19 vol%, well above the 16 vol% limit reported for non-selective Exhaust Gas Recirculation (EGR). Process modelling shows that the current class of gas turbine engines can operate without a significant deviation in the compressor and in the turbine performance. Compressor inlet temperature and CO2concentration in the working fluid are the two critical parameters affecting the gas turbine net power output and efficiency. A higher turbine exhaust temperature allows the generation of additional steam in the HRSG. This results in an increase in net power output of approximately 42 MW (5.2%) and 18 MW (2.3%), and in net thermal efficiency of 0.55%point and 0.83%point, for the investigated configurations with SEGR in parallel and SEGR in series, respectively. With 30 wt% aqueous monoethanolamine scrubbing technology, SEGR leads to operation and cost benefits. SEGR in parallel with 70% recirculation, 97% selective CO2transfer efficiency and 96% PCC efficiency results in a reduction of 46% in packing volume and 5% in specific reboiler duty, compared to air-based combustion CCGT with PCC, and of 10% in packing volume and 2% in specific reboiler duty, compared to 35% EGR. SEGR in series operating at 95% selective CO2transfer efficiency and 32% PCC efficiency results in a reduction of 64% in packing volume and 7% in specific reboiler duty, compared to air-based CCGT with PCC, and of 40% in packing volume and 4% in specific reboiler duty, compared to 35% EGR. On selecting a technology for SEGR applications, CO2selectivity, pressure drop and heat transfer flow rate are the operating parameters with a larger effect on the power plant performance with SEGR. It is important to minimise oxygen leakages from the air into the flue gas, minimise heat transfer that would otherwise increase CO2-enriched air temperature at compressor inlet, and minimise pressure drop, e.g. a 1 kPa pressure drop results in gas turbine derating of 2 MW (0.7%).