The ultra-supercritical pressure coal-fired power-generation technology (USCT) isa mature, advanced and efficient power generation technology in the world. Comparisonsamong several principal clean coal power-generatio...The ultra-supercritical pressure coal-fired power-generation technology (USCT) isa mature, advanced and efficient power generation technology in the world. Comparisonsamong several principal clean coal power-generation technologies show that USCT withpollutant-emission control equipment is superior to others in efficiency, capacity, reliability,investment and environment protection etc. Analyzing the main problems existing in thermalpower industry, it is concluded that the USCT is the preferential choice for China to developclean coal power-generation technology at present. Considering the foundation of thepower industry, the manufacturing industry for power generating equipment and otherrelated industries, it is concluded that China has satisfied the qualifications to develop USCT.展开更多
The COVID-19 lockdowns led to abrupt reductions in human-related emissions worldwide and had an unintended impact on air quality improvement.However,quantifying this impact is difficult as meteorological conditions ma...The COVID-19 lockdowns led to abrupt reductions in human-related emissions worldwide and had an unintended impact on air quality improvement.However,quantifying this impact is difficult as meteorological conditions may mask the real effect of changes in emissions on the observed concentrations of pollutants.Based on the air quality and meteorological data at 35 sites in Beijing from 2015 to 2020,a machine learning technique was applied to decouple the impacts of meteorology and emissions on the concentrations of air pollutants.The results showed that the real(“deweathered”)concentrations of air pollutants(expect for O 3)dropped significantly due to lockdown measures.Compared with the scenario without lockdowns(predicted concentrations),the observed values of PM_(2.5),PM_(10),SO_(2),NO_(2),and CO during lockdowns decreased by 39.4%,50.1%,51.8%,43.1%,and 35.1%,respectively.In addition,a significant decline for NO_(2)and CO was found at the background sites(51%and 37.8%)rather than the traffic sites(37.1%and 35.5%),which is different from the common belief.While the primary emissions reduced during the lockdown period,episodic haze events still occurred due to unfavorable meteorological conditions.Thus,developing an optimized strategy to tackle air pollution in Beijing is essential in the future.展开更多
Air pollution in modern city and industrial zones has become a serious public concern in recent years in China. Significance of air quality assessment and emission control strategy design is increasing. Most studies i...Air pollution in modern city and industrial zones has become a serious public concern in recent years in China. Significance of air quality assessment and emission control strategy design is increasing. Most studies in China focus on particulate matter(PM), especially PM2.5, while few account for photochemical secondary air pollutions represented by ozone(O3). In this paper, a procedure for air quality simulation with comprehensive air quality model with extensions(CAMx) is demonstrated for studying the photochemical process and ozone generation in the troposphere. As a case study, the CAMx photochemical grid model is used to model ozone over southern part of Beijing city in winter, 2011. The input parameters to CAMx include emission sources, meteorology field data, terrain definition, photolysis status, initial and boundary conditions. The simulation results are verified by theoretical analysis of the ozone generation tendency. The simulated variation tendency of domain-wide average value of hourly ozone concentration coincides reasonably well with the theoretical analysis on the atmospheric photochemical process, demonstrating the effectiveness of the procedure. An integrated model system that cooperates with CAMx will be established in our future work.展开更多
文摘The ultra-supercritical pressure coal-fired power-generation technology (USCT) isa mature, advanced and efficient power generation technology in the world. Comparisonsamong several principal clean coal power-generation technologies show that USCT withpollutant-emission control equipment is superior to others in efficiency, capacity, reliability,investment and environment protection etc. Analyzing the main problems existing in thermalpower industry, it is concluded that the USCT is the preferential choice for China to developclean coal power-generation technology at present. Considering the foundation of thepower industry, the manufacturing industry for power generating equipment and otherrelated industries, it is concluded that China has satisfied the qualifications to develop USCT.
基金This work was supported by the National Natural Science Foundation of China(Grant number 42077204)the National Key Research and Development Project(Grant number 2017YFC0210103)with data support provided by the National Earth System Science Data Center,National Science&Technology Infrastructure of China(http://www.geodata.cn).
文摘The COVID-19 lockdowns led to abrupt reductions in human-related emissions worldwide and had an unintended impact on air quality improvement.However,quantifying this impact is difficult as meteorological conditions may mask the real effect of changes in emissions on the observed concentrations of pollutants.Based on the air quality and meteorological data at 35 sites in Beijing from 2015 to 2020,a machine learning technique was applied to decouple the impacts of meteorology and emissions on the concentrations of air pollutants.The results showed that the real(“deweathered”)concentrations of air pollutants(expect for O 3)dropped significantly due to lockdown measures.Compared with the scenario without lockdowns(predicted concentrations),the observed values of PM_(2.5),PM_(10),SO_(2),NO_(2),and CO during lockdowns decreased by 39.4%,50.1%,51.8%,43.1%,and 35.1%,respectively.In addition,a significant decline for NO_(2)and CO was found at the background sites(51%and 37.8%)rather than the traffic sites(37.1%and 35.5%),which is different from the common belief.While the primary emissions reduced during the lockdown period,episodic haze events still occurred due to unfavorable meteorological conditions.Thus,developing an optimized strategy to tackle air pollution in Beijing is essential in the future.
文摘Air pollution in modern city and industrial zones has become a serious public concern in recent years in China. Significance of air quality assessment and emission control strategy design is increasing. Most studies in China focus on particulate matter(PM), especially PM2.5, while few account for photochemical secondary air pollutions represented by ozone(O3). In this paper, a procedure for air quality simulation with comprehensive air quality model with extensions(CAMx) is demonstrated for studying the photochemical process and ozone generation in the troposphere. As a case study, the CAMx photochemical grid model is used to model ozone over southern part of Beijing city in winter, 2011. The input parameters to CAMx include emission sources, meteorology field data, terrain definition, photolysis status, initial and boundary conditions. The simulation results are verified by theoretical analysis of the ozone generation tendency. The simulated variation tendency of domain-wide average value of hourly ozone concentration coincides reasonably well with the theoretical analysis on the atmospheric photochemical process, demonstrating the effectiveness of the procedure. An integrated model system that cooperates with CAMx will be established in our future work.
