In the world energy about 26% of all was derived from coal combustion. Nearly 80% of the electricity produced in China is generated from coal. Coal will play the most important role in the coming 50 years as the past ...In the world energy about 26% of all was derived from coal combustion. Nearly 80% of the electricity produced in China is generated from coal. Coal will play the most important role in the coming 50 years as the past century in China. However one consequentially of the mining and combustion of coal is the mobilization of trace elements, especially trace metals, which have environmental and human health significance. Information on concentrations and distributions of potentially toxic elements in coal, and information on the modes of occurrence of these elements and the relations of the minerals in coal can help to predict the behavior of the potentially toxic trace metals during cleaning, combustion, weathering, and leaching.展开更多
A quantitative environmental assessment method and the corresponding computer code are introduced in this paper. By the consideration of all fuel cycle steps,it gives that the public health risk of China nuclear power...A quantitative environmental assessment method and the corresponding computer code are introduced in this paper. By the consideration of all fuel cycle steps,it gives that the public health risk of China nuclear power industry is 5.2 × 10-1 man /(GW.a), the occupational health risk is 2.5 man /(GW.a), and the total health risk is 3.0 man /(GW.a). After the health risk calculation for coal mining, transport, burning up and ash disposal, it gives that the public health risk of China coal-fired power industry is 3.6mall/(GW-a), the occupational health risk is 50man /(GW.a), and the total is 54man /(GW.d). Accordingly, the conclusion that China nuclear power industry is an industry with high safety and cleanness is derived at the end.展开更多
Since the combustion system of coal-fired boiler in thermal power plant is characterized as time varying, strongly coupled, and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportio...Since the combustion system of coal-fired boiler in thermal power plant is characterized as time varying, strongly coupled, and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportional integral derivative (PID) control scheme. For the characteristics of the main steam pressure in coal-fired power plant boiler, the sliding mode control system with Smith predictive structure is proposed to look for performance and robustness improvement. First, internal model control (IMC) and Smith predictor (SP) is used to deal with the time delay, and sliding mode controller (SMCr) is designed to overcome the model mismatch. Simulation results show the effectiveness of the proposed controller compared with conventional ones.展开更多
Between the alternative sources available for the electricity production, still lacks reliability for the production in base units. For the electricity production from 500 MW to 1,000 MW or more, the coal-fired therma...Between the alternative sources available for the electricity production, still lacks reliability for the production in base units. For the electricity production from 500 MW to 1,000 MW or more, the coal-fired thermal and nuclear power plants with uranium have proved competitive and with a high level of reliability and maturation, besides presenting the fuel supply security. This paper presents an analysis of technical feasibility for the choice of the best technology for generating electricity on a large scale, based on coal-fired thermal or nuclear power plant using uranium. This paper takes in account the availability of fuel sources, investments costs, thermal power generation systems, pollutants emission and mitigation technologies, global efficiency, fuel consumption, costs of electricity, construction time and an average lifespan of the installation. Thus the analysis allows the most rational choice of technology for the production of electricity with lower electricity costs and lower COz emissions.展开更多
Based on thermodynamics and physical chemistry theory,the theoretical energy consumption (TEC) of the typical separating processes of Al,Ca and Mg has been calculated and analyzed.This paper attempts to prove that the...Based on thermodynamics and physical chemistry theory,the theoretical energy consumption (TEC) of the typical separating processes of Al,Ca and Mg has been calculated and analyzed.This paper attempts to prove that the thermal method is more reasonable than the electrolytic methods to separate Al,Ca and Mg under the domestic circumstances of the low efficiency of coal-firing power plant at present.展开更多
A finite element method is used to calculate the three-dimensional gas flow field in the inlet box of a large-size fluid machinery,The dynamic behaviors of solid particles through the inlet box are obtained numericall...A finite element method is used to calculate the three-dimensional gas flow field in the inlet box of a large-size fluid machinery,The dynamic behaviors of solid particles through the inlet box are obtained numerically by the 'one way coupling” method .The trajectories of different-sized particles and the distribution of particle positions on the outlet plane of inlet box are investigated.展开更多
基金SupportedbytheNationalNaturalScienceFoundationofChina (No 40 2 72 12 4,49872 0 5 4)
文摘In the world energy about 26% of all was derived from coal combustion. Nearly 80% of the electricity produced in China is generated from coal. Coal will play the most important role in the coming 50 years as the past century in China. However one consequentially of the mining and combustion of coal is the mobilization of trace elements, especially trace metals, which have environmental and human health significance. Information on concentrations and distributions of potentially toxic elements in coal, and information on the modes of occurrence of these elements and the relations of the minerals in coal can help to predict the behavior of the potentially toxic trace metals during cleaning, combustion, weathering, and leaching.
文摘A quantitative environmental assessment method and the corresponding computer code are introduced in this paper. By the consideration of all fuel cycle steps,it gives that the public health risk of China nuclear power industry is 5.2 × 10-1 man /(GW.a), the occupational health risk is 2.5 man /(GW.a), and the total health risk is 3.0 man /(GW.a). After the health risk calculation for coal mining, transport, burning up and ash disposal, it gives that the public health risk of China coal-fired power industry is 3.6mall/(GW-a), the occupational health risk is 50man /(GW.a), and the total is 54man /(GW.d). Accordingly, the conclusion that China nuclear power industry is an industry with high safety and cleanness is derived at the end.
基金Supported by the National Natural Science Foundation of China (61174059, 60934007, 61233004)the National Basic Research Program of China (2013CB035406)Shanghai Rising-Star Tracking Program (11QH1401300)
文摘Since the combustion system of coal-fired boiler in thermal power plant is characterized as time varying, strongly coupled, and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportional integral derivative (PID) control scheme. For the characteristics of the main steam pressure in coal-fired power plant boiler, the sliding mode control system with Smith predictive structure is proposed to look for performance and robustness improvement. First, internal model control (IMC) and Smith predictor (SP) is used to deal with the time delay, and sliding mode controller (SMCr) is designed to overcome the model mismatch. Simulation results show the effectiveness of the proposed controller compared with conventional ones.
文摘Between the alternative sources available for the electricity production, still lacks reliability for the production in base units. For the electricity production from 500 MW to 1,000 MW or more, the coal-fired thermal and nuclear power plants with uranium have proved competitive and with a high level of reliability and maturation, besides presenting the fuel supply security. This paper presents an analysis of technical feasibility for the choice of the best technology for generating electricity on a large scale, based on coal-fired thermal or nuclear power plant using uranium. This paper takes in account the availability of fuel sources, investments costs, thermal power generation systems, pollutants emission and mitigation technologies, global efficiency, fuel consumption, costs of electricity, construction time and an average lifespan of the installation. Thus the analysis allows the most rational choice of technology for the production of electricity with lower electricity costs and lower COz emissions.
文摘Based on thermodynamics and physical chemistry theory,the theoretical energy consumption (TEC) of the typical separating processes of Al,Ca and Mg has been calculated and analyzed.This paper attempts to prove that the thermal method is more reasonable than the electrolytic methods to separate Al,Ca and Mg under the domestic circumstances of the low efficiency of coal-firing power plant at present.
文摘A finite element method is used to calculate the three-dimensional gas flow field in the inlet box of a large-size fluid machinery,The dynamic behaviors of solid particles through the inlet box are obtained numerically by the 'one way coupling” method .The trajectories of different-sized particles and the distribution of particle positions on the outlet plane of inlet box are investigated.
