Integrating solar power utilization systems with coal-fired power units, the solar aided coal-fired power generation (SACPG) shows a significant prospect for the large-scale utilization of solar energy and energy savi...Integrating solar power utilization systems with coal-fired power units, the solar aided coal-fired power generation (SACPG) shows a significant prospect for the large-scale utilization of solar energy and energy saving of thermal power units. The methods and mechanism of system integration were studied. The parabolic trough solar collectors were used to collect solar energy and the integration scheme of SACPG system was determined considering the matching of working fluid flows and energy flows. The thermodynamic characteristics of solar thermal power generation and their effects on the performance of thermal power units were studied, and based on this the integration and optimization model of system structure and parameters were built up. The integration rules and coupling mecha- nism of SACPG systems were summarized in accordance with simulation results. The economic analysis of this SACPG system showed that the solar LEC of a typical SACPG system, considering CO2 avoidance, is 0.098 $/kW·h, lower than that of SEGS, 0.14 $/kW·h.展开更多
The complementarity of energy resources used in hybrid power generation can result in optimization of power capacity and reservation capabilities. This article is dedicated to the study of hybrid hydro PV systems. The...The complementarity of energy resources used in hybrid power generation can result in optimization of power capacity and reservation capabilities. This article is dedicated to the study of hybrid hydro PV systems. The goal is to establish the relationship between system performance and complementarity of energy resources. The study was carried out with computer simulations based on a method that uses ideal functions developed to describe the energy resources and determines a limit of performance. The results confirm expectations that performance, as measured by the total time of failure to meet demand, will be better as energy resources are complementary. Charts relating energy complementarity with failures are presented. The subsequent research work shall proceed to at least two different phases. In the first one, the method exposed in the present work shall be applied to real data and compared to the operation of existing hybrid plants. In the second phase, results shall be confronted with design parameters of hydro PV plants based on complementary resources. A next stage would be the enlargement of the method applied in this work for systems based on other energy resources, such as wind energy and ocean wave energy.展开更多
The performance of a 270 MW (9 × 30 MW) AES Corporation barge mounted gas turbine power plant in Nigeria is evaluated using the heat rate and entropy generation by the components of the plant to characterize the ...The performance of a 270 MW (9 × 30 MW) AES Corporation barge mounted gas turbine power plant in Nigeria is evaluated using the heat rate and entropy generation by the components of the plant to characterize the irreversibility in each component when operating at different loads between 90% and 25%. The power plants have the peculiarity that three of the plants were supplied by three (3) different Original Equipment Manufacturers (OEM);A, B and C. This study is sequel to the fact that the gas turbines were the first independent power plants in the country and after more than fifteen years of operation, it is reasonable to evaluate the performance of the major components. By analyzing the thermodynamic performance of these components, the study demonstrates the utility value of exergy efficiency as an important parameter in the evaluation of major components in a gas power plant. Exergy efficiency is shown to be an important parameter in ranking the power plant components, identifying and quantifying the possible areas of reduction in thermodynamic losses and improvement in efficiencies. A new relationship is derived to demonstrate the correlation between the exergy efficiency and the heat rate of a 30 MW gas power plant. The prediction of the derived relationship correlates well with the observed operational performance of the 30 MW power plants. The combustion chamber in each of the plants provides the maximum exergy destruction during operation. Its exergy efficiency is shown to exhibit good correlation with its energy efficiency and the plant rational exergy. The implication is that from an operational and component selection viewpoint in the specifications of a gas power plant, knowledge of the Heat Rate which is usually provided by the OEM is adequate to make a reasonable inference on the performance of some critical components of the plant.展开更多
Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart...Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart power grids. Linked with the flow structure and dynamic characteristic of electricity generation subsystem and its components, a simulation model is proposed. Thermo-dynamical performance on off-design conditions have been analyzed with constant air mass flux and constant gas combustion temperature. Some simulation diagrams of curve are plotted too. The contrast of varied operation mode thermal performance is made between CAES power plant and simple gas turbine power plant.展开更多
This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analys...This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analysis,especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large,aging fleet of NPPs. This paper addresses the overlap and relationship of structure aging to severe loading performance,with particular emphasis on containment structures.展开更多
对十一种植物花瓣、籽、果实或果皮中的原花青素主要单体和低聚体进行检测,分析比较不同植物中原花青素组成和含量的差异.十一种植物样品分别经85%乙醇超声提取、Oasis PRiME HLB固相萃取净化后,采用高效液相色谱法(HPLC)分离分析其中...对十一种植物花瓣、籽、果实或果皮中的原花青素主要单体和低聚体进行检测,分析比较不同植物中原花青素组成和含量的差异.十一种植物样品分别经85%乙醇超声提取、Oasis PRiME HLB固相萃取净化后,采用高效液相色谱法(HPLC)分离分析其中的儿茶素、表儿茶素、没食子酸、原花青素B_(2)、原花青素B_(4)、原花青素A_(2).结果表明,在所选色谱条件下,十一种植物中都能检出原花青素单体或低聚体,且含量以原花青素低聚体为主.其中葡萄籽中原花青素含量最高、种类最多,六种原花青素单体和低聚体均有检出;其次是玫瑰花瓣、花生红衣,分别检出儿茶素和没食子酸两种原花青素单体和原花青素B_(2)、原花青素B_(4)、原花青素A_(2)三种低聚体;蓝莓、核桃仁、黑枸杞和紫甘蓝除检出一种原花青素单体外,蓝莓和核桃仁中三种原花青素低聚体均有检出,而黑枸杞和紫甘蓝只检出了原花青素B_(2)和原花青素B_(4)两种低聚体;红皮土豆皮和紫薯皮中仅检测到了原花青素低聚体;火龙果皮和红辣椒中原花青素单体和低聚体种类少,含量低.此外,葡萄籽和皮、花生红衣和花生仁为同一植物的不同部位,其原花青素种类和含量差别很大.不同植物中原花青素的种类和含量不同;同种植物不同部位的原花青素种类和含量也不同.原花青素在不同植物中分布情况、组成差别和含量上的差异,为植物原花青素的构效关系研究及其开发利用奠定了基础.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50776028 and 50606010) the Program for New Century Excellent Talents in University (Grant No. NCET-05-0217)
文摘Integrating solar power utilization systems with coal-fired power units, the solar aided coal-fired power generation (SACPG) shows a significant prospect for the large-scale utilization of solar energy and energy saving of thermal power units. The methods and mechanism of system integration were studied. The parabolic trough solar collectors were used to collect solar energy and the integration scheme of SACPG system was determined considering the matching of working fluid flows and energy flows. The thermodynamic characteristics of solar thermal power generation and their effects on the performance of thermal power units were studied, and based on this the integration and optimization model of system structure and parameters were built up. The integration rules and coupling mecha- nism of SACPG systems were summarized in accordance with simulation results. The economic analysis of this SACPG system showed that the solar LEC of a typical SACPG system, considering CO2 avoidance, is 0.098 $/kW·h, lower than that of SEGS, 0.14 $/kW·h.
文摘The complementarity of energy resources used in hybrid power generation can result in optimization of power capacity and reservation capabilities. This article is dedicated to the study of hybrid hydro PV systems. The goal is to establish the relationship between system performance and complementarity of energy resources. The study was carried out with computer simulations based on a method that uses ideal functions developed to describe the energy resources and determines a limit of performance. The results confirm expectations that performance, as measured by the total time of failure to meet demand, will be better as energy resources are complementary. Charts relating energy complementarity with failures are presented. The subsequent research work shall proceed to at least two different phases. In the first one, the method exposed in the present work shall be applied to real data and compared to the operation of existing hybrid plants. In the second phase, results shall be confronted with design parameters of hydro PV plants based on complementary resources. A next stage would be the enlargement of the method applied in this work for systems based on other energy resources, such as wind energy and ocean wave energy.
文摘The performance of a 270 MW (9 × 30 MW) AES Corporation barge mounted gas turbine power plant in Nigeria is evaluated using the heat rate and entropy generation by the components of the plant to characterize the irreversibility in each component when operating at different loads between 90% and 25%. The power plants have the peculiarity that three of the plants were supplied by three (3) different Original Equipment Manufacturers (OEM);A, B and C. This study is sequel to the fact that the gas turbines were the first independent power plants in the country and after more than fifteen years of operation, it is reasonable to evaluate the performance of the major components. By analyzing the thermodynamic performance of these components, the study demonstrates the utility value of exergy efficiency as an important parameter in the evaluation of major components in a gas power plant. Exergy efficiency is shown to be an important parameter in ranking the power plant components, identifying and quantifying the possible areas of reduction in thermodynamic losses and improvement in efficiencies. A new relationship is derived to demonstrate the correlation between the exergy efficiency and the heat rate of a 30 MW gas power plant. The prediction of the derived relationship correlates well with the observed operational performance of the 30 MW power plants. The combustion chamber in each of the plants provides the maximum exergy destruction during operation. Its exergy efficiency is shown to exhibit good correlation with its energy efficiency and the plant rational exergy. The implication is that from an operational and component selection viewpoint in the specifications of a gas power plant, knowledge of the Heat Rate which is usually provided by the OEM is adequate to make a reasonable inference on the performance of some critical components of the plant.
文摘Besides pumped hydropower, Compressed Air Energy Storage (CAES) is the other solution for large energy storage capacity. It can balance fluctuations in supply and demand of electricity. CAES is essential part of smart power grids. Linked with the flow structure and dynamic characteristic of electricity generation subsystem and its components, a simulation model is proposed. Thermo-dynamical performance on off-design conditions have been analyzed with constant air mass flux and constant gas combustion temperature. Some simulation diagrams of curve are plotted too. The contrast of varied operation mode thermal performance is made between CAES power plant and simple gas turbine power plant.
文摘This paper focuses on how aging can affect performance of safety-related structures in nuclear power plant (NPP). Knowledge and assessment of impacts of aging on structures are essential to plant life extension analysis,especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large,aging fleet of NPPs. This paper addresses the overlap and relationship of structure aging to severe loading performance,with particular emphasis on containment structures.
文摘对十一种植物花瓣、籽、果实或果皮中的原花青素主要单体和低聚体进行检测,分析比较不同植物中原花青素组成和含量的差异.十一种植物样品分别经85%乙醇超声提取、Oasis PRiME HLB固相萃取净化后,采用高效液相色谱法(HPLC)分离分析其中的儿茶素、表儿茶素、没食子酸、原花青素B_(2)、原花青素B_(4)、原花青素A_(2).结果表明,在所选色谱条件下,十一种植物中都能检出原花青素单体或低聚体,且含量以原花青素低聚体为主.其中葡萄籽中原花青素含量最高、种类最多,六种原花青素单体和低聚体均有检出;其次是玫瑰花瓣、花生红衣,分别检出儿茶素和没食子酸两种原花青素单体和原花青素B_(2)、原花青素B_(4)、原花青素A_(2)三种低聚体;蓝莓、核桃仁、黑枸杞和紫甘蓝除检出一种原花青素单体外,蓝莓和核桃仁中三种原花青素低聚体均有检出,而黑枸杞和紫甘蓝只检出了原花青素B_(2)和原花青素B_(4)两种低聚体;红皮土豆皮和紫薯皮中仅检测到了原花青素低聚体;火龙果皮和红辣椒中原花青素单体和低聚体种类少,含量低.此外,葡萄籽和皮、花生红衣和花生仁为同一植物的不同部位,其原花青素种类和含量差别很大.不同植物中原花青素的种类和含量不同;同种植物不同部位的原花青素种类和含量也不同.原花青素在不同植物中分布情况、组成差别和含量上的差异,为植物原花青素的构效关系研究及其开发利用奠定了基础.
