黄河源区是黄河流域主要的产流区和水源涵养区,研究和探索该区域陆面水文过程对理解陆面过程及水文循环特征,揭示陆面—水文耦合过程具有重要的科学意义。本研究基于2009~2018年中国区域高时空分辨率地面气象要素驱动数据(China Meteoro...黄河源区是黄河流域主要的产流区和水源涵养区,研究和探索该区域陆面水文过程对理解陆面过程及水文循环特征,揭示陆面—水文耦合过程具有重要的科学意义。本研究基于2009~2018年中国区域高时空分辨率地面气象要素驱动数据(China Meteorological Forcing Dataset,简称CMFD)、全球高分辨率降水数据集(Climate Prediction Center Morphing Technique,简称CMORPH)、热带降雨测量卫星(Tropical Rainfall Measuring Mission,简称TRMM)及全球陆地数据同化系统(Global Land Data Assimilation System,简称GLDAS)降水,评估了四类降水产品在黄河源区的降水精度,在此基础上,利用最优降水数据驱动独立运行的天气研究预报及水文耦合模型系统(Weather Research and Forecasting Model Hydrological modeling system,简称WRF-Hydro),探究该模式在黄河源区径流模拟的适用性。结果表明:四类降水产品均能够反映出降水的分布特征,但在量值及细节捕捉上存在显著差异。CMFD在不同时空尺度上都能很好地捕捉到降水的演变特征,其与日观测降水的相关系数达到0.99,均方根误差仅为0.25 mm。在表征降水能力方面,四类降水产品总体表现为CMFD>CMORPH>TRMM>GLDAS,CMFD的平均探测成功率(Critical Success Index,简称CSI)在0.93以上。经参数率定后的WRF-Hydro模式在黄河源区月径流模拟方面表现较好,率定期纳什系数(Nash-Sutcliffe efficiency coefficient,简称NSE)均在0.92以上,而验证期丰水年模拟结果明显好于枯水年(NSE=0.15),这与降水和径流的非线性程度有关。本研究方案和结果为亚寒带半干旱气候区大尺度流域水文模拟及径流预测提供了一定的参考价值。展开更多
在人类活动加重气候变暖的背景下,极端水文气象事件发生概率增加。数值模式作为研究水循环和极端水文事件的有效工具,已在全球范围内得到广泛应用。为深入理解气候变化背景下全球陆地水循环时空演变规律,揭示大气-陆面-水文互馈机制,大...在人类活动加重气候变暖的背景下,极端水文气象事件发生概率增加。数值模式作为研究水循环和极端水文事件的有效工具,已在全球范围内得到广泛应用。为深入理解气候变化背景下全球陆地水循环时空演变规律,揭示大气-陆面-水文互馈机制,大气-陆面-水文耦合过程模拟研究已成为国际大气、水文等学科研究的热点之一。本文首先回顾和梳理了大气-陆面-水文耦合模式的发展历程,阐明了大气-陆面-水文耦合模式WRF-Hydro(Weather Research and Forecasting Model Hydrological modeling system)的优势,并系统总结了WRF-Hydro模式的主要敏感性参数分析及模式在对地表径流、土壤湿度、能量水分循环以及相关大气和水文过程等方面的应用。最后探讨WRF-Hydro大气-陆面-水文耦合模式未来发展趋势,提出应着眼于发展有效的尺度转换方案、完善参数化方案以及开展流域内大气、水文变量时空分布高分辨率模拟等方面,以期系统提升耦合模式对大气、陆面过程及水文过程的刻画能力。展开更多
The article discusses engineering approaches to solving the problem of oil vapours in generators. Due to the design characteristics of each power plant, it is difficult to find a typical solution. Nevertheless, the ar...The article discusses engineering approaches to solving the problem of oil vapours in generators. Due to the design characteristics of each power plant, it is difficult to find a typical solution. Nevertheless, the article suggests ways to reduce the amount of oil mist. For their implementation, a calculation methodology based on the substitution scheme of the hydraulic path of the bearing support unit is created which takes into account the design features of the bearing and the parameters of the environment around the oil bath. The methodology employed is presented. The numerical method of modelling the aerodynamic fields of the entire hydro generator is used to estimate the air flows and pressures in the oil bath zone of the thrust bearing. Additionally, the method made it possible to track suspected oil particles that could get from the thrust-bearing bath into the surrounding area of the generator. Measures are proposed to reduce the level of oil mist through the competent design of the oil vapour removal system from the bearing bath.展开更多
The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,...The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,renewable energy generation should be supplemented and enhanced,from real-time,minute-to-minute variations to annual alterations influencing long-termstrategy.Wind energy generation does not only fluctuate but is also challenging to accurately forecast the timeframes of significance to electricity decision makers;day-ahead and long-term making plans of framework sufficiency such as meeting the network peak load annually.A utility that integrates wind and solar energy into its electricity mix would understand how to adapt to uncertainty and variability in operations while sustaining grid stability.Due to hydropower’s adaptability,a system using hydropower as one of its generating resources could be precisely adapted to absorb the variability of wind and solar energy.The objective of this research study is to create a hybrid system comprising hydro-wind and solar(Hybrid-HWS)integration for power balancing in an isolated electrical network in Klipkop village,Pretoria region,South Africa.The desirability of designing and building goaf storage tank in regard to capability,the fullness of line throughoutwater pumping,dispensing,storage tank spillage,and pressure difference throughout liquid flow within the storage tanks were preliminary assessed using geotechnical and weather forecasting data from a distinctive area of Klipkop town in Pretoria,South Africa.Different facility hours premised on daylight accessibility are scheduled to balance maximum load at early and late hours.However,in the scenario of electrical power,time shift requiring storage for extended periods of time,such as in terms of hours,Hybrid-HWS has been found to have a crucial role.The results of simulations showed a coordinated process design for Hybrid-HWS Energy Storage(ES)to determine everyday strategic planning in reducing the variability of the system resulting from wind-solar-pumped hydro ES output inadequacies and satisfy daily load demands.It could be recommended that by considering the adaptability characteristics,extremely rapidly,ramping,peaking support and maximum stabilizing aid of the system could be archived with pump-hydro into the energy mix which can provide specific guidelines for energy policymakers.展开更多
The state of Cameroon, faced with the situation the electricity deficits, is promoting the development of renewable energies in general and to meet rural electrification needs in particular. The purpose of this work i...The state of Cameroon, faced with the situation the electricity deficits, is promoting the development of renewable energies in general and to meet rural electrification needs in particular. The purpose of this work is to study the feasibility of the MHP of Batcheu, to show its contribution to sustainable development in this locality and to prove that it is a profitable project. After study, it appears that the waterfall of Batcheu is favourable to the establishment of a MHP with an installed power of 260 kW with an operating diagram corresponding to a Francis turbine. Given that it is a renewable energy that can supply more than 800 households in rural areas, its contribution to sustainable development is obvious. Its investment cost is estimated at 171,465,396 FCFA. It is a profitable project with a payback time of 7 years and 2 months.展开更多
In Niger, a poor and arid country in West Africa, irrigated agriculture is undoubtedly the means with the greatest chance of ensuring food and nutritional security, increasing incomes and therefore reducing poverty, e...In Niger, a poor and arid country in West Africa, irrigated agriculture is undoubtedly the means with the greatest chance of ensuring food and nutritional security, increasing incomes and therefore reducing poverty, especially in rural areas. This research aims to analyze the profitability of irrigated agriculture at the level of the hydro-agricultural development of Konni. The methodological approach adopted is based on the method of “Rapid Participatory Diagnosis and Planning of actions to improve the performance of irrigated perimeters (DPRP)”. The documentary research made it possible to capitalize on the information available on the question. The collection of primary data in the field was carried out using questionnaires and interview guides submitted to actors directly or indirectly involved in the management of Konni’s AHA, taken individually or in focus group discussions. The data collected was processed with SPSS software to be analyzed and graphically illustrated with the Excel spreadsheet. The performance analysis made it possible to identify yields and constraints to the development of irrigated agriculture. The results show that on the Konni perimeter, there is a general trend towards a reduction in areas both in SS and in SH, with higher development rates in SH (80% to 90%), whereas they are very low in SS (8% to 25%). The main crops favored by Konni producers are onions, tomatoes, cabbage, corn and sorghum. Onion and tomato crops are more important sources of income than dune crops. In this context, the main challenges to be met for a better profitability of irrigated agriculture concern the socio-economic context of production, insufficient financing of infrastructures and their maintenance, small areas often below the break-even point, environmental degradation.展开更多
文摘黄河源区是黄河流域主要的产流区和水源涵养区,研究和探索该区域陆面水文过程对理解陆面过程及水文循环特征,揭示陆面—水文耦合过程具有重要的科学意义。本研究基于2009~2018年中国区域高时空分辨率地面气象要素驱动数据(China Meteorological Forcing Dataset,简称CMFD)、全球高分辨率降水数据集(Climate Prediction Center Morphing Technique,简称CMORPH)、热带降雨测量卫星(Tropical Rainfall Measuring Mission,简称TRMM)及全球陆地数据同化系统(Global Land Data Assimilation System,简称GLDAS)降水,评估了四类降水产品在黄河源区的降水精度,在此基础上,利用最优降水数据驱动独立运行的天气研究预报及水文耦合模型系统(Weather Research and Forecasting Model Hydrological modeling system,简称WRF-Hydro),探究该模式在黄河源区径流模拟的适用性。结果表明:四类降水产品均能够反映出降水的分布特征,但在量值及细节捕捉上存在显著差异。CMFD在不同时空尺度上都能很好地捕捉到降水的演变特征,其与日观测降水的相关系数达到0.99,均方根误差仅为0.25 mm。在表征降水能力方面,四类降水产品总体表现为CMFD>CMORPH>TRMM>GLDAS,CMFD的平均探测成功率(Critical Success Index,简称CSI)在0.93以上。经参数率定后的WRF-Hydro模式在黄河源区月径流模拟方面表现较好,率定期纳什系数(Nash-Sutcliffe efficiency coefficient,简称NSE)均在0.92以上,而验证期丰水年模拟结果明显好于枯水年(NSE=0.15),这与降水和径流的非线性程度有关。本研究方案和结果为亚寒带半干旱气候区大尺度流域水文模拟及径流预测提供了一定的参考价值。
文摘在人类活动加重气候变暖的背景下,极端水文气象事件发生概率增加。数值模式作为研究水循环和极端水文事件的有效工具,已在全球范围内得到广泛应用。为深入理解气候变化背景下全球陆地水循环时空演变规律,揭示大气-陆面-水文互馈机制,大气-陆面-水文耦合过程模拟研究已成为国际大气、水文等学科研究的热点之一。本文首先回顾和梳理了大气-陆面-水文耦合模式的发展历程,阐明了大气-陆面-水文耦合模式WRF-Hydro(Weather Research and Forecasting Model Hydrological modeling system)的优势,并系统总结了WRF-Hydro模式的主要敏感性参数分析及模式在对地表径流、土壤湿度、能量水分循环以及相关大气和水文过程等方面的应用。最后探讨WRF-Hydro大气-陆面-水文耦合模式未来发展趋势,提出应着眼于发展有效的尺度转换方案、完善参数化方案以及开展流域内大气、水文变量时空分布高分辨率模拟等方面,以期系统提升耦合模式对大气、陆面过程及水文过程的刻画能力。
文摘The article discusses engineering approaches to solving the problem of oil vapours in generators. Due to the design characteristics of each power plant, it is difficult to find a typical solution. Nevertheless, the article suggests ways to reduce the amount of oil mist. For their implementation, a calculation methodology based on the substitution scheme of the hydraulic path of the bearing support unit is created which takes into account the design features of the bearing and the parameters of the environment around the oil bath. The methodology employed is presented. The numerical method of modelling the aerodynamic fields of the entire hydro generator is used to estimate the air flows and pressures in the oil bath zone of the thrust bearing. Additionally, the method made it possible to track suspected oil particles that could get from the thrust-bearing bath into the surrounding area of the generator. Measures are proposed to reduce the level of oil mist through the competent design of the oil vapour removal system from the bearing bath.
基金This study was supported by the DUT Scholarship Scheme Masters:2022(RFA Smart Grid)Funding.
文摘The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,renewable energy generation should be supplemented and enhanced,from real-time,minute-to-minute variations to annual alterations influencing long-termstrategy.Wind energy generation does not only fluctuate but is also challenging to accurately forecast the timeframes of significance to electricity decision makers;day-ahead and long-term making plans of framework sufficiency such as meeting the network peak load annually.A utility that integrates wind and solar energy into its electricity mix would understand how to adapt to uncertainty and variability in operations while sustaining grid stability.Due to hydropower’s adaptability,a system using hydropower as one of its generating resources could be precisely adapted to absorb the variability of wind and solar energy.The objective of this research study is to create a hybrid system comprising hydro-wind and solar(Hybrid-HWS)integration for power balancing in an isolated electrical network in Klipkop village,Pretoria region,South Africa.The desirability of designing and building goaf storage tank in regard to capability,the fullness of line throughoutwater pumping,dispensing,storage tank spillage,and pressure difference throughout liquid flow within the storage tanks were preliminary assessed using geotechnical and weather forecasting data from a distinctive area of Klipkop town in Pretoria,South Africa.Different facility hours premised on daylight accessibility are scheduled to balance maximum load at early and late hours.However,in the scenario of electrical power,time shift requiring storage for extended periods of time,such as in terms of hours,Hybrid-HWS has been found to have a crucial role.The results of simulations showed a coordinated process design for Hybrid-HWS Energy Storage(ES)to determine everyday strategic planning in reducing the variability of the system resulting from wind-solar-pumped hydro ES output inadequacies and satisfy daily load demands.It could be recommended that by considering the adaptability characteristics,extremely rapidly,ramping,peaking support and maximum stabilizing aid of the system could be archived with pump-hydro into the energy mix which can provide specific guidelines for energy policymakers.
文摘The state of Cameroon, faced with the situation the electricity deficits, is promoting the development of renewable energies in general and to meet rural electrification needs in particular. The purpose of this work is to study the feasibility of the MHP of Batcheu, to show its contribution to sustainable development in this locality and to prove that it is a profitable project. After study, it appears that the waterfall of Batcheu is favourable to the establishment of a MHP with an installed power of 260 kW with an operating diagram corresponding to a Francis turbine. Given that it is a renewable energy that can supply more than 800 households in rural areas, its contribution to sustainable development is obvious. Its investment cost is estimated at 171,465,396 FCFA. It is a profitable project with a payback time of 7 years and 2 months.
文摘In Niger, a poor and arid country in West Africa, irrigated agriculture is undoubtedly the means with the greatest chance of ensuring food and nutritional security, increasing incomes and therefore reducing poverty, especially in rural areas. This research aims to analyze the profitability of irrigated agriculture at the level of the hydro-agricultural development of Konni. The methodological approach adopted is based on the method of “Rapid Participatory Diagnosis and Planning of actions to improve the performance of irrigated perimeters (DPRP)”. The documentary research made it possible to capitalize on the information available on the question. The collection of primary data in the field was carried out using questionnaires and interview guides submitted to actors directly or indirectly involved in the management of Konni’s AHA, taken individually or in focus group discussions. The data collected was processed with SPSS software to be analyzed and graphically illustrated with the Excel spreadsheet. The performance analysis made it possible to identify yields and constraints to the development of irrigated agriculture. The results show that on the Konni perimeter, there is a general trend towards a reduction in areas both in SS and in SH, with higher development rates in SH (80% to 90%), whereas they are very low in SS (8% to 25%). The main crops favored by Konni producers are onions, tomatoes, cabbage, corn and sorghum. Onion and tomato crops are more important sources of income than dune crops. In this context, the main challenges to be met for a better profitability of irrigated agriculture concern the socio-economic context of production, insufficient financing of infrastructures and their maintenance, small areas often below the break-even point, environmental degradation.
