A discussion on advanced methods of energy conversion- Magnetohydrodynamic power generation - The prospective economics and thermal efficiency of large scale open cycle m .h .d . stations

The overall thermal efficiency of several different fossil fuelled power stations is discussed using an m.h.d. generator and the conventional method of preheating the combustion with exhaust gases from the generator. Air preheat temperatures of between 1300 and 1700 °C are considered when over-all efficiencies of 51 and 61% may be attained. If the generator length is to be restricted to between 10 and 15 m in order to limit duct heat losses magnetic fields of 4 to 6 Wb/m 2 are required. The use of oxygen enrichment is found at present to be uneconomic but reacting methane with steam (an endothermic reaction) to give the fuel to be burnt is an attractive alternative process although not as good thermodynamically as air preheating. Economic considerations indicate that m.h.d. may only be useful for high cost fuels.

2019 ◽  
Vol 11 (19) ◽  
pp. 5441 ◽  
Author(s):  
Chao Ma ◽  
Sen Dong ◽  
Jijian Lian ◽  
Xiulan Pang

Hybrid energy storage systems (HESS) are an effective way to improve the output stability for a large-scale photovoltaic (PV) power generation systems. This paper presents a sizing method for HESS-equipped large-scale centralized PV power stations. The method consists of two parts: determining the power capacity by a statistical method considering the effects of multiple weather conditions and calculating the optimal energy capacity by employing a mathematical model. The method fully considers the characteristics of PV output and multiple kinds of energy storage combinations. Additionally, a pre-storage strategy that can further improve stability of output is proposed. All of the above methods were verified through a case study application to an 850 MW centralized PV power station in the upstream of the Yellow river. The optimal hybrid energy storage combination and its optimization results were obtained by this method. The results show that the optimal capacity configuration can significantly improve the stability of PV output and the pre-storage strategy can further improve the target output satisfaction rate by 8.28%.


1965 ◽  
Vol 59 (3) ◽  
pp. 505-522 ◽  
Author(s):  
Richard Young

The possible presence of very large petroleum and natural gas reserves in the area beneath the North Sea is currently the subject of intense investigation. If confirmed, as seems likely in at least some localities, this occurrence will raise legal problems of considerable interest and complexity. For the North Sea is not merely an oilfield covered by water: for centuries it has been one of the world's major fishery regions and the avenue to and from the world's busiest seaports. Thus all three of the present principal uses of the sea—fishing, navigation, and the exploitation of submarine resources—promise to meet for the first time on a large scale in an area where all are of major importance. The process of reconciling the various interests at stake will provide the first thoroughgoing test of the adequacy and acceptability of the general principles laid down in the 1958 Geneva Convention on the Continental Shelf and should add greatly to the practice and precedents available in this developing branch of the law. In the present article an attempt is made to review some of the geographical and economic considerations involved in the North Sea situation, to note some of the technical and legal developments that have already taken place, and to consider these elements in the light of the various interests and legal principles concerned.


2021 ◽  
Vol 11 (2) ◽  
pp. 727 ◽  
Author(s):  
Myeong-Hwan Hwang ◽  
Young-Gon Kim ◽  
Hae-Sol Lee ◽  
Young-Dae Kim ◽  
Hyun-Rok Cha

In recent years, photovoltaic (PV) power generation has attracted considerable attention as a new eco-friendly and renewable energy generation technology. With the recent development of semiconductor manufacturing technologies, PV power generation is gradually increasing. In this paper, we analyze the types of defects that form in PV power generation panels and propose a method for enhancing the productivity and efficiency of PV power stations by determining the defects of aging PV modules based on their temperature, power output, and panel images. The method proposed in the paper allows the replacement of individual panels that are experiencing a malfunction, thereby reducing the output loss of solar power generation plants. The aim is to develop a method that enables users to immediately check the type of failures among the six failure types that frequently occur in aging PV panels—namely, hotspot, panel breakage, connector breakage, busbar breakage, panel cell overheating, and diode failure—based on thermal images by using the failure detection system. By comparing the data acquired in the study with the thermal images of a PV power station, efficiency is increased by detecting solar module faults in deteriorated photovoltaic power plants.


2014 ◽  
Vol 953-954 ◽  
pp. 925-928 ◽  
Author(s):  
Bi Bin Huang

As the positive and important supplement to large-scale power generation, distributed generation (DG) will become key measure to promote energy conservation and solve the problems of climate change in China. Due to absence of universal authoritative definition of DG, this paper summarizes the basic characteristic of DG based on the definitions in typical countries (or organizations) and carried out general definition of DG considering our national conditions and power grid features. From the views of resource, incentive policy and industry, this paper analyzed the fundamental for DG development and compared the development status in typical countries.


2019 ◽  
Vol 16 (34) ◽  
pp. 71-78
Author(s):  
Akira Yamashita ◽  
Riichi Kitano ◽  
Akihiro Miyasaka ◽  
Takahisa Shodai

Author(s):  
Charles H. O. Lombard ◽  
Daniel N. J. Els ◽  
Jacques Muiyser ◽  
Albert Zapke

South Africa’s coal-fired power stations use super heated steam to drive generator turbines. In arid regions, air-cooled condensers (ACCs) are used to condense the process steam. These ACCs consists of an array of over 200 axial flow fans, each driven by a motor via a reduction gearbox. Distorted fan inlet air flow conditions cause transient blade loading, which results in variations in output shaft bending and torque. A measurement project was conducted where the input and output shaft of such a gearbox were instrumented with strain gauges and wireless bridge amplifiers. Gearbox shaft speed and vibration were also measured. Torsional and bending strains were measured for a variety of operational conditions, where correlations were seen between gearbox loading and wind conditions. The input side experienced no unexpected loads from the motor or changing wind conditions, whereas output shaft loading was influenced by the latter. Digital filters were applied to identify specific bending components, such as the influence of fan hub misalignment and dynamic blade loading. Reverse loading of the gearbox was measured during the fan stop period, and vibration analysis revealed torsional and gearbox vibrations. This investigation documented reliable full scale ACC gearbox loads.


2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Elizabeth Locke ◽  
Sally Hewlett
Keyword(s):  

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