scholarly journals Investigation of efficiency and quality of functioning of led lighting elements of electrical systems at the maximum permissible ambient temperature

Author(s):  
R. H. Tukshaitov ◽  
N. V. Rozhencova ◽  
A. R. Denisova

Based on the results of the study of the elements of the electrical system, the operability and quality of their functioning are determined by the example of the use of LED filament lamps for lighting during their continuous operation at the maximum permissible ambient temperature equal to 50 °С.THE PURPOSE. The relevance of this work is determined by the lack of information about the operability and quality of functioning of filament LED lamps during their continuous operation in conditions of elevated ambient temperature, taking place in boiler-turbine shops of thermal power plants, foundries of factories, bakeries of bakeries, in the tunnels of coal mines and divisions of other enterprises. It is established that the working life of the Gauss LED filament lamps with a power of 10 W, containing 4 filaments, is 70-75 days, and with 8 filaments only 22-24 days. Degradation of filament lamps with 8 filaments at the maximum permissible ambient temperature of 50 °С. occurs at a rate of 0.45-0.50 % per day. It is shown that a filament LED lamp with 4 filaments, if it is operated for 4.5 hours a day in conditions of elevated ambient temperature, can work for almost more than one year. METHODS. The resource of filament and typical LED lamps of different power is considered in comparative terms when they are operated at a relatively high ambient temperature.RESULTS. It is established that a 10 W filament LED lamp with 4 filaments has an energy resource, as well as a high-quality standard LED lamp. At the same time, the temperature of its body is no more than 40 °С, which is almost 2 times less. By increasing the distance between the filaments due to the use of a smaller number of filaments, it is possible to increase the power supply by 2 times and the corresponding luminous flux by 1.5 times. CONCLUSION. In preliminary experiments with a filament lamp of the new design of the Diall model, it was found that the use of longer filaments (45 mm) in it, instead of the previously used ones (30 mm), allows to increase the quality of their functioning by about 4 times when they are operated under the same ambient temperature conditions.

2019 ◽  
Vol 11 (16) ◽  
pp. 4261 ◽  
Author(s):  
Xuerong Li ◽  
Faliang Gui ◽  
Qingpeng Li

The development of clean energy is of great importance in alleviating both the energy crisis and environmental pollution resulting from rapid global economic growth. Hydroelectric generation is considered climate benign, as it neither requires fossil carbon to produce energy nor emits large amounts of greenhouse gases (GHG), unlike conventional energy generation techniques such as coal and oil power plants. However, dams and their associated reservoirs are not entirely GHG-neutral and their classification as a clean source of energy requires further investigation. This study evaluated the environmental impact of the Xiajiang hydropower station based on life cycle assessment (LCA) according to the 2006 Intergovernmental Panel on Climate Change (IPCC) guidelines, focusing specifically on GHG emissions after the submersion of the reservoir. Results reveal that although hydropower is not as clean as we thought, it is still an absolute “low emissions” power type in China. The amount of GHG emissions produced by this station is 3.72 million tons with an emissions coefficient of 32.63 g CO2eq/kWh. This figure is lower than that of thermal power, thus implying that hydropower is still a clean energy resource in China. Our recommendations to further minimize the environmental impacts of this station are the optimization of relevant structural designs, the utilization of new and improved construction materials, and the extension of farmland lifting technology.


2021 ◽  
Vol 3-4 (185-186) ◽  
pp. 109-125
Author(s):  
Myroslav Podolskyy ◽  
Dmytro Bryk ◽  
Lesia Kulchytska-Zhyhailo ◽  
Oleh Gvozdevych

An analysis of Ukraine’s sustainable development targets, in particular in the field of energy, resource management and environmental protection, are presented. It is shown that regional energetic is a determining factor for achieving the aims of sustainable development. Changes in the natural environment in Ukraine due to external (global) and internal (local) factors that are intertwined and overlapped can cause threats to socio-economic development. It is proved that in the areas of mining and industrial activity a multiple increase in emissions of pollutants into the environment are observed. The comparison confirmed the overall compliance of the structure of consumption of primary energy resources (solid fossil fuels, natural gas, nuclear fuel, oil and petroleum products, renewable energy sources) in Ukraine and in the European Union, shows a steaby trend to reduce the share of solid fuels and natural gas and increasing the shares of energy from renewable sources. For example, in Ukraine the shares in the production and cost of electricity in 2018 was: the nuclear power plants – 54.33 % and in the cost – 26.60 %, the thermal power – 35.95 and 59.52 %, the renewable energy sources – 9.6 and 13.88 %. The energy component must be given priority, as it is crucial for achieving of all other goals of sustainable development and harmonization of socio-economic progress. The paper systematizes the indicators of regional energy efficiency and proposes a dynamic model for the transition to sustainable energy development of the region.


Author(s):  
Suchismita Satapathy

All companies are dependent on their raw material providers. The same applies in the case of thermal power plants. The major raw material for a thermal power plant is the coal. There are a lot of companies which in turn provide this coal to the thermal power plant. Some of these companies are international; some are local, whereas the others are localized. The thermal power plants look into all the aspects of the coal providing company, before settling down for a deal. Some people are specifically assigned to the task of managing the supply chain. The main motive is to optimize the whole process and achieve higher efficiency. There are a lot of things which a thermal power plant looks into before finalizing a deal, such as the price, quality of goods, etc. Thus, it is very important for the raw material providers to understand each and every aspect of the demands of the thermal power plant. A combination of three methods—Delphi, SWARA, and modified SWARA—has been applied to a list of factors, which has later been ranked according to the weight and other relevant calculations.


2021 ◽  
Vol 3 (3(59)) ◽  
pp. 50-57
Author(s):  
Larisa Morozyuk ◽  
Viktoriia Sokolovska-Yefymenko ◽  
Yaroslav Petushkov ◽  
Maksym Sharaiev ◽  
Sergii Psarov

The object of research is a refrigerated complex for short-term storage of tropical fruits in conditions of significant seasonal and daily fluctuations in ambient temperature, that typical for regions with a tropical climate. One of the problems is that the complexes are autonomous small firms for the year-round processing and storage of tropical fruits, located far from the central electric networks. In the presence of solar radiation, the complexes receive energy from small solar power plants. Such complexes are called «trigeneration system». In the course of the study, data on modes were used low temperature heat treatment and preservation of various tropical fruits, ripening times and climatic conditions of Tunisia. It has been established that citrus fruits are stored in chambers with high temperature, olives are frozen and stored for a short time before processing. The total amount of heat entering the citrus chambers is determined by changes in the ambient temperature. The thermal load of the olives chamber is determined by the heat treatment time. It was found that the cargo capacity of chambers with different temperatures differs six times. The thermal load of the olive storage chambers is only four times less. This is due to the peculiarities of the building structure of the complex, technological processes of cooling and freezing. Based on the thermal calculation, the cooling of the chambers is provided by a two-stage booster refrigeration machine with CO2 refrigerant in a transcritical cycle. To ensure the operation of the complex, a solar photoelectric converter is designed. This ensures the environmental safety of the complex and the possibility of obtaining energy savings by regulating the thermal power of the compressors with frequency converters, depending on the ambient temperature. The designed complex can be offered to a private investor for practical implementation.


Author(s):  
Wen Qiu ◽  
Mingxuan Zhao ◽  
Lianhong Lv ◽  
Hong Luo

The total amount of greenhouse gas emissions directly or indirectly generated by thermal power enterprises at any given time can be offset through afforestation, energy conservation and emission reduction. The present situation and control methods of CO2 emission in China's coal-fired thermal power industry are introduced. The complex ecosystem is a unity of ecological functions composed of human society, economic activities and natural conditions. In the context of carbon neutrality and based on the theory of composite ecosystem, this paper divides the coal-fired thermal power plants in China into environmental management zones, calculates the atmospheric environmental capacity, and puts forward the concept of regional atmospheric environmental capacity, classification and zoning control. Finally, the management and control units are classified, and differentiated management and control requirements are put forward to provide a reference for regional air quality standard planning.


2020 ◽  
Vol 1 (1) ◽  
pp. 31-41
Author(s):  
Anton V. Nikonov

The article describes the difficulties faced by organizations engaged in engineering and geodetic work at power plants, with participation in procurement. It is shown that the majority of procurement participants are representatives of small and medium-sized businesses. The factors affecting the reduction in the price offer are given. It is noted that a decrease in the initial (maximum) price during the procurement procedures varies from 75 to 90%, which cannot but lead to a decrease in the quality of work, and often to falsification of reporting documentation. Conclusions are made on the example of three realized purchases by the definition of the contractor for geodetic work at thermal power plants.


2021 ◽  
Vol 22 (1) ◽  
pp. 287-297
Author(s):  
Dilnoza Umurzakova

The purpose of this article is to develop high-quality combined automatic control systems (ACS) for the water level in the drum of steam boilers of thermal power plants (TPPs), which can significantly improve the quality of regulation and increase the efficiency of TPPs in a wide range of load changes. To improve the quality of water level control in the drum of steam generators of nuclear power plants with a pressurized water-cooled power reactor (PWPR), it is proposed to use a combined automatic control system based on a control loop with a correcting PI-controller tuned to a symmetrical optimum, with smoothing the reference signal and device compensation of the most dangerous internal and external measurable disturbances. A technique has been developed for assessing the impact of changes in the quality characteristics of transients of combined self-propelled guns by the water level in the drum of steam boilers and steam generators on the safety, reliability, durability, and efficiency of thermal power equipment of thermal power plants. Comparison was made of direct indicators of the quality of three ACS (typical and three-pulse, digital system with an observer state, and the proposed combined ACS). The simulation results of transients of the proposed and typical three-pulse self-propelled guns confirmed the advantages of the first. ABSTRAK: Artikel ini bertujuan bagi membina sistem kombinasi automatik (ACS) berkualiti tinggi bagi aras air dalam drum dandang stim tenaga terma logi kuasa (TPP). Ini dapat meningkatkan mutu peraturan dan meningkatkan kecekapan TPP secara signifikan dengan pelbagai perubahan beban. Bagi meningkatkan kualiti kawalan aras air dalam drum penjana wap loji kuasa tenaga nuklear dengan reaktor berpendingin air bertekanan (PWPR). Gabungan sistem kawalan automatik berdasarkan gelung kawalan dengan pembetulan PI telah dicadangkan dan diselaraskan simetri secara optimum, dengan melancarkan isyarat rujukan dan pembetulan peranti dari gangguan yang boleh diukur dari dalam dan luar. Satu teknik telah dibina bagi menilai kesan perubahan ciri kualiti transien gabungan berjentera pada aras air di tong dandang stim dan drum penjana wap pada keselamatan, kebolehpercayaan, ketahanan dan kecekapan peralatan tenaga terma loji janakuasa. Perbandingan dibuat pada kualiti tiga ACS (sistem digital khas dan tiga signal dengan keadaan pemerhati dan gabungan ACS yang dicadangkan). Hasil sistem simulasi transien yang dicadangkan dan tiga signal biasa berjentera mengesahkan kelebihan pada yang pertama.


Author(s):  
William K. Gboney

It is estimated that within the next 40 years, solar thermal power plants would be capable of supplying more than half of the electricity needs of EUMENA. While solar irradiance differs widely in Europe due to seasonal variations, in the MENA region, there is abundant and continuous solar irradiance. This make the MENA region suitable for establishing CSP plants and exporting the electricity generated to Europe. This has driven many institutions and agencies, including the World Bank and the Desertec Foundation, to propose various schemes to promote the use of CSP systems in the MENA region. The objective of this paper is to examine the existing policy and regulatory frameworks in the MENA countries, identify any barriers and make recommendations on how to surmount these barriers, to increase the scale and scope of utilizing CSPs and other renewable energy technologies (RETs) in the region. The paper concludes by making a number of policy and regulatory recommendations to support utilization of solar thermal energy resource within the MENA region.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Rongrong Zhai ◽  
Yongping Yang ◽  
Yong Zhu ◽  
Denggao Chen

Solar aided coal-fired power plants utilize various types of solar thermal energy for coupling coal-fired power plants by using the characteristics of various thermal needs of the plants. In this way, the costly thermal storage system and power generating system will be unnecessary while the intermittent and unsteady way of power generation will be avoided. Moreover, the large-scale utilization of solar thermal power and the energy-saving aim of power plants will be realized. The contribution evaluating system of solar thermal power needs to be explored. This paper deals with the evaluation method of solar contribution based on the second law of thermodynamics and the principle of thermoeconomics with a case of 600 MW solar aided coal-fired power plant. In this study, the feasibility of the method has been carried out. The contribution of this paper is not only to determine the proportion of solar energy in overall electric power, but also to assign the individual cost components involving solar energy. Therefore, this study will supply the theoretical reference for the future research of evaluation methods and new energy resource subsidy.


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