The article deals with research in solar power plants and Renewable Energy Laboratory. The purpose of research was to study the infl uencing of partial shading on the energy effi ciency of photovoltaic installations in various connection options. As the title implies the article describes a study of the possibilities of increasing their energy effi ciency when operating under different conditions. It is spoken in detail about replacement of "block connection" panels to the "in-line connection", in case of partial shading by the previous string. It is shown that substitution allows to obtain a signifi cantly higher power-up to 8 times. It is examined that the horizontal arrangement of the panels instead of the vertical, under the same conditions, also allows up to 5 times the power of the partially shaded array in the case "in-line connection" and by 34% in the case of a "block connection". It is analyzed that parallel connection of partially shaded photovoltaic array with normally illuminated, requires voltage matching, for the selection of electrical energy at the point of maximum power, which makes it possible to obtain much more energy from the shaded array. It is experimentally shown that when using the "Intelligent maximum power selection device" that implements the voltage matching, it is possible to increase the array power up to 4 times with partial shading of 3 panels of 18. It should be noted that the choice of methods that allow receiving energy from shaded panels through individual matching converters does not permit signifi cantly increasing the energy production of partially shaded array. It is experimentally shown that as a result of their use the array power does not increase by more than 2.5%. The results of research can be used in the design of new installations based on photovoltaic cells and the modernization of existing ones.
When cultivating sugar beets, harvesting is one of the most labor-intensive operations. But in terms of quality and operational and technological performance, the machines used do not meet modern agrotechnical requirements, especially in conditions of high soil moisture (25 - 29%). With an increase in soil moisture, its adhesion to the working surfaces of the digging organs and the heap cleaner increases, reducing their separating ability. We propose to improve the cleaning technology by modernizing the design of the separating stars. This is achieved by using cylindrical brushes (in the amount of three pieces), which are mounted vertically to the horizontal plane of the star's rods. One end of the cylindrical brush is attached to one of the ends of the star bar, and the other end of the brushes is in the hollow bracket. All brushes are located at the same distance from each other along the periphery of the star. The second ends of the brushes, located in the hollow bracket, are fixed to each other and move freely in it. This improved design will allow the brushes to interact with the contaminated surface of the sprocket guard, improving their cleaning ability and eliminating cleaning breaks when working in harsh conditions.
This article is devoted to the relevant problem of increasing the efficiency of PV systems. The presented analysis discusses the available methods for improving the power generation of PV modules under partial shading. Mathematical models for power loss calculation were compiled based on the results of this analysis. The proposed approach minimizes the negative impact of partial shading on the energy production of PV modules. It is based on the equalization of voltages of parallel-connected arrays of modules by installing additional power elements in them. The proposed solution is promising for various areas; it allows for the minimization of the unfavorable influence of existing urban objects (buildings, trees, communications, etc.) on the energy efficiency of PV modules. The obtained results are useful for the sustainable development of the urban environment in the context of digital transformation. They are the basis for the promising methodology of the parametric optimization of power plants using renewable energy sources.
АннотацияВведение: требования по очистке и отведению поверхностного стока в последнее время ужесточаются. По этой причине, например, стали типовыми ситуации, связанные с отказами территориальных управлений Государственной экспертизы и Росрыболовства в согласовании осуществления деятельности по проектируемым объектам капитального строительства на основании статьи 60 Водного кодекса РФ, запрещающей осуществлять сброс в водные объекты сточных вод, не подвергшихся санитарной очистке и обезвреживанию. В этих условиях очень важной является информация о фактических расходах, образующихся в результате выпадения дождей, отличных от расчетных. В первую очередь сверхрасчетных дождей, расходы стока от которых невозможно измерить в связи с переходом сетей в напорный режим и подтоплением расходомеров. Цель исследования: совершенствование методов расчета расходов поверхностного стока, направленных на повышение достоверности их оценки и обоснования резервов в таких системах для сокращения затрат на стадии строительства и эксплуатации. Результаты: Для обоснования методов расчета расходов сточных вод общесплавных систем водоотведения проведены экспериментальные исследования на одном из бассейнов водоотведения Санкт-Петербурга общей площадью 96,97 га, максимальным уклоном поверхности -0,006 и средневзвешенным коэффициентом стока ψ ср = 0,46. В результате экспериментально установлено, что применение упрощённого гидравлического моделирования с учетом только уличных сетей (без включения дворовых) приводит к завышению расчетных расходов до 20 %. При этом экспериментально обоснован экспресс-метод оценки расходов сточных вод общесплавных систем водоотведения, допускающий применение гидравлического моделирования с учетом только уличных сетей, на которых смоделированы виртуальные емкости по объему, равные объему дворовых сетей, подключенных к ним. Экспериментально подтверждена возможность применения нормативных методик для определения на стадии эксплуатации максимального расхода сточных вод в зависимости от фактической q 20ф интенсивности дождя. Для повышения достоверности расчетов обязательным условием является применение коэффициента β не в виде константы, а определение его в зависимости от фактической q 20ф -интенсивности дождя по формуле β = 1,2915•q 20ф -0,055 Авторы Кармазинов Феликс Владимирович, д-р техн. наук ГУП «Водоканал Санкт-Петербурга»
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