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The economic development of the country establishes among its priorities, the achievement of the efficient use of energy in the pumping of water, which constitutes one of the fundamental links for Agriculture. In recent years, various solar pumps have been introduced in Cuba in order to economically empower various companies. Its evaluation allows obtaining information for decision-making with a view to its possible introduction into the country for these purposes. This work was developed at the Experimental Station of the Agricultural Engineering Research Institute with the aim of determining the technical and operating characteristics of the photovoltaic system and the Lorentz PS2-150-C- SJ5-8 Solar Pump. The methodology used consisted of measuring the electrical and hydraulic characteristics of the system at the time of its start-up, in addition to calculating the daily volume of water pumping. The results found showed that the average power obtained from the panels was 0,3 kW, the maximum pressure reached by the pump was 20 m.c.a. when the discharge was 1,52 m³/h and the maximum flow rate was 4,00 m³/h in 2 m.c.a. The daily volume of water in 7 hours of pumping was 28,02; 18,20 and 10,64 m³/day for heights of 2, 11 and 20 m.c.a. respectively. It was concluded that the behavior of the evaluated equipment is acceptable with respect to the characteristics provided by the manufacturer. [ABSTRACT FROM AUTHOR]

The present work was carried out with the aim of simulating the performance of the BSC 80/200 (130-65) centrifugal pump using the CFD method, thus obtaining the head-flow, power-flow and efficiency-flow characteristics curves. To carry out this project, specialized bibliography was taken into account in the parametric design of centrifugal pumps and in analysis by finite elements applied to fluids, later the design, 3D projection and computational simulation were carried out using ANSYS (CFX). The results include obtaining the three-dimensional models of the pump body and the three impellers (5 blades, 6 blades and 7 blades) and that the correlation in all the curves is as expected, corresponding to what is referred to in the specialized bibliography. It was concluded that the comparison of the results obtained through the CFD simulations taking into account the variations in the number of blades showed that the impeller that generates the best results is the one with 7 blades, reaching the best efficiency (90%), power (36,25 kW) for a 70% flow of design. [ABSTRACT FROM AUTHOR]

This article addresses the main shortcomings and opportunities regarding the regulation of environmental flows in Cuban legislation, particularly in Law N° 124. "On Terrestrial Waters" approved in 2017. Issues such as legal gaps and contradictions in the definition are addressed of the concept of environmental flow, its link to other aspects such as the integrated management of water resources (IWRM), as well as the regime for granting water rights in Cuba, developing concrete proposals for possible legal reform. [ABSTRACT FROM AUTHOR]

A methodology was developed with the objective of improving the management of micro irrigation systems in the province. The experiments were carried out in areas of University of Ciego de Ávila and "Ceballos" Agroindustrial Company. The work was developed during three years, where the technical - mechanical and hydraulic characteristics of emitters were evaluated, the obturation phenomenon was simulated, the operation of the system by two different criteria was evaluated and the methodology was developed and validated. It was obtained as result, that the hydraulic and mechanical characteristics of the drippers and irrigation taps are formed, basically, by the flowpressure curve, the manufacture variation coefficient and the ratio flow-temperature, which are fundamental parameters to perform an adequate management of micro-irrigation systems. The mathematical model of Bralts was very accurate, since the average relative error was lower than 0.23%, which demonstrates its accuracy and its ability to predict seals in micro-irrigation systems. The best results were obtained with the Bralts management criteria, from which a management diagram could be obtained to improve the operation of the irrigation system. With the validation of the proposed methodology in an irrigation subunit of "El Tezón" UBPC, a better management of the system and an increase in the average yield of guava at 3.79 t / h were achieved. [ABSTRACT FROM AUTHOR]

This work aims to develop a study of hydro mechanical design oriented axial piston pumps, spraying machines for agriculture, based not only on previous studies but on the experience gained during the years of work on this issue, since information is primarily aimed at existing selection and operation of this component it is not going well for the design, and this greatly impedes the development of these equipments in countries like Cuba that do not have a tradition and experience in this field, demonstrating the subject’s importance for the development of these equipments in the country. To achieve this, a calculation methodology specifically aimed at the design of such equipment, and we perform a statistical study based on data collected over a hundred pumps of foreign production of nineteen internationally recognized firms that analyze aspects such as: maximum speed of piston displacement, flow and pressure of work for these pumps, responding to international trends. The theoretical contribution of the research is that this study is an integrative methodological guide for the design of this type of pump and as practical contribution the manufacturing of these pumps with consequent replacement of imports and the implementation of the spray machine, primarily from domestic production, which currently requires this component. [ABSTRACT FROM AUTHOR]