scholarly journals Use of centrifugal pumps with shielded asynchronous motors in precision irrigation systems for precision agriculture

2021 ◽  
Vol 845 (1) ◽  
pp. 012134
Author(s):  
A G Chernykh

Abstract Precision irrigation in the context of precision farming principles should be based on a systematic approach to achieve the targets of meeting the average spatial needs of crops for water and dissolved nutrients. Precision irrigation, based on advanced irrigation management technologies, combined with remote sensing and simulation technologies, provides a practical solution to the problem of managing the spatial and temporal components of water to meet the specific needs of individual plants. The spatial component of water equivalent to its volume is supplied to the irrigation zone by means of supply water pipes, and the temporary component equivalent to its flow is provided by means of booster pumps. With intensive water consumption, the supply pipelines do not provide the irrigation systems with the required volumes of water. In this case, the static water supply is provided by using storage tanks. In this paper, the need to use a storage tank as a technical component of irrigation management is considered from the point of view of solving a specific management problem related to ensuring the current value of the green mass per unit area of sowing to the level of its calculated value. The use of a storage tank and a group of centrifugal pumps of a special hermetic design as pumping equipment allows you to obtain a closed-type irrigation scheme that has the necessary reserve of static and dynamic stability of the flow characteristics.

2019 ◽  
Vol 110 ◽  
pp. 01007
Author(s):  
Olga Dubrovskaya ◽  
Ivan Inzhutov ◽  
Anastasya Bobrik ◽  
Aleksey Klimov

Pumping equipment is one of the main systems of water supply and sewerage, where centrifugal pumps are mostly used due to the simple design and the optimal interval of the parameters of flow and pressure. The paper considers the development of a centrifugal pump from the point of view of system analysis, since this approach considers any technical object as a complex of interacting elements having the properties that are not reduced to the properties of individual elements designed to perform certain useful functions. The aim of the paper is to find patterns of development of the centrifugal pump as a technical system to predict its further evolution. Domestic and foreign patent fund of Class F 04 D in the amount of 724 units was used as the main source. In the paper, the device of the centrifugal pump as a technical system is divided into the following main structural subsystems: impeller blades, impeller disks; housing; pressure pipe and suction pipe. Each of these elements has its main useful function and a number of auxiliaries, which are discussed in detail. It is established that an increase in the degree of control of the centrifugal pump can be achieved by dynamization of transmission, specifically, the regulation of the revolutions transmitted from the engine to the impeller mechanically, with the help of fluid coupling and frequency converters.


Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1042 ◽  
Author(s):  
Laura García ◽  
Lorena Parra ◽  
Jose M. Jimenez ◽  
Jaime Lloret ◽  
Pascal Lorenz

Water management is paramount in countries with water scarcity. This also affects agriculture, as a large amount of water is dedicated to that use. The possible consequences of global warming lead to the consideration of creating water adaptation measures to ensure the availability of water for food production and consumption. Thus, studies aimed at saving water usage in the irrigation process have increased over the years. Typical commercial sensors for agriculture irrigation systems are very expensive, making it impossible for smaller farmers to implement this type of system. However, manufacturers are currently offering low-cost sensors that can be connected to nodes to implement affordable systems for irrigation management and agriculture monitoring. Due to the recent advances in IoT and WSN technologies that can be applied in the development of these systems, we present a survey aimed at summarizing the current state of the art regarding smart irrigation systems. We determine the parameters that are monitored in irrigation systems regarding water quantity and quality, soil characteristics and weather conditions. We provide an overview of the most utilized nodes and wireless technologies. Lastly, we will discuss the challenges and the best practices for the implementation of sensor-based irrigation systems.


2021 ◽  
Vol 15 (4) ◽  
pp. 546-553
Author(s):  
Ivan Plaščak ◽  
Mladen Jurišić ◽  
Dorijan Radočaj ◽  
Milan Vujić ◽  
Domagoj Zimmer

The introduction of precision agriculture increased the efficiency of plant production, while simultaneously reducing the production cost. Precision irrigation can be considered as the combination of sensors, computer software and irrigation systems. Precision irrigation has reduced water consumption and increased yields, and thus increased economic profits. The development of new crop monitoring technologies in precision irrigation has been made possible by the imaging and analysis of real-time crop condition data. The aim of this study was to describe the present state and possibilities of precision irrigation in practice in the EU and Croatia. An overview of the current precision irrigation technologies, as well as its adaptive management to the decision-making in agricultural water management, represents a fundamental basis for future practical studies in precision irrigation.


2017 ◽  
Vol 8 (2) ◽  
pp. 865-869
Author(s):  
S. Shahidian ◽  
J. M. R. Serrano ◽  
R. Hakimi

The purpose of this work was to evaluate the capacity of existing landscape irrigation equipment to deliver the expected irrigation depth at a level of uniformity that can potentially be used in a precision irrigation management environment. Popular pop-up sprayer systems from two leading manufacturers (Rain-bird and Hunter variable arc and fixed arc nozzles) were subject to spatial distribution tests, in order to establish the application patterns under ideal conditions. The results indicate that it is not possible to fully rely on the catalog application depth values, with some variable arc nozzles applying up to 200% of the catalog values. These nozzles can have low values of uniformity, with Christiansen´s uniformity coefficient, CU, of between 0.31 and 0.70, making it difficult to obtain good uniformity even under a back-to-back setting. These results indicate that variable arc nozzles are not recommended for use in precision agriculture. It is preferable to use fixed arc nozzles, after actual field evaluation.


Author(s):  
Ioan Lita ◽  
Daniel Alexandru Visan ◽  
Alin Gheorghita Mazare ◽  
Laurentiu Mihai Ionescu ◽  
Adrian Ioan Lita

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 507 ◽  
Author(s):  
Dariusz Wrzesiński ◽  
Leszek Sobkowiak

Identification of river flow regime and its possible changes caused by natural factors or human activity is one of major issues in modern hydrology. In such studies different approaches and different indicators can be used. The aim of this study is to determine changes in flow regime of the largest river in Poland—the Vistula, using new, more objectified coefficients and indices, based on data recorded in 22 gauges on the Vistula mainstream and 38 gauges on its tributaries in the multi-year period 1971–2010. The paper consists of three main parts: in the first part, in order to recognize changes in the flow regime characteristics along the Vistula, data from gauges located on the river mainstream were analyzed with the help of the theory of entropy. In the second part gauging stations on the Vistula mainstream and its tributaries were grouped; values of the newly introduced pentadic Pardé’s coefficient of flow (discharge) (PPC) were taken as the grouping criterion. In the third part of the study a novel method of determining river regime characteristics was applied: through the recognition of the temporal structure of hydrological phenomena and their changes in the annual cycle sequences of hydrological periods (characteristic phases of the hydrological cycle) on the Vistula River mainstream and its tributaries were identified and their occurrence in the yearly cycle was discussed. Based on the detected changes of the 73-pentad Pardé’s coefficients of flow four main types of rivers were distinguished. Transformation of the flow regime was reflected in the identified different sequences of hydrological periods in the average annual cycle. It was found that while transformation of the Vistula River regime occurred along its whole course, the most frequent changes were detected in its upper, mountainous reaches, under the influence of the flow characteristics of its tributaries. This allowed the Vistula to be considered the allochthonous river. These findings are interesting not only from a theoretical point of view, but they also can be valuable to stakeholders in the field of the Vistula River basin water management and hydrological forecasting, including flood protection, which has recently become a matter of growing concern due to the observed effects of climate change and human impact.


Perfusion ◽  
2021 ◽  
pp. 026765912199618
Author(s):  
Mirko Kaluza ◽  
Benjamin May ◽  
Torsten Doenst

Objective: The COVID-19 pandemic requires thinking about alternatives to establish ECMO when often-limited hardware resources are exhausted. Heart-lung-machines may potentially be used for ECMO but contain roller pumps as compared to centrifugal pumps in ECMO-circuits. We here tested roller pumps as rescue pump for ECMO-establishment. Methods: We set up in vitro circuits on roller pumps from C5 heart-lung-machine with 5 l/minutes flow. In two series, we placed either PVC or silicon tubing for an ECMO circuit into the roller pump. We assessed the mechanical stress on the tubing (aiming to run the pump for at least 1 week), measured the temperature increase generated by the friction and assessed flow characteristics and its measurement in simulated situations resembling tube kinking and suction. Results: The roller pumps led to expected and unexpected adverse events. PVC tubing burst between 36 and 78 hours, while silicon tubing lasted for at least 7 days. At 7 days, the silicone tubing showed significant signs of roller pump wear visible on the outside. The inside, however, was free of surface irregularities. Using these tubings in a roller pump led to a remarkable increase in circuit temperature (PVC: +12.0°C, silicone +2.9°C). Kinking or suction on the device caused the expected dramatic flow reduction (as assessed by direct measurement) while the roller pump display continued to show the preset flow. The roller pump is therefore not able to reliably determine the true flow rate. Conclusion: Roller pumps with silicone tubing but not PVC tubing may be used for running ECMO circuits. Silicone tubing may endure the roller pump shear forces for up to 1 week. Thus, repeated tubing repositioning may be a solution. Circuit heating and substantial limitations in flow detection should increase attention if clinical use in situations of crisis is considered.


Author(s):  
E A Bunt ◽  
B Parsons ◽  
F Holtzhausen

Examination of flows in a particular case of dissimilar pumps coupled in series or in parallel (without check valves) showed that the ‘classical’ graphical solution of combined characteristics in the [+H, +Q] quadrant did not accord with the output field in certain regions. To predict the full flow fields, it was necessary to take into account dissipative flow characteristics in two other quadrants: for low-output parallel flow (when there is still flow available from the pump of higher head when the ‘weaker’ pump's flow has been reduced to zero), that in the [+H, –Q] quadrant; and for high series flow (after the output head of the pump of lower maximum flow has been reduced to zero), that in the [–H, +Q] quadrant. This problem does not arise when the pumps have identical characteristics.


2010 ◽  
Vol 2 (1) ◽  
pp. 83-99
Author(s):  
Chen Jing ◽  
Kan Shizuan ◽  
Tong Zhihui

AbstractThis paper, based on historical research on irrigation administration in the Dongping area and on-site investigations into its current state, explores the benefits and problems produced by two institutional changes. As a common pool resource situation, irrigation systems’ “provision” and “appropriation” are two separate issues; any institutional change must thus offer two different solutions. The study concludes that the participatory changes undertaken in the Dongping irrigation area failed, in the end, to resolve the problem of irrigation system sustainability. In particular, it proved difficult for collective action to take place around provision, which led to difficulties in operating the irrigation system.


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