scholarly journals Improving Irrigation in Remote Areas: Multi-Objective Optimization of a Treadle Pump

Author(s):  
Pablo S. Santaeufemia ◽  
Nathan G. Johnson ◽  
Christopher McComb ◽  
Kenji Shimada

Water-lifting technologies in rural areas of the developing world have enormous potential to stimulate agricultural and economic growth. The treadle pump, a human-powered low-cost pump designed for irrigation in developing countries, can help farmers maximize financial return on small plots of land by ending their dependency on rain-fed irrigation systems. The treadle pump uses a suction piston to draw groundwater to the surface by way of a foot-powered treadle attached to each suction piston. Current treadle pump designs lift water from depths up to 7 meters at a flow-rate of 1–5 liters per second. This work seeks to optimize the design of the Dekhi style treadle pump, which has gained significant popularity due to its simplicity. A mathematical model of the working fluid and treadle pump structure has been developed in this study. Deterministic optimization methods are then employed to maximize the flow rate of the groundwater pumped, maximize the lift height, and minimize the volume of material used for manufacturing. Design variables for the optimization included the dimensions of the pump, well depth, and speed of various parts of the system. The solutions are subject to constraints on the geometry of the system, the bending stress in the treadles, and ergonomic factors. Findings indicate that significant technical improvements can be made on the standard Dekhi design, such as increasing the size of the pump cylinders and hose, while maintaining a standard total treadle length. These improvements could allow the Dekhi pump to be implemented in new regions and benefit additional rural farmers in the developing world.

2018 ◽  
Author(s):  
Christopher McComb ◽  
Pablo S Santaeufemia ◽  
Nathan G Johnson ◽  
Kenji Shimada

Water-lifting technologies in rural areas of the developing world have enormous potential to stimulate agricultural and economic growth. The treadle pump, a human-powered low-cost pump designed for irrigation in developing countries, can help farmers maximize financial return on small plots of land by ending their dependency on rain-fed irrigation systems. The treadle pump uses a suction piston to draw groundwater to the surface by way of a foot-powered treadle attached to each suction piston. Current treadle pump designs lift water from depths up to 7 meters at a flow-rate of 1–5 liters per second. This work seeks to optimize the design of the Dekhi style treadle pump, which has gained significant popularity due to its simplicity. A mathematical model of the working fluid and treadle pump structure has been developed in this study. Deterministic optimization methods are then employed to maximize the flow rate of the groundwater pumped, maximize the lift height, and minimize the volume of material used for manufacturing. Design variables for the optimization included the dimensions of the pump, well depth, and speed of various parts of the system. The solutions are subject to constraints on the geometry of the system, the bending stress in the treadles, and ergonomic factors. Findings indicate that significant technical improvements can be made on the standard Dekhi design, such as increasing the size of the pump cylinders and hose, while maintaining a standard total treadle length. These improvements could allow the Dekhi pump to be implemented in new regions and benefit additional rural farmers in the developing world.


Author(s):  
Amos G. Winter

The Leveraged Freedom Chair (LFC) is a low-cost, all-terrain, lever-propelled wheelchair designed primarily for use in developing countries. LFC technology was conceived because 70 percent of wheelchair users in these markets live in rural areas and no currently available mobility aid enables them to travel long distances on rough terrain and maneuver in tight, indoor confines. Because developing world markets impose constraints on cost, durability, and performance, a novel solution was required to satisfy stakeholder requirements. The key innovation behind the LFC is its single speed, variable mechanical advantage lever drivetrain. The user effectively changes gear by shifting his hands along the levers; grasping near the ends increases torque, while grasping near the pivots enables a larger angular displacement with every stroke, which increases speed. The drivetrain is made from low-cost bicycle parts found throughout the developing world, which enables the LFC to be sold for $200 and be repairable anywhere. During three user trials in East Africa, Guatemala, and India, stakeholder feedback was used to refine the chair between trials, resulting in a device 9.1 kg (20 lbs) lighter, 8.9 cm (3.5 in) narrower, and with a center of gravity 12.7 cm (5 in) lower than the first iteration. Survey data substantiated increases in performance after successive iterations. Quantitative biomechanical performance data were also measured during the Guatemala and India trials, which showed the LFC to be 76 percent faster and 41 percent more efficient during a common daily commute, and able to produce 53 percent higher peak propulsion force compared to conventional, pushrim-propelled wheelchairs. The LFC offers comparable performance at less than one-twentieth the cost of off road wheelchairs available in the rich world. Stakeholder feedback and the highly-constrained environment for which the LFC was created drove the technology towards a novel, innovative solution that offers a competitive advantage in both developing and developed markets. The paper concludes with a description of how the LFC is a “constraint-driven innovation.” This idea ties together the theories of “disruptive innovation” and “reverse innovation,” and may be used as a design tool for engineers striving to create technologies that have global impact.


Author(s):  
Neelesh Bhandari ◽  
Murali Damodaran

The rope washer pump is a hydraulic device in which the rope consisting of equally spaced washers is pulled upward to displace the fluid volume to the desired head before delivering it at the outlet. The straightforward working principle, the ease of manufacture, and the low cost are the main advantages of this pump over a reciprocating pump. The rope washer pump can be either driven by electric motor, by a wind mill, or manually for pumping brine water for salt harvesting in rural areas. In this study computational fluid dynamics (CFD) modeling of the rope washer pump is used to estimate the performance characteristics of the pump. Experimental studies of rope pump can only provide data related to flow rate and head it can achieve, while using CFD it is possible to obtain insight about the flow physics inside the pump. These insights can be used to propose design improvements for more efficient pump operation. Unsteady, incompressible Navier-Stokes equations are solved using a finite volume scheme on unstructured hybrid polyhedral-prismatic overset meshes to obtain flow parameters and the volume of fluid (VOF) interface tracking method is used to capture the free water surface inside the pump by tracking the volume fraction of fluid on each cell. The k-ε turbulence model is used to model turbulence and the motion of the washer is handled by using overset mesh technique for the computation. Leakage between the washer and housing is also considered in this computation. Pump characteristics are calculated for different pump speeds. Thus the flow variables obtained by computation are used to predict the efficiency and flow rate at different washer speed. The pump characteristics define the behavior of the rope washer and are characterized by effective flow rate, volumetric efficiency, power input and the pump torque. These performance characteristics are extracted from the computed flow fields and used for evaluating the optimum range of pump speed, with highest efficiency and flow-rate. This model can serve as a basis for future design optimization studies.


2021 ◽  
Vol 897 (1) ◽  
pp. 012003
Author(s):  
L F Patiño ◽  
U Azimov ◽  
C P Tavera-Ruiz ◽  
J M Castellanos ◽  
P Gauthier-Maradei ◽  
...  

Abstract This research study develops the design and model of a Solar Organic Rankine Cycle (SORC) coupled to a bio-digester for small-scale generation in rural areas, in Betulia, Colombia. Moreover, the model is optimised employing a Genetic Algorithm with the software Matlab and the thermodynamic library CoolProp. The objective variables were the mass flow rate of the working fluid, the pressure and temperature of the expander inlet, the solar collectors’ type and the temperature of the water circuit for the bio-digester. The results indicate an overall efficiency between 8.42 and 9.45% with a Levelized Cost of Energy (LCE) between 3.85 and 5.63 £/W. Additionally, the power output is directly related to the mass flow rate of the working fluid. Likewise, increasing the scale of the SORC decreases the LCE. Finally, the results suggest that a superheated fluid reduces the efficiency and the LCE and can deliver more heat to the bio-digester. It is advisable the utilisation of a scroll expander and a counter-flow plate exchanger with a Direct Vapour Generation configuration. The model is a flexible tool capable of integrating more equations and components, with the evaluation of different fitness functions.


Author(s):  
Vitaliy A. Zuyevskiy ◽  
Daniil O. Klimyuk ◽  
Ivan A. Shemberev

Gear pumps are an important element of many production systems and their replacement in case of failure can be quite expensive, so it is important to have a modern and well-tuned technology for their recovery. There are many methods for restoring the pump's performance, depending on the reason that led to its failure. (Research purpose) The research purpose is in determining what causes most often lead to loss of pump performance, and developing a recovery method that provides the greatest post-repair service life of the pump and low cost of repair. (Materials and methods) Authors took into account that the applied coatings must have sufficient adhesion strength and resistance to mechanical, thermal and corrosion loads during operation. It was found that most often significant leaks of the working fluid, leading to failure, occur due to an increase in the gap between the inner surface of the housing and the gears due to active wear of the housing wells. Authors determined that the method of electric spark treatment of worn-out housing wells is best suited to perform the task (a large post-repair resource and low costs). (Results and discussion) It was found by laboratory studies of the adhesion strength of electric spark coatings with various electrodes that the best transfer of the material to the substrate is provided by bronze electrodes BrMKts3-1. It was noted that the coatings applied using the BrMKts3-1 electrode have high strength properties. (Conclusions) Research conducted in the center for collective use "Nano-Center" VIM confirmed the possibility of effective recovery of the gear pump by electric spark treatment.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hannah R. Doran ◽  
Theo Renaud ◽  
Gioia Falcone ◽  
Lehua Pan ◽  
Patrick G. Verdin

AbstractAlternative (unconventional) deep geothermal designs are needed to provide a secure and efficient geothermal energy supply. An in-depth sensitivity analysis was investigated considering a deep borehole closed-loop heat exchanger (DBHE) to overcome the current limitations of deep EGS. A T2Well/EOS1 model previously calibrated on an experimental DBHE in Hawaii was adapted to the current NWG 55-29 well at the Newberry volcano site in Central Oregon. A sensitivity analysis was carried out, including parameters such as the working fluid mass flow rate, the casing and cement thermal properties, and the wellbore radii dimensions. The results conclude the highest energy flow rate to be 1.5 MW, after an annulus radii increase and an imposed mass flow rate of 5 kg/s. At 3 kg/s, the DBHE yielded an energy flow rate a factor of 3.5 lower than the NWG 55-29 conventional design. Despite this loss, the sensitivity analysis allows an assessment of the key thermodynamics within the wellbore and provides a valuable insight into how heat is lost/gained throughout the system. This analysis was performed under the assumption of subcritical conditions, and could aid the development of unconventional designs within future EGS work like the Newberry Deep Drilling Project (NDDP). Requirements for further software development are briefly discussed, which would facilitate the modelling of unconventional geothermal wells in supercritical systems to support EGS projects that could extend to deeper depths.


Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 500
Author(s):  
Jian Chen ◽  
Wenzhi Gao ◽  
Changhai Liu ◽  
Liangguo He ◽  
Yishan Zeng

This study proposes the improvement of the output performance of a resonant piezoelectric pump by adding proof masses to the free ends of the prongs of a U-shaped piezoelectric resonator. Simulation analyses show that the out-of-phase resonant frequency of the developed resonator can be tuned more efficiently within a more compact structure to the optimal operating frequency of the check valves by adjusting the thickness of the proof masses, which ensures that both the resonator and the check valves can operate at the best condition in a piezoelectric pump. A separable prototype piezoelectric pump composed of the proposed resonator and two diaphragm pumps was designed and fabricated with outline dimensions of 30 mm × 37 mm × 54 mm. Experimental results demonstrate remarkable improvements in the output performance and working efficiency of the piezoelectric pump. With the working fluid of liquid water and under a sinusoidal driving voltage of 298.5 Vpp, the miniature pump can achieve the maximum flow rate of 2258.9 mL/min with the highest volume efficiency of 77.1% and power consumption of 2.12 W under zero backpressure at 311/312 Hz, and the highest backpressure of 157.3 kPa under zero flow rate at 383 Hz.


Author(s):  
Matthew L. Cavuto ◽  
Matthew Chun ◽  
Nora Kelsall ◽  
Karl Baranov ◽  
Keriann Durgin ◽  
...  

Transfemoral (above-knee) amputees face a unique and challenging set of restrictions to movement and function. Most notably, they are unable to medially rotate their lower-leg and subsequently cross their legs. The best and most common solution to this issue today is a transfemoral rotator, which allows medial rotation of the leg distal to the knee through a lockable turntable mechanism. However, currently available transfemoral rotators can cost thousands of dollars, and few equivalent technologies exist in the developing world. This paper, supported by the results of field studies and user testing, establishes a framework for the design of a low-cost and easily manufacturable transfemoral rotator for use in the developing world. Two prototypes are presented, each with a unique internal locking mechanism and form. A preliminary field study was conducted on six transfemoral amputees in India and qualitative user and prosthetist feedback was collected. Both prototypes successfully allowed all subjects to complete tasks such as crossing legs, putting on pants, and tying shoes while maintaining functionality of walking and standing. Future iterations of the mechanism will be guided by a combination of the most positively received features of the prototypes and general feedback suggestions from the users.


Author(s):  
Qutaiba I. Ali ◽  
Issam Jafar

Aims: The aim of the Green Communication Infrastructure ‎‎(GCI) project is to understand the idea of a self ‎‎"sustainably" controlled correspondence foundation ‎fitting for smart city application fields. ‎ Background: This paper shows the endeavors to understand the idea of a ‎self "sustainably" energized communication foundation ‎fitting for smart city application fields. The recommended ‎Green Communication Infrastructure (CGI) comprises ‎different kinds of remote settled (or even versatile) hubs ‎performing diverse activities as per the application ‎requests. An imperative class of these hubs is the Wireless ‎Solar Router (WSR). Objective: The work in this venture was begun in 2009 with the aim ‎of demonstrating the essential advances that must be taken to ‎accomplish such framework and to proclaim the value of ‎embracing natural vitality assets in building mission ‎basic frameworks. Alternate destinations of this venture ‎are introducing a sensibly cost, solid, verified, and simple ‎to introduce correspondence foundation.‎ Method: The arrangement to actualize the GCI was accomplished ‎subsequent to passing two structure levels: device level and ‎system level. Result: The suggested system is highly applicable and serves a wide ‎range of smart city application fields and hence many ‎people and organizations can utilize this system. ‎ Conclusion: The presence of a reliable, secured, low cost, easy to install ‎and self-powered communication infrastructure is ‎mandatory in our nowadays. The communities in ‎developing countries or in rural areas need such a system ‎highly in order to communicate with other people in the ‎world which will affect positively their social and ‎economic situation.


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