Hydraulic Energy Research Articles

Experimental investigation of gabion inclined drops as a sustainable solution for hydraulic energy loss

Gabions are structures that control the erosion and scouring whilst provide an eco-friendly and sustainable solution, used also for energy loss. Despite a wide range of previous studies, different hydraulic aspects of gabions have not yet been understood well. In that sense, this study investigates the behavior of hydraulic parameters of solid and gabion inclined drops. The results indicated that with increasing the relative critical depth in both types, the relative energy loss reduces. A comparison between solid and gabion inclined drops showed that the relative energy loss and downstream relative depth increases by 82% and 50%, respectively. In all cases, downstream Froude number of the gabion inclined drop range is reduced from 4.17–8.52 to 1.28–2.64. Finally, equations to estimate main hydraulic parameters due to the use of gabion inclined drops and proper discussions about their effect on the sustainability of water infrastructures are presented.

Energy efficiency prediction model and energy characteristics of subsea disc pump based on velocity slip and similarity theory

The variable-speed energy efficiency prediction model (EEPM) of subsea disc pump is the key to achieve double gradient in deepwater drilling, and it has also been the difficulty of pressure control matching and energy conservation. In this paper, the radial slip vortices are fully considered, and average slip method of circumferential velocity, relative velocity and absolute velocity at impeller outlet is proposed. Based on hydraulic energy loss and mechanical energy loss, the calculation method of theoretical head and similar parabola in similarity theory is improved, and EEPM is established. In addition, a new multifunctional test system and data processing model are designed to reduce the error. The experimental results show that the accuracy of EEPM is increased by about 4% when deviating from the rated speed by more than 20%, and the accuracy is about 99% within 20%. From the simulation, the flow passage is mainly a mixed-type movement, such as S-type double vortex and O-type single vortex. The turbulence kinetic energy near the volute tongue is the largest. The study improves the energy efficiency of drilling pressure regulation, and also provides a new perspective to the energy efficiency optimization and energy conservation of similar centrifugal pump and vortex pump.

THE EFFECT OF ENVIRONMENTAL CONCERN ON RENEWABLE ENERGY AWARENESS, PERCEIVED BENEFIT AND INTENTION TO USE

Energy use-related environmental and social concerns and problems have led to the development of renewable (RE) energy types such as wind, solar, hydraulic, and geothermal energy. Increasing environmental concerns, as well as public awareness and positive attitudes towards sustainable energy types, have played an important role in this development. The present study investigated the effects of the mentioned environmental concerns on the attitudes towards renewable energy and renewable energy usage intention with a proposed structural model. In the first part of the proposed model, the effect of environmental concerns on the awareness and perceived benefits of RE, and in the second part, the effect of awareness and perceived benefits of RE on the RE usage intention was examined. Structural Equation Modelling (SEM) was used to test the model. Regarding the fitness of the model, the chi-square value was calculated as 141.77, and the (χ2/df) value as 2.36. Analysis results demonstrated that one unit increase in environmental concerns would increase awareness of RE by 0.63 and perceived benefits by 0.51 unit. It was also found that awareness of RE would increase the perceived benefits of RE and that especially the increase in awareness positively would affect RE usage intention.

Multifunctional and superhydrophobic cellulose composite paper for electromagnetic shielding, hydraulic triboelectric nanogenerator and Joule heating applications

• Multifunctional and superhydrophobic cellulose composite paper (CCP) is fabricated. • CCP shows a high EMI shielding effectiveness and electrical conductivity. • The superhydrophobic surface is used as the hydraulic triboelectric nanogenerator. • Surface temperature of CCP can reach 140 °C with a applied voltage of 6 V. Cellulose-based materials have attracted tremendous interest recently due to their fascinating merits of renewability, biodegradability, and low cost, holding great promise in electromagnetic protection, clean energy harvesting, and thermal management. However, the simple and effective integration of multiple functions into single cellulose material remains a challenge. Herein, we report the fabrication of a multifunctional and superhydrophobic cellulose composite paper (CCP) via coated MXene modified by in-situ polymerized polypyrrole and PDMS/candle soot on the opposite surface of the paper. CCP exhibits high-performance electromagnetic interference shielding effectiveness (~40 dB) while maintaining high electrical conductivity (1467 S/m). Moreover, the superhydrophobic surface of CCP can be used as the hydraulic triboelectric nanogenerator (H-TENG) to harvest water energy due to the liquid–solid contact triboelectrification and electrostatic induction. The hydraulic triboelectric energy can be captured and released when water droplets drop from a height of 2 cm and roll at a tilt angle of 20°, the output current can reach a peak of 0.8 nA. Furthermore, the surface saturation temperature of CCP can reach 140 °C with a low applied voltage of 6 V enabled by the Joule effect. Thus, CCP holds great potentials in applications of integrated smart electronics, clean energy harvesting, and thermal management.

Evaluation of the hydraulic potential with hydrokinetic turbines for isolated systems in locations of the Amazon region

In Brazil, the Amazon River has a high potential to harness hydraulic energy to generate electricity. This article presents a methodology to quantify the hydraulic potential for the hydrokinetic technology of the Amazon River’s segments, identifying and calculating the theoretical, geographic, technical and market potential of the places. The methodology uses the hydrodynamic behavior of the river as a base, using the computational code called SisBaHiA® to evaluate the potential in large segments of the Amazon River. It provides important technical inputs to guide the development of hydrokinetic technology in the Brazilian Amazon, where most of the systems are isolated, with diesel power plants (without access to the National Interconnected System) or communities without access to the power grids. It presents original and historical data in the characterization of the river that reflect the persistence of velocity. Our results indicate great potential for its development, as there is theoretical potential 12,028 MW, geographic 4.77 MW/km2, technical 1,479 MW and market 626 MW, where it would be possible to generate 7,969 GWh of renewable electricity and 909.72 MW of firm energy. This study contributes to the formulation of public policies to implement hydrokinetic technology for isolated systems in these and other places with similar environmental conditions.

Energy Recovery in Pressurized Hydraulic Networks

This paper aims to evaluate the possibility of using non-utilized hydraulic energy in urban water distribution systems. For this purpose, the viability and possible alternatives of installing conventional turbines or pumps working as turbines (PATs = Pumps as Turbines) at the head of pressure hydraulic networks in two towns in the province of Huelva have been studied: Canaveral de Leon and Aracena (Andalucia, southwest Spain). Sensitivity analyses are carried out for: (a) To study the feasibility and efficiency of installing turbines or PATs in the hydraulic networks; (b) To determine the required hydraulic capacity of the turbines or PATs; (c) To analyse the installation points in the pipeline network; and (d) To evaluate the possible generation of electrical energy. The evaluation of the recoverable amount of hydraulic energy in both water distribution systems requires the application of the energy conservation equation, taking into account the calculation of load losses, the Darcy-Weisbach equation. A diagram energy height-flow rate with different working ranges of commercial turbines/PATs was used for the selection of the appropriate hydraulic machine. The results obtained of the Aracena hydraulic network show that the best solution would be the installation of a 2 kW BANKI that could generate an approximate annual energy of 17,52 MWh/year. In the Canaveral de Leon water supply system a 0,75 kW BANKI turbine with an approximate annual energy generation of 6,57 MWh/year is proposed as the best solution.

Relaxation damage control via fatigue-hydraulic fracturing in granitic rock as inferred from laboratory-, mine-, and field-scale experiments

The ability to control induced seismicity in energy technologies such as geothermal heat and shale gas is an important factor in improving the safety and reducing the seismic hazard of reservoirs. As fracture propagation can be unavoidable during energy extraction, we propose a new approach that optimises the radiated seismicity and hydraulic energy during fluid injection by using cyclic- and pulse-pumping schemes. We use data from laboratory-, mine-, and field-scale injection experiments performed in granitic rock and observe that both the seismic energy and the permeability-enhancement process strongly depend on the injection style and rock type. Replacing constant-flow-rate schemes with cyclic pulse injections with variable flow rates (1) lowers the breakdown pressure, (2) modifies the magnitude-frequency distribution of seismic events, and (3) has a fundamental impact on the resulting fracture pattern. The concept of fatigue hydraulic fracturing serves as a possible explanation for such rock behaviour by making use of depressurisation phases to relax crack-tip stresses. During hydraulic fatigue, a significant portion of the hydraulic energy is converted into rock damage and fracturing. This finding may have significant implications for managing the economic and physical risks posed to communities affected by fluid-injection-induced seismicity.

Design and optimization investigation on hydraulic transmission and energy storage system for a floating-array-buoys wave energy converter

The energy density of wave power in China is relatively low compared with that of the wave power in Europe. Simply improving the shape or size of the energy-capturing mechanism for a wave energy converter (WEC) cannot directly result in a larger energy output. Instead, a solution of array-type energy-capturing mechanism integrating marine structure bares practical application potential to increase the power take-off (PTO) productivity. To exploit the conditions in China, a WEC system integrating oscillating-array-buoys with a floating platform is proposed and sea trials of a 10 kW prototype confirmed the feasibility of the floating-array-buoys WEC (FABWEC) system for wave energy conversion. However, sea trials data indicated that the energy conversion performance of the mechanical transmission design in the FABWEC system was relatively poor under the low wave energy density, suggesting the urgency of improving energy conversion and storage system to the increase of system performance. Herein, a hydraulic transmission and accumulator system (HTAS) is designed to replace the original mechanical transmission and flywheel system (MTFS), aiming to enhance the total energy conversion performance of the FABWEC system. The hydrodynamic simulation and numerical solution of the wave energy capture mechanism in the FABWEC system are carried out to facilitate the design and main components selection of the HTAS. And then the simulation and optimization of the designed HTAS are performed by the hydraulic simulation software. It is worth noting that there have been few reports on the operating performance of the HTAS with respect to buoys. In the hydraulic optimization process, the final optimization parameters of the HTAS are obtained by comparing the dynamic characteristics of the system, including system pressure, flow rate, motor torque and angular velocity, under the conditions with or without accumulator, with different buoy numbers and with different buoy phase differences. The simulated results show that the accumulator could effectively damp out the fluctuations in output power to turn the wave energy into a dispatchable power source; The energy conversion and output performances of the HTAS behave better with the increase of the buoys number and buoys phase difference, but the space and cost factors need to be taken into consideration in the actual operation; Within the research scope of this paper, the HTAS has an optimal performance for energy conversion and output when the number of buoys on one side of the floating platform is 5 and the phase difference between the buoys is 60°; Under the optimized conditions, the average output power of the hydraulic motor after stable operation of the HTAS can reach 5.8 kW. Significantly, the optimized HTAS could deliver the required electricity power steadily under the low wave energy density and has been practically applied to the next generation FABWEC prototype.

Demonstration of a piston type integrated high pressure pump-energy recovery device for reverse osmosis desalination system

Energy recovery device (ERD) plays a vital role in reducing the energy consumption of seawater reverse osmosis (SWRO) desalination process. Numerous investigations have been conducted for large scale ERDs, yet few studies for small scale ERDs (capacity less than 50 m3/d) have been reported. In this paper, a newly invented piston type integrated high pressure pump-energy recovery device (HPP-ERD), which synchronously pressurizes the raw seawater and recovers hydraulic energy from the concentrated brine, is introduced. The structure and working principle of the HPP-ERD is offered. Three versions of HPP-ERD prototypes are tested in a laboratory emulate platform and the test results can manifest the energy-saving feasibility of the HPP-ERD. A practical small scale SWRO project with a capacity of 50 m3/d using the HPP-ERD is surveyed. A performance analysis of the proposed project is implemented for one-month operating duration, which reveals the acceptable energy-saving capability and durability of the HPP-ERD under actual working circumstances. An economic analysis is finally performed and the analysis consequence indicates that the utilization of the HPP-ERD instead of a single high pressure pump can diminish both the payback period and the desalinated water cost of the proposed project remarkably.

Environmental triggers of faunal changes revealed by benthic foraminiferal monitoring

Benthic foraminifera are deemed sensitive indicators of environmental conditions. Triggers and magnitudes of faunal response to environmental changes are yet poorly constrained. Benthic foraminiferal faunas were monitored annually at Ria Formosa (Algarve, Portugal) coastal lagoon since 2013. Distinct environmental changes were recognised during the monitoring period. The relocation of a tidal inlet in winter 2015 effected faster flushing, higher tidal levels, and stronger currents in the Esteiro do Ancão tidal channel. The epibenthic foraminiferal species Asterigerinata mamilla increased in abundance and the population densities of the whole fauna were double as high as before inlet relocation. Enhanced sediment redeposition was recorded and extensive polychaete colonies successively replaced firmground patches with oysters. The standing stock of the foraminiferal fauna declined in the next year due to food impoverishment, while the high hydraulic energy levels and high percentages of Asterigerinata mamilla maintained. Benthic foraminifera responded much faster to environmental perturbations than macroorganisms identifying them as powerful proxies in environmental studies.

Energy recovery for hybrid hydraulic excavators: flywheel-based solutions

Hybridization is an effective method to reduce fuel consumption and emissions of toxic pollutants generated by hydraulic excavators (HEs). This paper first reviews various hybrid HEs architectures with electrical, hydraulic, or flywheel-based energy recovery systems (ERSs). Flywheel-based ERS is not widely used in HEs but has achieved widespread concern in the automotive field. In light of this, the differences between HEs and automobiles are discussed to highlight the potential of flywheel-based ERSs in HEs. Then, the paper compares corresponding energy storage devices in these ERSs from many aspects. The comparison shows that flywheels display many advantages over other energy storage devices. Meanwhile, the drawbacks of flywheels are discussed in detail, indicating that the drawbacks can be offset by other advantages. The results show that the flywheel-based ERS is competitive with the electrical and hydraulic competitors for HEs. Finally, the challenges to the flywheel technology and future work are presented.

Energy Consumption Structure and Its Improvement of Low-Lifting Capacity Scissor Lift

The article presents the experimental investigation of low-lifting capacity hydraulic scissor lift energy consumption. The analysis is based on experimental tests of two individual drives of the scissor lift: the conventional one and the variable-speed electro-hydraulic one. The investigation focuses on the study of the total energy consumption for lifting and lowering the scissor lift with different masses of transported cargo and also power consumptions of each element supplying these systems. Particular attention was paid to the significant impact of power supply on each control component as the main factor of reduction in the energetic efficiency of the low-lifting capacity scissor lift. A comparison of both drives indicated that the mass of transported cargo has a significant influence on the choice of the drive used. Results of the research show that significant energetic savings are obtained, as the modernized propulsion system consumes 67% energy of the standard one. A decrease in the percentage of energy losses with the increase in the mass handled led to the conclusion that the enhancement of propulsion systems in scissor lifts should be especially considered in machines carrying big loads.

Automotive Power Systems [Book News

The difficulty in presenting a book about automotive power systems is that they are complex, multidisciplinary technologies, requiring knowledge of mechanics, electrical engineering, and power electronics to be understood. This task was undertaken by the authors who are involved in both the industrial and academic industrial electronics arena. As the main challenge in vehicle electrification consists of replacing enginebased mechanical, pneumatic, or hydraulic ancillary energy sources with electrical energy processed through an electromagnetic device, the organization of this book follows the architecture of an electrical power system for a conventional engine-based vehicle. This is a well-written book with richly illustrated text consisting of 326 figures and 28 tables that achieve a balance between theory and practice. As all of the material is presented at an introductory level, the book is strongly recommended for students and recent graduates who are interested in automotive power electronics activities.

Impact of Water Demand Pattern Variation on Hydraulic Behavior and Water Quality in Water Distribution Systems

Water is the most valuable source for human life. Egypt is one of the driest countries facing an enormous shortage of potable water especially with the population increase and limited water resources. It is becoming aware of the need to preserve water and sustainable water management. Potable water supply pipes are important for delivering water to consumers and serving as the last process between the treatment plant and the consumer. Water demand can vary periodically over the course of the day and for the same average daily demand, the peak value of the demand pattern can vary. These variations in peak demand can have significant effect on the hydraulic behavior of pipes network, water quality, and energy consumption through it. A significant amount of cost is spent on energy consumption in the water supply pipes network. In this research, the effect of water demand pattern variation on hydraulic behavior, water quality and energy consumption in water supply pipes network is studied. EPANET2 software was used to perform the hydraulic analysis through extended period simulation through a hypothetical water supply pipes network. Five patterns of demand variation were adopted in this analysis called pattern demand for big city, village, rural area, industrial zone and hotels. It was found that the type of demand pattern has a significant effect on velocity through the different pipes and pressure head of the different nodes and chlorine decay through the network.

Use of a group of underwater hydraulic tarans for the water supply system

When choosing water-lifting equipment, a number of issues related to the type of water intake structure, the energy for driving the plant, the adopted pressure and control structures, and the automation system are solved. Their structures should be simple, convenient to operate, have an affordable cost, provide the required water supply to the above areas. For agricultural water supply and irrigation of land plots located above the water source, the equipment for lifting water using the energy of the water flow - a hydraulic ram - fully meets the requirements of all known means of mechanizing the water lift. The cascade hydraulic unit operates due to dispersed energy of open water flows and hydraulic impact energy. The use of a cascade hydraulic ram plant on the river will allow the water supply of individual consumers without the cost of electricity, which is absolutely safe for the environment. The proposed topic of work is therefore very relevant.

Determining physical and operational factors influencing pipeline leakage location pattern in water distribution networks using spatial poisson point process

There are four pillars in leakage management strategy for water distribution networks, consist of pressure management, speed of repairs, active leakage control, and asset management. Leakage can be managed by applying the right combination of those factors in the right leakage management strategy. This study conducted in Malang City, East Java, Indonesia. The factors that influence physical water loss in the water distribution system are analyzed by focusing on the physical and operational parameters. The data in this study consist of spatial data and quantitative data. Poisson distribution in the spatial point process is used as the leakage point distribution approximation. From the analysis, it is found that the distribution pattern of pipeline leakage location is categorized as inhomogeneous poisson process, with two types of intensity area. Based on the results of parameter estimation, it is found that the high-intensity area is affected by time of repairs, pipe diameter, pipe length ratio, water supply ratio, and pipe deterioration ratio but not affected by the hydraulic energy demand. While the low-intensity area is influenced by pipe diameter, pipe length ratio, water supply ratio, pipe deterioration ratio, and the hydraulic energy demand but not affected by the time of repairs.

A Computer Program to Support the Selection of Turbines to Recover Unused Energy at Hydraulic Networks

For this paper, a computer program was designed and developed to calculate which turbines could be placed in a water distribution system considering the hydraulic constraints. The aforementioned turbines are placed in locations where we have unused hydraulic energy, i.e., when this energy is dissipated by a regulating valve. In our case, what we do is place a turbine to make use of that excess energy. Once the data has been entered into the program, it provides the type or types of turbines that can be placed in each location, what power these turbines would be, and how much they would generate annually. The program offers us two calculation options. In the first, and simpler, one, it would be done using the net head at the location where the turbine is to be placed. For this option, it would only be necessary to introduce the flow rate, the net head, and the hours that the turbine will be in operation to perform the calculation. The second option would be in the case where we did not have the net head, and, instead, we had the gross head. In this case, we have to calculate the head losses. Normally, this would be the most used option because there are usually no pressure drops. To perform the calculation, in this case, it is necessary to know, apart from what is mentioned in the first option, the characteristics of the pipe (diameter, length, and material).

Water hydraulic soft actuators for underwater autonomous robotic systems

Pneumatic soft actuators are widely studied in soft robotics. However, they are difficult to be used in underwater systems because of air supply and their large air compressor. The existing hydraulic soft actuators are usually actuated by pump-valve system and controlled with pressure feedback. This process is complex, and unsuitable for small autonomous underwater systems. This study presents the deployment of three new soft actuators in underwater robotic systems: (i) a strong water hydraulic soft bending actuator (SWBA) for robotic grippers operated underwater; (ii) a flexible water hydraulic soft bending actuator (FWBA) proposed for a biomimetic fish tail and (iii) a flexible water hydraulic extending soft actuator (FWEA) to implement the crawling motion as a sea cucumber. They can deform under water hydraulic energy rather than pneumatic power, and are actuated with only pumps and controlled on the basis of the supplied voltage of the pump rather than the pressure measured by a pressure sensor. SWBA and FWBA have different bending performance with different gaps in their structures, and FWEA can extend itself with the pressurized water. A simple fabricating method for the three types of water hydraulic soft actuators is explored: casting with molds for different parts and bonding to a whole. Their bending or extending characteristics are tested through experiments for the underwater robotic system. Results show the feasibility and good performance of the constructed water hydraulic soft actuators. The three water hydraulic soft actuators are simple and suitable for small autonomous underwater systems. This research provides new hydraulic soft actuators with simple drive and control for underwater robotic system. The findings will promote the development and offer a new idea for underwater soft actuators.

A superhydrophobic magnetoelectric generator for high-performance conversion from raindrops to electricity

Abstract Traditional utilization of hydraulic power not only requires heavy and bulky electromagnetic generators but also is restricted by geographical condition and the scale of water sources. The development of new protocols which are miniature, flexible and able to generate electricity from disperse hydropower, such as raindrops, is highly required. In this study, we demonstrate the fabrication of a superhydrophobic magnetoelectric generator (SMEG) which is able to generate electricity from rainfall. The SMEG comprises three parts: a polymeric top containing a coil, tiny springs and a magnet/Ecoflex bottom. The tiny springs in the middle could deform/recover when the raindrops impact/leave the SMEG, allowing for the electrical generation of a charge density as high as 51.5 mC/m2, which is beyond the performances of currently reported surface-charge approaches. Related mechanism has been analyzed by the Maxwell numerical simulation, which guides further improvement of the SMEG by tailoring diverse parameters. Furthermore, by serving as the roof cornice at traditional Chinese buildings, the SMEG could convert flow-guiding rainfall impact to electricity, lightening a light-emitting diode or charging a capacitor to 0.78 V within 700 s. We believe that such a SMEG can extend the energy harvesting of disperse hydraulic energy.

A Survey of Powertrain Technologies for Energy-Efficient Heavy-Duty Machinery

This article presents a comprehensive, multidisciplinary overview of the development of powertrain technologies for energy-efficient heavy-duty earthmoving machines. The heavy-duty earthmoving equipment industry has been among the biggest contributors to emissions globally. However, due to high power demand and multidisciplinary powertrain structures, improving the energy efficiency of heavy-duty mobile machines has been a pressing and challenging task in the industry. To cope with this challenge, hydraulics and power electronics (PE) have been the key driving forces. As such, the relative developments in both fields are covered in this article. For hydraulics, developments of efficient hydraulic circuits will be overviewed in detail along with the introduction of hydraulic energy recovery technologies. In addition, developments of PE architectures in hybrid and electrified machines will be introduced. Furthermore, potential medium-voltage dc mining site power distribution and the valves of wide bandgap devices will also be discussed with the hope to open up new research opportunities in PE. Moreover, emerging hybrid electrohydraulic drive technology is introduced. Based on the overview in this article, it is anticipated that electrohydraulic hybridization will be the future trend in the earthmoving machine industry. Deeper collaboration between the two areas is desirable.