Energy Recovery Device Research Articles

Liquid flow and mixing investigation inside rotary energy recovery device: A numerical study

Liquid flow and mixing investigation inside rotary energy recovery device: A numerical study

Numerical investigation on a quaternary-driven rotary energy recovery device for desalination system: Performance evaluation and theoretical validation

Numerical investigation on a quaternary-driven rotary energy recovery device for desalination system: Performance evaluation and theoretical validation

A comprehensive modeling approach for intricate bearing flows within a rotary energy recovery device

A comprehensive modeling approach for intricate bearing flows within a rotary energy recovery device

Development of a Piezoceramic Harvester for Sea Waves Energy Recovery in Environmental Monitoring Buoys.

In the last decades, marine environment monitoring has gained significant attention as it plays a fundamental role in ecosystem health and anthropogenic impact evaluation. This study presents the development of a sea wave energy recovery device based on piezoceramic harvesting, designed to contribute to the energy self-sufficiency of an environmental monitoring buoy. The system consists of a flexible S-shaped arm anchored to the buoy structure; the buoyancy system at the free end converts wave-induced motion into mechanical stress, deforming the opposite side of the arm, where piezoceramic patches are installed to generate electrical power. An extensive experimental campaign was conducted to perform the electromechanical characterization of the device and to analyze the manufacturing quality of the arm, produced by stereolithographic additive manufacturing. The results demonstrate the ability to harvest kinetic energy across a range of wave frequencies and amplitudes. Under the best conditions, a maximum transfer electric power of 220.2 ± 3.7 µW was reached.

Synergetic Integration of Energy Recovery across Multiple Joint in Human Lower Limb Motion: A Biomechanical Exploration

Current energy harvesting devices in the field of human lower limb energy recovery have the problems of low energy recovery efficiency and large mass and volume. To solve these problems, this article proposes a multijoint synergistic energy recovery device based on the concept of synergistic energy recovery, with the aim of allowing one energy harvester to collect negative work from multiple joints simultaneously. The recovery efficiency of the harvester is improved by increasing the energy recovery source. The mechanism achieves synergistic recovery of negative work in multiple joints of the human lower limb. The mechanical structure consists of a four‐bar mechanism, limit switches, a planetary gear system, and a differential mechanism to complete the energy capture and coupling. Multiple energy streams are superimposed in an orderly manner without loss. The experimental results demonstrate the efficient output of this harvester in collecting and coupling energy in the negative work zone of the knee and hip joints. This integrated multijoint energy harvester achieves an output voltage of 118 V under normal human walking conditions. The device achieves a power output of 3.21 W and a power density of 7.32 W kg−1 at 2 Hz.

A techno-economic study on the utilisation of airborne wind energy for reverse osmosis seawater desalination.

Airborne wind energy is an emerging technology that can harness stronger and more consistent winds in higher altitudes using less mechanical and civil infrastructures than conventional wind energy systems. This article outlines a techno-economic study on using this technology for reverse osmosis seawater desalination in which a semi-permeable membrane process is used to remove salts and contaminants from water. To understand the techno-economic feasibility of such a system, this research work studies a 2MW airborne wind-driven reverse osmosis plant. Different energy recovery devices are also studied to find their impact on improving the desalination plant's techno-economic performance. Results show the techno-economic practicality of an airborne wind-driven reverse osmosis plant with a competitive levelised-cost-of-water compared to similar-sized wind and solar energy-driven seawater desalination systems.

Performance improvement of turbo energy recovery device in desalination using flow field simulation and uniform design experiment

Performance improvement of turbo energy recovery device in desalination using flow field simulation and uniform design experiment

Transient flow characteristics and energy loss investigation in a desalination energy recovery device under rotor system axial sliding conditions: Focusing on the turbine side

Transient flow characteristics and energy loss investigation in a desalination energy recovery device under rotor system axial sliding conditions: Focusing on the turbine side

Unsteady flow analysis in a double-suction pump as turbine impeller based on finite-time Lyapunov exponent

Pump as turbine (PAT) is an excellent energy recovery device. Understanding the flow characteristics of the key component, the impeller, is essential for further optimization and design of PAT. To analyze the unsteady flow characteristics inside the impeller of a double-suction PAT from a Lagrangian perspective, numerical simulations were conducted using the shear stress transport k–ω turbulence model for the design conditions. The finite-time Lyapunov exponent (FTLE) method was employed to extract the two-dimensional and three-dimensional Lagrangian coherent structures (LCSs) of the impeller over one cycle of unsteady velocity field. Results indicate that with time, the scale of the FTLE field gradually decreases, suggesting enhanced flow stability, reduced mixing efficiency, smoother flow structures, and increased flow convergence. In the two-dimensional perspective, high FTLE values concentrate at the inlet region of the passage, pressure side of the blades, and outlet region of the passage, spreading gradually over the entire blade surface, while low FTLE values predominantly concentrate on the blade surface with a diminishing area. The flow separation occurs at the leading edge of the impeller, the suction side of the impeller and the inlet region of the flow channel. In the three-dimensional perspective, different LCSs show varied changes at specific FTLE values, reflecting the impact of FTLE variation on the distribution of LCSs and indicating the evolution of flow states in fluid dynamics. Each moment of LCS exhibits a growth–stability–dissipation status transition. The FTLE method effectively reveals the flow variations inside the impeller of a double-suction PAT, offering a new perspective and tool for analyzing the turbulent structures in the complex flow field of PAT.

The Numerical Simulation and Performance Analysis of Seawater Desalination Unit: The Case of SWRO Station with Energy Recovery Devices (ERDs)

The demand for good quality drinking water is experiencing strong growth on a global scale, particularly in emerging countries, such as the BASIC countries (Brazil, South Africa, India, and China). For this reason, sea or brackish water desalination technology using membrane filtration technique is a very effective and sustainable method for dealing with this problem. In this work, the performance study of the reverse osmosis desalination plant of Nouadhibou-Mauritania coupled or not to an energy recovery unit was carried out using the Matlab/Simulink software. The objective of this work is to study the functional and productive performance of the reverse osmosis unit by examining the importance of the pressure exchanger in such systems, by acting on the mixing rate of feed water with the flow of water delivered by the pressure exchanger. This study shows that the exploited Energy Recovery devices (ERDs) have a very favorable economic and energetic profitability of 75% reduction, which reduces the specific power consumption by 5 instead of 14.5 kWh/m3 in the case of a system without and with the ERDs, for productivity of 800 m3/d and a recovery rate of 20%.

Fluid Transient Analysis for Enhanced Performance of an Energy Recovery Device for a Small-Scale Reverse Osmosis Desalination Unit

Abstract This article presents a comprehensive study of a double-acting cylinder (DAC) energy recovery device (ERD). The DAC was specifically designed, manufactured, and experimentally tested within a small-scale 5 m3/day brackish water reverse osmosis (RO) unit. The distinctive advantage of the DAC lies in its ability to operate without an extra booster pump, thereby reducing initial costs and streamlining system complexity. A comparative analysis was conducted between the station operating without any ERD and the station equipped with a DAC. For both scenarios, a parametric study was carried out to analyze the relationship between specific energy consumption (SEC) and recovery ratio at varying recovery percentages (10%, 15%, 20%, 25%, and 30%) for different salinity levels. This analysis was conducted across various feed flowrates, with the percentage reduction in SEC calculated for each case. The results show the DAC's ability to effectively reduce the SEC by up to 40%. Additionally, the study investigated brine-feed stream mixing within the DAC, highlighting its capability to prevent undesirable mixing despite internal leakage. However, its widespread adoption has been hindered by realizable pressure fluctuations associated with its implementation, which can lead to rapid fatigue failure. To address this issue, a direct-contact air vessel was integrated into the system to minimize pressure fluctuations and enhance the performance of the DAC. Its optimal size was determined through numerical analysis using the method of characteristics, with detailed design equations presented for future reference. The results affirm the indispensable function of the air vessel in attenuating unsteady effects.

Sustainable Water Purification Techniques: A Review Of Solar-Based Desalination Methods

Global water scarcity continues to pose a critical challenge, driving the need for sustainable water purification solutions. Solar desalination has emerged as a promising approach due to its reliance on renewable solar energy and minimal environmental impact. This study systematically reviews and synthesizes findings from a comprehensive set of 100 peer-reviewed articles to evaluate advancements in solar desalination technologies, including solar stills, photovoltaic-powered reverse osmosis (PV-RO) systems, hybrid solar desalination, and the application of nanotechnology. The review highlights significant progress in improving the efficiency, scalability, and cost-effectiveness of these systems, particularly through innovations such as multi-stage designs, advanced membrane materials, energy recovery devices, and the integration of phase change materials (PCMs) for thermal storage. Additionally, the incorporation of nanomaterials has proven effective in enhancing thermal conductivity and reducing fouling, thereby optimizing water output and system longevity. Findings also reveal the substantial environmental benefits of solar desalination, which can reduce the carbon footprint of water production by up to 70%, aligning with the United Nations Sustainable Development Goals (SDGs) related to clean water access and climate action. However, challenges remain, particularly concerning the initial capital costs and the need for further technological advancements to achieve widespread adoption. This review underscores the critical role of continued research, innovation, and supportive policies in scaling solar desalination technologies as a sustainable solution to global water scarcity.

Unsteady flow analysis in a pump as turbine impeller based on proper orthogonal decomposition and dynamic mode decomposition methods

Pump as turbine (PAT) is an efficient, simple, and cost-effective equipment combining pump and turbine and is one of the excellent energy recovery devices. It is helpful to master the flow characteristics of the key component impeller for the further optimization and design of the PAT. To analyze the unsteady flow features in the impeller of a double-suction pump operating as a turbine, numerical simulations were conducted using the shear stress transport (SST) k-ω turbulence model at the designed operating conditions. By utilizing proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) methods on the unsteady velocity field of a single cycle, the dominant modes up to the fourth order, along with their respective space–time information, can be extracted. The velocity field and vorticity field analysis were performed on the first four modes extracted using two different methods. Additionally, the vortex structures were extracted using the Ω method. The analysis demonstrates that the POD and DMD methods effectively decompose the intricate flow characteristics within the impeller into dynamic–static interference modes, fundamental modes, and dissipative modes. The dynamic–static interference mode is dominant, reflecting the flow characteristics influenced by the stationary components within the impeller. The vortex structure is mainly small tubular vortex and point vortex. The fundamental mode captures the steady flow field characteristics caused by the blade channel geometry. The vortex structure is mainly continuous tubular vortex and the diameter becomes larger. The dissipative mode reflects the flow separation generated on the blades by disturbances from the stationary components. The vortex structure is dominated by point vortex and discontinuous tubular vortex. Comparing the outcomes of the two modal analysis methods shows that the POD method has a distinct advantage in showcasing key changing nodes. In contrast, the DMD method is superior in isolating modes with a single frequency and in determining their stability.

Techno-economic comparison between commercial energy recovery devices in complex Water Distribution Networks

Water Distribution Networks (WDN) proved to be viable for the exploitation of throttling hydraulic energy. Researchers often focused their attention on the study of Pumps as Turbines (PaTs) for WDNs without considering other solutions. Actually, PaTs are not the only machines that can be employed. Indeed, other solutions exists, e.g. Cross-Flow Turbines, and commercially available Energy Harvesting Control Valves. The novelty of this study regards the selection, for each node, of the best technology among these machines rather than choosing only among PaTs, in order to help the water utilities in the techno-economic decision processes. Regarding PaTs, the authors have updated and integrated PaT-ID, their proprietary decision making tool. A complex real WDN has been used as a case study, characterized by 8 reservoirs and 16 Pressure Reducing Valves (PRVs) installed to balance the network and to reduce water leakages. Although all the three considered type of devices show at least 40% of recovered available energy within the WDN, the best solution form an energy point of view not always could be feasible from an economic point of view.

Application of an energy recovery device with RO membrane for wave powered desalination

A Wave-Driven Desalination System (WDDS) represents an efficient method for harnessing wave energy to facilitate water desalination. Nonetheless, various challenges impede its path to commercial viability. There is a requirement to connect the WDDS to an Energy Recovery Device (ERD), but this is challenging due to the inherent variations in pressure and flow. This unique study demonstrates the working of a small scale WDDS system using a Spiral Wound Reverse Osmosis (SWRO) membrane with a permeate capacity of ∼2 m3/day. The study demonstrates the possibilities to reduce high specific energy consumption (SEC) in WDDS by incorporating a Clark pump as an ERD. The study is the first time an evaluation of an SWRO membrane and Clark pump in-the-loop has been evaluated using variable feed flow and pressure. The utilization of the Clark pump notably reduces SEC to about 3.5 kWh/m3, which is comparable to that of commercial desalination plants. Furthermore, the Clark pump aids in maintaining a consistent permeate recovery rate of 10 % under rectified sinusoidally varying flow conditions – representing the operating conditions more closely to that of practical devices.

Performance characteristics of two-phase impulse turbines for energy recovery in thermal systems

Performance characteristics of two-phase impulse turbines for energy recovery in thermal systems

Effect of crosslinker molecular weight on the characteristics of thermoelectric ionogels

Abstract The present study investigates an ionic thermoelectric gel with adjustable functionality through the manipulation of crosslinker molecular weight. The thermoelectric properties of 2-hydroxyethyl acrylate (2-HEA) ionogels, prepared using PEGDA200, PEGDA575, and PEGDA1000 as crosslinkers, were thoroughly examined. Furthermore, dynamic thermal mechanical analysis (DMA) and X-ray diffraction (XRD) techniques were employed to elucidate the underlying reasons for variations in the thermoelectric material properties resulting from changes in crosslinker molecular weight. Notably, the thermoelectric gel synthesized with PEGDA575 exhibited a remarkable thermal power output of 19.19 mV•K-1 along with a tensile capacity of 231%. Additionally, the developed ionic thermoelectric capacitor demonstrated an impressive energy density of 4.288 J•m−2, thereby showcasing its potential application in flexible low-grade heat energy recovery devices.

Effect of blade profile on the hydraulic performance of a double-suction centrifugal pump as turbine based on enstrophy dissipation theory

Pump as turbine (PAT) is widely used in micro hydropower stations and chemical industries as an economical energy recovery device. The special impeller with forward-curved blades can significantly improve the efficiency of PAT and expand its high-efficiency range due to the suitable blade profile, which is more appropriate for PAT's operation mode than the backward-curved blades. To study the influence of the forward blade on a double-suction centrifugal PAT performance, three forward-curved blade schemes with different blade angle conditions are compared with the original backward-curved blade scheme. The three forward-curved blade schemes have the highest efficiency when the inlet angles are 60°, 90°, and 120°, respectively, and the appropriate blade outlet angle. The results showed that the forward-curved blade is suitable for high-flow rate operating conditions in double-suction centrifugal PAT. The PAT with a forward-curved blade impeller has higher efficiency and a broader high-efficiency region than the backward-curved blade impeller. The double-suction centrifugal PAT's main energy loss comes from the impeller's turbulent loss. The forward-curved blade reduces the impeller's turbulence loss and improves the PAT's efficiency at large flow rates. The research in this paper provides a theoretical basis for the design and application of double-suction centrifugal PAT.

Design and research of energy recovery devices for new energy vehicles

Design and research of energy recovery devices for new energy vehicles

A system-level CFD simulation model for investigating the energy dissipation mechanism of seawater pump and rotary energy recovery device in SWRO desalination system

A system-level CFD simulation model for investigating the energy dissipation mechanism of seawater pump and rotary energy recovery device in SWRO desalination system