Single Pump Research Articles

Optimization of Pump Start-Up Depth in Drainage Pumping Station Based on SWMM and PSO

The pumps in multistage drainage pumping stations are often subject to frequent start-up and shutoffs during operation because of unreasonable start-up depths of the pumps; this will reduce the service lives of the pumps. To solve this problem, an optimization method for minimizing pump start-up and shutoff times is proposed. In this method, the operation of pumps in pumping station was optimized by constructing a mathematical optimization model. The storm water management model (SWMM) and particle swarm optimization (PSO) method were used to solve the problem and the optimal start-up depth of each pump is obtained. Nine pumping stations in Beijing were selected as a case study and this method was applied for multistage pumping station optimization and single pumping station optimization in the case study. Results from the case study demonstrate that the multistage pumping station optimization acquired a small number of pump start-up/shutoff times, which were from 8 to 114 in different rainfall scenarios. Compared with the multistage pumping station optimization, the single pumping station optimization had a bigger number of pump start-up/shutoff times, which were from 1 to 133 times, and the pump operating time was also longer, from 72 min to 7542 min. Therefore, the multistage pumping station optimization method was more suitable to reduce the frequency of pump start-up/shutoffs.

Reduction of radial thrust by using triple-volute casing

Abstract A complete centrifugal pump is designed and manufactured. The volute is designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single-, double-, triple-volute centrifugal pump at 500, 800, and 900 rpm for each case. The results reveal that the non-dimensional performance curves for the three pumps are identical. The efficiency is increased due to the presence of the partition vane. The use of multiple-volute reduces the radial thrust. This reduction is more significant as the operation departs the BEP. At shut off, where the problem is most critical, the use of two- and three-volute reduces the radial thrust by 54% and 72%, respectively, below the thrust of a single volute pump.

Extremum Seeking Control for optimization of a feed-forward Pelton turbine speed controller in a fixed-displacement hydraulic wind turbine concept

With the sustained drive towards higher power ratings for offshore wind turbines, the size of the turbine rotor and drivetrain components scale accordingly. Compact hydraulic transmissions are widely applied in high-load systems and form a business case for application in multi-megawatt offshore turbines. The Delft Offshore Turbine (DOT) is a hydraulic wind turbine concept replacing conventional drivetrain components with a single seawater pump. In the DOT concept, pressurized seawater is directed to a Pelton turbine-generator combination, located at a central electricity generation platform. An in-field test campaign is performed using a prototype DOT turbine with a retrofitted 500 kW hydraulic drivetrain, consisting of fixed-displacement components. As a result of this configuration, a feed-forward Pelton speed controller is derived and implemented for operating the Pelton turbine at maximum efficiency. However, the controller tuning is based on estimations of physical system properties, of which the resulting optimality is unknown. For verification of the implementation, the model-free, gradient-based and data-driven Extremum Seeking Control (ESC) optimization scheme is employed. Results show fast convergence of the algorithm and an average maximum power increase of 3 %. The algorithm is well suited for application to real-world systems, due to its simplicity and ease of tuning.

Effect of grounded electrode size on a single stage EHD gas pump performance in a square channel

Flows driven by a single-stage electrohydrodynamic (EHD) gas pump in a square channel are critically examined in this study. The flows produced by the pump with three different sizes of the grounded electrode (in terms of its length): 1.27-cm, 2.54-cm, and 5.08-cm (0.5-inch, 1-inch, and 2-inch) are first examined by numerical simulation, are then validated by experimental data. The numerical study enables vivid flow visualizations inside the channel, providing a great insight into the development of induced flows. The results show that the EHD pump with 1.27-cm-long (0.5-inch-long) grounded electrode can produce and sustain air flows with a maximum volume flow rate of 17 L/s, which is considerably better than conventional cooling fans.

Fuzzy Reliability-Vulnerability for Evaluation of Water Supply System Performance

The reliability of water supply system is a critical factor in the development and the ongoing capability to succeed in life and people's health. Determining of its, with high certainty, for performance of water supply system is developed to ensure the sustainability of system. Reliability (Re) plays a great role in evaluation of system sustainability. The probability approaches have been used to evaluate the reliability problems of systems. The probability approach is failed to address the problems of reliability evaluation that comes by subjectivity, human inputs and lack of history data. This research proposed two models; I) traditional model: fuzzy reliability measure suggested by Duckstein and Shresthaand then developed by El-Baroudy; and II) developed model: fuzzy reliability-vulnerability model. The two models implemented and evaluation of water supply system by using two hypothetical systems (G and H). System (G) consists of a single pump and System (H) consists of a two parallel pumps. Triangular and trapezoidal membership functions (MFs) are used to investigate of the reliability measure to the form of the membership function. The results agree with expectations that the reliability of parallel component system {ReH (0.53)} is higher than the reliability of single component system {ReG (0.47)}. Moreover, the result by using fuzzy set reduces the effect of subjectively in process of decision-making (DM). The fuzzy reliability vulnerability is able to handle different fuzzy representations and different operation environment of system

Primary Step Towards In Situ Detection of Chemical Biomarkers in the UNIVERSE via Liquid-Based Analytical System: Development of an Automated Online Trapping/Liquid Chromatography System.

The search for biomarkers in our solar system is a fundamental challenge for the space research community. It encompasses major difficulties linked to their very low concentration levels, their ambiguous origins (biotic or abiotic), as well as their diversity and complexity. Even if, in 40 years’ time, great improvements in sample pre-treatment, chromatographic separation and mass spectrometry detection have been achieved, there is still a need for new in situ scientific instrumentation. This work presents an original liquid chromatographic system with a trapping unit dedicated to the one-pot detection of a large set of non-volatile extra-terrestrial compounds. It is composed of two units, monitored by a single pump. The first unit is an online trapping unit able to trap polar, apolar, monomeric and polymeric organics. The second unit is an online analytical unit with a high-resolution Q-Orbitrap mass spectrometer. The designed single pump system was as efficient as a laboratory dual-trap LC system for the analysis of amino acids, nucleobases and oligopeptides. The overall setup significantly improves sensitivity, providing limits of detection ranging from ppb to ppt levels, thus meeting with in situ enquiries.

Research on the effects of dual pumping on fast light propagation in an Er3+-doped optical fiber

In this paper, we propose a general theory for the coherent population oscillation effect in an -doped optical fiber under dual-frequency laser pumping at room temperature. We aim at comparing the effect of dual pumping (1480 nm and 980 nm) with single pumping of 980 nm and single pumping of 1480 nm on time advancement. According to the numerical calculations, we analyze the relationships between relative modulation attenuation and modulation frequency, plus fractional advancement and modulation frequency under the dual-frequency pumping laser with co-propagation. Compared to single pumping, a greater change in the group refractive index can be found. The maximum time advancement of 0.24 ms under a dual-frequency pump laser with co-propagation is obtained. Moreover, we demonstrate the influence of the pump ratio M on time advancement with modulation frequencies of 40 Hz, 100 Hz and 200 Hz. The ability to control the group velocity of light could have an important application for photonics.

Computational comparison of a novel decentralized photovoltaic district heating system against three optimized solar district systems

Abstract Climate change is one of the biggest challenges at the present time, and to tackle such issue, solar energy and efficient buildings, in general, can be used. The goal is to design and optimize photovoltaic based decentralized district heating system and later compare it—economically and technically—against three different optimized typologies of solar district heating system in Nordic conditions. The photovoltaic based decentralized system consists of one centralized low temperature tank charged by photovoltaic and air-water heat pumps and a borehole thermal energy storage, while the decentralized high temperature tank charged by an individual water-water heat pump in each house. The centralized warm tank charges the borehole thermal energy storage. The other three systems are photovoltaic based centralized, roof-mounted solar thermal based centralized and roof-mounted solar thermal based decentralized district heating systems. In solar thermal based systems, collectors are used to directly charge the short-term storage tanks instead of the photovoltaics/heat pump combination. The proposed system is simulated using TRNSYS software. Lastly, purchased electricity and life cycle costs of the system are minimized using multi-objective optimization and the genetic algorithm. The results indicated that the decentralized photovoltaic based system outdoes all the other systems in terms of techno-economic performance. The purchased electricity can be reduced by 22% while at the same time life cycle cost can be reduced up to 40%, compared to the worst optimized system (solar thermal based centralized system). Moreover, the decentralized photovoltaic based energy system has a payback period of 9–27 years, compared to the solar thermal based system and the conventional single building-heat pump system, i.e. around 17–58 years and 15 years, respectively. The highest renewable energy fraction for heating can be close to 99% for this system. The decentralization and electrical based district systems are better in terms of life cycle cost, payback period and in terms of technical performance, compared to traditional single house and solar thermal based district heating systems.

Magnetocardiography with a 16-channel fiber-coupled single-cell Rb optically pumped magnetometer

We have constructed a low-cost, portable, high-sensitivity 16-channel optically pumped magnetometer (OPM), operating in the spin-exchange relaxation-free regime, and demonstrated its applications in magnetocardiography (MCG). The decrease in the cost of sensors by an order of magnitude is achieved by the 16-channel operation realized in a single module using a single large flat pancake rubidium vapor cell, broad pump and probe laser beams, and a 16-channel photodiode array. The OPM is also based on a fiber-coupled nearly parallel-beam configuration to facilitate multichannel design and make the system portable. For human MCG experiments, the 16-channel OPM which includes optical components is placed inside a wooden enclosure for laser safety. The enclosure is set on a nonmagnetic table inside a magnetically shielded room, while the lasers and electronics are placed outside the shielding room, to avoid magnetic noise. We show that the 16-channel OPM enables simultaneous imaging of human cardiac activity on a large area of the chest in a single scan. The multichannel capability will accelerate clinical MCG imaging to reduce the procedure time and patient fatigue.

Experimental and Numerical Investigation of Resonance Characteristics of Novel Pumping Element Driven by Two Piezoelectric Bimorphs

This paper describes the vibration characteristics of a dual-bimorph piezoelectric pumping element under fluid–structure coupling. Unlike the single bimorph used in most previous studies, the proposed device comprises two piezoelectric bimorphs within an acrylic housing. Amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) was used to examine the visible displacement fringes in order to elucidate the anti-phase as well as in-phase motions associated with vibration. Analysis was also conducted using impedance analysis and laser Doppler vibrometer (LDV) based on the measurement of point-wise displacement. The experimental results of resonant frequencies and the corresponding mode shapes are in good agreement with those obtained using finite element analysis. The gain of flow rate obtained by the anti-phase motion of the dual-bimorph pumping element is larger than both those obtained by in-phase motion and the single bimorph pumping element. This work greatly enhances our understanding of the vibration characteristics of piezoelectric pumping elements with two bimorphs, and provides a valuable reference for the further development of bionic pump designs.

A Review of Design Considerations of Centrifugal Pump Capability for Handling Inlet Gas-Liquid Two-Phase Flows

Most of the pumps working under two phase flows conditions are used in petroleum industry applications, like electrical submersible pumps (ESP) for hydrocarbon fluids, in chemistry, nuclear industries and in agriculture for irrigation purposes as well. Two-phase flows always deteriorate overall pump performances compared with single flow conditions. Several papers have been published aiming to understand flow physics and to model all the main mechanisms that govern gas pocket formation and surging phenomena. These mechanisms depend on the pump type, the impeller geometry, the rotational speed, design and off-design liquid flow rate conditions, the volumetric gas fraction, the fluid properties and the inlet pressure. In the present paper, a review on two phase performances from various centrifugal pumps designs is presented, mainly based on experimental results. The main focus is devoted to detect the significant geometrical parameters that: (1) Modify the pump head degradation level under bubbly flow regime assumption; (2) Allow single stage centrifugal pumps keep working under two-phase flow conditions with high inlet void fraction values before pump shut down, whatever the pump performance degradations and liquid production rates should be. Because most of the published experimental studies are performed on dedicated laboratory centrifugal pump models, most of the present review is based on air-water mixtures as the working fluid with inlet pressures close to atmospheric conditions. The following review supposes that gas phase is considered as a non-condensable perfect gas, while the liquid phase is incompressible. Both phases are isolated from external conditions: neither mass nor heat transfer take place between the phases.

Toward attosecond pulse synthesis from solids: Spectral shaping, field autocorrelation, and two-color harmonic generation

Harmonic generation from solid surfaces is a promising tool for producing high energy attosecond pulses. We report shaping of the harmonic spectrum to achieve the bandwidth necessary for attosecond pulse generation. The shaping is demonstrated for lower as well as for higher harmonics using single and two-pulse pumping. The measured harmonic field autocorrelation function exhibits attosecond spikes in good agreement with the harmonic spectrum. Double slit experiments reveal a high spatial coherence of the harmonic beam.

Numerical Analysis of the Deterministic Stresses Associated to Impeller-Tongue Interactions in a Single Volute Centrifugal Pump

In this paper, a deterministic stress decomposition is applied over the numerical three-dimensional flow solution available for a single volute centrifugal pump. The numerical model has proven in previous publications its robustness to obtain the impeller to volute-tongue flow interaction, and it is now used as starting point for the current research. The main objective has been oriented toward a detailed analysis of the lack of uniformity in the flow that the volute tongue promotes on the blade-to-blade axisymmetric pattern. Through this analysis, the fluctuation field may be retrieved and main interaction sources have been pinpointed. The results obtained with the deterministic analysis become of paramount interest to understand the different flow features found in a typical centrifugal pump as a function of the flow rate. Moreover, this postprocessing tool provides an economic and easy procedure for designers to compare the different deterministic terms, also giving relevant information on the unresolved turbulence intensity scales. Complementarily, a way to model the turbulent effects in a systematic way is also presented, comparing their impact on the performance with respect to deterministic sources in a useful framework, that may be applied for similar kinds of pumps.

Pump as turbine applied to micro energy storage and smart water grids: A case study

The need of energy storage in micro scale is recently emerging and becoming more relevant in the rising era of decentralised renewable energy production. This paper provides a technical overview of the design and the outcomes of a first-of-its-kind Pumped Hydro Energy Storage (PHES) micro facility. The described micro-PHES is integrated in a smart grid and it is designed to store energy produced by the connected renewable energy sources. Interestingly, this micro-PHES runs with a single centrifugal pump for both pumping and generating phases. Variable speed regulation allows the pump to constantly operate at the maximum hydraulic efficiency in order to deal with load variations. In the same way, the pump running in reverse, namely Pump as Turbine (PaT), runs at the most suitable speed and it keeps high efficiency (near to 0.71%) over a range of 40–120% of the nominal load design. The pump/PaT is selected according to the presented methodology and it is experimentally characterized in the current case study. The PHES implementation is defined in relation with the smart grid consumption and renewable energy production and it reaches a total round-trip yield up to 42%. In addition, this paper defines the techno-economic parameters for a micro-PHES cost-effective solution and provides an important dataset for micro-PHES feasibility breakdown. The use of a storm-water basin as reservoir produces an expense cut greater than 28% of the total direct cost. This constitutes a valid economic advantage to be integrated in future smart water grid’s designs. Also, the system with the described features can reach a Levelised Cost of Energy (LCOE) of 0.58–1.06 €/kWh in micro-PHES.

Gold-implanted plasmonic quartz plate as a launch pad for laser-driven photoacoustic microfluidic pumps

Enabled initially by the development of microelectromechanical systems, current microfluidic pumps still require advanced microfabrication techniques to create a variety of fluid-driving mechanisms. Here we report a generation of micropumps that involve no moving parts and microstructures. This micropump is based on a principle of photoacoustic laser streaming and is simply made of an Au-implanted plasmonic quartz plate. Under a pulsed laser excitation, any point on the plate can generate a directional long-lasting ultrasound wave which drives the fluid via acoustic streaming. Manipulating and programming laser beams can easily create a single pump, a moving pump, and multiple pumps. The underlying pumping mechanism of photoacoustic streaming is verified by high-speed imaging of the fluid motion after a single laser pulse. As many light-absorbing materials have been identified for efficient photoacoustic generation, photoacoustic micropumps can have diversity in their implementation. These laser-driven fabrication-free micropumps open up a generation of pumping technology and opportunities for easy integration and versatile microfluidic applications.

Design Analysis of Pump as Turbine for a Coastal Region of Nigeria

This research details the design analysis process of a 100 kW Pump as Turbine (PAT) micro hydro system for Sangama Community in the Asari-Toru Local Government of Rivers State, Nigeria. In order to achieve this, governing equations of fluid flow in pumps and pipes were applied to determine suitable design parameters of the system components, and also to select appropriate pump configuration. A design software, PAT+, was built in C# to help perform the design computations involved, although the software can be applied to PAT design for any expected power rating and desired system efficiency. From the results obtained, t was seen that a single stage pump of 28644 rpm operating at a head of 19.23 metres was suitable to generate the expected power. Parameters were varied and plots generated to show the effect of some parameters on the other, and it was deduced that the system head is inversely proportional to the flow rate. Also, for higher power outputs, higher design heads would be needed, although expected design output of a PAT should not exceed 100kW.

Design Analysis of Pump as Turbine for a Coastal Region of Nigeria

This research details the design analysis process of a 100 kW Pump as Turbine (PAT) micro hydro system for Sangama Community in the Asari-Toru Local Government of Rivers State, Nigeria. In order to achieve this, governing equations of fluid flow in pumps and pipes were applied to determine suitable design parameters of the system components, and also to select appropriate pump configuration. A design software, PAT+, was built in C# to help perform the design computations involved, although the software can be applied to PAT design for any expected power rating and desired system efficiency. From the results obtained, t was seen that a single stage pump of 28644 rpm operating at a head of 19.23 metres was suitable to generate the expected power. Parameters were varied and plots generated to show the effect of some parameters on the other, and it was deduced that the system head is inversely proportional to the flow rate. Also, for higher power outputs, higher design heads would be needed, although expected design output of a PAT should not exceed 100kW.

Visualizing the connection between edge states and the mobility edge in adiabatic and nonadiabatic topological charge transport

The ability to pump quantised amounts of charge is one of the hallmarks of topological materials. An archetypical example is Laughlin's gauge argument for transporting an integer number of electrons between the edges of a quantum Hall cylinder upon insertion of a magnetic flux quantum. This is mathematically equivalent to the equally famous suggestion of Thouless' that an integer number of electrons are pumped between two ends of a one-dimensional quantum wire upon sliding a charge-density wave over a single wave length. We use the correspondence between these descriptions to visualise the detailed dynamics of the electron flow during a single pumping cycle, which is difficult to do directly in the quantum Hall setup, because of the gauge freedom inherent to its description. We find a close correspondence between topological edge states and the mobility edges in charge-density wave, quantum Hall, and other topological systems. We illustrate this connection by describing an alternative, non-adiabatic mode of topological transport that displaces precisely the opposite amount of charge as compared to the adiabatic pump. We discuss possible experimental realisations in the context of ultracold atoms and photonic waveguide experiments.

Characterization of ZAO® sintered getter material for use in fusion applications

The use of non-evaporable getter (NEG) pumps is common in many UHV applications, and the properties of the new sintered getters based on the ZAO®alloy make them appealing for applications dealing with large fluxes of hydrogen and its isotopes, as typically occurs in fusion research. In particular, the use of NEG pumps is interesting for the vacuum system of negative ion-based neutral beam injectors, which require huge deuterium gas throughputs for long durations. The key advantages of a NEG pumping solution are the high specific pumping speed and capacity, the ability to withstand a large number of absorption/desorption cycles, the ease of integration. In addition, NEG do not release hydrogen unless power is supplied to heat them, addressing an important safety issue related to uncontrolled release in case of power outage or subsystem failures.This paper reports the experimental characterization of ZAO®sintered getters, in pressure regimes and sorption amounts relevant for the use in the next generation NBI. Single discs and complete pumps were characterized in different conditions of H2/D2 pressure between 10−4 and 10-1Pa and operating temperatures up to 150°C. In particular, the feasibility of getter regeneration within time windows compatible with current NBI operation scenarios was demonstrated.

Experimental investigation of accidental scenarios using a scale water model of a HLM reactor

The thermal-hydraulics challenges of a nuclear reactor are numerous and their investigation is crucial for the design and safety of new reactors. Numerical simulation through CFD codes or System thermal hydraulics codes can address a lot of the different challenges; nevertheless the use of water modeling for the study and validation of the thermal hydraulic behavior of a new primary system remains a valuable tool. A water model of the pool-type liquid metal-cooled MYRRHA reactor has been developed at the von Karman Institute in collaboration with SCK•CEN. It is a full Plexiglas model at a geometrical scale 1/5 of the design version 1.2 of MYRRHA. The scaling was performed by respecting as much as possible the Richardson, Euler, Reynolds and Péclet numbers’ similarity with MYRRHA. This transparent water model allows the application of optical measurement techniques for the flow characterization. Different transient tests relevant for MYRRHA have been defined by SCK•CEN. These test cases have been studied using the water model facility. They include the study of the transient thermal hydraulic behavior when switching from forced to Loss-of-Flow (LOF), the failure of a single pump, the failure of one of the four heat exchangers and the loss of coolant inventory (LOC). Results of phenomenological behavior are presented as well as the time–dependent variation of temperatures recorded with different arrays of thermocouples immersed inside the upper plenum.