Pump Energy Research Articles

Replenishing the Indus Delta through multi-sector transformation

The Indus River Basin (IRB) is a severely water-stressed and rapidly developing home to an estimated 250 million people in South Asia. An acute deficit of environmental flows (EFs) in the basin’s delta negatively impacts geomorphology and surrounding ecosystems. Here, a sub-national model of the IRB’s integrated water–energy–land systems is applied to quantify multi-sector transformations and system costs for enhancing EFs to the Indus Delta. The results show that increasing the average outflows from the basin relative to historical policy levels by 2.5 and 5 times would increase sectoral costs for upstream water users between 17–32 and 68–72% for low and high ecological potential targets. The enhanced EFs result in more energy for pumping and treating water upstream from the delta and a net increase in irrigation and energy investments. The EF policy costs are minimized by 7–14% through cooperation across countries and 6–9% through the coordinated implementation of water efficiency measures in the irrigation, conveyance, power plant cooling, and water treatment sectors. The results underscore the crucial role of a multi-sector, multi-scale collaboration in achieving EF targets in water-stressed river basins for ecosystem adaptation to climate vulnerability, restoration of the delta, and socio-economic benefits.

Performance evaluation of a novel multi-tray packed bed solid desiccant dehumidification system.

Configuration of the solid desiccant bed plays a critical role in the development of cost-effective thermally driven desiccant air-conditioning systems. In the present study, a novel multi-tray packed bed solid desiccant dehumidifier (MPBDD) was developed that can be used in conjunction with a traditional vapor-compression system. The proposed configuration aims to achieve high moisture removal from the air and minimize the system power consumption. A lab-scale test rig was designed, fabricated, and tested under different operation conditions. The effect of the inlet humidity, temperature, and flow velocity on the system performance has been experimentally investigated. Experimental results show that the proposed configuration exhibited an adsorption capacity of about 27% higher than that of the conventional systems. Moreover, the pressure drop through the newly designed desiccant bed was found to be 87% lower than that of the conventional wheel design. A dimensionless number called Total Performance Factor (TPF) was defined to be the ratio of heat dissipated for desiccant to pumping energy expended overcoming pressure drop in the device. It was found that in certain experiments it attained an average value of around 250. In this regard, the present study is critical for achieving high dehumidification capacity as well as energy savings in air conditioning applications.

Maximum ecological function performance for a three-reservoir endoreversible chemical pump

Abstract Endoreversible chemical pump (ECP) is a theoretical model of electrochemical, photochemical, solid-state apparatus and mass exchangers. ECP can be classified as two-, three- and four-mass-reservoir devices. The usual performance indicators for ECPs are energy pumping rate (EPR) and coefficient of performance (COP). Energy-based ecological function objective (EFO) is introduced to performance optimization of three-reservoir ECP. Optimization relationships between EFO and COP with linear and diffusive mass transfer laws (MTLs) are deduced. Numerical examples are provided, and influences of cycle parameters and MTLs on optimal EFO performances are analyzed. For linear MTL, compared performances at maximum EFO point and point where dimensionless EPR is 0.016, COP increases 14.4% and entropy generation rate (EGR) drops 52% with only 30% loss of EPR. For diffusive MTL, compared performances at maximum dimensionless EFO point and point where dimensionless EPR is 0.01, COP increases 11.3% and EGR drops 46.9% with only 30% loss of EPR. It demonstrates that EFO is a trade-off between EPR and dissipation of EPR, which is beneficial to utilize energy effectively. With the same chemical potentials of three reservoirs, the maximum dimensionless EFO and the corresponding COP with linear MTL are bigger than those with diffusive MTL.

Investigation of the integrated fuel cell, battery, and heat pump energy systems

The integration of an advanced fuel cell battery electric vehicle was proposed to extend the driving range, increase the overall energy efficiency, and produce an additional cabin space heating service for on-board vehicle application in winter. The adopted heat pump absorbs heat from the fuel cell and battery during charging and discharging scenarios at the heat pump's cold end and transfers it to the cabin supply air for cabin heating. A numerical model for the proposed system was developed and validated by published experimental results. A comprehensive evaluation of the influence of fuel cell output current, battery discharging rate, ambient air temperature, evaporator coolant inlet temperature and refrigerant subcooling degree on the Coefficient of Performance (COP), outlet air temperature, and Equivalent Effective Battery Capacity (EEBC) were conducted. In addition, in this study, a detailed comparison of proposed system to previously published existing systems was carried out in terms of COP, heating capacity, EEBC, and operating price in order to examine the advantages of the proposed system. Results showed that the proposed system was not sensitive to ambient air temperature, but evaporator coolant inlet temperature had the greatest impact on COP, compared to other defined independent variables. A maximum COP of 6.07 could be observed when the evaporator coolant inlet temperature was 32 °C. Although increasing fuel cell output current and battery discharging rate could increase heating capacity, it would decrease outlet air temperature as well. The price of a single charging cycle for running for a 4-hour period was estimated. Compared to conventional Electric Vehicle Air Source Heat Pump (EVASHP) system and Positive Temperature Coefficient (PTC) heaters, the proposed system has the lowest cost which was £10.40per charging cycle while the others are £13.8 and £19.2 respectively when providing the same EEBC and heating capacity. Additionally, the payback period was 10,500 charging cycles. Overall, this study provides a potential solution for efficient cabin heating of electric vehicles in extremely cold weather with twice the EEBC of the existing EVASHP system and with 2.8 times of a PTC system both at −20 °C and the operating price is also 1/3 lower than the existing EVASHP. Meanwhile, the COP of the proposed system is 2.3 times that of the existing systems. It can sufficiently increase the driving range of electrical vehicles in winter and eliminate driving range anxiety.

Analysis and Design of Low-Loss and Fast All-Optical Switch Elements on Silicon Nitride for Integrated Quantum Photonics

Fast and ultra-low loss single-photon switching and routing are essential for photonic quantum computation and communication. To address this need in a scalable fashion, all-optical switches that can be fabricated in an ultra-low loss and mature Si <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{3}$</tex-math></inline-formula> N <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{4}$</tex-math></inline-formula> photonic integrated circuit (PIC) foundry platform are designed and optimized for sub-ns switching times suitable for deterministic quantum-dot single-photon sources. The working principle relies on cross-phase modulation (XPM) of the single photons with a 1550-nm pump pulse and is enhanced by a ring resonator. Two different designs of the primary switch element are theoretically studied, namely a ring resonator intensity switch (RRIS) based on resonance shifting due to XPM and a ring resonator phase switch (RRPS) acting as an all-optical phase shifter in a Mach–Zehnder interferometer. As a novel approach to speed up the switching, chirped pre-emphasis and wipe sections for the pump pulses are utilized. A design tool is established from analytical expressions and serves as starting point for further optimization using a dedicated travelling-wave model (TWM). The TWM demonstrates the feasibility of both designs to be driven by either the proposed pre-emphasis pulse shape or a train of chirped Gaussian pulses. While the RRPS turns out to require less pump energy, its operation is more sensitive to pump-power fluctuations. Insertion losses below 0.1 dB and a power consumption below 5 nJ at 1 GHz switching rates for both configurations prove the potential of this concept for scalable quantum photonic applications.

Dynamic optimization of chilled water pump operation to reduce HVAC energy consumption

• Actual building energy performance and HVAC system have been simulated. • Optimal control is developed to optimize chilled water pump operation by integrated ANN and GA method. • ANN model has successfully modeled the dynamic relationship between pump operation, indoor temperature, and weather conditions. • Optimization of chilled water flowrate could reduce pump energy consumption by 51.11%. Energy consumption in building has been increasing significantly due to higher demand on cooling system. It consumes a large share of total building energy usage. A proper operation control strategy for this system promises the large energy saving. This paper proposes the optimization of chilled water pump operation to improve the cooling system efficiency in a building. The method is developed by combining the artificial neural network and genetic algorithm. This study aims to develop a control method that can determine the optimal chilled water flow rate to absorb the heat on cooling system during the operation. The building energy performances are modeled using EnergyPlus software, while the control strategy is developed in MATLAB. Input output data sharing between MATLAB and EnergyPlus is performed by BCVTB (Building Controls Virtual Test). The dynamic optimization of chilled water flow rate is carried out continuously during real time operation. The developed control performance has been tested under various operating condition including variable outdoor temperature, sudden change of load condition, and different indoor temperature set point. The results show that the optimization of chilled water flow rate on large cooling system could reduce the energy consumption of chilled water pump as 51.11%.

Effect of Flow Configurations on the Desalination Performance of Symmetrical Desalination Battery with Intercalation Electrodes

A three-dimensional analytical model of symmetrical desalination battery (SDB) is established to investigate the effect of different flow configurations on the desalination performance of SDB from the aspects of pressure drop, salt adsorption capacity (SAC), average salt adsorption rate (ASAR) and energy consumption. In addition, the effects of flow channel width and electrode thickness on the desalination performance are also considered. The simulation results show that the pump energy consumption can be saved by increasing the area difference between the inlet and outlet of the SDB and shortening the distance between them. Reducing the outlet area or setting the inlet at corners of the SDB can obviously alleviate the uneven reaction of active material in the intercalation electrode. Compared with the basic configuration, the SAC, ASAR and energy consumption of the SDBs are increased by placing the inlet and outlet on the electrodes. The SDB with the configuration of intermediate inflow and circumferential outflow obtains the lowest dilution concentration among the five configurations. Increasing the channel width can improve the ASAR but increase the charging energy consumption. The increase of electrode thickness increases the SAC and charging energy consumption of the SDB but decreases the ASAR of the SDB.

A Single-Event-Hardened Scheme of Phase-Locked Loop Microsystems for Aerospace Applications.

In order to improve the ability of the phase-locked loop (PLL) microsystem applied in the aerospace environment to suppress the irradiation effect, this study presents an efficient charge pump hardened scheme by using the radiation-hardened-by-design (RHBD) technology. In this study, the sensitivity analysis of the single-event transient (SET) at different nodes of charge pump and different bombardment energies is carried out. Without changing the original structure and loop parameters, a hardened scheme of phase-locked loop to suppress the single-event effect is proposed. A digital control circuit is added between the charge pump and low-pass filter, which greatly reduces the sensitivity of the charge pump to the SET. The classical double-exponential current pulse model is used to simulate the SET effect on the unreinforced and reinforced phase-locked loops, and the reliability of the proposed reinforcement scheme is verified. The simulation results based on the SMIC 130 nm standard complementary metal-oxide-semiconductor (CMOS) process show that the peak value of the transient response fluctuation of the phase-locked loop using the proposed single-event-hardened scheme decreased by 94.2%, the lock recovery time increased by 75.3%, and the maximum phase shift decreased by 90.8%. This shows that the hardened scheme can effectively reduce the sensitivity of the PLL microsystems to the SET effects.

Assessment of Rainwater Harvesting Facilities Tank Size Based on a Daily Water Balance Model: The Case of Korea

Factors affecting rainwater resource management for the present and future include population growth, urbanization, and climate change. Rainwater harvesting (RWH) allows multiple urban water-related issues to be mitigated. In this study, a spreadsheet-based daily water balance model was developed to analyze the existing laws and regulations regarding the storage tank size of RWH facilities. Six buildings at different locations were selected for this study. Two are office buildings, two are school buildings, and two are sports buildings. The term “RWH facility evaluation criteria” is collectively used for rainwater supply satisfaction rate, rainwater guarantee rate, and rainwater utilization rate. A green roof can hold the rainwater for some time, reducing the peak flow and runoff volume. The results provide evidence that, among the selected studied buildings, buildings having a combination of a green roof and RWH facility score the highest in terms of RWH facility evaluation criteria, even though the actual tank size is much smaller than the standard tank size. This is the case with the Yesan County Office, in which a green roof connected to a small (66 m3) rainwater storage tank is installed. As a green roof can decrease the runoff volume, the rainwater can be managed efficiently with less pumping energy and only a small storage tank.

Current progress in Ce3+-doped selenide glasses for mid-infrared lasers

The influence of rare earth dopant concentration on selenide laser glass quality was investigated. A problem to be solved was identified – an increase in rare earth doping level leads to optical losses due to light scattering by heterogeneous inclusions and to the decrease of the optical damage threshold. The room temperature laser system consisting of 4.6 μm pulsed Fe:ZnSe pump laser and Ce3+:Ge20Sb10Ga5Se65 bulk glass was demonstrated. The slope efficiency of Ce3+:glass laser with respect to the absorbed pump energy reached 25% with a maximum output energy of 45 mJ.

The Combined Effects of the Membrane and Flow Channel Development on the Performance and Energy Footprint of Oil/Water Emulsion Filtration.

Membrane filtration is a promising technology for oil/water emulsion filtration due to its excellent removal efficiency of microdroplets of oil in water. However, its performance is highly limited due to the fouling-prone nature of oil droplets on hydrophobic membranes. Membrane filtration typically suffers from a low flux and high pumping energy. This study reports a combined approach to tackling the membrane fouling challenge in oil/water emulsion filtration via a membrane and a flow channel development. Two polysulfone (PSF)-based lab-made membranes, namely PSF- PSF-Nonsolvent induced phase separation (NIPS) and PSF-Vapor-induced phase separation (VIPS), were selected, and the flow channel was modified into a wavy path. They were assessed for the filtration of a synthetic oil/water emulsion. The results showed that the combined membrane and flow channel developments enhanced the clean water permeability with a combined increment of 105%, of which 34% was attributed to the increased effective filtration area due to the wavy flow channel. When evaluated for the filtration of an oil/water emulsion, a 355% permeability increment was achieved from 43 for the PSF-NIPS in the straight flow channel to 198 L m-2 h-1 bar-1 for the PSF-VIPS in the wavy flow channel. This remarkable performance increment was achieved thanks to the antifouling attribute of the developed membrane and enhanced local mixing by the wavy flow channel to limit the membrane fouling. The increase in the filtration performance was translated into up to 78.4% (0.00133 vs. 0.00615 kWh m-3) lower in pumping energy. The overall findings demonstrate a significant improvement by adopting multi-pronged approaches in tackling the challenge of membrane fouling for oil/water emulsion filtration, suggesting the potential of this approach to be applied for other feeds.

Managed Aquifer Recharge as a Low-Regret Measure for Climate Change Adaptation: Insights from Los Arenales, Spain

In view of heightened climate change (CC), adaptation strategies are imperative to diminish the impacts on social and environmental assets. Two approaches are commonly used to formulate adaptation measures, namely bottom-up and top-down, each with inherited limitations. A sound bridge between both approaches is low-regret adaptive measures, which result in win-win scenarios, as they provide solutions to current pressures and contribute to building CC adaptive capacity. Managed aquifer recharge (MAR) is a term that includes a series of techniques that enhance groundwater storage for later use or environmental purposes. MAR is often mentioned in the literature as a CC adaptation measure. Nonetheless, few examples explicitly prove this point. We show through the Los Arenales MAR systems (Central Spain) that MAR is a low-regret CC adaptive measure. We evaluate a series of social and environmental challenges that MAR systems contribute to solving, as well as their attributes that diminish the expected impacts of CC in the study area. MAR in the Los Arenales groundwater body has resulted in an overall increase in groundwater levels; a reduction in groundwater pumping energy and costs and CO2 emissions; restoration of a surface water body; improvement in rural population indexes; and enhanced groundwater demand control and CC adaptive capacity through irrigation communities. To cope with CC, the Los Arenales MAR systems can be operated even if decreasing streamflow precludes the use of river water surpluses; they provide surface storage volume to mitigate flooding; and they decrease the impacts of droughts and water scarcity. This research proves that MAR is a water management tool capable of providing solutions to several pressures simultaneously in the present and future, an attribute particularly useful when dealing with adaptation gaps in developing countries, rural areas, or regions lacking long-term climatic data.

SCADA based intake monitoring for improving energy management plan: Case study

Intake is one of the most important pumping stations in water treatment plant (WTP) and greatly effects the overall plant efficiency. Intake mainly consist of high-tension (HT) motor pump such as vertical turbine pump and submersible pump. The required power supply for intake is generally fed from the main grid through distribution company/department. At the same time, high operational cost of the diesel generator (DG) power back up source results in a huge burden. Also, internet of things (IoT) and Supervisory control and data acquisition (SCADA) based system is widely used nowadays. Therefore, study regarding monitoring strategies of intake is very important and is rarely to be found. In this paper, monitoring strategies of Greater Aizawl Water Supply Schemes phase II is studied. The main objectives are; to study and analyze pump energy consumption (viz. Feeder Current, Frequency etc.); to implement ladder logic for monitoring energy parameters using MOVEREAL. The study shows monitoring of intake energy parameters as well as the feeding substation, showing that SCADA can be efficiently used as an energy management plan.

SUPERRADIATION OF CLASSICAL OSCILLATORS AT CONSTANT PUMPING

The dependence of the generation efficiency in the superradiance regime of an ensemble of oscillators on the pump energy input rate, as well as on the characteristics of the change in the pump phase, is studied. It is assumed that the pumping phase can vary both in time and in space. The most efficient pumping method remains the mode with slow energy input into the system, in comparison with the characteristic generation time, and the nature of the distribution of the field phase along the system can be either random or with a certain spatial period, but slightly changing with time.

Operational optimisation of an air-source heat pump system with thermal energy storage for domestic applications

Electricity-driven air-source heat pumps are a promising element of the transition to lower-carbon energy systems. In this work, operational optimisation is performed of an air-source heat pump system aimed at providing space heating and domestic hot water to a single-family dwelling. The novelty of this work lies in the development of comprehensive thermal network models of two different system configurations: (i) a standard configuration of a heat pump system coupled to a hot-water cylinder; and (ii) an advanced configuration of a heat pump system coupled to two phase-change material thermal stores. Three different objective functions (operational cost, coefficient of performance, and self-sufficiency from a locally installed solar-PV system) are investigated and the proposed mixed-integer, non-linear optimisation problems are solved by employing a genetic algorithm. Simulations are conducted at two carefully selected European locations with different climate characteristics (Oban in Scotland, UK, and Munich in Southern Germany) over four seasons represented by typical weather weeks. Comparison of key results against a conventional operating strategy reveals that the use of smart operational strategies for the operation of the heat pump and thermal stores can lead to considerable economic savings for consumers and significant performance improvements over the system lifetime. Optimising the operation of the standard configuration leads to average annual cost savings of up to 22% and 20% at the UK and German locations, respectively. The optimisation of the advanced configuration with the two PCM stores shows even higher potential for economic savings – up to 39% and 29% per year at the respective locations – as this configuration allows for greater operational flexibility, and high-electricity-price periods can be almost completely avoided. Depending on the objective function, configuration and location, the system seasonal coefficient of performance varies between 2.4 and 2.8. Lastly, a significant (up to four-times) increase in the fraction of heat pump energy demand covered by an appropriately-sized rooftop PV system is demonstrated, increasing from 8% to 34% at the UK location and from 6% to 24% at the German location. The analysis highlights trade-offs between the objective functions, while the time-resolved results can be used to guide the future development of smart controllers for these applications.

Scaling of the terahertz emission from liquid water lines by plasma reshaping.

Liquids are proposed to be promising terahertz (THz) sources. However, the detected THz electric field is limited by the collection efficiency and saturation effect. A simplified simulation based on the interference of ponderomotive-force-induced dipoles indicates that, by reshaping the plasma, the THz radiation is concentrated in the collection direction. Experimentally, by using a cylindrical lens pair to form a line-shaped plasma in transverse section, the THz radiation is redirected, and the pump energy dependence follows a quadratic trend, indicating that the saturation effect is significantly weakened. As a result, the detected THz energy is enhanced by a factor of ∼5. This demonstration provides a simple but effective way of further scaling detectable THz signals from liquids.

Short-term assessment of pumped hydro energy storage configurations: Up, down, or closed?

We study the energy generation and storage problem for various types of two-reservoir pumped hydro energy storage facilities: open-loop facilities with the upper or lower reservoir fed by a natural inflow and closed-loop facilities. We formulate this problem as a stochastic dynamic program under uncertainty in the streamflow rate and electricity price. We include the streamflow rate and electricity price as exogenous state variables in our formulation. We compare the short-term total cash flows obtained by running different pumped hydro energy storage configurations in a market setting where the electricity price can be negative. We first derive theoretical bounds on the revenue gains and losses from switching from one configuration to another. We then conduct numerical experiments by employing time-series models to formulate the evolution of our exogenous state variables. We consider three distinct seasons with different streamflow rates, different negative price occurrence frequencies, and different reservoir capacities. Our results show that: (1) The open-loop facility with the upstream flow can yield cash flows that are up to four times as large as those of the closed-loop facility; (2) The cash flow from operating a large closed-loop facility can be achieved by operating an open-loop facility with 10 times smaller reservoirs; and (3) The open-loop facility with the downstream flow can be more advantageous than the open-loop facility with the upstream flow (with an improvement of more than 10% in the cash flow) if the negative electricity price occurs more than 30% of the time.

Optimization of Condensate Transfer Pump in the Hydrocarbon Condensate Stabilization Unit of Natural Gas Liquefaction Plant – An Industrial Case

PT. Badak NGL is a commercial LNG producer located in Bontang, Indonesia. In recent years, the decline in LNG production of PT. Badak NGL results in a lower hydrocarbon condensate flow rate. To prevent power losses since its pump operated at below rating, a new operation scheme was proposed. This new scheme adjusts the way of pump is operated without any alteration in terms of pump characteristics. Three pumps operated intermittently for 8 hours per day at a maximum flow rate. The pump power consumption was calculated based on electric current data monitored relay panel. The results show that the pump energy saved by 60% with the absolute value of annual energy efficiency of 957.7 MWh. This study contributes to reducing the greenhouse effect by 412 tons eq CO and the annual production cost of around USD 130,000. The new scheme reliability examines by evaluating pump vibration, pump performance, hydrocarbon condensate quality, and condensate tank liquid level. The result shows that the pump’s vibration in the range of 0.21 in/sec with a steady winding temperature.

Pump-guided nonlinear film for phase conjugation.

It is known that phase conjugation technique is achieved by the nonlinearity of materials, and widely adopted in various applications, such as high-resolution imaging, signal amplification, and target detecting. Here, we have proposed a field-enhancement method for the degenerate four wave mixing (FWM) for phase conjugation purpose. In this method, a thin film waveguide with nonlinear property is utilized to confine and guide the pumps, achieving the enhanced FWM within a flexible structure. Compared to existing degenerate FWM methods, three merits are introduced by the proposed pump-guided nonlinear film. First, the pump is confined and guided in the nonlinear waveguide, and the pump energy is concentrated to achieve high power level of the phase-conjugated signals. Second, less pump energy leaks out from the thin film, with less interference to the phase-conjugated signals. The last one is that pump-guided film can be engineered into flexible shapes for different practical applications. Based on these advantages, the phase conjugation property is numerically verified for high-resolution image reconstruction, even with damping of waveguide or in the presence of the metallic particles and the dielectric blocks.

Performance optimization of diffusive mass transfer law irreversible isothermal chemical pump

Performance optimization of generalized irreversible isothermal chemical pump (GICP) cycle with two-mass-reservoirs is performed. Three types of losses, that is, irreversible mass-transfer (IMT) between reservoir and working medium, internal dissipation (ID) inside working medium, and mass-leakage (ML) between reservoirs are included in GICP cycle. Diffusive mass transfer law (MTL) is assumed in IMT and ML processes. Performance relationship between rate of energy pumping (REP) and coefficient of performance (COP) is obtained using numerical examples, and it includes special examples with different loss items, which are derived analytically. The COP versus REP characteristic behaves a parabolic-like cure, that is, COP has maxima at an optimal REP. The COP and REP of GICP with diffusive MTL are compared with those with linear MTL. The effects of chemical potential ratio of mass-reservoirs, IMT, ML and ID on the COP versus REP characteristics are also shown. Maximum COP and the corresponding REP with diffusive MTL are smaller than those with linear one. COP increases monotonically as REP decreases when ML can be ignored. If ML is considered, COP versus REP characteristic behaves parabolic-like one whether ID is ignored or not. Optimal performances are affected by ML qualitatively and by ID quantitatively.