Electric Pump Research Articles

INFLUENCE OF GENERATED PUMP ELECTRIC FIELD ON MULTIHARMONIC INTERACTION OF WAVES IN AMPLIFICATION SECTION OF SUPERHETERODYNE FEL

In the cubic nonlinear approximation, we analyze the processes of generating the electric pump field by an electron beam and its effect on the amplification of space charge waves (SCW) in the amplification section of a parametric superheterodyne free-electron laser (FEL). We found that the generated pump electric field amplitude is within 21…33% of the amplitude of the external pump electric field. We showed that the generated pump electric field is in phase with the external one. It leads to an increase in the growth increments of SCW; therefore, the length of the SCW amplification section is reduced by 22%. We found out that this field does not destroy the mode of amplification of multi-harmonic SCW. Thus, the studied effect makes it possible to create FELs with smaller longitudinal dimensions and powerful electromagnetic waves with a complex multi-harmonic spectrum.

Energy Efficiency of Using Hybrid Heating Points in Conditions of Integration of Electrical and Thermal Networks of Urban Neighborhoods. Part 1. Justification of the Feasibility of Using Hybrid Thermal Points

The paper discusses the circumstances and technical solutions that contribute to the integration of electrical and thermal networks of urban neighborhoods within the framework of a surplus of electricity generating capacities arising from the imbalance in the development of energy generation and consumption, stochastic processes of market economy development, the transfer of energy-intensive industrial production to other countries, the desire to diversify fuel energy resources, passion for the construction of energy sources for alternative energy resources in counterbalance to traditional energy facilities without taking into account all aspects of the interaction of the former with the environment, etc. With regard to district heating systems of electrical and thermal networks of urban neighborhoods, the use of hybrid heating points is achieved, which, unlike standard solutions, are equipped with electric boilers, thermal accumulators and heat pumps. According to the time of use of generating capacities, preference should be given to options for covering the hot-water load. Based on the average daily load, the power usage time in this case lies in the range of 6000–6500 hours / year. When choosing the capacity of the equipment, it should be borne in mind that the daily load of hot water supply is extremely uneven and also depends on the day of the week, while the maximum load exceeds the average daily by 2.5 – 3.0 times. When integrating electricity and heat supply systems, it is advisable to consider options for only night-time electricity consumption or night-time consumption plus consumption during the hours of daytime failures of the electricity consumption schedule. If during the new construction the power of the electrical network may vary depending on the selected option, then during the modernization of the heat supply system, the problem is solved if there is a limitation on the available electrical power. Therefore, the definition of these restrictions is a separate issue. In comparison with the direct consumption of electricity for the needs of heat supply, which is a priori energetically and economically inefficient, the use of hybrid systems in heat supply allows us to solve the multifunctional task of increasing the reliability of energy supply and the stability of the functioning of the power system, which is primarily achieved by solving the problem of balancing the capacity of production and energy consumption from the position of aligning schedules of energy generation and consumption.

Investigation of Gas-liquid Separation Experiment of Electric Pump Drainage and Gas Extraction Unit in High Gas-liquid Ratio Gas Wells

Given the prominent problem of water in the Tarim basin of China with high formation temperature and large water production, a preferred scheme of electric pump drainage and gas extraction unit for gas fields with a high gas-liquid ratio is proposed by the mechanical principle and structural design method. Then, the corresponding electric pumps were developed, and the drainage and gas extraction scheme of a permanent magnet electric pump unit with gas-liquid separation in the way of an inverted deflector is designed. Through indoor experiments simulating the downhole gas-liquid ratio environment, the gas-liquid separation ability and adaptability of the design scheme under different good conditions are verified. The results obtained demonstrate that the cable connection process can meet the requirements of high-pressure resistance (≥25 MPa), and the gas-liquid separation effect is very good in vertical wells by adopting the inverted deflector scheme. The separation effect exceeded 90% under different working conditions (production from 30 to 150 m3/day and inhalation gas-liquid ratio from 50% to 95% and even higher) in the experiment with high gas content. The results will promote the gas recovery rate of high gas-liquid ratio gas fields and improve extraction efficiency.

Theoretical and experimental evaluation of electric coolant pump benefits in real driving cycles

Engine thermal management is a promising option to reduce fuel consumption and harmful emissions of Internal Combustion Engines. This is particularly suitable to support the transition towards a carbon-neutral transportation sector, considering that the role of combustion engines is expected to persist in the near and medium future. In this study, a prototype pump electrically actuated was compared to a mechanical pump of a downsized gasoline engine that propels a real vehicle. In the first phase of the analysis, the cooling circuit was tested from a hydraulic point of view on all its branches using an engine mounted on a bench equal to that working on the vehicle. The hydraulic circuit was fully characterized via pressure transducers and flow meters in all branches for different thermostat lifts, representing different coolant temperatures. On the same bench, the OEM pump and an electrically actuated one, suitably redesigned on an operating point more representative of the real operating conditions, were tested. A vehicle propelled with the same tested engine (having a conventional mechanically actuated pump) was run on the road following three different driving cycles. The engine revolution speeds were registered, as well as the temperature of the cooling fluid. The electric and mechanical pumps were compared using the performance maps previously obtained. The electric pump speed was set to deliver the same coolant flow rate as the OEM pump, following the same sequence of thermostat lifts. The results show that a 60 % average reduction of the pump energy consumption is possible, leading to an average specific CO2 emission reduction of 1 g/km. This result is even more relevant during urban driving, with emission savings hitting 2.5 g/km.

Heat-power peak shaving and wind power accommodation of combined heat and power plant with thermal energy storage and electric heat pump

Heat-power peak shaving and wind power accommodation of combined heat and power plant with thermal energy storage and electric heat pump

Thermo-economic optimization of a 100 kW air-to-water heat pump for heating purposes in residential units

In order to reach the ambitious objectives of carbon neutrality by 2050 and the limitation of the ambient temperature rise at 1.5 °C, several intensive energy fields such as heating and cooling appliances should be decarbonized. On this regard, electric heat pumps represent the most promising solutions to replace old and inefficient conventional boilers and comply with the ecological transition through the increase of electric energy production by means of renewable sources. In this paper, a thermo-economic optimization analysis of a 100 kW air-to-water electric heat pump is proposed. The appliance is designed to produce hot water at 55 °C. The developed model employs phenomenological equations calibrated on real data and manufacturer datasheets for compressor, heat exchangers, and costs. Different design options, including the heat exchangers size and the choice of the working fluid (among R32, propane R290, ammonia R717, R454C), are presented and discussed. The Pareto analysis is then employed to find the best possible configurations in terms of costs and performance.

Ammonia heat pumps for district heating: thermo-economic optimization analysis based on evaporator geometry for either direct expansion or chilled water configurations

Electric heat pumps are recognized as a key technology for decarbonization and have received increasing policy support in several countries over the last few years. These devices offer a highly efficient form of electric heating and could make an important contribution to the transition to a low carbon future, especially in case of district heating systems. Within this context, this paper presents a thermo-economic optimization analysis of a 7.35 MW electric heat pump system employed for district heating purposes and using ammonia as working fluid. The implemented code gathers multiple sub-models calibrated ad-hoc from real data or manufacturers’ datasheets. The heat exchangers are simulated by considering phenomenological equations and well-known heat transfer coefficient and pressure drop prediction methods. The optimization analysis is performed at constant condensation temperature that guarantees in/out hot water temperatures of 30/62 °C and is focused on the matching between compressor and evaporator heat exchanger, by considering either a direct expansion system or a chilled water heat pump. Both the coefficient of performance (COP) and the set-up costs are considered as optimization performance indicators for the construction of the Pareto front.

Hydrodynamics of transient processes in a well with an electric submersible pump

The relevance. Associated with the problem of increase in efficiency of algorithms for monitoring and controlling the dynamic operation modes of wells equipped with an electric submersible pump with adjustable supply. The result summarizes and develops the previously published solution on the design of a dynamic well model, through the transition from linearized correlations to quadratic relationships between states at key points of a lift. These points properly reflect the observed forms of behavior in transient and equilibrium operating modes at full start-stop control ranges. The main aim. Updated description of a comprehensive quadratic barometric model of the «reservoir–lift–electric pump–well head» type well, focused on the tasks of automatic control and regulation in real time. Objects. Well with frequency-regulated submersible pump. Methods. Material balance, percolation, hydrostatics, quadratic kinetics of friction losses, numerical modeling of differential equations, finite-dimensional description of the complex hydrodynamics of the well, taking into account the potential and kinetic head losses in the lift. Results: (1) Updated mathematical description of the hydrodynamics of the well with an electric submersible pump creates the basis for: more reliable solution of inverse problems of parametric model support according to the data of field control, refined assessment of the adjustment potential, predicting the dynamics of a possible system output beyond the boundaries of functional stability, technologies of numerical and analytical design of optimal solutions when selecting the parameters of arrangement and laws of operational regulation, synthesis of dynamic observers of an extended state vector synchronously operating with the dynamics of controlling well-head and deep pressure. (2) The results of the computational analysis demonstrate a complex behavior that does not match the graph of the inflow and pump supply, when changing the frequency and wellhead pressure. This explains the observed effect of the multi-tempoity of transient processes during starts and stops and possible instability of the supply with a sharp decrease in frequency. (3) Estimates of discrepancy between the solutions for a quadratic model and a linearized prototype indicate an increase in errors of linearized analysis with strong deviations of operating modes from the equilibrium-calculated states. The refinements in dynamically disturbed operating modes delivered by the updated model are important for improving the reliability of operational control systems and parametric estimation for data control mode states.

Gas lifting design and application in geothermal wells: A case study from West Anatolia, Turkiye

The gas content of the producing fluid has crucial effects on the production performance of geothermal wells. The decline of non-condensable gases (NCG) could result in significant performance reduction of the wells. Artificial production techniques such as pumps (i.e., Line Shaft Pump and Electrical Submersible Pump) and gas lifting are the widely known methods for enhancing the production performance of wells. Due to the high-temperature working environment and the well's inclination, pumps might be inconvenient for geothermal wells. Continuous injection of gases such as nitrogen (N2) and carbon dioxide (CO2) serving as gas lifting might be the appropriate method to enhance production from geothermal wells suffering from low gas content and reservoir pressure. This study investigates production enhancement with gas lifting in a geothermal field in Turkiye. The study aims to fill the gap of gas lifting in the geothermal industry as an alternative to downhole pumps such as ESP and LSP. The sensitivity analyses were performed on the design parameters such as injection depth, rates, tubing size, number of valves, and injectate gas type influencing the production performance of gas lifting. The study found that gas lifting is an optimization problem that needs to be solved by considering gas sources, infrastructure sizes, wellbore geometry, and operating parameters.

An entropy efficiency model and its application to energy performance analysis of a multi-stage electric submersible pump

The electric submersible pump (ESP) is a compact multi-stage pump that is widely used in the oil industry. In this study, using the numerical simulations with entropy efficiency (EE) model, the high hydraulic loss region within the ESP hydraulic system is captured, and the energy degradation distribution within the internal flow field is investigated and its inter-stage variability is analyzed. The input power of the ESP hydraulic system is transformed into an entropy-reducing flow, and then the EE is defined to develop a connection between localized energy degradation and the efficiency of the hydraulic system. It was found that there were significant differences among the EEs of the three stages of the ESP hydraulic system. The EE of the first stage reaches 1.29 and 1.32 times that of the second and third (final) stage respectively under overload conditions. However, the overall energy characteristics of the hydraulic system are dominated by the energy dissipation in the second and third stage. In addition, The EE for characterization of pump performance is consistent with the existing research methods in the literature, but it has the advantage of quantifying the correlation between the localized flow field structure and the efficiency of the hydraulic system. This research can provide guidance for the design optimization of ESPs and performance evaluation of related equipment which has theoretical and practical significance.

Designing electricity distribution networks: The impact of demand coincidence

With the global effort to reduce carbon emissions, clean technologies such as electric vehicles and heat pumps are increasingly introduced into electricity distribution networks. These technologies considerably increase electricity flows and can lead to more coincident electricity demand. In this paper, we analyze how such increases in demand coincidence impact future distribution network investments. For this purpose, we develop a novel model for designing electricity distribution networks, called the distribution network reconfiguration problem with line-specific demand coincidence (DNRP-LSDC). Our analysis is two-fold: (1) We apply our model to a large sample of real-world networks from a Swiss distribution network operator. We find that a high demand coincidence due to, for example, a large-scale uptake of electric vehicles, requires a substantial amount of new network line construction and increases average network cost by 84% in comparison to the status quo. (2) We use a set of synthetic networks to isolate the effect of specific network characteristics. Here, we show that high coincidence has a more detrimental effect on large networks and on networks with low geographic consumer densities, as present in, e.g., rural areas. We also show that expansion measures are robust to variations in the cost parameters. Our results demonstrate the necessity of designing policies and operational protocols that reduce demand coincidence. Moreover, our findings show that operators of distribution networks must consider the demand coincidence of new electricity uses and adapt investment budgets accordingly. Here, our solution algorithms for the DNRP-LSDC problem can support operators of distribution networks in strategic and operational network design tasks.

Pseudo-optimal discharge pressure analysis of different CO2 electric vehicle heat pumps based on cabin thermal model

The discharge pressure of electric vehicle heat pumps, aiming for peak COP values, is termed the pseudo-optimal discharge pressure for dynamic regulation, distinguishing it from the optimal discharge pressure at a constant compressor speed. A theoretical model was presented to analyze the impacts of operational parameters considering the variation of cabin loads with operating conditions. Based on simulation results, the effects of ambient temperature, cabin temperature, drive speed, and supply air flow rate on the pseudo-optimal discharge pressure were investigated for single-stage and two-stage compression systems, respectively. Among them, the ambient temperature had the highest degree of influence, more than 45 % in different systems. Heat recovery in electrical systems introduced slight variations, less than 1 bar, to the pseudo-optimal discharge pressure by affecting the evaporation temperature. While the trend remains consistent across the different systems, the values of pseudo-optimal discharge pressure are higher for the two-stage compression. At −10/20 °C, two-stage compression provides a 49.42 % higher COP compared to single-stage while maintaining a safe discharge temperature. In addition, the heating efficiency under the improved prediction can be increased by 18.49 % compared to the existing research. Predictions for the pseudo-optimal discharge pressure provide a basis for effective and cleaner control of electric vehicle heat pumps.

Analysis of two-phase gas-liquid flow in an Electric Submersible Pump using A CFD approach

This study comprehensively analyzes a mixed-flow Electric Submersible Pump's (ESP) performance under challenging conditions of low flow rates and high gas fractions. The research leverages a computational model built on the Eulerian-Eulerian methodology, adeptly solving the 3D incompressible Navier-Stokes equations for each phase. To ensure an encompassing depiction of the flow dynamics within the ESP, the model considers critical parameters such as the bubble diameter and interphase forces, including drag, lift, and virtual mass force.Key findings reveal that the ESP's performance deteriorates markedly under the studied conditions. One of the primary influencers is the phenomenon of gas locking, where gas accumulation within the impeller hampers the consistent flow of liquid, thereby degrading the pump's efficiency. In addition, the model delineated the occurrence of the surging phenomenon across diverse gas volume fractions and rotational speeds, which further exacerbates the reduction in the ESP's performance. Intriguingly, the bubble diameter was identified as a decisive factor, especially at minuscule flow rates. Large bubble diameters instigate the formation of gas pockets on the suction side of the vane, culminating in a segregated flow pattern and further declining pump efficiency.On the other hand, the drag force is the primary interaction force between phases of gas-liquid flow. Other interfacial forces, such as lift and virtual mass force, change the pump's performance but do not affect the gas flow and distribution patterns for a one-stage configuration. Results show that the Schiller-Neuman drag coefficient offers a better fit than the Bozano-Dente coefficient.Conclusively, the study underscores the indispensable role of nuanced computational models in elucidating the intricate flow dynamics within ESPs, especially under conditions fraught with operational challenges. The insights gleaned enrich our understanding of ESP performance dynamics and provide a roadmap for designing more resilient and efficient pumping systems in the future.

Research on early warning model of electric submersible pump wells failure based on the fusion of physical constraints and data-driven approach

At present, there are too few characteristic parameters for early identification of electric submersible pump (ESP) wells failures. In addition, existing predictive models rely only on data-driven techniques, which do not provide a comprehensive understanding of the intrinsic mechanisms behind the occurrence of failures. This article presents the development of a health index calculation approach for evaluating the operational status of the ESP wells. The wellbore energy conservation equation and the health index calculation formula were employed to develop a physical constraints (PC) for the loss function in the network model of Long Short-Term Memory (LSTM). This constraint was then utilized to construct the PC-LSTM ESP health warning model. The study examines the health index trends associated with three types of faults: ESP clogging, sand production in oil wells, and reservoir pressure rise. The results indicate that the PC-LSTM network structure exhibits faster convergence during training. In relation to the accuracy of prediction, PC-LSTM demonstrates a notable enhancement. Specifically, when the ESP clogging fault, the traditional LSTM achieves a mean relative error (MRE) of 211.15%, whereas the PC-LSTM achieves a reduced MRE of 12.74%. Similarly, for sand production in oil wells, the traditional LSTM yields an MRE of 19.07%, while the PC-LSTM achieves a reduced MRE of 9.62%. Lastly, in the scenario of reservoir pressure rise, the traditional LSTM exhibits an MRE of 41.07%, whereas the PC-LSTM achieves a reduced MRE of 12.74%. In the meantime, the model demonstrates a high level of accuracy in capturing the pre- and post-trends of the health status of the ESP wells. This improved prediction accuracy and interpretability of the underlying mechanisms serve as valuable tools for analyzing the lift performance of ESP wells and providing early warning signals for potential failures.

Predictive Maintenance System for Rotating Machinery Onboard Ships for Detecting Performance Degradation

Maintenance of rotating machinery is crucial for extending the lifespan and increasing the reliability of equipment onboard ships. Presently, breakdown and preventive methodologies are used for the maintenance of equipment. Further, dataloggers collect critical machinery parameters, and parameter data is used for real-time parameter monitoring. The availability of such extensive monitoring data has also led to the adoption predictive maintenance methodologies in the industry, wherein machine learning-based analysis of recorded data is used to predict impending defects and prompt required maintenance. In this paper, we propose a predictive maintenance system that records data through a network of sensors installed over multiple electrical motor pump sets onboard the ship and uses statistical analysis to detect equipment degradation. Our system has been deployed onboard a ship to undertake real-time predictive maintenance of electrical motor pump sets used in firemain, AC plants, stabilizers, steering pumps and other auxiliary engine room machinery.

Data-based, high spatiotemporal resolution heat pump demand for power system planning

Decarbonizing the residential building sector by replacing gas boilers with electric heat pumps will dramatically increase electricity demand. Existing models of future heat pump demand either use daily heating demand profiles that do not capture heat pump use or do not represent sub-national heating demand variation. This work presents a novel method to generate high spatiotemporal resolution residential heat pump demand profiles based on heat pump field trial data. These spatially varied demand profiles are integrated into a generation, storage, and transmission expansion planning model to assess the impact of spatiotemporal variations in heat pump demand. This method is demonstrated and validated using the British power system in the United Kingdom (UK), and the results are compared with those obtained using spatially uniform demand profiles. The results show that while spatially uniform heating demand can be used to estimate peak and total annual heating demand and grid-wide systems cost, high spatiotemporal resolution heating demand data is crucial for spatial power system planning. Using spatially uniform heating demand profiles leads to 15.1 GW of misplaced generation and storage capacity for a 90% carbon emission reduction from 2019. For a 99% reduction in carbon emissions, the misallocated capacity increases to 16.9-23.9 GW. Meeting spatially varied heating load with the system planned for uniform national heating demand leads to 5% higher operational costs for a 90% carbon emission reduction. These results suggest that high spatiotemporal resolution heating demand data is especially important for planning bulk power systems with high shares of renewable generation.

Pseudo electric field and pumping valley current in graphene nanobubbles

Pseudo electric field and pumping valley current in graphene nanobubbles

Optically Reconfigurable THz Metamaterial with Switchable Wideband Absorption and Transmission

We present an optically reconfigurable multifunctional metamaterial with switchable wideband absorption and transmission across the THz frequency range. The reconfigurability is achieved by introducing optically active silicon into the resonator of the metamaterial unit which could be effectively modulated through external electrical pumping. When the silicon conductivity reaches 50,000 S/m, the metamaterial shows significant absorption of electromagnetic waves ranging from 3.1 to 10 THz. By reducing the applied external pump power and decreasing the silicon conductivity to 150 S/m, the proposed metamaterial exhibits transmission of the incident waves at 5.12 THz with a transmission coefficient of 61%. The proposed optically reconfigurable metamaterial has the advantages of simple structure, wideband absorption, and switchable between absorption and transmission modes, showing potential applications in stealth, communication, or radar systems.

Mothers' Willingness to Use Workplace Lactation Supports: Evidence from Formally Employed Mothers in Central Kenya

BackgroundFormally employed mothers are vulnerable to early cessation of exclusive breastfeeding. Kenyan national policy requires employer-provided maternity benefits and workplace lactation supports. ObjectiveThe objective of this study was to evaluate willingness to use nationally mandated workplace lactation supports among formally employed women in Kenya. MethodsWe conducted a cross-sectional survey among 304 mothers of children ages ≤12 mo in Naivasha, Kenya, who were currently formally employed and employed before delivery of the most recent child to assess availability of and willingness to use current and potential future workplace lactation supports. ResultsThe most available reported workplace lactation supports were schedule flexibility to arrive late or leave early (87.8%) or visit a child to nurse during lunch (24.7%), followed by company-funded community-based daycare (7.6%). Few (<4.0%) reported the availability of lactation rooms, on-site daycares, transportation to breastfeed during lunch, refrigerators for expressed milk, or manual or electric breastmilk pumps. If made available, >80% of mothers reported moderate or strong willingness to use flexible schedules to arrive late or leave early, break during lunch, and transportation to visit a child to nurse. A moderate proportion reported strong willingness to use on-site daycares (63.8%), company-funded community-based daycare (56.9%), on-site lactation rooms (60.5%), refrigeration for expressed milk (49.3%), manual (40.5%), and electric pumps (27.6%). Mothers expressed fear of missing production targets and reported more willingness to use on-site compared with off-site daycare to save transportation time but noted concerns about chemical exposures and early arrival times with young infants. Hesitations regarding the use of on-site lactation rooms included concerns about privacy, milk identification and storage, and use and sharing of pumps. ConclusionsFlexible schedules were the workplace lactation supports in highest demand among formally employed mothers. Maternal willingness to use lactation rooms, refrigeration, and pumping equipment was moderate to low, suggesting sensitization may help to increase demand as the implementation of Kenyan policies moves forward.

Achievable load shifting potentials for the European residential sector from 2022–2050

This paper develops quantitative predictions for residential electricity demand and the potential for load shifting for Europe at a fine spatial scale for years 2022–2050. To date only theoretical and spatially coarse measurements of this potential exist for a subset of technologies used in the residential sector. As the EU moves towards an ‘Energy Union’, it will be increasingly necessary to consider the whole integrated energy system across the EU and thereby databases with large spatial coverage are needed. To fill this need, we generate hourly load profiles for the residential sector for key electricity consuming devices that take into account the most recent empirical studies of usage patterns, and of the cost and willingness of households to participate in load shifting programs. Additionally, we extend the list of investigated technologies by the important classes of electric mobility and heat pumps for electric space heating. Predictions and insights provided in our article serve multiple use cases, i. they can be used in energy system models to assess the value of load shifting for the future energy system including system costs, ii. they enable infrastructure planners and grid operators to calibrate their expectations of the future role of load shifting in the electricity systems and iii. enable policy makers and to include load shifting in their considerations of future market designs.