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This study presents a new dual-mode propulsion system that utilizes an electrically pumped hydrogen peroxide and kerosene supply system, specifically designed for advanced spacecraft orbit and attitude control. The system incorporates two distinct electric pumps, one for hydrogen peroxide and another for kerosene, each engineered to optimize the propellant feed for the orbit control and attitude control engines. This configuration enables precise propellant management and thrust control, which are critical for the stringent demands of modern space missions. The dual-mode capability of the propulsion system allows for the use of hydrogen peroxide both as a monopropellant in the attitude control engine and as an oxidizer in combination with kerosene in the orbit control engine. This approach simplifies the propulsion architecture while maximizing the efficiency and utility of hydrogen peroxide as a propellant. The electric pumps are essential in providing high-pressure propellant delivery, which is necessary to achieve the desired combustion characteristics and thrust parameters. Performance evaluations of the propulsion system demonstrated significant results. The orbit control engine achieved a combustion chamber pressure of 5.9 MPa and a combustion efficiency of 98.42 %. The attitude control engine, operating at a peak pressure of 4.9 MPa, exhibited a stable pulsative mode, maintaining consistent pressure levels throughout its operational cycle. These performance metrics highlight the effectiveness of the electric pump technology in enhancing propulsion system responsiveness and efficiency. This propulsion system is expected to improve spacecraft maneuverability and reduce operational costs, making it suitable for long-duration space missions. • A versatile dual-mode space propulsion system with electric pump-fed technology. • Advanced electric pumps enable adjustable thrust and precise control. • Confirmed system feasibility and performance through successful ground tests. • Achieved high efficiency and specific impulse in propulsion engines. • Utilized hydrogen peroxide for eco-friendly, non-toxic propulsion. [ABSTRACT FROM AUTHOR]

Studies on electric turbopumps for liquid rocket engines have recently increased. However, it has not been used in large-scale engines for heavy launch vehicles because the mass of power electronic devices, such as batteries and motors, has become too large. This paper proposes partial electric rocket engine cycles, in which all propellants are pressurized by conventional gas-turbine-driven turbopumps; however, an additional electric pump is used only to increase the pressure of the turbine inlet flow. It was found that the turbine flow rate was reduced and the total specific impulse increased using a reasonable sized electric turbopump for engines based on the expander bleed cycle. As a result, the launch capacity of a launch vehicle increases, even when accepting the extra mass of the electric turbopump system. The design feasibility of the electric turbopump was discussed, and it was concluded that such an electric pump system is feasible for upper-stage rocket engines using the current level of power electronics devices. [ABSTRACT FROM AUTHOR]

This paper describes an approach in improving the performance of the position sensorless control of electric oil pumps with a permanent magnet synchronous motor. Electric oil pumps are widely applied for the lubricating and cooling of e-Axles in HEV and BEV which operate from −40 to 130 °C. The accuracy of the estimation obtained from the sensorless control based on the motor model depends on the accuracy of motor parameters and input values. At a lower speed and lower temperature region, the parameter variation and input measurement errors have gained greater influence over the accuracy of the estimation. This paper describes how to overcome this weakness of the sensorless drive via applying a robust position estimator with electrical parameter adaptation and compensation of a phase voltage measurement error. Experimental results with various types of pumps show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The traditional 70 MPa liquid hydrogen (LH 2) refueling stations (HRSs) require LH 2 pumps with high outlet pressures, leading to high initial investment, energy consumption, and difficulty in developing an LH 2 pump meeting requirements. Existing LH 2 HRSs using thermal compression eliminate the need for pressurization equipment but result in significant waste due to low-pressure hydrogen venting. Therefore, we have pioneered a novel pump-thermal synergistic pressurization process for an efficient LH 2 HRS system. The process utilizes a 45 MPa LH 2 pump and an electric heating method, allowing easily controllable heat input. This study constructs a thermodynamic model for this system that includes the dynamic operational processes of all core components. Based on the established model, the outlet parameters of the LH 2 pump, characteristic parameters of the pressure vessel, the refueling process, and the operation of the entire system are investigated. By dynamic simulation of the whole HRS system with pump and thermal compression, it is found that the specific energy consumption for hydrogen refueling is reduced to 0.55 kWh/kg, with the pump consuming 0.2 kWh/kg while thermal compression consuming 0.35 kWh/kg. After optimizing control strategies, the cycle venting of the pressure vessel and the residual hydrogen gas after re-heating and pressurization account for only 11.6%, and further utilization through the pump pressurization cycle can achieve high utilization with no residuals. This system effectively reduces the initial investment and energy consumption for LH 2 HRSs. It simplifies the structure, facilitating the retrofit of existing stations and promoting the construction and application of HRSs. [Display omitted] • An advanced hydrogen refueling station with pump and thermal compression is proposed. • A simulation model is developed for HRS with pump and thermal compression. • Thermodynamic analysis of HRS with pump and thermal compression is conducted. [ABSTRACT FROM AUTHOR]

A thermomagnetic pump is understood as a heated section of a convective loop with a ferrofluid with a non-uniform magnetic field imposed on this section. The part of the heat generated in the pump is transferred by the ferrofluid and absorbed in a cooling radiator, and the other part is dissipated in the environment. The aim of the work is to search for a functional relationship between the velocities of thermomagnetic convection and pump parameters. The problem is solved analytically in the approximation of small Reynolds numbers for a pump containing an electric heater with a circular channel. Equations are obtained that determine the velocity of the convective flow in a parametric form, taking into account the geometry and magnetic field strength and the field dependence of the pyromagnetic coefficient of the ferrofluid. The role of the parameter is played by the spatial decrement of the temperature decay along the contour axis. It is shown that in the case of low Biot numbers the velocity of the flow increases according to the root law with increasing heater power and does not depend on the diameter of the channel. The analytical results are compared with the experimental data for combined (thermomagnetic and gravitational) convection. Neglecting gravitational convection at high heater power leads to an underestimation of the flow velocity by 20–30%. It can be expected that in the case of reduced gravity, the resulting formulas will describe the flow velocity with an accuracy of a coefficient close to unity. [ABSTRACT FROM AUTHOR]

Building renovation is a key initiative to promote energy efficiency, the integration of renewable energy sources (RESs), and a reduction in CO2 emissions. Supporting these goals, emerging research is dedicated to energy communities and positive energy districts. In this work, an urban neighborhood of six buildings in Trento (Italy) is considered. Firstly, the six buildings are modeled with the Urban Modeling Interface tool to evaluate the energy performances in 2024 and 2050, also accounting for the different climatic conditions for these two time periods. Energy demands for space heating, domestic hot water, space cooling, electricity, and transport are computed. Then, EnergyPLAN coupled with a multi-objective evolutionary algorithm is used to investigate 12 different energy decarbonization scenarios in 2024 and 2050 based on different boundaries for RESs, energy storage, hydrogen, energy system integration, and energy community incentives. Two conflicting objectives are considered: cost and CO2 emission reductions. The results show, on the one hand, the key role of sector coupling technologies such as heat pumps and electric vehicles in exploiting local renewables and, on the other hand, the higher costs in introducing both electricity storage to approach complete decarbonization and hydrogen as an alternative strategy in the electricity, thermal, and transport sectors. As an example of the quantitative valuable finding of this work, in scenario S1 "all sectors and EC incentive" for the year 2024, a large reduction of 55% of CO2 emissions with a modest increase of 11% of the total annual cost is identified along the Pareto front. [ABSTRACT FROM AUTHOR]

Nutrition in early life plays a key role in shaping an infant's future health. There is limited understanding of the perspectives of Vietnamese mothers with children under 24 months of age regarding breastmilk expression, donation and use. In this cross‐sectional study, an online survey was administered through two parenting social media communities to assess opinions on breastmilk expression, breastmilk donation including contributions from bereaved mothers and the use of donor human milk. A 4‐point Likert scale was used to evaluate respondents' opinions, and demographic and breastfeeding information was collected. Among 375 respondents, almost 30% had received breastmilk from another woman, either through direct breastfeeding (14.7%), expressed breastmilk (12.5%) or from a human milk bank (2.7%). In this survey of 375 mothers, 84.0% indicated they would store excess breastmilk, while 75.7% and 69.6% would donate to a human milk bank or another mother, respectively. When faced with insufficient breastmilk, 88.5% of mothers would seek ways to increase supply, whereas 23.8% considered using commercial milk formula. Regarding milk expression among the 375 mothers, 78.4% preferred electric pumps, compared to 48.6% for manual pumps and 45.9% for hand expression. Additionally, 80.5% of the 375 mothers would suggest donating stored milk to bereaved peers and 85.6% would suggest mothers with mild COVID‐19 to continue breastfeeding with precautions. These findings indicate that this sample has positive views on breastfeeding, breastmilk donation and the use of donor human milk. [ABSTRACT FROM AUTHOR]

The development of electric gerotor pumps is a complex multiphysical optimization problem. To develop optimal systems, accurate simulation models are required to increase digital reliability. An important challenge is the accurate prediction of the pump behavior for extreme temperatures in automotive applications from − 40 °C to 110 °C, where the viscosity of the fluid changes significantly. Therefore, simulation-based methods (numerical methods for calculating viscous friction) were developed and validated by measurements, including climatic chamber tests. The results show a strong correlation between simulated and measured performance characteristics, especially in terms of volumetric flow rate ( < 5 % ), pump torque and efficiency ( < 7 % ) at different temperature and viscosity conditions over a wide speed range (1000–5000 rpm) and different system pressures (0.5–5 bar). A novel method for simulating the cold start behavior of pumps (journal bearing approach for outer gear in pump housing) was introduced and validated by measurements. The methods presented significantly reduce the need for physical testing and accelerate the development process, as the pump behavior at each operating point can be accurately predicted before a hardware prototype is built. This improves the understanding of gerotor pump characteristics and provides insights to further improve the model-based development of electric oil pumps for the automotive industry. [ABSTRACT FROM AUTHOR]

India is the world's largest user of groundwater for irrigation, with approximately 32 million pumps running on diesel, electric, and solar power. Subsidized electricity has led to an increase in the adoption of electric pumps by farmers, with increasing electrification rates and rising diesel costs contributing to the trend. Government subsidies have been instrumental in enhancing smallholder irrigation pump access. However, subsidies on irrigation pumps may exacerbate undesirable groundwater depletion. In smallholder settings where the capital needed to purchase irrigation equipment exceeds farmers' means, "irrigation-asa-service" and "rental pumps" with organized and affordable volumetric pricing could offer viable solutions. This policy brief provides key learnings on the Indian irrigation pump market and its policy and environmental implications, based on semi-structured interviews and secondary data collected. [ABSTRACT FROM AUTHOR]

Yam is a versatile crop and plays a vital role in tropical regions, where it can be transformed into various food products. Peeling is an essential step in the processing of yam, as it increases its value. While manual peeling with knives is common in households, larger-scale production requires the use of yam peeling machines. The objective of this study was to analyze and enhance the performance of an existing yam peeling machine. The key components of the machine include the machine frame, a wire mesh-like drum, a speed reduction gear motor, a pumping machine, sprockets, pipes, and a water container. The yam peeler is powered by a three-phase 2 hp electric motor. The machine was tested on three different types of yams with varying moisture contents and at different speeds. Various performance parameters such as peeling efficiency, peeling capacity, flesh loss, and time efficiency were evaluated. Statistical analysis and SPSS models were utilized to examine the relationship between different factors and the performance metrics of the machine. The study revealed that as the peeling speed increased, the efficiency decreased. The peeling efficiency ranged from 63.27% to 92.74%, peeling capacity ranged from 2.28 kg/h to 11.34 kg/h, and flesh loss varied from 7.26% to 36.73%. The moisture content of the yams, peeling speeds, and tuber morphology were found to have significant effects on peeling efficiency, flesh loss, peeling capacity, and time efficiency. The yam peeler production cost is estimated to be $150. The machine demonstrated suitability for small-scale food industries due to its low cost and minimal maintenance requirements. [ABSTRACT FROM AUTHOR]

In the process of oil production, wells containing gas can impact the efficiency of electric submersible pump (ESP), potentially causing gas lock. This issue can lead to the loss of lifting capacity in ESP, affecting the normal production of oil wells. To address this problem, the concept of gas separation before mixing transportation has been proposed, and a gas–liquid separation–mixing device has been designed. Experimental tests on the gas–liquid two-phase flow under various working conditions were conducted. A numerical model of the physical process was developed and validated with the experimental results. The results indicate that when the inlet flow rate exceeds 8.75 m3/h, the gas phase can be effectively accumulated in the center of the main pipeline after flowing through the guide vanes, thereby achieving efficient gas–liquid separation. Centrifugal number, which is defined as the ratio of axial flux of centrifugal force to axial flux of gravity, was proposed for evaluating the flow characteristics. When the centrifugal number exceeds 6.5, a high-quality gas core is formed in the pipe. At high inlet gas content, the volume fraction of gas in the main pipe initially decreases to 2% as the flow rate increases to 15 m3/h. However, at a flow rate of 30 m3/h, the volume fraction gradually rises to 30%, which results in a significant amount of gas being forced into the main pipe. The results are beneficial for expanding the use of ESP and improving the lifting efficiency in the development of oil field with high gas content. [ABSTRACT FROM AUTHOR]

Reducing the power consumption of oil production wells is one of the important directions of oil industry development in the context of transition of many fields to the late stages of operation. At the same time, there is often a need to limit hydrocarbon production, which is often accomplished by shutting down wells completely. In this paper, the authors propose an approach to improve the energy efficiency of the electric centrifugal pump unit through the use of periodic operation mode, which allows to reduce the specific power consumption of the electric centrifugal pump unit. Also, this mode can be considered as a way to regulate the well flow rate. According to the results of calculations it was obtained that the reduction of specific power consumption of the unit when operating at nominal frequency can reach 5% relative to the continuous mode of operation. An assessment was made of the effect of reducing the frequency of the supply voltage in a periodic mode on the parameters of the operation of the installation and it was found that the well flow rate increased by 1.43% with a reduction in specific power consumption by 1.64%. [ABSTRACT FROM AUTHOR]

In the context of the energy transition, the share of new loads such as charging infrastructure for electromobility and electric heat pumps as well as feed-ins such as photovoltaic systems will steadily increase. This results in an increased degree of complexity for strategic network planning. In particular, the power flow analyses for the dimensioning of transformers and lines per network level currently still require different methods for the correct dimensioning of these equipment. They need to be carried out in separate data sets. For the dimensioning of the equipment simultaneity factors are predominantly used for realistic load assumptions in strategic network planning. These simultaneity factors and resulting load assumptions are determined from the planning perspective of the transformers and from the planning perspective of the lines per network level to be able to dimension the corresponding equipment. This results in different power flow results for the analysis and evaluation of different network levels in particular. This contribution presents a new concept for network modelling in which the simultaneity of the different planning perspectives of the different network levels results from a single power flow calculation in a coherent data set. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Chemical & Petroleum Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigates the consequences of agricultural activities on groundwater depletion, with a specific focus on the overproduction of water-intensive crops. Addressing this existing research gap, this study challenges the prevailing notion that groundwater depletion reduces agricultural activity. Instead, our study reveals a significant relationship between intensified cropping practices, particularly the production of water-intensive crops (Paddy, Sugarcane and Wheat) and the depletion of groundwater. Further, we identify how subsidized electricity helps to accelerate groundwater depletion. Therefore, we use variables related to groundwater and agricultural practices for the period 2004–2020. In doing so, we find that the Northern states of India are most vulnerable in terms of groundwater depletion (PNB: 59.92, SGD: 106.3), followed by southern, central, western, eastern and northeastern states. Additionally, the regression results suggest that our main variables, magnitude of electricity consumption in agriculture and irrigation intensity of water-intensive crops, have a positive and significant impact on groundwater depletion. In fact, our study found that other variables such as cropping intensity (CI), state population (SP), agriculture credit (AC) and total electric pumps (TP) are also significant and positively associated with groundwater depletion while the magnitude of annual rainfall (AR) shows a negative impact on groundwater depletion. Based on the findings, this study presents an alternative perspective that underscores the contribution of ineffective government policies in regulating subsidize electricity and the cultivation of water-intensive crops, leading to the exploitation of groundwater resources in Indian states with regional variations. These findings emphasize the critical and immediate need for effective regulations on the production of water-intensive crops to address this pressing issue. [ABSTRACT FROM AUTHOR]

In recent years, companies have employed numerous methods to lower expenses and enhance system efficiency in the oilfield. Energy consumption has constituted a significant portion of these expenses. This paper introduces a normalized consumption factor to effectively evaluate energy consumption in the oilfield. Statistical analysis has been conducted on nearly 45,000 wells from six fields in China. Critical factors such as lifting method, daily production, pump depth, gas–oil ratio (GOR), and well deviation angle were evaluated individually. Results revealed that higher production could lead to lower normalized consumption for beam pumps, progressive cavity pumps, and electric submersible pump systems, thus enhancing system efficiency. Additionally, a higher GOR might result in lower normalized consumption for the beam pump system, while the deviation angle of the well showed negligible impact on the normalized consumption factor. This manuscript offers a method to assess the impacts of artificial lift methods on production and discusses suggestions for reducing consumption associated with each lifting method in the oilfield. [ABSTRACT FROM AUTHOR]

The European Union faces the pressing challenge of decarbonising the buildings sector to meet its climate neutrality goal by 2050. Buildings are significant contributors to greenhouse gas emissions, primarily through energy consumption for heating and cooling. This study uses the advanced PRIMES-BuiMo model to develop state-of-the-art innovative pathways and strategies to decarbonise the EU buildings sector, providing insights into energy consumption patterns, renovation rates and equipment replacement dynamics in the EU and in two representative Member States, Sweden and Greece. The model-based analysis shows that the EU's transition towards climate neutrality requires significant investment in energy efficiency of buildings combined with decarbonisation of the fuel mix, mostly through the uptake of electric heat pumps replacing the use of fossil fuels. The Use Case also demonstrates that targeted policy interventions considering the national context and specificities are required to ensure an efficient and sustainable transition to zero-emission buildings. The analysis of transformational strategies in Greece and Sweden provides an improved understanding of the role of country-specific characteristics on policy effectiveness so as to inform more targeted and contextually appropriate approaches to decarbonise the buildings sector across the EU. [ABSTRACT FROM AUTHOR]

Transformative actions are crucial across all sectors emitting greenhouse gases. Nonetheless, energy transition research to date displays a notable imbalance, with a larger emphasis on the supply side than on the demand side. The present study addresses this inequity by focusing on residential sector space heating demand, a frequently overlooked energy service that currently contributes substantially to global greenhouse gas emissions. Our primary objective is to pinpoint effective climate policies and space heating strategies that align with the EU's ambitious targets for emission reduction. We employ the recently developed TIMES-Europe model to conduct a comprehensive analysis of the residential sector's policy frameworks, technological advancements, and associated costs. This analysis aims to determine the measures necessary to meet ambitious climate objectives within the European context. To achieve this, we formulate four distinct scenarios, each representing varying levels of ambition and collaboration among EU member states, thereby providing insight into the pathways toward achieving these targets. By implementing current intended EU policies on the renovation of dwellings, we project a substantial reduction of at most 850 PJ, or, i.e., a 19% decrease, in yearly energy demand for space heating between 2020 and 2050. In contrast, if the recent pace of dwelling renovation within the EU were to continue, space heating energy savings from renovation would only amount to less than 400 PJ/yr (i.e., a 9% reduction) in the same period. In our more ambitious climate scenarios, phasing out fossil fuels leads to widespread electrification of the European residential sector, and by 2050, electricity from heat pumps and electric boilers accounts for over 68% of the total residential sector space heating demand. The outcomes of our study underline the importance of implementing the currently planned EU policies. We also demonstrate the necessity for collaboration among EU member states in order to attain the common European climate targets under the most effective resource allocation. [ABSTRACT FROM AUTHOR]

Optimizing hybrid thermal systems for domestic heating systems is essential to achieve maximum energy efficiency, lower carbon emissions, and decrease overall expenses. This research focuses on utilizing solar energy through evacuated tube solar water systems in conjunction with fuel-based (LPG or diesel) boilers or electric heat pumps for heating residential homes in various climate zones across Jordan. The contributions of each subsystem of thermal energy production were assessed using a one-year dynamic simulation using simulation software TSOL and Meteonorm. A variety of optimization methods are then employed to study and compare several parameters, including station rankings as well as technical and environmental factors. The optimization methods Best-Worst Method BWM yields the highest and lowest weights for the total solar fraction and solar contribution to heating, respectively. After station rankings were conducted using the ARAS, VIKOR, TOPSIS, MOORA, and AHP methodologies, the Maan and Amman stations were identified as most relevant and inappropriate for ETSW use. The annual production of 115.38 GJ utilizing ETSW at the stations under study reduced CO2 emissions by 12.18 tons. The largest losses, accounting for 60.25% and 33.86% of the total losses, respectively, were identified as thermal and optical losses for Maan station. Thus, this study's findings demonstrate the potential of optimized hybrid thermal systems, integrating solar energy with conventional heating methods, to significantly enhance energy efficiency, reduce carbon emissions, and lower overall expenses in residential heating across diverse climate zones in Jordan. [ABSTRACT FROM AUTHOR]

The electric submersible pump (ESP) is a crucial apparatus utilized for lifting in the oil extraction process. Its lifting capacity is enhanced by the multi-stage tandem structure, but variations in energy characteristics and internal flow across stages are also introduced. In this study, the inter-stage variability of energy characteristics in ESP hydraulic systems is investigated through entropy production (EP) analysis, which incorporates numerical simulations and experimental validation. The EP theory facilitates the quantification of energy loss in each computational subdomain at all ESP stages, establishing a correlation between microscopic flow structure and energy dissipation within the system. Furthermore, the underlying causes of inter-stage variability in ESP hydraulic systems are examined, and the advantages and disadvantages of applying the EP theory in this context are evaluated. Consistent energy characteristics within the ESP, aligned with the distribution of internal flow structure, are provided by the EP theory, as demonstrated by our results. The EP theory also enables the quantitative analysis of internal flow losses and complements existing performance analysis methods to map the internal flow structure to hydraulic losses. Nonetheless, an inconsistency between the energy characterization based on EP theory and the traditional efficiency index when reflecting inter-stage differences is identified. This inconsistency arises from the exclusive focus of the EP theory on flow losses within the flow field, disregarding the quantification of external energy input to the flow field. This study provides a reference for the optimization of EP theory in rotating machinery while deeply investigating the energy dissipation characteristics of multistage hydraulic system, which has certain theoretical and practical significance. [ABSTRACT FROM AUTHOR]

Electric water pumps (EWPs) are characterized by small sizes and variable operating conditions. Efficient operation of such a pump is important for the whole thermal management system. Here, comprehensive hydraulic optimization was performed to improve the performance of an EWP. The computational fluid dynamics technique was used to assist in the optimization. The numerical scheme was validated using experimental data. Variations in the blade number, blade profile, and blade inlet edge were implemented. The results showed that solely increasing the blade number leads to an increase in the pump head but cannot guarantee high pump efficiency. A combination of adjusting the blade wrap angle and extending the blade inlet edge toward the pump inlet promotes increases in both the pump head and efficiency. With the improvement in pump performance, the characteristics of the flow field alter remarkably. The pressure at the blade inlet is reduced, and the turbulent kinetic energy near the impeller blade decreases overall. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Chemical & Petroleum Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To achieve climate and energy goals in the building sector, the current pace of renovating existing structures must double, overcoming prevailing barriers. Key Performance Indicators play a pivotal role in science-based decision making, emphasizing both direct and indirect benefits of building retrofits. The authors aim to contribute to proper metric identification for multi-perspective building performance assessment and formulate a methodology supporting energy planning decisions. They introduce the Global Cost per Emission Savings (GCES), an aggregated indicator encompassing both public (CO2 emissions) and private (global cost) perspectives of diverse retrofit technologies for building HVAC systems. Applied to the Italian residential building stock via the Reference Building approach, the methodology is tested using condensing gas boilers, biomass boilers, and electric heat pumps, revealing diverse environmental and economic performances. Addressing the establishment of effective decision-support tools for policymakers, the paper explores the potential impact of various policies on the favorability of technologies. Different policy scenarios are delineated to analyze how distinct approaches may influence the attractiveness of technologies. Notably, in the baseline scenario, biomass boilers hold an advantage over heat pumps according to the GCES index. However, scenarios involving technology-specific incentives or a greenhouse gases emission tax failed to alter the technological ranking, leaving heat pumps financially uncompetitive. In contrast, the TXPM scenario positions heat pumps as the most financially appealing option, penalizing biomass boilers for high particulate matter emissions. [ABSTRACT FROM AUTHOR]

In this paper, we present a comprehensive assessment of the effects of residential loads, electric vehicles (EVs), and electric heat pumps (HPs) on low-voltage (LV) grids in urban, suburban, and rural areas of Germany. Firstly, real data are used to determine the typical structures for each LV grid region. Secondly, nine scenarios are defined with different levels of EV and HP penetration. Thirdly, the Low Voltage Load Flow Calculation in the DIgSILENT PowerFactory is performed for all scenarios while taking the simultaneity factor (SF) for each load type into consideration to calculate the minimum voltage and maximum loadings of transformer and lines in each grid; this allows for the grid's potential bottlenecks to be identified. The network simulations are carried out with the consideration of charging powers of 11 kW and 22 kW in order to evaluate how an increasing EV load in the future may affect the grid's parameters. To the best of our knowledge, no study in the literature has simultaneously addressed all of the aforementioned topics. The results of this study provide a useful framework that distribution system operators (DSOs) may apply to anticipate the forthcoming challenges and figure out when grid reinforcement will be required. [ABSTRACT FROM AUTHOR]

Optimal operation of petroleum production is important in a transition from energy systems based on fossil fuel to sustainable systems. One sub-process in petroleum production deals with transport from the (subsea) well-bore to a topside separator. Good control design for such operation requires a dynamic model of the petroleum flow from the well-bore to the separator. Here, such a dynamic model is considered for liquid production (oil/water) using an electric submersible pump (ESP) to aid in counteracting gravity and friction forces. Based on an existing model used for industrial control design, one goal is to report a complete dynamic model in a single paper. Emphasis is put on dimensionless equipment models for the simple change of units, and the model is developed from physical laws for easy replacement of sub-models, if needed. All the necessary information (equations, parameters) for model implementation is provided, and two candidate equation-based modeling languages are selected and compared: Modelica and ModelingToolkit [MTK] for Julia. The simulation results are virtually identical for the two languages and make sense from physics; however, there is a minor discrepancy in one plot—likely caused by slight differences in accuracy in handling initialization in the implicit algebraic equations. The implementation structures of the model in Modelica and MTK are similar. Modelica is a mature and excellent modeling tool, handles large-scale models, and has tools for producing C code and integration with other tools. MTK is still in rapid development, supports more model types than Modelica, and is integrated in an eco-system with excellent support for control design, optimization, model fitting, and more. To illustrate the suitability of using the developed model for control design, a simple PI controller is designed within the eco-system of MTK/Julia. [ABSTRACT FROM AUTHOR]

An electric coolant pump (ECP) serves as a critical component in the thermal management of electric vehicles. To fulfill the requirements of pressurizing and circulating coolant for various components, a complex structure with multiple pipes is integrated into the pump inlet. This study focuses on the design and analysis of three suction pipe structures: a straight pipe (Case A), a bend (Case B), and a combination of a bend with manifolds (Case C). The objective of this study is to explore the impacts of suction pipe structures on the hydraulic performance, flow pattern, temperature distribution, and vorticity of ECP. Taking into account the variability of coolant physical parameters with temperature, ECP is numerically simulated using the unsteady Reynolds-averaged Navier-Stokes (RANS) equation and the shear stress transport k-. turbulence model. The experimental and numerical results exhibit good agreement. Case A demonstrates the highest efficiency, Case B follows as the second most efficient, and Case C displays the lowest efficiency. However, the pressure rise remains essentially consistent in all cases. The average efficiencies of Cases B and C are 1.18% and 2.13% lower than that of Case A. The temperature of ECP increases with an increase in the coolant temperature. The temperature of the printed circuit board (PCB) surpasses that of the motor. Case A exhibits the most favorable flow pattern, while Case C demonstrates the least favorable. The bend introduces secondary flow, further intensified by the manifold, leading to an increase in vorticity. The high-vorticity zones expand as the flow rate increases. This study offers valuable insights into the optimization of the ECP suction pipe structure. [ABSTRACT FROM AUTHOR]

Considering present opportunities for modernizing accelerated preventive protection (APP) for VVER-1200 reactors, a methodology for selecting two APP groups is presented. Using the described methodology and selection criteria, two APP groups (APP1 and APP2) are selected for modes of disabled RCPSs and two electric feeding pumps during operation at a rated power level. The study represents an important stage in the modernization of the safety algorithm, i.e., accelerated preventive protection of the reactor. The results presented in the article are relevant for research and development purposes, as well as for safety analysis. [ABSTRACT FROM AUTHOR]

The auxiliary feedwater electric pump, which is vital in nuclear power units, demands exceptional seismic reliability. The impact of the seismic excitation direction on the seismic response of the complex auxiliary feedwater electric pump structure remains inadequately understood, thereby introducing uncertainties into seismic analysis and equipment installation procedures. To address this challenge, this study centers on a representative horizontal multi-stage centrifugal pump based on the finite element model and modal analysis. Utilizing the response spectrum method and the square root of the sum of the squares (SRSS) vibration pattern superposition principle, the research comprehensively explores the seismic response characteristics of individual pressure-bearing components and key rotor positions under seismic excitation from various angles. Findings reveal intricate variations in maximum stress and displacement responses for each pressure-bearing component under safe shutdown earthquake (SSE) level seismic excitation, corresponding to different input angles of seismic spectra. In assessing the seismic operability of the clearance between the impeller and the stator, the direction near 45° exhibits the maximum displacement response, highlighting the need for focused attention in testing and verification checks. The methodologies and conclusions presented in this paper offer valuable insights for designing, optimizing, and installing horizontal multi-stage centrifugal pumps, including auxiliary feedwater electric pumps, providing valuable guidance for future applications in the field. [ABSTRACT FROM AUTHOR]

In the EU, the building sector is responsible for 40% of the global energy consumption for final uses and 36% of the carbon dioxide (CO2) emissions. Heat pumps allow for the replacement of conventional systems based on fossil fuels with the perspective of combining PV and solar thermal collectors. In order to rationalize the use of the solar source, this paper examined the self-consumption electricity share, the CO2 equivalent emissions, and the domestic hot water demand covered by renewable sources which were determined in two opposite climatic conditions. These involved both electric and thermal storage systems and considered two different control strategies. The first is commonly used for the management of air-conditioning systems, the second was specifically conceived to maximize the exploitation of the solar source. Results showed that the latter significantly reduced grid dependence in both locations, determining the direct satisfaction of 76% of the thermal and electric loads through the PV self-consumption, determined by 18 kWp of installed PV and a battery capacity of 24 kWh. In terms of equivalent CO2 emissions, when the two control strategies were compared, a remarkable reduction in emissions was registered for the latter, with percentages ranging between 8% and 36% as a function of PV surface and battery capacity. The analysis of domestic hot water supplies revealed disparities between the two localities: the colder first, relied more on heat pumps for water heating, while the warmer second, benefitted from the large availability of solar radiation. [ABSTRACT FROM AUTHOR]

Background: Formally employed mothers are vulnerable to early cessation of exclusive breastfeeding. Kenyan national policy requires employer-provided maternity benefits and workplace lactation supports. Objective: The objective of this study was to evaluate willingness to use nationally mandated workplace lactation supports among formally employed women in Kenya. Methods: We 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. Results: The 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. Conclusions: Flexible 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. [ABSTRACT FROM AUTHOR]

The electric pump in the propellant supply system, with a wide range of fast thrust adjustment capabilities, can significantly enhance rocket motor performance. Previous research has focused on the performance and feasibility of hydrogen peroxide electric pumps for hybrid rocket motors; however, their dynamic characteristics remain unclear. This study numerically and experimentally investigated the transition stages in the flow field and head for an electric pump during the start-up of a hybrid rocket motor, as well as analyzed the effect of pipeline length between the pneumatic valve and the adjustable Venturi on the flow field and head. The simulation and experimental results indicate that during the start-up of the hybrid rocket motor, six transient stages are recorded when the pipeline length between the pneumatic valve and adjustable Venturi is 3 m. The head and internal flow field of the electric pump during the transient process were determined by the throttling position as well as by the filling status of the pipeline. The simulation results suggest that the shorter the pipeline length, the steadier and safer is the supply system. Our investigation provides a practical optimization strategy for electric pump supply systems in rocket motors. • The transient process of the electric pump during start-up of the hybrid rocket motor was obtained. • Physical mechanisms for the variation of head and internal flow field were obtained. • The effect of pipeline length on the transient process of the electric pump was obtained. [ABSTRACT FROM AUTHOR]

The Total Equivalent Warming Impact (TEWI) index is conventionally used to evaluate emissions from heating, ventilation, air conditioning and refrigeration (HVAC&R) systems. However, a more comprehensive indicator, the Expanded Total Equivalent Warming Impact (ETEWI), has been proposed to overcome the limits of TEWI index and to consider additional environmental impacts such as the effects of urban heat island and the natural gas losses along high-pressure pipelines supplying gaseous fuel to natural gas-fired power plants. In this study, TEWI and ETEWI metrics are applied to an air-to-water electric heat pump (EHP) serving a university building in Benevento (Southern Italy). Real data on EHP electricity consumption have been derived from the entire building's electric load and compared to measured data. ETEWI index has been estimated in two scenarios, one considering the impact of refrigerant charge variation on the performance of the EHP and its environmental impact and the other disregarding it. Additionally, carbon dioxide emission factors for electricity production have been forecasted from 2021 to 2033 to determine the indirect term of ETEWI index. Over the lifetime of the EHP, ETEWI increases by 4.8% compared to TEWI when the variation of refrigerant charge level is not considered. However, this percentage growth is equal to 6.5% when the impact of refrigerant charge change is accounted too. In the latter scenario, the indirect term of ETEWI decreases from 22.7 tCO 2 in 2015 to 12.0 tCO 2 in 2033 when the forecast of the carbon dioxide emission factors for electricity production is taken into account. [ABSTRACT FROM AUTHOR]

A conventional intelligent fault diagnosis approach for electric submersible pumps (ESPs) is heavily dependent on manual expertise for feature extraction. Meanwhile, a conventional convolutional neural network (CNN) exhibits an excess of parameters and requires a substantial volume of training samples. In this paper, a fault diagnosis algorithm of ESPs based on a Bayesian optimization-one-dimensional convolutional neural network-support vector machine (BO-1DCNN-SVM) is proposed by combining a 1DCNN with a SVM and using the algorithm BO to tune the improved 1DCNN. First, the method uses the self-extracting feature capability of the 1DCNN to solve the problem that traditional diagnosis methods over-rely on manual experience extraction. Meanwhile, the last layer of the convolutional neural network Softmax layer is replaced by the SVM to effectively process a few sample data. The accuracy and generalization ability of the fault classification of the electric submersible pump are improved. Then, the Bayesian optimization algorithm is used to find the optimal combination of hyperparameters for the improved 1DCNN-SVM model to further improve the prediction performance of the fault diagnosis model. Finally, the experimental results achieved a classification accuracy of 96.64%, which is 5% higher than existing CNN approaches with data samples of similar scale in this paper. The proposed method also proved to be highly accurate and robust in fault diagnosis. [ABSTRACT FROM AUTHOR]

In this paper, the performance of an innovative micro-combined cooling, heating, and power (CCHP) system, based on an internal combustion engine fueled with syngas from woody biomass, is analyzed. In particular, a numerical model, which considers a direct coupling between the internal combustion engine and the gasifier as a novel aspect, was developed, validated and applied to three different case studies to perform an energetic, economic and environmental analysis. For each considered case, the CCHP system was equipped with a reversible electric air–water pump and a back-up boiler. The energy analysis shows that the user characterized by a high uniformity of the thermal load exploits the CCHP system in the optimal way as it allows for the highest thermal self-consumption rate. On the contrary, for the cases in which the thermal request is not uniform, a high electric surplus is recorded. In this case, the adoption of the heat pump allows to compensate for this disadvantage by recovering the electric surplus, thus achieving a thermal integration and CO2 emissions reduction of about 15.8% with respect to the case in which no heat pump is used. Overall, the results demonstrate the affordability of the biomass-based CCHP system, which is of increasing importance in this period of contingent international political crisis. [ABSTRACT FROM AUTHOR]

The electric pump integrated into propellant supply system boasts the expansive capacity for swift thrust adjustments, making it an indispensable asset for optimizing the performance of a hybrid rocket motor. Although previous studies have explored the efficacy and practicability of hydrogen peroxide electric pumps in hybrid rocket motors, the implications of their filling process on start-up have remained elusive. In this study, the filling process and its effect on the start-up of the electric pump were numerically and experimentally investigated. The experimental and simulation results show that the electric pump cannot be completely filled by opening only the valve upstream of the pump and that there are still areas of air in the pump after the filling process. The results of the start-up process of the electric pump with different filling conditions indicate that the air, filling and acceleration process increase the pressure and axial force fluctuation, decrease the efficiency and compromise the operational stability of the pump after start-up. The results of the filling process of the electric pump at 2000 rpm demonstrate that filling the pump after starting it further reduces its efficiency and operational stability. This study provides practical guidance for filling electric pump supply systems and starting electric pumps of the rocket engines, which ensures the stable operation of rocket engines. • The filling process of electric pump in a hybrid rocket motor was studied by simulation and test. • The start-up process of the electirc pump with different filling conditions was investigated. • The filling process of the electric pump at 2000 rpm was investigated. [ABSTRACT FROM AUTHOR]

Heat pumps offer an efficient electrification of space heating but can significantly vary the magnitude and duration of house-level electrical demand, especially when replacing fuel-fired heating systems. This paper uses a simulation-based approach to simulate the electrical demand variations of air-source heat pumps (ASHPs) in six Canadian cities (Halifax, Montreal, Toronto, Winnipeg, Vancouver, Whitehorse) when replacing natural gas or electric baseboard heating. Detailed housing models (including a highly zoned model capturing room-based baseboard controls) are combined with a series of custom non-HVAC load profiles and an enhanced data-driven ASHP model to assess the variation that occupancy, climate, and type of heat pump integration can have on electrical demand. ASHPs are shown to increase the magnitude and duration of electrical demand when replacing natural gas furnaces, although selection of climate-appropriate systems (e.g. cold climate units in colder climates) may reduce the magnitude and coincidence of this demand. Where heat pumps replace electric baseboards, HVAC demand may decrease by up to 3.4 kW during ASHP operating periods and remain equal when the ambient temperatures are below the ASHP cutoff. A study of simple mitigation measures through varying temperature setpoints demonstrates the ability of proper controls to reduce electrical demand during high-demand periods. [ABSTRACT FROM AUTHOR]

In view of the failure phenomenon that the 4 inch T type structure stainless steel fluid end of the electric fracturing pump suffers many fatigue cracks in the cross-bore area, and the damage life between each cylinder and different areas within the cylinder is not uniform, which leads to the short fatigue life of the fluid end. To find out the failure causes and extend the fatigue life, the fluid end is optimized based on the concept of equal life. Firstly, according to the working conditions of the fluid end, the static analysis of the cylinder under 10 rated working conditions and one pressure test condition is carried out. The calculated results all meet the static strength requirements. Secondly, based on the static finite element analysis results of 10 kinds of actual working conditions, the cyclic peaks were found through the constant amplitude alternating load, and the fatigue life and distribution law of the fluid end were calculated. Then, by comparing with the damage data summarized in the field construction, it is found that the calculated fatigue life and distribution area of the fluid end are in good agreement with the actual damage life and the overall situation of the area. Finally, by increasing the single-side margin e to 80 mm, the fatigue life of cylinders 1 and 5 is extended by 66.4%, and the fatigue life of fluid end is extended by 58.7%. The fatigue life of fluid end is increased by 7.9% through orthogonal optimization of the intersecting line fillet radius R1 is 15 mm, the bottom fillet radius R2 is 12 mm, and the cutting depth of arc groove D is 230 mm. The fluid end fatigue life is extended by 71.3% total. The results show that the fluid end fatigue life analysis method by finding the cycle peak can be used to calculate the fluid end fatigue life accurately. The equal life parameter optimization method combining single factor and orthogonal test is of reference significance for the optimization of fluid end structural parameters and the extension of fluid end fatigue life of other types of fracturing pumps. [ABSTRACT FROM AUTHOR]