Mass Flow Data Research Articles

Experimental Investigations on the Impact of Hydrogen Injection Apertures in Pulsed Detonation Combustor

Combustion through detonation marks an important leap in efficiency over standard deflagration methods. This research introduces a Pulsed Detonation Combustor (PDC) model that uses Hydrogen as fuel and Oxygen as an oxidizer, specifically targeting carbon-free combustion efforts. The PDC aerodynamic features boost operating cycle frequency and facilitate Deflagration-to-Detonation Transition (DDT) within distances less than 200 mm by means of Hartmann–Sprenger resonators and cross-flow fuel/oxidizer injection. The achievement of quality mixing in a short-time filling process represents not only higher cycle operation but also enhanced performances. The scope of this paper is to assess the impact of different fuel injectors with different opening areas on the performances of the PDC. This assessment, expressed as a function of the Equivalence Ratio (ER), is conducted using two primary methods. Instantaneous static pressures are recorded and processed to extract the maximum and average cycle pressure and characterize the pressure augmentation. Thrust measurements obtained using a load cell are averaged over the detonation cycle to calculate the time-averaged thrust. The specific impulse is subsequently determined based on these thrust measurements and the corresponding mass flow data.

Life cycle assessment and life cycle cost analysis of surgical mask from production to recycling into hydrogen process

Global greenhouse gas emissions and medical supply management systems are facing increasing challenges at the social, environmental, and economic levels. This study aims to propose a multi-objective assessment method coupled with life cycle assessment and life cycle cost analysis to evaluate the entire process of medical supply represented by surgical mask from production to recycling into hydrogen from environmental and economic perspectives. Mass and energy flow data are obtained from literature and the hydrogen production process by plasma gasification of surgical mask established using Aspen Plus. The results reveals that the life cycle energy consumption, global warming potential, acidification potential and photochem ozone creation potential in the surgical mask collection, pretreatment, plasma gasification and waste heat recovery stage account for 77.34%, 40.20%, 46.00% and 44.63% of the entire life cycle, respectively. Operating costs have a significant impact and using of fully automatic equipment and improving the energy consumption of plasma torches are critical to reducing system operating costs. A sensitivity analysis of the four modes of hydrogen transport is performed, and the best mode of hydrogen transport is proposed. This study provides basic information reference for the medical product management system.

Development of a Novel Ground Test Facility for Aircraft Environmental Control System

Abstract In this article, the development and experimental investigation of a Boeing 737 aircraft environmental control system (ECS) passenger air conditioner (PACK) has been reported. The PACK is the heart of the ECS that conditions bleed air prior to supplying it to the cabin and avionics bay. Its capability to mask fault occurrences has resulted in increased unscheduled maintenance of the system. As such it has been a key research topic to understand PACK performance characteristics in order to support an accurate diagnostic solution. This article is a continuation of the authors’ work on the development of a systematically derived PACK simulation model and reports the overall development and qualification of a novel in situ ground test facility (GTF) for the experimental investigation of a B737-400 aircraft PACK under various operating modes, including the effect of trim air system. The developed GTF enables the acquisition of the temperature, pressure, and mass flow data throughout the PACK. The overall process of instrumentation selection, installation, sensor uncertainty, and testing in terms of data repeatability and consistency has been reported. The acquired data are then employed to conduct verification and validation of the SESAC (simscape ECS simulation under all conditions) simulation framework. The reported research work therefore enables the advancement in the level of scientific understanding corresponding to the ECS PACK operation under real operating conditions, and therefore supports the development of a robust simulation framework for ECS fault diagnostics at the system level.

Distribution of trace substances in the coolant of a BWR fuel element

A transport model was developed and numerically solved for trace substances dissolved in the coolant flowing through a complete BWR fuel element. The integration of the trace substance transport equations is carried out on the same computational grid used by a two-phase three-field subchannel code, the output of which provides the necessary coolant mass flow data, including field exchange terms. The results consist of complete, field specific trace substance distributions within the domain of the simulation and with the same spatial resolution as used by the subchannel code. Downstream the onset of annular flow, it was observed that the trace substance concentrations in liquid films on heated rods are significantly higher than the concentrations in droplets and in films on unheated surfaces. A mechanistic model for disturbance waves was further introduced to assess the additional trace substance concentration increase in the time period of base film evaporation between two successive disturbance waves. The highest trace substance concentrations were found next to part-length rods in the corner of the considered fuel assembly just upstream of the two uppermost spacer grids, which approximately corresponds to the location of trace substance deposition observed during fuel inspections at a Swiss nuclear power plant.

Strategies of eliminating nuclear waste using accelerator-driven system in the transition stage for sustainable and clean nuclear energy in China

Based on the current situations and development tendencies of nuclear energy in China, three scales of nuclear-energy development are predicted. This work explores the strategies of transmuting the Minor Actinides (MAs) in the spent nuclear fuel using Accelerator-Driven Subcritical systems (ADS) to achieve the transition to sustainable and clean nuclear fission energy. The mass-flow data of fuel cycle with time for ADS transmutation system is obtained through simulations, which provides the basic reference for the fuel fabrication, the reprocessing scale and the interim storage of discharged fuel in Chinese ADS systems arranged in different stages. The time required for eliminating over 95% MAs inventory from Pressurized Water Reactor (PWR) spent fuel is discussed. The mass and toxicity of final high-level waste in different stages are analyzed to demonstrate the excellent ability of ADS to eliminate the mass of MAs and the inventory of high-level waste.

The graphical design space for the primary drying phase of freeze Drying: Factors affecting the dried product layer resistance

An emerging approach to process development of a lyophilized pharmaceutical product is to construct a graphical design space for primary drying as an aid to process optimization. The purpose of this paper is to further challenge the assumption in earlier work that the maximum values of the resistance of dried product layer, Rp, is approximately constant and is independent of process conditions within the “acceptable” region of the design space. Three model formulations containing bovine serum albumin as the model protein were chosen to represent: (a) an amorphous system, (b) a crystalline system, and (c) a mixed system where both an amorphous and a crystalline component were present. Low temperature differential scanning calorimetry (DSC) and freeze dry microscopy (FDM) experiments were conducted to estimate critical product temperature. A conservative lyophilization cycle was conducted for each formulation to collect mass flow data and individual design spaces were then established. A series of lyophilization cycles were then conducted using process conditions that resided within the individual design space and the resultant product temperature and resistance of dried product layer (Rp) values were compared between the individual cycles within each formulation. The data indicated that the Rp was component dependent with the mannitol formulation exhibiting higher Rp values than the sucrose formulation. Interestingly, when mannitol was retained amorphous, the formulation exhibited a lower Rp, similar to that of the sucrose formulation. The mixed formulation exhibited intermediate Rp values. Crystallization of mannitol is hypothesized to facilitate a decrease in the size of the ice porous structure by making the water vapor flow path tortuous, thereby increasing the Rp of mannitol formulations. Within the “acceptable” zone of the individual design space, Rp was dependent on the process condition with more aggressive shelf temperature cycles resulting in lower Rp. Specific Surface Area measurements of freeze-dried solids demonstrated that more aggressive conditions resulted in smaller surface area. Freeze-dried solids of crystalline formulations consistently exhibited higher specific surface area than the amorphous formulations.

Filtering harbor craft vessels’ fuel data using statistical, decomposition, and predictive methodologies

Filtering is the process of defining, recognizing, and correcting flaws in given data so that the influence of inaccuracies in input data on subsequent studies is minimized. This paper aims to discuss the characteristics of some filtering methods from various topics. Wavelet transform and frequency (Fourier) transform are considered for the decomposition methodologies whereas descriptive statistics is used for the statistical methodology. The Kalman filter and autoencoder neural network are also explored for the predictive methodologies. All the aforementioned methodologies are discussed empirically using two metrics of R-squared and mean absolute error. This paper aims to study the effectiveness of these filtering techniques in filtering noisy data collected from mass flowmeter reading in an unconventional situation i.e., on a tugboat while in operation to measure fuel consumption. Finally, the performance of various filtering methods is assessed, and their effectiveness in filtering noisy data is compared and discussed. It is found that the Haar wavelet transforms, Kalman filter and the descriptive statistics have a better performance as compared to their counterparts in filtering out spikes found in the mass flow data.

Assessing data in the informal e-waste sector: The Agbogbloshie Scrapyard

The Old-Fadama-Scrapyard, better known as Agbogbloshie, is located in Accra, Ghana. Over the last 20 years, the area has developed into a large scrapyard, where the informal sector processes mainly electronic waste (e-waste) and scrap metals. However, unsafe treatment methods, such as the open burning of cables and foams, and the spilling of hazardous liquids onto the ground, cause environmental pollution and create health risks by releasing persistent organic pollutants (POPs) and heavy metals.There is a recognized lack in literature of data on e-waste mass and material flows due to the lack of applicable methods to measure e-waste quantities in an informally managed treatment system. However, to establish sustainable e-waste management, e-waste mass and material flow data are crucial prerequisites. Therefore, the material flow analysis (MFA) methodology is proposed as a means for data collection within a limited time frame in the informal e-waste recycling context.In this case study, mass and material flows of e-waste processed at Agbogbloshie were estimated using two different approaches: Firstly, the kind, measures, constitution of load and number of loaded entering and exiting vehicles was observed and documented, and second, to validate the data collected, the mass and material flow of e-waste treatment processes on site were observed and documented.The resulting annual mass flows range between 13,090 t/a and 17,094 t/a of e-waste. Based on the data for Ghana from the Global E-waste Monitor, an average of 15,092 t/a (approximately 39% of the Ghanaian e-waste generation) is treated in Agbogbloshie.

Real-time monitoring of volume flow, mass flow and shredder power consumption in mixed solid waste processing

Real-time material flow monitoring is not yet implemented in mixed solid waste processing, but it is important for an efficient quality assured production and the development of the smart waste factory. The present paper shows results of practical investigation of the Real-Time Material Flow Monitoring in a large-scale Solid Recovered Fuel (SRF) production plant and a semi large-scale processing line (Technical line 4.0) using mixed solid waste. The investigations aimed to research the fundamentals for generating mass flow data from volume flow data and volume and mass flow data from shredder power consumption. It could be shown that a mass determination from volume flow data with the help of density determinations can be practically realized in a good approximation (deviation < 1%) to the gravimetrically determined mass in an SRF production plant. With R2 = 0.47, the power consumption of a shredder in the SRF plant shows a low to medium correlation to the corresponding volume flow. In the 31 tests with the Technical Line 4.0, both, the mass flow and the volume flow could be measured in real-time. Combining these data results in the temporal density curve and shows strong fluctuations for shredded commercial waste. Comparing the mean bulk densities for each test with those from the density determinations of taken samples shows a robust correlation (R2 = 0.82). Analyzes of the material composition of the shredded mixed solid waste show strong correlations to bulk density for the proportions of the fractions rest (positive correlation) and plastics (negative correlation).

Hydrodynamic resistance parameters of regenerator filler materials at cryogenic temperatures

Prototypical cryocooler regenerators were assembled with several common regenerator filler materials and were tested under periodic helium flow at room and cryogenic temperatures. The mass flow and pressure drop data were analysed to determine the friction factor, Darcy Permeability and Forchheimer coefficients. The results are compared to previous investigations, and the relevance of room-temperature models and correlations to cryogenic temperatures is assessed. It is shown that within the range of parameters tested, room-temperature hydrodynamic parameters such as friction factor can be used at cryogenic temperatures. Empirical correlations with improved accuracy are developed for the friction factor for each of the tested filler materials.

A comprehensive analysis of operations and mass flows in postharvest processing of washed coffee

Although coffee is one of the most valuable and widely traded agricultural commodity in the world (US$83 billion in 2017 revenue), little information exists in the scientific literature regarding coffee bean postharvest processing. In particular, sustainability analyses require information on the coffee bean mass and property changes during processing, from harvest to final consumption. In this study, a detailed analysis of the washed or wet-processed method for coffee postharvest processing is provided. Mass flow data were collected through site visits, surveys, laboratory measurements, and interviews with coffee wet and dry mill operators in several countries throughout Central America and Mexico, as well as roasters and cafés in the United States, to establish representative mass flow rates and process flow diagrams from harvest to cup. Results indicate that 100 kg of harvested coffee cherries will on average yield 2.6 kg of mass consumed by humans as exported coffee, equivalent to approximately 839 metric cups (250 ml) of drip brew coffee or 897 metric shots (30 ml) of espresso. The remaining 97.4 kg provide opportunities for development of alternative products, and other economic uses. Importantly, the data suggests that more mass is lost during depulping in practice than previously indicated by laboratory measurements. This study provides a foundation for further investigations in the fields of equipment improvement, byproduct utilization, and environmental and economic sustainability of the coffee processing and distribution chain.

Development of a Small Aviation Two-stroke Kerosene Engine Fuel Injection Controller

Background: The study of kerosene fuel for gasoline engines is of great significance to the supply, management, storage, transportation of military fuel, as well as its safety. A small aviation twostroke kerosene engine fuel injection controller is the key technology of kerosene engines. It is very important to improve the performance of kerosene engine by controlling the air-fuel ratio accurately. Objective: In this study, the initial injection pulse spectrum was firstly obtained by numerical calculation in the absence of kerosene injection pulse spectrum, and then the injection controller was designed based on the initial injection pulse spectrum. Methodology: Firstly, a numerical model of the whole engine was established by using BOOST software. The air mass flow data of the inlet was obtained through numerical calculation. The amount of initial engine fuel injection was calculated according to the requirements of air-fuel ratios in each working condition, from which an initial injection pulse spectrum was obtained. Then, based on Freescale 16-bit embedded micro-controller MC9S12DP512, a kerosene engine fuel injection controller was developed, together with the circuit. According to the initial fuel injection pulse spectrum, a twodimensional interpolation algorithm was developed by using assembly language and C language mixed programming, and the anti-electromagnetic interference ability of the controller was further enhanced. Finally, the accuracy of the initial injection pulse spectrum and the performance and reliability of the injection controller of the kerosene engine were verified by the kerosene engine bench test. Results: The experimental results show that the numerical model was accurate, and the development time of the injection controller reduced by using the numerical model to calculate the initial injection pulse spectra. Conclusion: The developed controller was observed to be stable and reliable, which can meet the control requirement.

Environmental impact of recycling spent lithium-ion batteries

Lithium-ion batteries are used for energy storage and as an energy source in a wide range of applications from small handheld to powering consumer-driven vehicles. With the global change from fuel-based vehicles to electric vehicles and the rise in use of batteries for other functions, it is imperative to start considering industrial-scale recycling of spent batteries to recover the critical components and reduce the ecological footprint generated by untreated disposal of the batteries. The present work was carried with the objective to check the environmental impact of leaching with mild phosphoric acid by using the material and energy flow data obtained from laboratory experiments. Lithium and cobalt were recovered from dead cell phone batteries that were composed of Lithium Cobalt Oxide (LiCoO2) on aluminum foils as cathodes and graphite on copper foils as anodes. The mass and energy flow data from the experiments performed were tabulated and used for the estimation of the environmental impact by executing a Life Cycle Impact Assessment (LCIA) using Umberto NXT universal software with ReCiPe (endpoint) method of analysis.

The environmental performance of enhanced metal recovery from dry municipal solid waste incineration bottom ash

This study assesses the environmental performance of the municipal solid waste (MSW) incineration bottom ash (IBA) treatment plant in Hinwil, Switzerland, a large-scale industrial plant, which also serves as a full-scale laboratory for new technologies and aims at an optimal recovery of metals in terms of quantity and quality. Based on new mass-flow data, we perform a life cycle assessment that includes the recovery of iron, stainless steel, aluminium, copper, lead, silver and gold. Fraction-specific modelling allows for investigating the effect of the metal fraction quality on the subsequent secondary metal production as well as examining further metal recycling potentials in the residual IBA. In addition, the implications on the landfill emissions of IBA residues to water were quantified. The impact assessment considered climate change, eco- and human toxicity and abiotic resource depletion as indicators.Results indicate large environmental savings for every impact category, due to primary metal substitution and reduction of long-term emissions from landfills. Metal product substitution contributes between 75% and >99% to these savings in a base scenario (1′000-year time horizon), depending on the impact category. Reductions in landfill emissions become important only when a much longer time horizon was adopted. The metal-based analysis further illustrates that recovering heavy non-ferrous metals – especially copper and gold – leads to large environmental benefits. Compared to the total net savings of energy recovery (215 kg CO2-eq per tonne of treated waste, average Swiss plant), enhanced metal recovery may save up to 140 kg CO2-eq per tonne of treated waste.

Power Management for Plug-in Hybrid Electric Vehicle with Automated Mechanical Transmission using Multiple Dimensional Scaling Method

Background: The study of kerosene fuel for gasoline engines is of great significance to the supply, management, storage and transportation of military fuel, as well as its safety. Small aviation two-stroke kerosene engine fuel injection controller is the key technology of kerosene engines. It is very important to improve the performance of kerosene engine by controlling the air-fuel ratio accurately. Objective: The initial injection pulse spectrum was firstly obtained by numerical calculation in the absence of kerosene injection pulse spectrum, and then the injection controller was designed based on the initial injection pulse spectrum. Methodology: Firstly, a numerical model of the whole engine was established by using BOOST software. The air mass flow data of the inlet was obtained through numerical calculation. The amount of initial engine fuel injection was calculated according to the requirements of air-fuel ratios in each working condition, from which an initial injection pulse spectrum was obtained. Then, based on Free scale 16-bit embedded micro-controller MC9S12DP512, a kerosene engine fuel injection controller was developed, together with the circuit was also designed. According to the initial fuel injection pulse spectrum, a two-dimensional interpolation algorithm was developed by using assembly language and C language mixed programming, and the anti-electromagnetic interference ability of the controller was further enhanced. Finally, the accuracy of the initial injection pulse spectrum and the performance and reliability of the injection controller of the kerosene engine were verified by the kerosene engine bench test. Conclusion: The experimental results show that the numerical model was accurate, and the development time of the injection controller was shortened by using the numerical model to calculate the initial injection pulse spectra. The developed controller was stable and reliable, which can meet the control requirement.

The curvature of an evaporating meniscus in a pressure driven flow through cylindrical pores

AbstractThe pressure driven flow of a vapor near saturation through an anodic alumina membrane with a thickness of 0.1 mm and a pore diameter of 37 nm is considered. Near saturation, the vapor condenses and liquid flows trough a part of the membrane. By applying a theoretical description of the flow process, the curvature of the menisci is determined from mass flow data. It is assumed that the downstream front of the membrane is either adiabatic, or diabatic, or it is connected via a heat transfer coefficient to the environment. In addition, an isothermal description of the flow is applied. Depending on the boundary condition or the description of the flow, the curvature of the meniscus within the membrane varies greatly.

Towards 4th generation district heating: Prediction of building thermal load for optimal management

One of the requirements for the transition from conventional district heating (DH) systems to 4th generation DH (4GDH) systems is the knowledge of system dynamics. Forecast of thermal request profiles of buildings is crucial to optimize the operating conditions. In fact, when this is available, the thermal load evolution at the plants can be estimated and proper energy saving actions can be implemented. In this paper, a smart and fast approach for estimating the daily thermal request of buildings in large networks is presented. The methodology uses only data available from the smart meters installed in the building substations (mass flow and temperature data). For the users where smart meter data are not available an alternative approach is proposed. The methodology is shown to be suitable for applications involving a) a very large number of buildings b) necessity of forecast of an area c) measured data, which might be affected by gaps d) low computational time requirements. Experimental data show that, despite the simplicity, the method predicts the thermal request very accurately. Furthermore, the forecasted thermal request are here effectively used with the aim of reducing the peak load in one of the largest DH systems in Europe.

Periodic flow hydrodynamic resistance parameters for woven screen matrices at cryogenic temperatures

The regenerator is a critical component in all Stirling and Pulse Tube cryocoolers. It generally consists of a microporous metallic or rare-earth filler material contained within a cylindrical shell. Accurate modelling of the hydrodynamic and thermal behaviour of different regenerator materials is crucial to the successful design of cryogenic systems. Previous investigations have used experimental measurements at steady and periodic flow conditions in conjunction with pore-level CFD analysis to determine the pertinent hydrodynamic parameters, namely the Darcy permeability and Forchheimer coefficients. Due to the difficulty associated with experimental measurement at cryogenic temperatures, past investigations were mostly performed at ambient conditions and their results are assumed to be appropriate for cryogenic temperatures. In this study, a regenerator filled with woven screen matrices such as 400 mesh T316 stainless steel were assembled and experimentally tested under periodic helium flow at cryogenic temperatures. The mass flow and pressure drop data were analysed using CFD to determine the dimensionless friction factor, Darcy Permeability and Forchheimer coefficients. These results are compared to previous investigations at ambient temperature conditions, and the relevance of room-temperature models and correlations to cryogenic temperatures is critically assessed.

Preliminary analysis of dry-steam geothermal power plant by employing exergy assessment: Case study in Kamojang geothermal power plant, Indonesia

The objectives of this study are to perform the exergy analysis and ambient temperature optimization of the Kamojang geothermal power plant by employing Engineering Equation Solver (EES). The geothermal capacity is 55MW and the field is vapor-dominated reservoir with temperature 245°C. In the initial state temperature, pressure and mass flow data are collected from the plant operation. The study results show that system has overall efficiency of 35.86% which means that only 111,138.92kW electrical power can be extracted from 309,000kW thermal power being produced by 10 production wells of Kamojang. This low efficiency is due to irreversibility associated with different processes and components in the system. The largest irreversibility occurs in condenser due to which 53% of total energy is disposed into the environment. Ambient temperature at Kamojang varies from 17 to 20°C. The effect of this variation in temperature is also investigated and it is observed that higher temperature does not have any significant impact on system efficiency.

Core Design Studies of a Fast Reactor and Accelerator-Driven System for Two-Stage Fast Spectrum Fuel Cycle Option

This paper presents the core design studies of a sodium-cooled fast reactor (SFR) and a sodium-cooled accelerator-driven system (ADS) for a two-stage fast-spectrum fuel cycle to enhance uranium resource utilization and reduce nuclear waste generation. The first-stage SFR starts with low-enriched uranium (LEU) fuel and operates with the recovered uranium and plutonium from the discharged fuels and natural uranium at equilibrium. The recovered minor actinides (MAs) are sent to the second-stage ADS, where they are burned in an inert matrix fuel form. Reference core designs were developed for a 1000-MW(thermal) LEU-fueled breakeven fast reactor (LEUBFR) and an 840-MW(thermal) MA-fueled ADS blanket. The SFR starts with uranium fuel with a 235U enrichment of 13.6% and reaches a fuel-breakeven core after 14 cycles with an 18-month cycle length. At the equilibrium state, one ADS supports 37 fast reactors. Using the performance parameters of SFR and ADS, the proposed two-stage fuel cycle was evaluated. The results of the equilibrium cycle analysis showed that the two-stage fuel cycle option could achieve a high reduction in waste generation because of the continuous recycling of the plutonium and MAs. In addition, the mass flow data showed that this two-stage fuel cycle option increases the efficiency of natural uranium utilization and reduces the nuclear waste generation compared to the conventional two-stage fuel cycle options based on thermal and fast-spectrum systems.