Selected Operation Parameters Research Articles

The Effect of Ecological Agents Added to Lubricating Oil on Selected Operating Parameters of an Internal Combustion Engine

This article presents the influence of ecological measures, i.e., the addition of effective microorganisms and silver compounds to lubricating oil, on the operating parameters of an internal combustion engine. The basic diagnostic parameters of a reciprocating engine that determine its technical condition are described. In the Materials and Methods section, the research stand and materials are presented. The main section of the article presents a comparison of pure oil and oil with the addition of effective microorganisms and silver compounds. It was found that the addition of effective microorganisms and silver compounds to oil reduces the emission of toxic components into the atmosphere with exhaust gas, and the other engine operation parameters for each load value indicate that these additives do not cause deterioration in the technical condition of the tested engine. Of all the agents used, the addition of ceramic tubes gives the best results, as it is an additive that does not affect the properties of the oil in its composition. The advantage of ceramic tubes is the slow release of effective microorganisms, which has an impact on the oil’s performance, and thus on engine operation. Further research will examine how these additives affect the anti-seizure and anti-wear properties of the lubricating oil used, which should give a broader view of the impact of these additives on the technical condition of the piston engine in operation.

Mixing Characteristics and Parameter Effects on the Mixing Efficiency of High-Viscosity Solid–Liquid Mixtures under High-Intensity Acoustic Vibration

High-intensity acoustic vibration is a new technology for solving the problem of uniform dispersion of highly viscous materials. In this study, we investigate the mixing characteristics of high-viscosity solid–liquid phases under high-intensity acoustic vibration and explore the effect of vibration parameters on the mixing efficiency. A numerical simulation model of solid–liquid–gas multiphase flow, employing the volume of fluid (VOF) and discrete phase model (DPM), was developed and subsequently validated through experimental verification. The results show that the movement and deformation of the gas–liquid surface over the entire field are critical for achieving rapid and uniform mixing of the solid–liquid phases under acoustic vibration. Increasing the amplitude or frequency of vibration can intensify the movement and deformation of the free surface of gas and liquid, improve the mixing efficiency, and shorten the mixing time. Under the condition of constant acceleration, the mixing efficiency of materials is higher at low frequency and high amplitude. Further, we define a relationship that predicts desirable mixing conditions as a function of amplitude and frequency. This serves as a valuable reference guide for evaluating the minimum requirements when selecting operating parameters.

Testing and Analysis of Selected Operating Parameters of a Vehicle Powered by Fuel with the Addition of Biocomponents

The most common fuel used for powering compression ignition engines is diesel, whose main components are petroleum products. The constantly growing energy demand involves the implementation of new technical solutions and applying alternative fuels, including renewable ones, such as rapeseed oil, sunflower oil, peanut oil, and animal fats. The most commonly used biofuels are those obtained from chemically processed rapeseeds (transesterification) to provide them with physical–chemical properties similar to diesel fuel. The study presents the results of tests of a power unit fueled with different mixtures of diesel oil and fatty acid methyl esters. The experiment was carried out for a compression ignition engine of 81 kW power with direct fuel injection. Performance parameters of the vehicle power unit and its computer software were modified for the needs of the tests. Those modifications involved increasing the fuel dose and the fuel injection pressure. The test results were statistically analyzed. Based on the results, a simulation of power and torque was performed, depending on the vehicle computer system adjustment and the fuel mixture used. A simulation of the vehicle movement in a non-homogeneous environment (variable road conditions) was performed concerning the vehicle motion kinematics. The simulations were carried out in a V-SIM 5.0 program. The simulation was performed at five speeds, respectively: 0 km/h, 25 km/h, 50 km/h, 75 km/h, and 100 km/h. The simulation made it possible to determine speed, acceleration, time, and distance. The analysis shows that the highest acceleration of 3 m/s2 was obtained for the BIO50 mixture, regulation V. The longest road section needed to achieve the maximum speed (100 km/h) was recorded for the BIO10 mixture, regulation II. The simulation duration ranged from 17.9 s to 17.74 s, depending on the adopted variant.

Miscanthus-Derived Energy Storage System Material Production.

Carbon derived from various biomass sources has been evaluated as support material for thermal energy storage systems. However, process optimization of Miscanthus-derived carbon to be used for encapsulating phase change materials has not been reported to date. In this study, process optimization to evaluate the effects of selected operation parameters of pyrolysis time, temperature, and biomass:catalyst mass ratio on the surface area and pore volume of produced carbon is conducted using response surface methodology. In the process, ZnCl2 is used as a catalyst to promote high pore volume and area formation. Two sets of optimum conditions with different pyrolysis operation parameters in order to produce carbons with the highest pore area and volume are determined as 614 °C, 53 min, and 1:2 biomass to catalyst ratio and 722 °C, 77 min, and 1:4 biomass to catalyst ratio with 1415.4 m2/g and 0.748 cm3/g and 1499.8 m2/g and 1.443 cm3/g total pore volume, respectively. Carbon material produced at 614 °C exhibits mostly micro- and mesosized pores, while carbon obtained at 722 °C comprises mostly of meso- and macroporous structures. Findings of this study demonstrate the significance of process optimization for designing porous carbon material to be used in thermal and electrochemical energy storage systems.

Valorisation of Waste Tyre via Pyrolysis: Advances and Perspectives

This paper first reviews the serious environmental concerns and waste management due to the rapid increase in the vast quantity of waste tyre globally. It then articulates the importance of pyrolysis as an attractive technical route for valorising waste tyre. A systematic summarisation on pyrolysis reaction chemistry is presented, including those for both waste tyre and its individual components. The key factors, including feedstock properties, reactor configurations, and reaction conditions that influence the properties and distribution of pyrolysis products and transformation and fate of impurities, are discussed. Such knowledge is essential to selecting operating parameters for optimal pyrolysis products and process performance. Potential applications of waste tyre pyrolysis products (i.e., char, oil, and gas) are subsequently surveyed and summarised. The important roles of key impurities (especially sulfur) and their derivatives, which are major constraints for commercialisation of waste tyre pyrolysis technologies, are also discussed. Remediation strategies of these impurities in pyrolysis products are summarised, compared, and benchmarked. The recent progress in process development, techno-economic analysis, and life cycle analysis of waste tyre pyrolysis processes is also covered. In closing, the remaining challenges and research gaps in the field of waste tyre pyrolysis are identified and future research perspectives are outlined.

Design of Hardware and Software Equipment for Monitoring Selected Operating Parameters of the Irrigator.

The aim of this paper was to design a device for monitoring the work of irrigation technology (in our case, irrigation by sprinkler). Two devices for monitoring selected irrigation operating parameters for two hose reel irrigation machines were designed. During the monitored period of connection of the equipment to the sprinkler, 15 irrigation doses were carried out for both sprinklers. Irrigation operating characteristics working pressure, hose reel speed and selected weather conditions temperature and humidity were monitored. When evaluating the results, we proved the need to monitor the operation of the sprinkler not only by the coefficient of variation Cv, but also by introducing the coefficient of non-uniformity a. The results obtained indicate variability with respect to a particular irrigation dose and the applicable assessment method. The results were reviewed by one-way ANOVA analysis where observed coefficients and irrigation dose were considered as dependence factors. The results indicate a statistically significant impact of the applied quality coefficient of work and thus the impact of a particular device (p < 0.05, Fcrit = 2.77). When evaluating the effect of the included irrigation dose, we also showed a statistically significant effect in both facilities (p < 0.05, F = 1.92). By checking the operation of the hose reel irrigation machine, we managed to successfully apply the proposed classifications, which also perform the function of fault prediction. The proposed facilities show that proper plant operation and timely response can help create more efficient and sustainable irrigation services, not only saving water but also reducing costs for the owner.

Impact of Select Geometric and Operational Parameters on Hydrodynamics in Dissolution Apparatus 2 (Paddle Apparatus): A Design of Experiments Analysis Based on Computational Fluid Dynamics Simulations

PurposeA Design of Experiments (DOE) analysis driven by Computational Fluid Dynamics (CFD) simulations was used to evaluate individual and two-factor interaction effects of varying select geometric and operational parameters on the hydrodynamics in dissolution apparatus 2 (paddle apparatus).MethodsSimulations were run with meshing controls and solution strategies retained from a mesh-independent validated baseline model. Distance between vessel and impeller bottom surfaces, impeller offset, vessel radius and impeller rotation speed were considered as input parameters. The velocity magnitudes at four locations near the vessel bottom surface were considered as output parameters. Response surfaces and Pareto charts were generated to understand individual and two-factor interaction effects of input parameters on the output parameters.ResultsImpeller offset has a dominating influence of a linear and quadratic nature on the output parameters and affects overall hydrodynamics. Changes to other input parameters have limited influence on velocity magnitudes at locations closest to the vessel axis and on overall hydrodynamics. However, these parameters have important influences of varying degrees on velocity magnitudes at locations away from the vessel axis.ConclusionsThe hydrodynamics in Apparatus 2 is influenced differently by different parameters and their combinations. Impeller offset has a stronger influence when compared to parameters that do not alter apparatus symmetry.

Comparative Analysis of Tests under Real Conditions and CFD Model for Selected Operation Parameters of a Mobile Fan Used by Fire Protection Units

Mobile overpressure fans are popular tools used in rescue and extinguishing operations carried out by Fire Protection Units. They are used for exhaust and venting buildings from harmful products of thermal decomposition occurs due to fire. Health and human life may depend on the proper operations of this type of equipment. The aim of the article is to compare the results of real research with numerical analysis. The Scientific and Research Centrum for Fire Protection – National Research Institute test infrastructure was used for research. These test conditions were correlated during CFD (Computional Fluid Dynamics) analysis. The parameters resulting from the operation of the mobile overpressure fan are as follow: the shape of the stream and the distribution of the air flow velocity profile for the distances: 1.5 and 3.0. To perform tests, the representative ventilator was used – being a part of Fire Protection Units equipment. The obtained result provided information on discrepancies in the results of real and simulation studies, indicating further development directions of the research methodology of numerical studies, enabling future support for real studies. The error of the CFD model in relation to the actual tests for measuring the velocity of the flowing air is 0.18 to 18%.

Evaluation of Synergies of a Biomass Power Plant and a Biogas Station with a Carbon Capture System

The global carbon emissions from the tertiary sector have increased during the last years, becoming a target sector for carbon capture technologies. This study analyzes the potential application of a carbon capture system (CCS) to the usage of biogas from a livestock waste treatment plant (LWTP) and solid biomass. The proposed BECCS system fulfils the requirement of energy demands of the LWTP and generates electricity. The CCS is sized to consume the biogas produced and the selected operation parameters ensure a high capture efficiency. The BECCS is completed by a Rankine cycle fed by solid biomass and waste heat from the capture process is sized and implemented to produce electricity and steam. The proposed concept handles 1534 kW of solid biomass and 1398 kW of biogas to produce 746.20 kWe and cover the heat demand of a LWTP, 597 kWth. The avoided CO2 emissions sum up to 1620 ton CO2/year. The economic calculations show the limitation of this concept deployment under current prices of electricity and CO2 allowances. Results show the potential feasibility under future scenarios with 5 to 6 payback periods whenever public policies support the use of CCS and EU ETS evolves towards higher prices of carbon allowances.

Factors affecting thin coal seam shearer drum coal-loading performance by a model test method

To solve the problem of a low coal-loading rate being exhibited by the drum shearer on Chinese thin coal seams, systematic tests and research were performed to study the pivotal factors’ influences on drum coal-loading rate using a model test method. The effects of the drum hub diameter, cutting depth, vane helix angle, drum rotation speed and hauling speed on drum coal-loading rate were determined under circumstances of coal-loading with drum ejection and pushing modes, and reasons for these phenomena were analyzed. The results indicate that the influence of the drum cutting depth on the drum coal-loading rate is the most significant. The parameters of hub diameter, drum rotation speed and hauling speed can influence the drum coal-loading rate by cutting the coals’ filling rate in the drum. The parameters of vane helix angle and drum rotation speed can influence drum coal-loading rates by influencing the ratio of cutting coals’ tangential and axial speed in the drum. The coal-loading rate with drum ejection is clearly higher than that observed with drum pushing. Research in this study can provide support to design the drum structure and select drum operational parameters for a thin coal seam shearer.

Effect of Operating Parameters on Performance and Safety Evaluation of a Biogas-fueled SOFC/GT Hybrid System

In this work, a detailed model of solid oxide fuel cell (SOFC)/micro gas turbine (GT) hybrid system with a recirculation process is established on MATLAB/Simulink platform. A typical farm biogas is chosen as fuel for the hybrid system, and the coupling effects of recirculation ratio, steam/carbon (S/C) ratio and fuel/air ratio on the operating performances and safety characteristics of the hybrid system and components (such as fuel cell, reformer and gas turbine) are carefully studied. Among the calculated results, the recirculation ratio of 0.4, the S/C ratio of 2.5 and the fuel/air ratio of 0.13 are selected as appropriate parameters for operation, in this case the total output work of hybrid system is 177 kW, and electrical efficiency could reach 59.4%. Results show that under properly selected operation parameters, the biogas-fueled hybrid system has good performance characteristics with both high efficiency and enough safety range.

Air manifolds for straw-fired batch boilers – Experimental and numerical methods for improvement of selected operation parameters

Air manifolds are used in straw-fired batch boilers to provide appropriate excess air as well as homogeneous air distribution in the primary and secondary combustion chambers.The paper presents the results of variant analysis of operation of the air manifold responsible for providing air for the combustion process in a biomass-fired batch boiler. An experimental stand consisting of a set of velocity sensors has been constructed to analyse the operation of the air manifold. The results of the experimental studies were implemented in a computational fluid dynamics model, which allowed to determine the elements of the manifold construction which are crucial from the point of view of the efficient combustion and acceptable low level of the fan’s energy consumption. As a next stage of the studies, a new design of the manifold has been developed and modelled. The results of the studies and the recommendations for designing air manifolds have been presented.

The Effect of Selected Operating Parameters, Material Pairing, and Gear Size on the Wear Behavior of Grease Lubricated, Small Module Gears

The wear behavior of grease lubricated gears is significantly affected by a number of factors besides the composition of the grease that is used for lubrication. A main influence factor on the wear behavior of grease lubricated gears is the lubrication supply mechanism (“circulating” or “channeling”), which is, among other things, strongly affected by the rotational speed of the gears. Especially at higher rotational speed, the dominant grease lubrication supply mechanism for grease lubricated gears tends to be channeling, which generally promotes increased wear on account of limited lubricant availability in the mesh as well as limited heat dissipation from the mesh. Experimental investigations conducted herein have shown that the gear wear behavior, especially at higher rotational speed, can be influenced by the internal geometry of the gear casing as well as by the direction of rotation of the gears. Additional investigations that were conducted focus on the effect of the material pairing and heat treatment on the wear behavior of grease lubricated gears in comparison to a case-carburized reference gear set. Furthermore, the effect of the gear size on the lubrication supply mechanism and thus on the wear behavior was investigated. For both gear sizes investigated (mn = 1.0 mm and mn = 0.6 mm), circulating was observed at low rotational speeds. At high rotational speeds, channeling effects were dominant.

Maximum likelihood positioning algorithm for high-resolution PET scanners.

In high-resolution positron emission tomography (PET), lightsharing elements are incorporated into typical detector stacks to read out scintillator arrays in which one scintillator element (crystal) is smaller than the size of the readout channel. In order to identify the hit crystal by means of the measured light distribution, a positioning algorithm is required. One commonly applied positioning algorithm uses the center of gravity (COG) of the measured light distribution. The COG algorithm is limited in spatial resolution by noise and intercrystal Compton scatter. The purpose of this work is to develop a positioning algorithm which overcomes this limitation. The authors present a maximum likelihood (ML) algorithm which compares a set of expected light distributions given by probability density functions (PDFs) with the measured light distribution. Instead of modeling the PDFs by using an analytical model, the PDFs of the proposed ML algorithm are generated assuming a single-gamma-interaction model from measured data. The algorithm was evaluated with a hot-rod phantom measurement acquired with the preclinical hyperion II (D) PET scanner. In order to assess the performance with respect to sensitivity, energy resolution, and image quality, the ML algorithm was compared to a COG algorithm which calculates the COG from a restricted set of channels. The authors studied the energy resolution of the ML and the COG algorithm regarding incomplete light distributions (missing channel information caused by detector dead time). Furthermore, the authors investigated the effects of using a filter based on the likelihood values on sensitivity, energy resolution, and image quality. A sensitivity gain of up to 19% was demonstrated in comparison to the COG algorithm for the selected operation parameters. Energy resolution and image quality were on a similar level for both algorithms. Additionally, the authors demonstrated that the performance of the ML algorithm is less prone to missing channel information. A likelihood filter visually improved the image quality, i.e., the peak-to-valley increased up to a factor of 3 for 2-mm-diameter phantom rods by rejecting 87% of the coincidences. A relative improvement of the energy resolution of up to 12.8% was also measured rejecting 91% of the coincidences. The developed ML algorithm increases the sensitivity by correctly handling missing channel information without influencing energy resolution or image quality. Furthermore, the authors showed that energy resolution and image quality can be improved substantially by rejecting events that do not comply well with the single-gamma-interaction model, such as Compton-scattered events.

Flux balancing of light and nutrients in a biofilm photobioreactor for maximizing photosynthetic productivity

This article reports a combined experimental and numerical study on the efficient operation of Porous Substrate Bioreactors. A comprehensive model integrating light transport, mass transport, and algal growth kinetics was used to understand the productivity of photosynthetic biofilms in response to delivery rates of photons and nutrients. The reactor under consideration was an evaporation driven Porous Substrate Bioreactor (PSBR) cultivating the cyanobacteria Anabaena variabilis as a biofilm on a porous substrate which delivers water and nutrients to the cells. In an unoptimized experimental case, this reactor was operated with a photosynthetic efficiency of 2.3%, competitive with conventional photobioreactors. Moreover, through a scaling analysis, the location at which the phosphate delivery rate decreased the growth rate to half of its uninhibited value was predicted as a function of microorganism and bioreactor properties. The numerical model along with the flux balancing techniques presented herein can serve as tools for designing and selecting operating parameters of biofilm based cultivation systems for maximum productivity.

Increasing efficiencies of microbial fuel cells for collaborative treatment of copper and organic wastewater by designing reactor and selecting operating parameters

Organic matters and copper ions can be collaboratively removed from wastewater using a microbial fuel cell (MFC). High collaborative efficiencies for both organic matter and copper ions removal have not been achieved yet in previous studies. We demonstrate here that high collaborative efficiencies can be achieved by designing reactor construction and selecting operational parameters based on the results of linear sweep voltammetry (LSV). When the MFC was constructed as 1:2 volume ratio of anode to cathode chamber and operated at optimal conditions, 83% COD removal and 87% copper ion removal were obtained at the same time. In addition, the Cu-MFC also performed a high coulombic efficiency (CE) of 89% for organic treatment, a cathodic efficiency of 80% for copper ion removal, and a maximum power density of 2.0 W/m(2).

Selection and Analysis of Parameters in Model Test of Ice Breaking by Air Cushion Vehicle

In order to validate the theory and select effective operational parameters in practical ice-breaking by air cushion vehicle (ACV), experimental study should be carried on firstly. The relationships of corresponding parameters between ACV model and prototype and between the ice-like material and the real ice are established on the basis of the similarity theory and the differential equation of thin elastic vibrating plate under static or moving load. According to geometric and dynamic similarity between model and prototype, for the conditions of different water depth, ice thickness, mass and velocity of ACV in actual operating mode, the pressure and velocity of ACV model, the elastic modulus and density of ice-like material in model test can be determined, the method of extending the model test results to prototype is proposed.

Comparison of numerical and experimental performance criteria of an ammonia–water bubble absorber using plate heat exchangers

A mathematical model for ammonia–water bubble absorbers was developed and compared with experimental data using a plate heat exchanger. The analysis was performed carrying out a sensitive study of selected operation parameters on the absorber thermal load and mass absorption flux. Regarding the experimental data, the values obtained for the solution heat transfer were in the range 0.51–1.21 kW m −2 K −1 and those of the mass absorption flux in the range 2.5–5.0 × 10 −3 kg m −2 s −1. The comparison between experimental and simulation results was acceptable being the maximum difference of 11.1% and 28.4% for the absorber thermal load and the mass absorption flux, respectively.

Influence of Selected Operating Parameters on Fungal Biomass Production in Corn-Ethanol Wastewater

Wastewater from a corn wet-milling ethanol plant was treated with Rhizopus microsporus mold in a continuous biofilm reactor (attached growth system). Plastic composite support tubes, composed of 50% (w/w) polypropylene and 50% (w/w) agricultural products were used as support media. The effects of operating pH (3.5, 4.0, and 4.5) and hydraulic retention times (HRTs) (5.0, 3.75, 2.5, and 1.25 h) on fungal growth, chemical oxygen demand (COD) removal and unwanted bacterial growth were evaluated under nonaseptic conditions. COD removal and biomass production were highest at pH 4.0 with lowest bacterial competition. Maximum COD removal of up to 80% was achieved at a 5.0 h HRT with a biomass yield of 0.44 g volatile suspended solids per g COD removed. A higher biomass yield was achieved at a shorter HRT of 2.5 h due to increased substrate availability; however, the biofilm was more sensitive to changes in wastewater composition. A HRT of 3.5–4 h was considered optimal in achieving organic removal and fungal biomass production. Significant loss of fungal biomass due to washout occurred at a 1.5 h HRT. Undesirable bacterial populations as a fraction of total biomass decreased with reducing HRT, excluding the 1.25 h HRT. Reductions in COD removal and biomass production were observed with decreases in aeration rate (1.0–0.25 L/min or 0.8–0.2 vvm (air volume per reactor working volume per minute). The recovered fungal biomass was found to contain protein of up to 40% (dry mass basis), which could serve as a source of high-value animal feed.

Investigation of hydrocarbon reforming processes for micro-cogeneration systems

Hydrogen is the lightest chemical element and offers the best energy-to-weight ratio of any fuel. Hydrogen is colorless, odorless and its only by-product is water. It offers cost-effective solutions to reduce greenhouse gas emissions (in accordance with the Kyoto Protocol), improve air quality, diversify energy supply and reduce noise. The use of hydrogen with the practical application of household fuel cells such as micro-cogeneration and fuel-cell vehicles signifies a paradigm shift from a society that burns fossil fuels, to a society based around hydrogen. In the short term, hydrogen could be used in urban vehicles, which would reduce emissions in city centers. In the long term, it could be used in combined heat/power generation, in industry, in residential applications and in every form of transport like ships, trains and airplanes. There are several methods of producing hydrogen from fossil resources such as natural gas or naphtha, for example, steam reforming, partial oxidation and autothermal reforming. Among these, steam reforming of natural gas is a widely used method of extracting hydrogen by a process in which natural gas and steam are caused to react in a reactor filled with a catalyst. In this article, the effects of reforming operation parameters on the product distribution and conversion efficiency of hydrocarbon mixtures were discussed. The investigated reforming options are autothermal reforming (ATR), steam reforming (SR) and partial oxidation (POX). The ASPEN-HYSIS 3.2 process simulation software code has been utilized for the calculations of the whole fuel processing systems. Natural gas fuel has been simulated and applied to the flow-sheet model. It is desired to produce hydrogen-rich reformate gas with as low as possible CO formation. Different parametric process simulation studies have been studied such as reactor temperature affects the steam to carbon (S/C) and oxygen to carbon (O 2/C) ratios. Net electrical and fuel processing efficiencies of all selected options have been investigated as well. The results indicate that these selected operation parameters are very important for the appropriate selection of the most efficient system approach.