scholarly journals Synthesis of precision dosing system for liquid products based on electropneumatic complexes

2021 ◽  
Vol 6 (2 (114)) ◽  
pp. 125-135
Author(s):  
Oleksandr Gavva ◽  
Liudmyla Kryvoplias-Volodina ◽  
Sergii Blazhenko ◽  
Serhii Tokarchuk ◽  
Anastasiia Derenivska
Keyword(s):  
Boundary Conditions ◽  
Pressure Control ◽  
Experimental Sample ◽  
Control Laws ◽  
Standard Scale ◽  
Study Results ◽  
Liquid Products ◽  
Synthesis Of Precision ◽  
Proportional Feedback ◽  
Product Pipeline

This paper reports the construction of a mathematical model for the process of dosing liquid foods (non-carbonated drinking water). The model takes into consideration the differential equations of changes in the kinematic parameters of the liquid in a dosing device's channels and the corresponding accepted initial and boundary conditions of the process. The boundary conditions account for the influence of software-defined airlift dosing modes using the driver and the geometry of the product pipeline. The current's value measured in mA (with an accuracy of 0.001 mA) relative to the standard scale Imin is Imax=4...20 mA. Individual stages of the dosing process were analytically described, followed by the analysis of separate stages and accepted assumptions. The accuracy achieved when testing the experimental sample of the dispenser, with the repetition of the dose displacement process, ranged between 0.35 % and 0.8 %. The reported results are related to the established dosage weight of 50 ml when changing the initial level of liquid in the tank of the dosing feeder by 10 mm. An experimental bench has been proposed for investigating the functional mechatronic dosing module under the software-defined modes to form and discharge a dose of the product. The bench operates based on proportional feedback elements (4–20 mA) for step and sinusoidal pressure control laws in the dosing device. The control model with working dosing modes has been substantiated. The control models built are based on proportional elements and feedback. During the physical and mathematical modeling, the influence of individual parameters on the accuracy of the product dose formation was determined; ways to ensure the necessary distribution of compressed air pressure, subject to the specified productivity of the dosing feeder, were defined. The study results make it possible to improve the operation of precision dosing systems for liquid products based on electro-pneumatic complexes

A multi-layer cellular automata approach for algorithmic generation of virtual case studies: VIBe

2010 ◽  
Vol 61 (1) ◽  
pp. 37-45 ◽  
Author(s):  
R. Sitzenfrei ◽  
S. Fach ◽  
H. Kinzel ◽  
W. Rauch
Keyword(s):  
Boundary Conditions ◽  
Case Studies ◽  
Real World ◽  
New Technologies ◽  
Single Case ◽  
Software Tool ◽  
Simulation Software ◽  
Data Availability ◽  
Study Results

Analyses of case studies are used to evaluate new or existing technologies, measures or strategies with regard to their impact on the overall process. However, data availability is limited and hence, new technologies, measures or strategies can only be tested on a limited number of case studies. Owing to the specific boundary conditions and system properties of each single case study, results can hardly be generalized or transferred to other boundary conditions. virtual infrastructure benchmarking (VIBe) is a software tool which algorithmically generates virtual case studies (VCSs) for urban water systems. System descriptions needed for evaluation are extracted from VIBe whose parameters are based on real world case studies and literature. As a result VIBe writes Input files for water simulation software as EPANET and EPA SWMM. With such input files numerous simulations can be performed and the results can be benchmarked and analysed stochastically at a city scale. In this work the approach of VIBe is applied with parameters according to a section of the Inn valley and therewith 1,000 VCSs are generated and evaluated. A comparison of the VCSs with data of real world case studies shows that the real world case studies fit within the parameter ranges of the VCSs. Consequently, VIBe tackles the problem of limited availability of case study data.

scholarly journals Self-Management Intervention of Elderly Hypertension: A Literature Review

2021 ◽  
Author(s):  
Endah Sri Wijayanti ◽  
Moses Glorino Rumambo Pandin
Keyword(s):  
Literature Review ◽  
Narrative Analysis ◽  
The Elderly ◽  
Pressure Control ◽  
Self Management ◽  
Cross Sectional ◽  
Management Intervention ◽  
Management Interventions ◽  
Study Results ◽  
Research Findings

Background: Indonesia is an archipelago with various cultured, will bee affects all aspects of people's lives, including beliefs related to health behavior and health care. One problem that needs serious attention is the elderly group because the elderly are a vulnerable group who have a high risk of experiencing health problems, such as anemia with hypertension, so they need good care management. The research objective was to determine self-management intervention for hypertensive elderly. Methods: This research is a literature review with five databases (Scopus, CINAHL, ScienceDirect, PubMed, Proquest), the study design used is an experimental, descriptive, cross-sectional, and review systematic, in March 2021. Guidelines for using JBI to measure quality and listing check out Prisma in this review guide. A feasibility study based on title, abstract, full text, and research methodology. The data analysis used narrative analysis based on the research findings. Results: Twelve articles met the predefined review inclusion criteria. The study found eight interventions for self-management in elderly hypertension, namely: 1) Knowledge of hypertension, 2) Regulation of physical activity, 3) Limitation of alcohol and cigarette consumption, 4) Sleep rest and stress management, 5) Diet and body weight management, 6) Blood pressure control, 7) Family and social support, 8) Adherence to therapy regimens. Conclusion: The conclusion of the study results obtained eight elderly self-management interventions, this done properly will affect compliance in optimizing the health of the elderly.

Experimental and Numerical Analysis of the Transient Behavior of the Oil De-Congealing Process in an Aero Fuel-Cooled Oil Cooler Under Low-Temperature Conditions

2021 ◽  
Author(s):  
Foster Kwame Kholi ◽  
Jaehyun Park ◽  
Kyeongho Lee ◽  
Man Yeong Ha ◽  
Michael Klingsporn ◽  
...  
Keyword(s):  
Low Temperature ◽  
Boundary Conditions ◽  
Critical Role ◽  
Transient Behavior ◽  
Analysis Model ◽  
Practical Applications ◽  
Fuel Flow ◽  
Commercial Code ◽  
Study Results ◽  
Oil Cooler

Abstract The fuel-cooled oil cooler (FCOC) in the lubrication circuit plays a critical role in the aero gas-turbine engine's aerothermal management. However, the low temperature of the operating environment can congeal the oil and reduce the FCOC efficiency. The oil bypass valve (OBV) installed on the FCOC prevents pressure loss. Its failure may cause overheating, requiring preemptive performance prediction. Experimental and numerical analyses were used to evaluate the cooler's de-congealing performance under typical boundary conditions of pressure and temperature, OBV configurations, and re-routing of feed oil and fuel flow paths. The temporal variation of oil and fuel mass flow rates, temperature, and pressure of the feed oil and fuel provided an insight into the de-congealing process and duration. The experimental data were used to develop a one-dimensional (1D) flow and thermal network analysis model based on the effectiveness (e)-NTU method to predict the transient oil de-congealing performance of the FCOC. The customized commercial code predicted the de-congealing phenomena using empirical correlations with property correction schemes, showing good agreement with the experiment. The findings revealed various ways to enhance the de-congealing performance of the FCOC. The study results showed that the operating boundary conditions, OBV location and status, and flow arrangements affect de-congealing behavior and time. The present numerical model provides results quickly and can effectively predict experimentally costly and complicated cases. The attempted estimates of steady heat rejection and detailed methodology could guide future studies and practical applications.

Pressure Control Systems for Tyre Preservation in Forestry Machinery and Forest Soils

2021 ◽  
Vol 18 (3) ◽  
pp. 95-102
Author(s):  
Ol’ga Kunickaya ◽  
Edward Hertz ◽  
Igor Kruchinin ◽  
Evgeniy Tikhonov ◽  
Nikolai Ivanov ◽  
...  
Keyword(s):  
Control System ◽  
Soil Compaction ◽  
Humus Content ◽  
Pressure Control ◽  
Correct Choice ◽  
Negative Influence ◽  
Temperature Control System ◽  
Tyre Pressure ◽  
Study Results ◽  
Pressure Control System

Most forestry machinery today has a wheel-driven engine, and its tyre pressure has a significant impact on the compaction and degradation of the forest soil, causing environmental damages. Not only the durability of the tyres but also the driving characteristics and productivity of wheeled forest machines depend on the correct choice of pressure and competent operation. This work aims to analyse modern tyre pressure control technologies to develop an automated tyre pressure control system for wheeled forest machinery and lower the environmental impact. A new tyre pressure control system in forest machines was developed using a PressurePro solution, which contributes to a lower negative influence on the soil and reduces expenses for diagnostics and fuel. The study results of the tyre-to-ground contact pressure show that the installation of an automatic tyre pressure control system leads to its decrease by 20%. However, as the number of passes increases, the pressure might slightly increase. The study of humus content and soil compaction demonstrates that reduced tyre pressure and its automatic control contribute to a minimal reduction in humus content and soil compaction over time. Installation of the tyre pressure and temperature control system on forestry machines allows the system to be implemented quickly due to the simplicity of installation and operation.

Experimental study of the solid fouling effect on the air-cooled apparatus characteristics

2021 ◽  
Vol 12 (1) ◽  
pp. 1-9
Author(s):  
Larisa Morozyuk ◽  
Viktoriia Sokolovska-Yefymenko ◽  
Andrii Moshkatiuk ◽  
Bohdan Hrudka
Keyword(s):  
Experimental Study ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
Experimental Sample ◽  
Qualitative Composition ◽  
Aerodynamic Properties ◽  
Study Results ◽  
Heat Exchange Surface ◽  
Air Condenser ◽  
Exchange Surface

External fouling on the heat exchange surface of air-cooled apparatus are formed during operation, which leads to a significant increase in energy consumption and deviations from the optimal operating mode of the entire system. This phenomenon is a problem for all energy conversion systems. This paper presents the experimental study results of a complex of a commercial cooled object with real fouling on the air condenser surface. To study the effect of fouling, an experimental bench was developed – a single-stage refrigerating machine that provides cold supply to a thermostatic chamber. Three types of fouling were used: sand, fluff and dust. Fouling were picked from the operating condensers and identical in the type of heat exchange surface to the experimental sample. With a change in the quantitative and qualitative composition of the fouling, the air condenser thermal and aerodynamic characteristics and the energy efficiency of the machine as a whole were determined. The experiment showed that at maximum fouling of the heat exchange surface with sand and fluff, air movement stops. This means that at a certain thickness of sand and fluff layer, an air impermeable dense structure is formed. Dust with the same form of filling the free space for the flow remains permeable to air. Experiments showed that the qualitative composition of the fouling is the main factor that determines the heat exchanger performance. It was found that from the experimental set of fouling, roadside dust has the greatest negative effect on the condenser characteristics and the machine as a whole. The aerodynamic properties of the heat exchanger depend to some extent on the qualitative composition of the fouling. As a conclusion, it was suggested that the process nature of air flow passing through the investigated fouling can be described as gas flows in porous media.

scholarly journals Mechanical Properties of the Hard Sandstone Fracture Surface under Hydrochemical Corrosion

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Bin-wei Xia ◽  
Ming-xiang Xu ◽  
Chao Pan
Keyword(s):  
Shear Strength ◽  
Fracture Surface ◽  
Pressure Control ◽  
Solution Concentration ◽  
Surface Shear ◽  
Surface Strength ◽  
Soaking Time ◽  
Quantitative Expression ◽  
Hard Roof ◽  
Study Results

To realize a quantitative expression of change laws of the fracture surface shear strength with hydrochemical damage and to obtain optimal weakening effect of solution on the fracture surface strength, hard roof sandstone specimens containing hydraulic fracture surfaces from the Tashan Coal Mine located in Datong were subjected to a shear test after corrosion using solutions at different concentrations. The relational expression between shear strength and porosity of the fracture surface was established, and new damage parameters were introduced to describe the evolution laws of the shear strength of sandstone specimens with change in test conditions. Results were as follows. (1) Under sealed hydrochemical environment, corrosion effect on sandstone strengthened, and porosity and roughness gradually increased with increasing solution concentration and soaking time. (2) At a solution concentration of 3%-10%, shear strength and roughness of the fracture surface initially increased and then decreased. Hydrochemical solution concentration and action time were important factors that caused strength attenuation of the fracture surface. (3) When the solution concentration was greater than 3%, the roughness of the fracture surface increased with corrosion time, but its strength showed the tendency to stabilize. The shear strength of the fracture surface increased with shear displacement at a concentration of 5%. The study results can provide a new idea for strong strata pressure control through ground hydrofracturing hard roof.

scholarly journals Simulation of an offshore wind farm using fluid power for centralized electricity generation

2016 ◽  
Author(s):  
Antonio Jarquin Laguna
Keyword(s):  
Electricity Generation ◽  
Wind Farm ◽  
Pressure Control ◽  
Fluid Power ◽  
Offshore Wind ◽  
Operational Parameters ◽  
Turbulent Wind ◽  
Central Platform ◽  
Study Results ◽  
The Time Domain

Abstract. A centralized approach for electricity generation within a wind farm is explored through the use of fluid power technology. This concept considers a new way of generation, collection and transmission of wind energy inside a wind farm, in which electrical conversion does not occur during any intermediate conversion step before the energy has reached the offshore central platform. A numerical model was developed to capture the relevant physics from the dynamic interaction between different turbines coupled to a common hydraulic network and controller. This paper presents two examples of the time-domain simulation results for a hypothetical hydraulic wind farm subject to turbulent wind conditions. The performance and operational parameters of individual turbines are compared with those of a reference wind farm with conventional technology turbines, using the same wind farm layout and environmental conditions. For the presented case study, results indicate that the individual wind turbines are able to operate within operational limits with the current pressure control concept. Despite the stochastic turbulent wind input and wake effects, the hydraulic wind farm is able to produce electricity with reasonable performance in both below and above rated conditions.

Control of Electro-Hydraulic Poppet Valves via Online Learning and Estimation

2005 ◽  
Author(s):  
Patrick Opdenbosch ◽  
Nader Sadegh
Keyword(s):  
Online Learning ◽  
Pressure Control ◽  
Recursive Least Squares ◽  
Control Input ◽  
General Terms ◽  
Neural Network Structure ◽  
Control Application ◽  
Control Methodology ◽  
Proportional Feedback ◽  
Poppet Valves

Online learning state trajectory control applied to Electro-Hydraulic Poppet Valves (EHPV) is considered herein. The control problem is to track a desired flow conductance coefficient KV for pressure or flow control applications. In general terms, the control methodology employed herein computes the input signal sent to the valve from the addition of three components. The first component comes from an experimentally approximated inverse input-output map of the system which gives a nominal input. The second component is computed through a neural network structure called the Nodal Link Perceptron Network that learns online the adjustment of this nominal map. The third component is an adaptive proportional feedback control input. This last component uses two system parameters known as the Jacobian and the Controllability parameter, which are estimated online via a recursive least squares algorithm with forgetting factor. The proposed controller is explored through experimental data on a pressure control application and the results are discussed.

scholarly journals ORC Optimal Design through Clusterization for Waste Heat Recovery in Anaerobic Digestion Plants

2021 ◽  
Vol 11 (6) ◽  
pp. 2762
Author(s):  
Guido Francesco Frate ◽  
Andrea Baccioli ◽  
Elena Lucchesi ◽  
Lorenzo Ferrari
Keyword(s):  
Anaerobic Digestion ◽  
Boundary Conditions ◽  
Power Output ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Pressure Control ◽  
Gas Temperature ◽  
Part Load ◽  
Sliding Pressure

Waste heat recovery (WHR) systems through organic rankine cycles (ORCs) in anaerobic digestion plants may improve cogeneration efficiency. Cogeneration unit power output, flue gas temperature, and mass flow rate are not constant during the day, and the thermal load requested by digesters shows seasonal variations. For this reason, a proper design of the ORC is required. In this study, a design methodology is proposed, based on the clustering of the boundary conditions expected during one year of operation and the anaerobic digestion plant operation. The design has to be a compromise between part-load operation and nominal power rating. In this study, the ORC design boundary conditions were partitioned into four representative clusters with a different population, and the centroid of each cluster was assumed as a potential representative boundary condition for the cycle design. Four different ORC designs, one for each cluster, were defined through an optimization problem that maximized the cycle net power output. ORC designs were compared to those resulting from the seasonal average boundary conditions. The comparison was made based on the ORC off-design performance. Part-load behavior was estimated by implementing a sliding-pressure control strategy and the annual production was therefore calculated. ORC off-design was studied through a detailed Aspen HYSYS simulation. Simulations showed that the power output of each design was directly connected to the cluster population. The design obtained from the most populated cluster generated 10% more energy than that from a system designed by taking into account only the year average conditions.

scholarly journals Analyses of the Load Following Capabilities of Brayton Helium Gas Turbine Cycles for Generation IV Nuclear Power Plants

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
A. Gad-Briggs ◽  
P. Pilidis ◽  
T. Nikolaidis
Keyword(s):  
Power Output ◽  
Nuclear Power ◽  
Power Plants ◽  
Pressure Control ◽  
Reactor Power ◽  
Critical Parameters ◽  
Power Performance ◽  
Load Following ◽  
Study Results ◽  
Cycle Efficiency

The control system for generation IV nuclear power plant (NPP) design must ensure load variation when changes to critical parameters affect grid demand, plant efficiency, and component integrity. The objective of this study is to assess the load following capabilities of cycles when inventory pressure control is utilized. Cycles of interest are simple cycle recuperated (SCR), intercooled cycle recuperated (ICR), and intercooled cycle without recuperation (IC). First, part power performance of the IC is compared to results of the SCR and ICR. Subsequently, the load following capabilities are assessed when the cycle inlet temperatures are varied. This was carried out using a tool designed for this study. Results show that the IC takes ∼2.7% longer than the ICR to reduce the power output to 50% when operating in design point (DP) for similar valve flows, which correlates to the volumetric increase for the IC inventory storage tank. However, the ability of the IC to match the ICR's load following capabilities is severely hindered because the IC is most susceptible to temperature variation. Furthermore, the IC takes longer than the SCR and ICR to regulate the reactor power by a factor of 51 but this is severely reduced, when regulating NPP power output. However, the IC is the only cycle that does not compromise reactor integrity and cycle efficiency when regulating the power. The analyses intend to aid the development of cycles specifically gas-cooled fast reactors (GFRs) and very high temperature reactors (VHTRs), where helium is the coolant.

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