Andoniaina M. Randriambololona, M. Shaeri, Soroush Sarabi
The present study investigates the dependency of prediction accuracy of an artificial neural network (ANN) on the network architecture using 65 different neural networks from seven architecture patterns. The accuracy of the ANNs is compared based on their capability to predict heat transfer coefficients of air-cooled heat sinks operating in laminar flow. Scattered input data is used for training the networks to make the modelling more realistic and closer to practical applications. The input variables for the neural network are heat sink width, channel height, channel length, number of channels, fin thickness, and Reynolds number. The output is heat transfer coefficient. The training process for all ANNs is performed using ReLU as the activation function. The accuracy of the neural networks is evaluated by the root mean square error. It is found that the prediction accuracy of an ANN is strongly dictated by the optimization of the network architecture, which corresponds to the proper number of hidden layers and the number of neurons at each layer. The most accurate architecture in the present study predicts heat transfer coefficients of 60% and 86% of heat sinks within ±10% and ±20% of the true values, respectively. However, an ANN with an unoptimized architecture results in a substantially reduced accuracy such that it predicts heat transfer coefficients of only 19% and 30% of heat sinks within ±10% and ±20% of the true values, respectively.
{"title":"Prediction Accuracy of Artificial Neural Networks in Thermal Management Applications Subject to Neural Network Architectures","authors":"Andoniaina M. Randriambololona, M. Shaeri, Soroush Sarabi","doi":"10.11159/htff22.175","DOIUrl":"https://doi.org/10.11159/htff22.175","url":null,"abstract":"The present study investigates the dependency of prediction accuracy of an artificial neural network (ANN) on the network architecture using 65 different neural networks from seven architecture patterns. The accuracy of the ANNs is compared based on their capability to predict heat transfer coefficients of air-cooled heat sinks operating in laminar flow. Scattered input data is used for training the networks to make the modelling more realistic and closer to practical applications. The input variables for the neural network are heat sink width, channel height, channel length, number of channels, fin thickness, and Reynolds number. The output is heat transfer coefficient. The training process for all ANNs is performed using ReLU as the activation function. The accuracy of the neural networks is evaluated by the root mean square error. It is found that the prediction accuracy of an ANN is strongly dictated by the optimization of the network architecture, which corresponds to the proper number of hidden layers and the number of neurons at each layer. The most accurate architecture in the present study predicts heat transfer coefficients of 60% and 86% of heat sinks within ±10% and ±20% of the true values, respectively. However, an ANN with an unoptimized architecture results in a substantially reduced accuracy such that it predicts heat transfer coefficients of only 19% and 30% of heat sinks within ±10% and ±20% of the true values, respectively.","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122190111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract Modelling droplet evaporation is of great importance for many applications, such as inkjet printing, spray coating and combustion of fuel droplets [1, 2]. The key issues in the context of modelling droplet evaporation involve free-surface capturing [3], the phase change from liquid to vapour [4], and accurate calculations of the surface tension force [5]. Inaccurate calculations of surface tension force generate spurious currents or velocities which appear around the interface. Spurious currents destabilize the simulations and even influence the internal flow inside the droplets when studying droplets numerically [6]. In view of the issues mentioned above, we develop an improved Coupled Level Set and Volume of Fluid (i-CLSVoF) framework without explicit interface reconstruction for modelling micro-sized droplets with and without evaporation. A new surface tension force model with additional filtering steps is developed and implemented in the i-CLSVoF framework to suppress un-physical spurious velocities. Numerical benchmark cases demonstrate the excellence of the i-CLSVoF framework in reducing the un-physical spurious velocities (the un-physical spurious velocity converges to 10 −10 which is small enough to eliminate the influence of un-physical spurious velocities on the numerical stabilities). A simple yet efficient velocity-potential based approach is proposed to reconstruct a divergence-free velocity field for the advection of the free surface when the phase changes. The new approach fixes the numerical issues resulting from the evaporation-induced
{"title":"Modelling Droplet Evaporation with an Improved Coupled Level Set and Volume of Fluid (I-Clsvof) Framework","authors":"Huihuang Xia, M. Kamlah","doi":"10.11159/htff22.127","DOIUrl":"https://doi.org/10.11159/htff22.127","url":null,"abstract":"Extended Abstract Modelling droplet evaporation is of great importance for many applications, such as inkjet printing, spray coating and combustion of fuel droplets [1, 2]. The key issues in the context of modelling droplet evaporation involve free-surface capturing [3], the phase change from liquid to vapour [4], and accurate calculations of the surface tension force [5]. Inaccurate calculations of surface tension force generate spurious currents or velocities which appear around the interface. Spurious currents destabilize the simulations and even influence the internal flow inside the droplets when studying droplets numerically [6]. In view of the issues mentioned above, we develop an improved Coupled Level Set and Volume of Fluid (i-CLSVoF) framework without explicit interface reconstruction for modelling micro-sized droplets with and without evaporation. A new surface tension force model with additional filtering steps is developed and implemented in the i-CLSVoF framework to suppress un-physical spurious velocities. Numerical benchmark cases demonstrate the excellence of the i-CLSVoF framework in reducing the un-physical spurious velocities (the un-physical spurious velocity converges to 10 −10 which is small enough to eliminate the influence of un-physical spurious velocities on the numerical stabilities). A simple yet efficient velocity-potential based approach is proposed to reconstruct a divergence-free velocity field for the advection of the free surface when the phase changes. The new approach fixes the numerical issues resulting from the evaporation-induced","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121108272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Lopez, Abdulrahman A. Khateeb, A. Alqahtani, P. Cissé, M. Alhajri, Dilip R. Maniar, Vishal Nayyar
– Heat exchanger leaks are common failures in gas and oil industry. However, the root causes of failure are not always obvious to identify. Therefore, utilizing advanced analysis tools such as computational fluid dynamics and finite element analysis are vital to better understand the problem. Here, we discuss a real case of a heat exchanger facing repeated leaks in an oil and gas industry. Detailed computational fluid dynamics analysis is used to determine the impact of temperature gradient on displacement of the heater flanges and gaskets. The simulated conditions include 5 steady-state and transient operating conditions. The analysis results show that thermal expansion cause loss of bolt load and further reduces gasket contact pressure. Maximum gasket scuffing due to differential radial thermal expansion could result in gasket damage over repeated thermal cycles. This finding is the most likely root cause of the repeated heater leaks. The results discuss additional potential root causes of the leaks mainly related to gasket damage due to thermal expansion behavior. The results of this work will be used for future work utilizing finite element analysis tools.
{"title":"Temperature Gradient Impact on Heat Exchanger Leaks Using CFD Analysis","authors":"C. Lopez, Abdulrahman A. Khateeb, A. Alqahtani, P. Cissé, M. Alhajri, Dilip R. Maniar, Vishal Nayyar","doi":"10.11159/htff22.192","DOIUrl":"https://doi.org/10.11159/htff22.192","url":null,"abstract":"– Heat exchanger leaks are common failures in gas and oil industry. However, the root causes of failure are not always obvious to identify. Therefore, utilizing advanced analysis tools such as computational fluid dynamics and finite element analysis are vital to better understand the problem. Here, we discuss a real case of a heat exchanger facing repeated leaks in an oil and gas industry. Detailed computational fluid dynamics analysis is used to determine the impact of temperature gradient on displacement of the heater flanges and gaskets. The simulated conditions include 5 steady-state and transient operating conditions. The analysis results show that thermal expansion cause loss of bolt load and further reduces gasket contact pressure. Maximum gasket scuffing due to differential radial thermal expansion could result in gasket damage over repeated thermal cycles. This finding is the most likely root cause of the repeated heater leaks. The results discuss additional potential root causes of the leaks mainly related to gasket damage due to thermal expansion behavior. The results of this work will be used for future work utilizing finite element analysis tools.","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"33 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123143850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
- The gas hydrate formation process is divided in two main phases: the initial nucleation and the following massive growth phase. The time required for the production of a quantifiable quantity of hydrates is referred as “induction time”. Different solutions have been proposed to measure this interval; however, the low accuracy of the measure and the difficulties in evaluating it in the medium – scale lab reactors, have been not still solved. The most diffused technique consists of the visual confirmation of the production of a numerable quantity. In this work, a new alternative approach was proposed and experimentally validated. Being the formation process exothermic, the formation of the target quantity of hydrates leads to the appearance of peaks in temperature in a confined environment. These peaks cannot be exploited, due to their casual occurrence, associated to the stochastic nature of the process. Differently, the quantity of heat produced, can be directly used to calculate the moles of hydrates formed; thus, it allows to characterize the induction period for the process. In this research, the induction time was evaluated during the formation of methane and carbon dioxide hydrates, in order to detect any potential difference between the two species .
{"title":"Identification of a New Experimental Method to Measure the Induction Time for Gas Hydrates","authors":"A. Gambelli, F. Rossi","doi":"10.11159/iccpe22.121","DOIUrl":"https://doi.org/10.11159/iccpe22.121","url":null,"abstract":"- The gas hydrate formation process is divided in two main phases: the initial nucleation and the following massive growth phase. The time required for the production of a quantifiable quantity of hydrates is referred as “induction time”. Different solutions have been proposed to measure this interval; however, the low accuracy of the measure and the difficulties in evaluating it in the medium – scale lab reactors, have been not still solved. The most diffused technique consists of the visual confirmation of the production of a numerable quantity. In this work, a new alternative approach was proposed and experimentally validated. Being the formation process exothermic, the formation of the target quantity of hydrates leads to the appearance of peaks in temperature in a confined environment. These peaks cannot be exploited, due to their casual occurrence, associated to the stochastic nature of the process. Differently, the quantity of heat produced, can be directly used to calculate the moles of hydrates formed; thus, it allows to characterize the induction period for the process. In this research, the induction time was evaluated during the formation of methane and carbon dioxide hydrates, in order to detect any potential difference between the two species .","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123177749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
- The development of green corrosion inhibitors are highly demanded because of the increasing demand of green chemistry in the area of science and technology. Use of plant extracts as corrosion inhibitors has attracted significantly attention. The present study investigates corrosion inhibition of pineapple crown extract for steel 39 in 1M H₂SO 4 and 1M HCl. The weight loss method is used for inhibitor efficiency testing. The inhibition efficiency of inhibitor increases with the increases of concentration of inhibitor. Use of this inhibitor in concentration 3g/L present protection efficiency 82.88 % for steel 39 in aggressive media. The results present that pineapple crown extract is a good choice for steel 39 and environment, too.
{"title":"Pineapple Crown Extract As Green Inhibitor for Steel 39 in Acidic Media","authors":"A. Jano, Alketa Lame, E. Kokalari","doi":"10.11159/iccpe22.114","DOIUrl":"https://doi.org/10.11159/iccpe22.114","url":null,"abstract":"- The development of green corrosion inhibitors are highly demanded because of the increasing demand of green chemistry in the area of science and technology. Use of plant extracts as corrosion inhibitors has attracted significantly attention. The present study investigates corrosion inhibition of pineapple crown extract for steel 39 in 1M H₂SO 4 and 1M HCl. The weight loss method is used for inhibitor efficiency testing. The inhibition efficiency of inhibitor increases with the increases of concentration of inhibitor. Use of this inhibitor in concentration 3g/L present protection efficiency 82.88 % for steel 39 in aggressive media. The results present that pineapple crown extract is a good choice for steel 39 and environment, too.","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125447553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
- Injection water pH affects the release of fines in sandstones. The force equilibrium between fines and sand governs the attachment or release of fines in the system. At a pH higher than a critical value, fines are released and block the pores, causing formation damage. The fines release can be avoided by adjusting the pH and using nanofluids. This paper introduces the concept of DLVO modelling to estimate the critical pH before and after the application of nanofluids without extensive experimentation. Scanning electron microscopy determines the average size of in-situ fines collected from sandstone core. Injection brine of 11700ppm and 0.1wt% nanofluid are prepared, zeta potentials of dispersed sand are measured with varying pH from 2 to 12, and the resulting attractive and repulsive surface forces between fines and sand grains are quantified. The DLVO models are developed to predict the mobilization of fines and a critical pH before and after the application of silica nanofluids. The zeta potentials are measured by a Zetasizer and are in the range of -5 mV (less repulsion) to -31 mV (more repulsion). Furthermore, the application of nanofluids increases the zeta potential to a range of -3 mV to -24.9 mV, indicating a compression in electric double layers. Measured zeta potentials, ionic strength, and fine size are used as inputs to compute surface forces, and DLVO models are developed. The critical pH, at which total DLVO interactions shift from negative to positive, as predicted by the model, is about 8. The DLVO model also predicted an improved critical pH of 11 following the use of nanofluids, demonstrating a reduction in repulsion forces. DLVO modelling approach helps estimate a critical pH before and after applying nanofluids, and nanotechnology validates nanoparticles' ability to control fines migration and improve critical pH for waterflooding and alkaline flooding operations.
{"title":"Prediction of Critical pH for Fines Migration Pre and Post Nanofluid Treatment in Sandstone Reservoirs using the DLVO Modelling","authors":"R. Muneer, M. Hashmet, P. Pourafshary","doi":"10.11159/iccpe22.126","DOIUrl":"https://doi.org/10.11159/iccpe22.126","url":null,"abstract":"- Injection water pH affects the release of fines in sandstones. The force equilibrium between fines and sand governs the attachment or release of fines in the system. At a pH higher than a critical value, fines are released and block the pores, causing formation damage. The fines release can be avoided by adjusting the pH and using nanofluids. This paper introduces the concept of DLVO modelling to estimate the critical pH before and after the application of nanofluids without extensive experimentation. Scanning electron microscopy determines the average size of in-situ fines collected from sandstone core. Injection brine of 11700ppm and 0.1wt% nanofluid are prepared, zeta potentials of dispersed sand are measured with varying pH from 2 to 12, and the resulting attractive and repulsive surface forces between fines and sand grains are quantified. The DLVO models are developed to predict the mobilization of fines and a critical pH before and after the application of silica nanofluids. The zeta potentials are measured by a Zetasizer and are in the range of -5 mV (less repulsion) to -31 mV (more repulsion). Furthermore, the application of nanofluids increases the zeta potential to a range of -3 mV to -24.9 mV, indicating a compression in electric double layers. Measured zeta potentials, ionic strength, and fine size are used as inputs to compute surface forces, and DLVO models are developed. The critical pH, at which total DLVO interactions shift from negative to positive, as predicted by the model, is about 8. The DLVO model also predicted an improved critical pH of 11 following the use of nanofluids, demonstrating a reduction in repulsion forces. DLVO modelling approach helps estimate a critical pH before and after applying nanofluids, and nanotechnology validates nanoparticles' ability to control fines migration and improve critical pH for waterflooding and alkaline flooding operations.","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130011506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Danny Xavier Villalva León, G. García-Ros, J. Sánchez-Pérez, E. Castro-Rodríguez,, María Rosa Mena-Requena, M. Conesa
Extended Abstract In recent decades, advances in electronics have made it possible to use increasingly complex instrumentation within the many disciplines encompassed by engineering and, specifically, in soil mechanics. Thus, both at the level of field measurements and at the laboratory level, a wide variety of classic instruments, such as strain gauges, force or interstitial pressure transducers, are being modernized, with the electronic nature becoming increasingly important to the detriment of the mechanics. But, in addition to the electronic adaptation of these classic sensors used in soil mechanics, which allows for greater simplicity in data acquisition and subsequent computerized processing, in recent years a series of new techniques (in a more or less experimental phase) are being incorporated into the study of soil mechanics, to provide additional information, sometimes very valuable, to that obtained by classical methods. Within these new techniques is the study of acoustic emissions produced in soils when they are subjected to loading processes or imposed displacement. Based on this technique, scarcely studied to date, an investigation has been initiated that aims to characterize the acoustic emissions generated by soil grains when they are subjected to compression and/or shear processes. The investigations, which are being carried out at the Laboratory of Geotechnics of the Universidad Politécnica de Cartagena
{"title":"An Overview of the Study of Acoustic Emissions in Soil Mechanics","authors":"Danny Xavier Villalva León, G. García-Ros, J. Sánchez-Pérez, E. Castro-Rodríguez,, María Rosa Mena-Requena, M. Conesa","doi":"10.11159/icmie22.122","DOIUrl":"https://doi.org/10.11159/icmie22.122","url":null,"abstract":"Extended Abstract In recent decades, advances in electronics have made it possible to use increasingly complex instrumentation within the many disciplines encompassed by engineering and, specifically, in soil mechanics. Thus, both at the level of field measurements and at the laboratory level, a wide variety of classic instruments, such as strain gauges, force or interstitial pressure transducers, are being modernized, with the electronic nature becoming increasingly important to the detriment of the mechanics. But, in addition to the electronic adaptation of these classic sensors used in soil mechanics, which allows for greater simplicity in data acquisition and subsequent computerized processing, in recent years a series of new techniques (in a more or less experimental phase) are being incorporated into the study of soil mechanics, to provide additional information, sometimes very valuable, to that obtained by classical methods. Within these new techniques is the study of acoustic emissions produced in soils when they are subjected to loading processes or imposed displacement. Based on this technique, scarcely studied to date, an investigation has been initiated that aims to characterize the acoustic emissions generated by soil grains when they are subjected to compression and/or shear processes. The investigations, which are being carried out at the Laboratory of Geotechnics of the Universidad Politécnica de Cartagena","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134328999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ice accretion upon a surface is of interest in areas such as wind power, electric power transmission and vehicles in cold climate. Ice assimilation appears when humid air or water droplets impacts and freezes on a cold surface. In the study presented in this paper, droplets are deposited onto aluminium plates constructed to generate a specific contact angle between the droplet and substrate. Five contact angles are investigated and Particle Image Velocimetry (PIV) is used to analyse the internal flow. The droplets are studied along the vertical centerline and at horizontal lines at distances of 50% and 75% of the total height of the droplet. From the results it is found that a lower contact angle will increase the magnitude of the internal flow close to the edges. A larger contact angle will instead increase the magnitude of the flow in the center of the droplet. For a droplet with lower contact angle it was furthermore found that there is a triangular area inside the droplet with close to zero velocity.
{"title":"Influence of Contact Angle on the Internal Flow in a Freezing Water Droplet","authors":"Erik Fagerström, A. Ljung","doi":"10.11159/htff22.153","DOIUrl":"https://doi.org/10.11159/htff22.153","url":null,"abstract":"Ice accretion upon a surface is of interest in areas such as wind power, electric power transmission and vehicles in cold climate. Ice assimilation appears when humid air or water droplets impacts and freezes on a cold surface. In the study presented in this paper, droplets are deposited onto aluminium plates constructed to generate a specific contact angle between the droplet and substrate. Five contact angles are investigated and Particle Image Velocimetry (PIV) is used to analyse the internal flow. The droplets are studied along the vertical centerline and at horizontal lines at distances of 50% and 75% of the total height of the droplet. From the results it is found that a lower contact angle will increase the magnitude of the internal flow close to the edges. A larger contact angle will instead increase the magnitude of the flow in the center of the droplet. For a droplet with lower contact angle it was furthermore found that there is a triangular area inside the droplet with close to zero velocity.","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133831551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Inhibition Efficiency of Pineapple Crown Extract for Iron B500 in H2SO4and Hcl Media\u0000Load","authors":"A. Jano, Alketa Lame, E. Kokalari","doi":"10.11159/iccpe22.113","DOIUrl":"https://doi.org/10.11159/iccpe22.113","url":null,"abstract":"","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130470720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Haslavsky, H. Vitoshkin, Mordehai Barak, A. Arbel
: The total energy saving effect of different types of greenhouse thermal/shade screens was determined by measuring and calculating the overall heat transfer coefficients (U-values) for single and several layers of screens. The measurements were carried out using the hot box method, and the calculations were performed according to the ISO Standard 15099. The goal was to examine different types of materials with a wide range of thermal radiation properties used for thermal screens in combination with a dehumidification system in order to improve greenhouse insulation. The experimental results were in good agreement with the calculated heat transfer coefficients. It was shown that a high amount of infra-red (IR) radiation can be blocked by the greenhouse covering material in combination with moveable thermal screens. The aluminum foil screen could be replaced by transparent screens, depending on shading requirements. The results indicated that using a single layer, the U-value was reduced by approximately 70% compared to covering material alone, while the contributions of additional screen layers containing aluminum foil strips could reduce the U-value by approximately 90%. It was shown that three screen layers are sufficient for effective insulation.
{"title":"Heat Transfer Coefficients of Layers of Greenhouse Thermal Screens","authors":"V. Haslavsky, H. Vitoshkin, Mordehai Barak, A. Arbel","doi":"10.11159/htff22.110","DOIUrl":"https://doi.org/10.11159/htff22.110","url":null,"abstract":": The total energy saving effect of different types of greenhouse thermal/shade screens was determined by measuring and calculating the overall heat transfer coefficients (U-values) for single and several layers of screens. The measurements were carried out using the hot box method, and the calculations were performed according to the ISO Standard 15099. The goal was to examine different types of materials with a wide range of thermal radiation properties used for thermal screens in combination with a dehumidification system in order to improve greenhouse insulation. The experimental results were in good agreement with the calculated heat transfer coefficients. It was shown that a high amount of infra-red (IR) radiation can be blocked by the greenhouse covering material in combination with moveable thermal screens. The aluminum foil screen could be replaced by transparent screens, depending on shading requirements. The results indicated that using a single layer, the U-value was reduced by approximately 70% compared to covering material alone, while the contributions of additional screen layers containing aluminum foil strips could reduce the U-value by approximately 90%. It was shown that three screen layers are sufficient for effective insulation.","PeriodicalId":385356,"journal":{"name":"Proceedings of the 8th World Congress on Mechanical, Chemical, and Material Engineering","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128061038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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