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Luís Frölén Ribeiro is a Coordinator Professor of the Mechanical Technology Department of the Instituto Politécnico de Bragança, Portugal, and is the Director of Master Course on Renewable Energy and Energy Efficiency in the same institution. He is also an Associated Researcher of the Laboratório Associado em Energia, Transportes e Aeronáutica LAETA - INEGI, focusing on industry applied research.
This paper presents a model to assess strategies for bettering a hexane condensation system from an olive oil extraction refinery in Portugal’s mountainous north. The water used as a cooling fluid is discharged with a higher temperature than the mountain river, provoking the deterioration of the aquatic flora and fauna, leading to high environmental impact. The model allowed the comparison of solutions for different temperatures of discharge for summer and winter and possible heat recovery back to the factory. The current condensation system power is 1.838 MW and consists of a four-walled pond of 115.3 m3 that cools down the submerged hexane pipes. Nudging in the pond’s structure leads to the introduction of internal channels to increase the turbulence, thus increasing the hexane–water heat exchange rate. Heat recovery of 19.38 kW is possible for the water coming from the pond in the drying bagasse process inside the factory, before discharge into the river. However, the model demonstrates that the decrease in temperature after the heat recovery process falls short of avoiding thermal pollution, leading to complementary actions such as shading the channel or changing the discharge velocity or angle to mitigate the thermal pollution locally.
Luís Frölén Ribeiro; Oscar Antonio Aguilera; Zulimar Hérnandez. Thermal Pollution Mitigation and Energy Harnessing of the Condensation Process of an Olive Oil Extraction Refinery: A Case Study. Environments 2021, 8, 84 .
AMA StyleLuís Frölén Ribeiro, Oscar Antonio Aguilera, Zulimar Hérnandez. Thermal Pollution Mitigation and Energy Harnessing of the Condensation Process of an Olive Oil Extraction Refinery: A Case Study. Environments. 2021; 8 (8):84.
Chicago/Turabian StyleLuís Frölén Ribeiro; Oscar Antonio Aguilera; Zulimar Hérnandez. 2021. "Thermal Pollution Mitigation and Energy Harnessing of the Condensation Process of an Olive Oil Extraction Refinery: A Case Study." Environments 8, no. 8: 84.
This paper presents the turbulent pipe flow analysis of the friction factor’s uncertainty for two different experimental scenarios: high-precision and standard engineering instruments. One deduced the uncertainty function of the implicit Colebrook’s correlation and five of the most accurate and fast explicit correlations. The joint propagation of uncertainties is evaluated, sorted and mapped for the probabilities of intersection of the Colebrook’s uncertainties against the alternative correlations. The maps display the fastest to the slowest equation for standard engineering and high-precision instruments, respectively for 50% and 95% intersection. For the standard engineering instruments, the least accurate of the explicit correlations are applicable and within the Colebrook uncertainty bounds. The most accurate correlations are necessary for specific roughness and Reynolds’o domains cases and for high-precision research instruments. Results also show that, for high-precision scenarios with a 95% uncertainty fit, there is still room for improvement in the explicit correlations.
Luiz Eduardo Muzzo; Gláucio Kenji Matoba; Luís Frölén Ribeiro. Uncertainty of pipe flow friction factor equations. Mechanics Research Communications 2021, 116, 103764 .
AMA StyleLuiz Eduardo Muzzo, Gláucio Kenji Matoba, Luís Frölén Ribeiro. Uncertainty of pipe flow friction factor equations. Mechanics Research Communications. 2021; 116 ():103764.
Chicago/Turabian StyleLuiz Eduardo Muzzo; Gláucio Kenji Matoba; Luís Frölén Ribeiro. 2021. "Uncertainty of pipe flow friction factor equations." Mechanics Research Communications 116, no. : 103764.
Drying food involves complex physical atmospheric mechanisms with non-linear relations from the air-food interactions, and those relations are strongly dependent on the moisture contents and the type of food. Such dependence makes it complex to design suitable dryers dedicated to a single drying process. To streamline the design of a novel compact food-drying machine, a heat pump dryer component design optimization algorithm was developed as a subprogram of a Computer Aided Engineering tool. The algorithm requires inputting food and air properties, the volume of the drying container, and the technical specifications of the heat pump off-the-shelf components. The heat required to dehumidify the food supplied by the heat exchange process from condenser to evaporator, and the compressor’s requirements (refrigerant mass flow rate and operating pressures) are then calculated. Compressors can then be selected based on the volume and type of food to be dried. The algorithm is shown via a flow chart to guide the user through three different stages: Changes in drying air properties, heat flow within dryer and product moisture content. Example results of how different compressors are selected for different types of produces and quantities (Agaricus blazei mushroom with three different moisture contents or fish from Thunnini tribe) conclude this article.
Bernardo Andrade; Ighor Amorim; Michel Silva; Larysa Savosh; Luís Frölén Ribeiro. Heat Pump Dryer Design Optimization Algorithm. Inventions 2019, 4, 63 .
AMA StyleBernardo Andrade, Ighor Amorim, Michel Silva, Larysa Savosh, Luís Frölén Ribeiro. Heat Pump Dryer Design Optimization Algorithm. Inventions. 2019; 4 (4):63.
Chicago/Turabian StyleBernardo Andrade; Ighor Amorim; Michel Silva; Larysa Savosh; Luís Frölén Ribeiro. 2019. "Heat Pump Dryer Design Optimization Algorithm." Inventions 4, no. 4: 63.
Drying food involves complex physical atmospheric mechanisms with non-linear relations from the air-food interactions and those relations are strongly dependent on the moisture contents and the type of food. Such dependence makes it complex to design suitable dryers dedicated to a single drying process. To streamline the design of a novel compact food-drying machine, a heat pump dryer component design optimization algorithm was developed as a subprogram of a Computer Aided Engineering tool. The algorithm requires inputting food and air properties, the volume of the drying container and the technical specifications of the heat-pump off-the shelf components. The heat required to dehumidify the food supplied by the heat exchange process from condenser to evaporator, and the compressor’s requirements (refrigerant mass flow rate and operating pressures) are then calculated. Compressors can then be selected based in the volume and type of food to be dried. The algorithm is shown via a flow chart to guide the user through 3 different stages: Changes in drying air properties, Heat flow within dryer and Product moisture content. Example results of how different compressors are selected for different type of produces and quantities (Agaricus Blazei mushroom with 3 different moisture contents or fish from Thunnini tribe) conclude this article.
Bernardo Andrade; Ighor Amorim; Michel Silva; Larysa Savosh; Luís Frölén Ribeiro. Heat Pump Dryer Design Optimization Algorithm. 2019, 1 .
AMA StyleBernardo Andrade, Ighor Amorim, Michel Silva, Larysa Savosh, Luís Frölén Ribeiro. Heat Pump Dryer Design Optimization Algorithm. . 2019; ():1.
Chicago/Turabian StyleBernardo Andrade; Ighor Amorim; Michel Silva; Larysa Savosh; Luís Frölén Ribeiro. 2019. "Heat Pump Dryer Design Optimization Algorithm." , no. : 1.
The long-range and short-range WindScanner systems (LRWS and SRWS), multi-Doppler lidar instruments, when combined together can map the turbulent flow around a wind turbine and at the same time measure mean flow conditions over an entire region such as a wind farm. As the WindScanner technology is novel, performing field campaigns with the WindScanner systems requires a methodology that will maximize the benefits of conducting WindScanner-based experiments. Such a methodology, made up of 10 steps, is presented and discussed through its application in a pilot experiment that took place in a complex and forested site in Portugal, where for the first time the two WindScanner systems operated simultaneously. Overall, this resulted in a detailed site selection criteria, a well-thought-out experiment layout, novel flow mapping methods and high-quality flow observations, all of which are presented in this paper.
Nikola Vasiljević; José M. L. M. Palma; Nikolas Angelou; José Carlos Matos; Robert Menke; Guillaume Lea; Jakob Mann; Michael Courtney; Luis Ribeiro; Vitor Costa Gomes. Perdigão 2015: methodology for atmospheric multi-Doppler lidar experiments. Atmospheric Measurement Techniques 2017, 10, 3463 -3483.
AMA StyleNikola Vasiljević, José M. L. M. Palma, Nikolas Angelou, José Carlos Matos, Robert Menke, Guillaume Lea, Jakob Mann, Michael Courtney, Luis Ribeiro, Vitor Costa Gomes. Perdigão 2015: methodology for atmospheric multi-Doppler lidar experiments. Atmospheric Measurement Techniques. 2017; 10 (9):3463-3483.
Chicago/Turabian StyleNikola Vasiljević; José M. L. M. Palma; Nikolas Angelou; José Carlos Matos; Robert Menke; Guillaume Lea; Jakob Mann; Michael Courtney; Luis Ribeiro; Vitor Costa Gomes. 2017. "Perdigão 2015: methodology for atmospheric multi-Doppler lidar experiments." Atmospheric Measurement Techniques 10, no. 9: 3463-3483.
Filipe Gomes; João Correia Lopes; José Laginha Palma; Luís Frölén Ribeiro. [email protected]: The e-Science Platform for WindScanner.eu. Journal of Physics: Conference Series 2014, 524, 1 .
AMA StyleFilipe Gomes, João Correia Lopes, José Laginha Palma, Luís Frölén Ribeiro. [email protected]: The e-Science Platform for WindScanner.eu. Journal of Physics: Conference Series. 2014; 524 ():1.
Chicago/Turabian StyleFilipe Gomes; João Correia Lopes; José Laginha Palma; Luís Frölén Ribeiro. 2014. "[email protected]: The e-Science Platform for WindScanner.eu." Journal of Physics: Conference Series 524, no. : 1.
The current trend of increasing the electricity production from wind energy has led to the installation of wind farms in areas of greater orographic complexity, raising doubts on the use of simple, linear, mathematical models of the fluid flow equations, so common in the wind energy engineering. The present study shows how conventional techniques, linear models and cup anemometers, can be combined with flow simulation by computational fluid dynamics techniques (nonlinear models) and measurements by sonic anemometers, and discuss their relative merits in the characterisation of the wind over a coastal region—a cliff over the sea. The computational fluid dynamic techniques were particularly useful, providing a global view of the wind flow over the cliff and enabling the identification of separated flow regions, clearly unsuitable for installation of wind turbines. These locations display a pulsating flow, with periods between 1 and 7 min, in agreement with sonic anemometer measurements, and both a turbulence intensity and a gust factor well above the wind turbine design conditions.
J.M.L.M. Palma; F.A. Castro; L.F. Ribeiro; A.H. Rodrigues; A.P. Pinto. Linear and nonlinear models in wind resource assessment and wind turbine micro-siting in complex terrain. Journal of Wind Engineering and Industrial Aerodynamics 2008, 96, 2308 -2326.
AMA StyleJ.M.L.M. Palma, F.A. Castro, L.F. Ribeiro, A.H. Rodrigues, A.P. Pinto. Linear and nonlinear models in wind resource assessment and wind turbine micro-siting in complex terrain. Journal of Wind Engineering and Industrial Aerodynamics. 2008; 96 (12):2308-2326.
Chicago/Turabian StyleJ.M.L.M. Palma; F.A. Castro; L.F. Ribeiro; A.H. Rodrigues; A.P. Pinto. 2008. "Linear and nonlinear models in wind resource assessment and wind turbine micro-siting in complex terrain." Journal of Wind Engineering and Industrial Aerodynamics 96, no. 12: 2308-2326.
An overview of the Energy Balance Experiment (EBEX-2000) is given. This experiment studied the ability of state-of-the-art measurements to close the surface energy balance over a surface (a vegetative canopy with large evapotranspiration) where closure has been difficult to obtain. A flood-irrigated cotton field over uniform terrain was used, though aerial imagery and direct flux measurements showed that the surface still was inhomogeneous. All major terms of the surface energy balance were measured at nine sites to characterize the spatial variability across the field. Included in these observations was an estimate of heat storage in the plant canopy. The resultant imbalance still was 10%, which exceeds the estimated measurement error. We speculate that horizontal advection in the layer between the canopy top and our flux measurement height may cause this imbalance, though our estimates of this term using our measurements resulted in values less than what would be required to balance the budget.
Steven P. Oncley; Thomas Foken; Roland Vogt; Wim Kohsiek; H. A. R. DeBruin; Christian Bernhofer; Andreas Christen; Eva Van Gorsel; David Grantz; Christian Feigenwinter; Irene Lehner; Claudia Liebethal; Heping Liu; Matthias Mauder; Andrea Pitacco; Luis Ribeiro; Tamas Weidinger. The Energy Balance Experiment EBEX-2000. Part I: overview and energy balance. Boundary-Layer Meteorology 2007, 123, 1 -28.
AMA StyleSteven P. Oncley, Thomas Foken, Roland Vogt, Wim Kohsiek, H. A. R. DeBruin, Christian Bernhofer, Andreas Christen, Eva Van Gorsel, David Grantz, Christian Feigenwinter, Irene Lehner, Claudia Liebethal, Heping Liu, Matthias Mauder, Andrea Pitacco, Luis Ribeiro, Tamas Weidinger. The Energy Balance Experiment EBEX-2000. Part I: overview and energy balance. Boundary-Layer Meteorology. 2007; 123 (1):1-28.
Chicago/Turabian StyleSteven P. Oncley; Thomas Foken; Roland Vogt; Wim Kohsiek; H. A. R. DeBruin; Christian Bernhofer; Andreas Christen; Eva Van Gorsel; David Grantz; Christian Feigenwinter; Irene Lehner; Claudia Liebethal; Heping Liu; Matthias Mauder; Andrea Pitacco; Luis Ribeiro; Tamas Weidinger. 2007. "The Energy Balance Experiment EBEX-2000. Part I: overview and energy balance." Boundary-Layer Meteorology 123, no. 1: 1-28.
The eddy-covariance method is the primary way of measuring turbulent fluxes directly. Many investigators have found that these flux measurements often do not satisfy a fundamental criterion—closure of the surface energy balance. This study investigates to what extent the eddy-covariance measurement technology can be made responsible for this deficiency, in particular the effects of instrumentation or of the post-field data processing. Therefore, current eddy-covariance sensors and several post-field data processing methods were compared. The differences in methodology resulted in deviations of 10% for the sensible heat flux and of 15% for the latent heat flux for an averaging time of 30 min. These disparities were mostly due to different sensor separation corrections and a linear detrending of the data. The impact of different instrumentation on the resulting heat flux estimates was significantly higher. Large deviations from the reference system of up to 50% were found for some sensor combinations. However, very good measurement quality was found for a CSAT3 sonic together with a KH20 krypton hygrometer and also for a UW sonic together with a KH20. If these systems are well calibrated and maintained, an accuracy of better than 5% can be achieved for 30-min values of sensible and latent heat flux measurements. The results from the sonic anemometers Gill Solent-HS, ATI-K, Metek USA-1, and R.M. Young 81000 showed more or less larger deviations from the reference system. The LI-COR LI-7500 open-path H2O/CO2 gas analyser in the test was one of the first serial numbers of this sensor type and had technical problems regarding direct solar radiation sensitivity and signal delay. These problems are known by the manufacturer and improvements of the sensor have since been made.
Matthias Mauder; Steven P. Oncley; Roland Vogt; Tamas Weidinger; Luis Ribeiro; Christian Bernhofer; Thomas Foken; Wim Kohsiek; Henk A. R. De Bruin; Heping Liu. The energy balance experiment EBEX-2000. Part II: Intercomparison of eddy-covariance sensors and post-field data processing methods. Boundary-Layer Meteorology 2006, 123, 29 -54.
AMA StyleMatthias Mauder, Steven P. Oncley, Roland Vogt, Tamas Weidinger, Luis Ribeiro, Christian Bernhofer, Thomas Foken, Wim Kohsiek, Henk A. R. De Bruin, Heping Liu. The energy balance experiment EBEX-2000. Part II: Intercomparison of eddy-covariance sensors and post-field data processing methods. Boundary-Layer Meteorology. 2006; 123 (1):29-54.
Chicago/Turabian StyleMatthias Mauder; Steven P. Oncley; Roland Vogt; Tamas Weidinger; Luis Ribeiro; Christian Bernhofer; Thomas Foken; Wim Kohsiek; Henk A. R. De Bruin; Heping Liu. 2006. "The energy balance experiment EBEX-2000. Part II: Intercomparison of eddy-covariance sensors and post-field data processing methods." Boundary-Layer Meteorology 123, no. 1: 29-54.