21 documents found, page 1 of 3
Evaluating the thermal performance and environmental impact of agricultural gre...
Hamdane, Samia; Pires, Luís Carlos Carvalho; Silva, Pedro Dinho da; Gaspar, Pedro DinisThe thermal performance and environmental impact of agricultural greenhouses (GH) connected to earth-to-air heat exchanger (EAHE) systems depend on the ambient temperature, soil temperature, EAHE system, and greenhouse specifications. The impact of an EAHE system on the temperature and humidity of a GH microclimate, as well as its effects on CO2 emissions and heating energy consumption, are determined experimen...
Energy Requirements and Photovoltaic Area for Atmospheric Water Generation in D...
Correia, Vasco; Silva, Pedro D.; Pires, Luís Carlos CarvalhoAtmospheric water generation (AWG) is a technological innovation that facilitates the extraction of water from the atmosphere using various techniques. In response to mounting concerns regarding water scarcity in multiple regions globally, AWG has emerged as a promising solution for providing potable water in areas where conventional water sources are limited or contaminated. AWG systems can be implemented acro...
Computational Modeling of the Thermal Behavior of a Greenhouse
Lebre, Bruno Miguel Carapito; Silva, Pedro Dinho da; Pires, Luís Carlos Carvalho; Gaspar, Pedro DinisThe need for production of all kinds of crops in high quantities and over the entire year makes the agricultural sector one of the major energy consumers. The optimization of this consumption is essential to guarantee its sustainability. The implementation of greenhouses is a strategy that allows assurance of production needs and possesses large optimization potential for the process. This article studies diffe...
Experimental study of a hybrid solar photovoltaic, thermoelectric and thermal m...
Matias, Flávio; Pires, Luís Carlos Carvalho; Gaspar, Pedro Dinis; Silva, Pedro D.Nowadays, solar energy, which can be photovoltaic and thermal, is a clean and reliable source of energy for the production of electric and thermal power. However, new ways for improving photovoltaic efficiency are fundamental for an extensive application of this technology. Most of the energy absorbed by the PV panel converts itself into heat, which usually is lost and does not have any energetic value. The per...
Breast Skin Temperature Evaluation in Lactating and Non-lactating Women by Ther...
Gouveia, Ana; Pires, Luís Carlos Carvalho; Garcia, Nuno; Barbosa, Ana; Jesus, Ana; Pombo, Nuno; Soares, Marta; Oliveira, J. Martinez deDuring pregnancy and lactation, woman breasts feel changes like blood flow increasement, associated with a higher breast temperature. We performed an exploratory study of the breast skin temperature of lactating and non-lactating women based on thermography, with a qualitative analysis of the temperature patterns and a quantitative evaluation of the differences. Frontal breast thermograms of four non-lactating ...
Experimental tests using deactivation of coolant fluid circulation to mitigate ...
Panoias, Pedro; Silva, Pedro Dinho da; Gaspar, Pedro Dinis; Pires, Luís Carlos Carvalho; Nunes, JoséThe use of cold for conservation of food products requires large consumption of electricity. In order to obtain lower temperatures than those available in the same space, the evaporator coils, generally operate at temperatures lower than the freezing point of the water. The ice formed on the surface is detrimental both to the thermal and the energetic level of the refrigeration system. Thus, ice removal is crit...
Thermal performance, usage behavior and food waste of domestic refrigerators in...
Galvão, Diogo Alexandre Sobreiro; Gaspar, Pedro Dinis; Silva, Pedro Dinho da; Pires, Luís Carlos CarvalhoFood safety and quality as well as storage conditions leading to food waste are related to the reduced thermal performance of domestic refrigerators, the mismanagement of food stored in it or the misuse of the equipment. This paper analyses the operative conditions of refrigerators in the student community of the University of Beira Interior (Covilhã, Portugal). A test sample of 51 appliances in the student hou...
Development of an experimental unit for studying the solar drying process
Parente, Daniel; Pires, Luís Carlos Carvalho; Silva, Pedro Dinho da; Nunes, JoséThe removal of moisture by drying, prevents the growth and reproduction of these microorganisms, which cause rotting, and minimizes many of the reactions of deterioration from moisture, revealing itself a crucial preservation method. Portugal is a country with great potential for exploitation of solar energy, the implementation of a drying system based on this renewable source, facing devices with high energy c...
Experimental evaluation of water production from atmospheric air by vapour comp...
Miranda, Rui; Pires, Luís Carlos Carvalho; Silva, Pedro Dinho daThe problem of water scarcity is nowadays one of the themes under discussion around the world. Currently arise increasingly prevention measures, as well as have been developed and improved systems of production, treatment and storage of water. Based on this serious problem lived by a considerable part of the world's population, the present work proposes the use of a simple dehumidification system to obtain wate...
Experimental comparison between R409A and R437A performance in a heat pump unit
Duarte, Miguel Vicente; Pires, Luís Carlos Carvalho; Silva, Pedro Dinho da; Gaspar, Pedro DinisThis paper reports an experimental comparison between the use of the refrigerants R409A and R437A in a heat pump unit designed and developed to work with R12. Although the use of both refrigerants in new equipments were abolished in EU and US according the new F-Gas Regulation of EU and SNAP, they still being used as options for R12 in old equipments, especially in developing countries. Both refrigerants were s...