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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Thermal Storage for Electric Vehicle Cabin Heating in Cold Weather Conditions

Hadden, Trevor January 2017 (has links)
With global warming, an inevitable threat to humanity, significant efforts in all carbon emitting industries are required. Electric vehicles are a suitable alternative to the petroleum dominated automotive industry. However, obstacles like charging infrastructure and limited range still stand in the way of their continued acceptance. This limited driving range can be further reduced in cold weather due to decreased battery efficiency and increased heating load. The heating in most electric vehicles is provided by an electrical positive temperature coefficient resistor. This architecture can lead to reductions in range of over 50 %. A thermal storage system has been devised and presented in this thesis which can partially or fully offset the thermal requirements. This is accomplished by pre-heating a thermal storage tank which then uses sensible energy to provide the heat for the cabin and battery pack. The system has been shown to reduce consumption and improve driving range in low ambient temperature conditions. This system successfully offers a potential solution to the concern of large range fluctuations due to different ambient temperatures. After producing a representative electric vehicle model in AMESim, it was compared to the Nissan Leaf with acceptable errors. The range implications for this baseline electric vehicle are then presented. A coolant based, thermal storage tank is then added to the model and simulated across a variety of temperatures and thermal storage masses. The results show that an 80 kg, 80 °C coolant tank can provide all the heating requirements for a 36 km, hour and 9 minute city drive cycle. Offering a calculated consumption reduction of up to 36 % at -30 °C as compared to the baseline electric vehicle model. Furthermore, a yearly analysis was performed based on this cycle and the results have shown that an optimal 30 kg thermal storage tank can decrease the yearly average consumption by up to 20 Wh/km or 12 %. / Thesis / Master of Applied Science (MASc)
2

Avaliação da qualidade do ar de cabines de veículos automotores recém-manufaturados / Evaluation of new vehicles cabin indoor air quality

Valvassori Filho, Auzebio 23 September 2008 (has links)
Cabines de veículos automotores recém-manufaturados podem ser consideradas críticas quando se avalia a qualidade do ar interno, pois concentrações de compostos orgânicos voláteis encontram-se em níveis mais altos que os ambientes externos. Determinadas substâncias presentes no ar da cabine podem ser prejudiciais ao ser humano em função da sua toxicidade, pricipalmente nos grandes centros urbanos. A avaliação do ar da cabine automotiva se faz necessária. Nesse estudo, foi feita uma avaliação da qualidade do ar interno da cabine de 7 veículos populares recém-manufaturados contendo materiais de acabamento interno iguais. Um total de 46 compostos orgânicos voláteis foi identificado, sendo que 14 deles são compostos carbonílicos e 32 são hidrocarbonetos alifáticos e aromáticos, compostos halogenados e um nitrogenado. Os compostos carbonílicos foram identificados e quantificados por cromatografia a líquido e os outros VOCs apenas identificados por GC-MS. No ar interno da cabine dos veículos estudados, as concentrações médias encontradas para os compostos carbonílicos (µg/m3) em ordem decrescente foram: formaldeído (165,3); acetona (67,5); acetaldeído (56,8); isovaleraldeído (40,8); propionaldeído (21,1); butiraldeído (17,9); crotonaldeído (14,9); hexaldeído (14,9) valeraldeído (9,8); 2.5- dimetilbenzaldeído (9,3); otolualdeído (8,4); p/m tolualdeído (6,8); acroleína (4,2) e benzaldeído (3,8). Com relação aos outros VOCS foram identificados o metilbutano, que apresentou a maior porcentagem de abundância relativa, 8,5%, seguido de outros hidrocarbonetos com abundância relativa entre 5 e 2% , como, 2,7,10-trimetildodecano, 2,2,6-trimetildecano, ciclopentano, 2,3,4-trimetildecano, n-pentano, 3,6-dimetilundecano, 4-metildodecano, 4,6- dimetildodecano, 3,6-dimetildecano e 1,2-dimetilbenzeno. Dois derivados de hidrocarbonetos halogenados também foram encontrados, sendo que o triclorofluormetano foi o majoritário com 5,7%, e um composto nitrogenado, a acetonitrila com 5,4%. Os compostos derivados do benzeno identificados foram: 1,2-dimetilbenzeno, etilbenzeno, metilbenzeno, 1-etil-3- metilbenzeno, 1-etil-3-metilbenzeno e 1,3,5-trimetilbenzeno que perfazem 6,6 % de abundância relativa. O mais abundante entre os aromáticos foi o 1,2-dimetilbenzeno (2,5%). Os resultados experimentais revelaram também a liberação de VOCs pelos materiais de acabamento interno dos veículos automotores recém-manufaturados. / New motor vehicles cabins may be critical when considering the internal air quality, because concentrations of volatile organic compounds are at levels higher than the outdoors. Certain substances present in the cabin air can be harmful to humans according to their toxicity, mainly in the big cities. Assessment of the cabin air becomes necessary. In this study, cabin air quality was assessed and 7 popular new vehicles containing same interior trim materials were evaluated. A total of 46 volatile organic compounds were identified, with 14 of them were carbonylic compounds and 32 are aliphatic and aromatic hydrocarbons, halogenated compounds and a nitrogenated compound. The carbonylic compounds were identified and quantified by the liquid chromatography and other VOCs only identified by GC-MS. Cabin air vehicles studied showed the following average concentrations found for carbonylic compounds ( µg/m3) in a descending order: formaldehyde (165.3), acetone (67.5); acetaldehyde (56.8); Isovaleraldehyde ( 40.8); propionaldehyde (21.1); butyraldehyde (17.9); crotonaldeído (14.9); hexaldeído (14.9) Valeraldehyde (9.8); dimetilbenzaldeído-2.5 (9.3); the - tolualdeído (8.4), p / m - tolualdeído (6.8); acrolein (4.2) and benzaldehyde (3.8). Concerning the other VOCs the following compounds were identified: methylbutane, which had the highest percentage of relative abundance, 8.5%, followed by other hydrocarbons with relative abundance between 5 and 2%, 2,7,10-trimetildodecano, 2.2 ,6- Trimetildecano, ciclopentano, 2,3,4-trimetildecano, n-pentane, 3.6-dimetilundecano, 4- metildodecano, dimetildodecano-4.6, 3.6 and 1.2-dimetildecano-dimetilbenzeno. Two halogenated hydrocarbons were also found, and triclorofluormetano had the biggest relative abundance percentage 5.7%, and a nitrogen compound, the acetonitrile with 5.4%. The benzene compounds identified were: 1.2-dimetilbenzeno, ethylbenzene, methylbenzene, 1- ethyl-3-methyl, ethyl-1-and 3-methyl 1,3,5-trimethylbenzene which comprise 6.6% of relative abundance. 1.2-dimetilbenzeno was the most abundant aromatic compound with relative abundance 2.5%. Results also showed that VOCs were released by studied vehicles interior trim materials.
3

Avaliação da qualidade do ar de cabines de veículos automotores recém-manufaturados / Evaluation of new vehicles cabin indoor air quality

Auzebio Valvassori Filho 23 September 2008 (has links)
Cabines de veículos automotores recém-manufaturados podem ser consideradas críticas quando se avalia a qualidade do ar interno, pois concentrações de compostos orgânicos voláteis encontram-se em níveis mais altos que os ambientes externos. Determinadas substâncias presentes no ar da cabine podem ser prejudiciais ao ser humano em função da sua toxicidade, pricipalmente nos grandes centros urbanos. A avaliação do ar da cabine automotiva se faz necessária. Nesse estudo, foi feita uma avaliação da qualidade do ar interno da cabine de 7 veículos populares recém-manufaturados contendo materiais de acabamento interno iguais. Um total de 46 compostos orgânicos voláteis foi identificado, sendo que 14 deles são compostos carbonílicos e 32 são hidrocarbonetos alifáticos e aromáticos, compostos halogenados e um nitrogenado. Os compostos carbonílicos foram identificados e quantificados por cromatografia a líquido e os outros VOCs apenas identificados por GC-MS. No ar interno da cabine dos veículos estudados, as concentrações médias encontradas para os compostos carbonílicos (µg/m3) em ordem decrescente foram: formaldeído (165,3); acetona (67,5); acetaldeído (56,8); isovaleraldeído (40,8); propionaldeído (21,1); butiraldeído (17,9); crotonaldeído (14,9); hexaldeído (14,9) valeraldeído (9,8); 2.5- dimetilbenzaldeído (9,3); otolualdeído (8,4); p/m tolualdeído (6,8); acroleína (4,2) e benzaldeído (3,8). Com relação aos outros VOCS foram identificados o metilbutano, que apresentou a maior porcentagem de abundância relativa, 8,5%, seguido de outros hidrocarbonetos com abundância relativa entre 5 e 2% , como, 2,7,10-trimetildodecano, 2,2,6-trimetildecano, ciclopentano, 2,3,4-trimetildecano, n-pentano, 3,6-dimetilundecano, 4-metildodecano, 4,6- dimetildodecano, 3,6-dimetildecano e 1,2-dimetilbenzeno. Dois derivados de hidrocarbonetos halogenados também foram encontrados, sendo que o triclorofluormetano foi o majoritário com 5,7%, e um composto nitrogenado, a acetonitrila com 5,4%. Os compostos derivados do benzeno identificados foram: 1,2-dimetilbenzeno, etilbenzeno, metilbenzeno, 1-etil-3- metilbenzeno, 1-etil-3-metilbenzeno e 1,3,5-trimetilbenzeno que perfazem 6,6 % de abundância relativa. O mais abundante entre os aromáticos foi o 1,2-dimetilbenzeno (2,5%). Os resultados experimentais revelaram também a liberação de VOCs pelos materiais de acabamento interno dos veículos automotores recém-manufaturados. / New motor vehicles cabins may be critical when considering the internal air quality, because concentrations of volatile organic compounds are at levels higher than the outdoors. Certain substances present in the cabin air can be harmful to humans according to their toxicity, mainly in the big cities. Assessment of the cabin air becomes necessary. In this study, cabin air quality was assessed and 7 popular new vehicles containing same interior trim materials were evaluated. A total of 46 volatile organic compounds were identified, with 14 of them were carbonylic compounds and 32 are aliphatic and aromatic hydrocarbons, halogenated compounds and a nitrogenated compound. The carbonylic compounds were identified and quantified by the liquid chromatography and other VOCs only identified by GC-MS. Cabin air vehicles studied showed the following average concentrations found for carbonylic compounds ( µg/m3) in a descending order: formaldehyde (165.3), acetone (67.5); acetaldehyde (56.8); Isovaleraldehyde ( 40.8); propionaldehyde (21.1); butyraldehyde (17.9); crotonaldeído (14.9); hexaldeído (14.9) Valeraldehyde (9.8); dimetilbenzaldeído-2.5 (9.3); the - tolualdeído (8.4), p / m - tolualdeído (6.8); acrolein (4.2) and benzaldehyde (3.8). Concerning the other VOCs the following compounds were identified: methylbutane, which had the highest percentage of relative abundance, 8.5%, followed by other hydrocarbons with relative abundance between 5 and 2%, 2,7,10-trimetildodecano, 2.2 ,6- Trimetildecano, ciclopentano, 2,3,4-trimetildecano, n-pentane, 3.6-dimetilundecano, 4- metildodecano, dimetildodecano-4.6, 3.6 and 1.2-dimetildecano-dimetilbenzeno. Two halogenated hydrocarbons were also found, and triclorofluormetano had the biggest relative abundance percentage 5.7%, and a nitrogen compound, the acetonitrile with 5.4%. The benzene compounds identified were: 1.2-dimetilbenzeno, ethylbenzene, methylbenzene, 1- ethyl-3-methyl, ethyl-1-and 3-methyl 1,3,5-trimethylbenzene which comprise 6.6% of relative abundance. 1.2-dimetilbenzeno was the most abundant aromatic compound with relative abundance 2.5%. Results also showed that VOCs were released by studied vehicles interior trim materials.
4

Modelling and analysis of an air-conditioning system for vehicles based on magnetocaloric refrigeration

Torregrosa Jaime, Bárbara 01 September 2016 (has links)
[EN] This PhD thesis studies the application of the magnetic refrigeration technology in the air-conditioning system of automobiles. Thermal models of each of the components of such a system have been developed with the purpose of determining accurately its global performance. A dynamic one-dimensional model of a parallel-plate active magnetic regenerator (AMR) has been developed. The model is based in a new numerical scheme that reduces the computation time by 88% compared to the most commonly employed method. The model reproduces very accurately the passive regenerator cases with analytic solution and has been thoroughly validated against experimental results of both passive regenerator and AMR tests. The inclusion in the model of the magnetocaloric properties experimentally measured with a sample of the employed material, the demagnetizing effect, the fluid flow maldistribution and the losses to the ambient in the experimental setup have all been keys to obtain a good agreement with the experiments. The influence of the uncertainties and simplifications assumed when modelling these physical phenomena has been analyzed in detail, which has allowed the validation of different approaches. Besides, a dynamic model of the air-conditioning (AC) system of an electric vehicle has been developed. Thermal models of each of the system components have been included, namely the cabin, the hydraulic loops with the air-to-coolant heat exchangers and the electric auxiliaries. The modelling methodology employed is based on the combination of the conservation equations with the semi-empirical fitting of the global heat transfer coefficient. Excellent validation results have been obtained with experimental results in a wide range of operating conditions. The vehicle model has been employed to obtain the cooling and heating demand of a commercial full electric minibus, as well as the working temperatures. A broad optimization study has been carried out with the AMR model with the purpose of determining the design and working parameters of such a refrigerator that fulfil the cooling requirements of the vehicle with a minimum combined total system mass (affecting the weight of the vehicle and the economic cost) and electric consumption. The electric demand of the electrical AC auxiliaries has also been considered. Additionally, the heating performance of the optimal designs has been calculated. The application of AMR refrigerators in mobile air-conditioning systems is analyzed in comparison to the features of current vapor-compression systems. / [ES] En la presente tesis doctoral se ha estudiado la aplicación de un refrigerador magnético en un sistema de aire acondicionado para automóviles. Con el fin de determinar las prestaciones de dicho sistema de manera global y precisa, se ha desarrollado un modelo térmico de cada uno de sus componentes. Por un lado, se ha desarrollado un modelo dinámico unidimensional de regenerador magnético activo (AMR) de placas planas paralelas, basado en un nuevo esquema numérico que reduce el tiempo de cálculo hasta en un 88% respecto al esquema más empleado. El modelo reproduce con gran exactitud los casos de regenerador con solución analítica y ha sido validado exhaustivamente con resultados experimentales funcionando como regenerador pasivo y como AMR. Para obtener buenos ajustes ha sido clave la inclusión en el modelo de las propiedades magnetocalóricas medidas experimentalmente con una muestra del material empleado, el efecto desmagnetizante, la mala distribución del fluido y las pérdidas hacia el ambiente del montaje experimental. La influencia de las incertidumbres y las simplificaciones en el modelado de estos fenómenos se ha analizado detalladamente, lo cual ha permitido validar diferentes aproximaciones. Por otro lado, se ha desarrollado un modelo dinámico del sistema de aire acondicionado de un vehículo eléctrico. Se incluye el modelo térmico de la cabina, los bucles hidráulicos para la distribución de la potencia térmica con los intercambiadores de calor agua-aire y los auxiliares eléctricos. La metodología empleada para el desarrollo de estos modelos, basada en la combinación de ecuaciones de conservación con el ajuste semi-empírico de los coeficientes globales de transmisión de calor, ha producido excelentes resultados de validación con resultados experimentales en un amplio rango de condiciones de funcionamiento. El modelo del vehículo se ha empleado para obtener la demanda de refrigeración y calefacción de un minibús eléctrico comercial, así como las temperaturas de funcionamiento del sistema. Con el modelo de AMR se ha llevado a cabo un amplio estudio de optimización para determinar los parámetros de diseño y de funcionamiento de dicho refrigerador que cubren las necesidades de refrigeración del vehículo una masa del conjunto del sistema y un consumo eléctrico mínimos, incluyendo el consumo de los auxiliares. Adicionalmente se han calculado las prestaciones de calefacción de las combinaciones óptimas. La aplicabilidad de este sistema en automóviles se analiza en comparación con un sistema equivalente de compresión de vapor. / [CA] En aquesta tesi doctoral s'ha estudiat l'aplicació d'un refrigerador magnètic en un sistema d'aire condicionat per a automòbils. A fi de determinar les prestacions d'aquest sistema de manera global i precisa, s'ha desenvolupat un model tèrmic de cadascun dels components. D'una banda, s'ha desenvolupat un model dinàmic unidimensional de regenerador magnètic actiu (AMR) de plaques planes paral·leles, basat en un nou esquema numèric que redueix el temps de càlcul fins d'un 88% respecte a l'esquema més emprat. El model reprodueix amb gran exactitud els casos de regenerador amb solució analítica, i ha sigut validat exhaustivament amb resultats experimentals funcionant com a regenerador passiu i com a AMR. Per a obtenir bons ajustos ha sigut clau la inclusió en el model de les propietats magnetocalòriques mesurades experimentalment amb una mostra del material emprat, l'efecte desmagnetitzador, la mala distribució del fluid i les pèrdues cap a l'ambient del muntatge experimental. La influència de les incerteses i les simplificacions en la modelització d'aquests fenòmens s'ha analitzat detalladament, la qual cosa ha permès validar diferents aproximacions. D'altra banda, s'ha desenvolupat un model dinàmic del sistema d'aire condicionat d'un vehicle elèctric. S'hi inclouen el model tèrmic de la cabina, els bucles hidràulics per a la distribució de la potència tèrmica amb els bescanviadors de calor aigua-aire i els auxiliars elèctrics. La metodologia emprada per al desenvolupament d'aquests models, basada en la combinació d'equacions de conservació amb l'ajust semiempíric dels coeficients globals de transmissió de calor, ha produït excel·lents resultats de validació amb resultats experimentals en un ampli rang de condicions de funcionament. El model del vehicle s'ha emprat per a obtenir la demanda de refrigeració i calefacció d'un minibús elèctric comercial, així com les temperatures de funcionament del sistema. Amb el model d'AMR s'ha dut a terme un ampli estudi d'optimització per determinar els paràmetres de disseny i de funcionament de la refrigeradora esmentada que cobreixen les necessitats de refrigeració del vehicle, una massa del conjunt del sistema i un consum elèctric mínims, incloent el consum dels auxiliars. Addicionalment s'han calculat les prestacions de calefacció de les combinacions òptimes. L'aplicabilitat d'aquest sistema en automòbils s'analitza comparant-la amb la d'un sistema equivalent de compressió de vapor. / Torregrosa Jaime, B. (2016). Modelling and analysis of an air-conditioning system for vehicles based on magnetocaloric refrigeration [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68503 / TESIS / Premios Extraordinarios de tesis doctorales

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