The thesis deals with the evaluation of indoor environment cab passenger car, with a focus on thermal comfort of passengers. The theoretical part contains the fundamentals of heat transfer, analysis of the aspects affecting human thermal comfort and its assessment methods. A brief description of the ventilation and air conditioning systems used in passenger cars is mentioned. The practical part includes numerical simulations of indoor environment, in selected driving modes and at different climatic conditions. Results of simulations lead to evaluation the status of the internal environment in terms of thermal comfort.

[EN] This PhD study deals with the modelling of an adsorption system designed to provide air conditioning for vehicles, and is driven by the waste heat available from the water/glycol cooling circuit of the engine. The system is based on the sequential heating/cooling of two sorption beds containing a solid sorption material which desorbs or adsorbs water vapour. The condensation of the vapour is carried out by a cooling circuit while the subsequent evaporation of the condensed liquid is employed to produce the cooling effect, generating chilled water, which is then employed to cool down the air of the cabin. The developed model is fully dynamic and is based on zero-dimensional lumped parameter models for all the necessary components of the overall system including the engine, the beds, the heating circuit, the cooling circuit, the chilled water circuit and the vehicle cabin. The sorption bed model takes into account the non-equilibrium of the adsorption and desorption processes and is able to work with any kind of adsorbent materials, but the study has been restricted to silica gel and zeolite which are among the most appropriate materials for this application. The model is employed to simulate a standard driving cycle of a vehicle, evaluating the instantaneous available heat from the engine cooling system and the dynamic behaviour of the described sorption A/C system, resulting in the estimation of the evolution of the cabin temperature along the cycle. The model of the overall system has been developed under the MATLAB Simulink programming environment. The model of the adsorption system has been first validated against experimental results, showing its excellent capabilities to predict the dynamic behaviour of the system. The model was then used to analyse the influence of the main design parameters of the bed and the main operation parameters on the system's performance: cooling capacity and coefficient of performance (COP). This was done in order to provide rules for the optimal design and operation of this kind of systems. Finally, the model has been employed to analyse the overall system (engine, adsorption system, heating and cooling circuits, chilled water circuit and cabin) performance along a standard driving cycle, under various operation strategies with regards to the initial state of the adsorbent material in the beds, and operation conditions both for a car and a truck. The results show the difficulties of activating the system at the initial periods of the cycle, when the engine is warming up, and the difficulties to synchronise the operation of the system with the availability of waste energy. They also highlight the limitation in capacity of the designed system, showing that it would not able to fulfil the comfort requirements inside the cabin in hot days or after soaking conditions. Part of this PhD study was carried out in the frame of an R&D project called "Thermally Operated Mobile Air Conditioning Systems - TOPMACS", financially supported by the EU under the FP6 program, which was devoted to the evaluation of the feasibility and performance of potential sorption system solutions for the air conditioning of vehicles. / [ES] Esta tesis doctoral se centra en el modelado de un sistema de adsorción diseñado para proporcionar aire acondicionado de vehículos a partir del calor residual disponible en el circuito de refrigeración de agua/glicol del motor. El sistema se basa en el calentamiento/enfriamiento secuencial de dos reactores que contienen un material adsorbente sólido que desorbe o absorbe vapor de agua. La condensación del vapor se lleva a cabo mediante un circuito de refrigeración, mientras que la posterior evaporación del agua condensada se emplea para producir agua fría, que se emplea finalmente en enfriar el aire de la cabina. El modelo desarrollado es completamente dinámico y se basa en modelos cero dimensionales de parámetros concentrados, para todos y cada uno de los componentes del sistema global incluyendo el motor, los reactores, el circuito de calentamiento, el circuito de enfriamiento, el circuito de agua fría y la cabina del vehículo. El modelo del reactor contempla el no equilibrio de los procesos de adsorción o desorción y es capaz de trabajar con cualquier par de materiales adsorbentes. No obstante el estudio se ha restringido a gel de sílice y zeolita que se encuentran entre los materiales más adecuados para esta aplicación. El modelo se emplea para simular un ciclo de conducción estándar del vehículo, evaluando el calor disponible instantáneamente en el sistema de refrigeración del motor, y el comportamiento dinámico del sistema descrito adsorción-Aire Acondicionado, permitiendo como resultado principal la estimación de la evolución de la temperatura de la cabina a lo largo el ciclo. El modelo del sistema global se ha desarrollado en el marco del entorno de programación MATLAB Simulink. El modelo del sistema de adsorción se ha validado primero contra resultados experimentales demostrando las excelentes capacidades del modelo para predecir el comportamiento dinámico del sistema. A continuación, el modelo se ha aplicado para analizar la influencia de los principales parámetros de diseño del reactor, y de los principales parámetros de operación, sobre el rendimiento del sistema: la capacidad y coeficiente de operación (COP), con el fin de proporcionar directrices para el diseño y operación óptima de este tipo de sistemas. Por último, el modelo ha sido empleado para analizar el funcionamiento y prestaciones del sistema en su conjunto (motor, sistema de absorción, los circuitos de calefacción y refrigeración, circuito de agua fría, y la cabina) a lo largo de un ciclo de conducción estándar, bajo diferentes estrategias de operación en lo que se refiere al estado inicial del material adsorbente en los reactores, y las condiciones de operación, para el caso de un coche, y para el de un camión. Los resultados muestran las dificultades de la activación del sistema en los periodos iniciales del ciclo, cuando el motor se está calentando, y las dificultades para sincronizar el funcionamiento del sistema con la disponibilidad de energía térmica excedente del motor, así como la limitación en la capacidad de enfriamiento del sistema diseñado, que no resulta capaz de satisfacer los requerimientos mínimos de confort dentro de la cabina en los días calurosos o de enfriarlo con suficiente rapidez cuando el vehículo ha estado estacionado bajo el sol durante varias horas. Parte de este estudio de doctorado se ha llevado a cabo en el marco de un proyecto de I + D denominado " Thermally Operated Mobile Air Conditioning Systems - TOPMACS", financiado parcialmente por la UE en el marco del programa FP6, y que perseguía la evaluación de la viabilidad y el potencial de aplicación de soluciones de sistemas de adsorción activadas por el calor residual del motor para el aire acondicionado de vehículos. / [CA] Aquesta tesi doctoral es centra en el model d'un sistema d'adsorció dissenyat per a proporcionar aire acondicionat a vehicles a partir de la calor residual disponible al circuit de refrigeració d'aigua / glicol del motor. El sistema es basa en l'escalfament / refredament seqüencial de dos reactors que contenen un material adsorbent sòlid que desorbeix o absorbeix vapor d'aigua. La condensació del vapor es porta a terme mitjançant un circuit de refrigeració, mentre que la posterior evaporació de l'aigua condensada s'utilitza per a produir aigua freda, que s'empra finalment en refredar l'aire de la cabina. El model desenvolupat és completament dinàmic i es basa en models zero dimensionals de paràmetres concentrats, per a tots i cada un dels components del sistema global incloent el motor, els reactors, el circuit d'escalfament, el circuit de refredament, el circuit d'aigua freda i la cabina del vehicle. El model del reactor contempla el no equilibri dels processos d'adsorció o desorció i és capaç de treballar amb qualsevol parell de materials adsorbents. No obstant això, l'estudi s'ha restringit a gel de sílice i zeolita que es troben entre els materials més adequats per a aquesta aplicació. El model s'utilitza per a simular un cicle de conducció estàndard del vehicle, avaluant la calor disponible instantàniament en el sistema de refrigeració del motor, i el comportament dinàmic del sistema descrit Adsorció-Aire Acondicionat, permetent com a resultat principal l'estimació de l'evolució de la temperatura de la cabina al llarg del cicle. El model del sistema global s'ha desenvolupat en l'entorn de programació MATLAB Simulink. El model del sistema d'adsorció s'ha validat primer amb resultats experimentals demostrant les excel¿lents capacitats del model per a predir el comportament dinàmic del sistema. A continuació, el model s'ha aplicat per analitzar la influència dels principals paràmetres de disseny del reactor, i dels principals paràmetres d'operació, sobre el rendiment del sistema: la capacitat i coeficient d'operació (COP), amb la finalitat de proporcionar directrius per al disseny i operació òptima d'aquest tipus de sistemes. Finalment, el model ha estat utilitzat per analitzar el funcionament i prestacions del sistema en el seu conjunt (motor, sistema d'absorció, els circuits de calefacció i refrigeració, circuit d'aigua freda, i la cabina) al llarg d'un cicle de conducció estàndard, sota diferents estratègies d'operació pel que fa a l'estat inicial del material adsorbent en els reactors, i les condicions d'operació, per al cas d'un cotxe, i per al d'un camió. Els resultats mostren les dificultats de l'activació del sistema en els períodes inicials del cicle, quan el motor s'està escalfant, i les dificultats per sincronitzar el funcionament del sistema amb la disponibilitat d'energia tèrmica excedent del motor, així com la limitació en la capacitat de refredament del sistema dissenyat, que no resulta capaç de satisfer els requeriments mínims de confort dins de la cabina en els dies calorosos o de refredar amb suficient rapidesa quan el vehicle ha estat estacionat sota el sol durant diverses hores. Part d'aquest estudi de doctorat s'ha dut a terme en el marc d'un projecte d'I + D denominat "Thermally Operated Mobile Air Conditioning Systems - TOPMACS", finançat parcialment per la UE en el marc del programa FP6, i que perseguia l'avaluació de la viabilitat i el potencial d'aplicació de solucions de sistemes d'adsorció activats per la calor residual del motor per a l'aire condicionat de vehicles. / Verde Trindade, M. (2015). MODELLING AND OPTIMIZATION OF AN ADSORPTION COOLING SYSTEM FOR AUTOMOTIVE APPLICATIONS [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/54120

The purpose of this thesis work was to study the airflow patterns and the particle distribution in a generic car cabin in order to evaluate the air quality and find how it can be improved. A 3D CAD model was created using the Solidworks software program and meshed using ICEM CFD software. The ICEM CFD software was used to generate the mesh and ANSYS FLUENT was adapted for the simulation. In total, 12 different cases were simulated by considering different inlet velocities and vent setup. The predicted results were further used to analyze the airflow and particle distribution in the entire car cabin. With higher inlet velocity there were more particles being transported to the rear part of the cabin. In general, the particle concentration was higher in the front of the cabin when they were introduced through the inlets, especially with low inlet velocities. Opening the recirculation vents resulted in a slight reduction of the flow to the rear side and reduced the particle distribution accordingly. When smoke particles were introduced in the rear seats, they mostly stayed in the rear of the cabin, especially with low inlet flow velocities as the air did not mix sufficiently. Overall a higher inlet airflow velocity reduced the number of particles that were trapped on the front and rear seats. However, an increase in the number of particles that were trapped on the ceiling, floor and walls were obtained. / Syftet med den här avhandlingen var att studera luftflödesmönster och partikelfördelningen i en generell bilkabin för att utvärdera luftkvaliteten och se hur man kan förbättra den. En 3D CAD-modell skapades med hjälp av Solidworks och ett rutnät skapades med hjälp av ICEM CFD. ICEM CFD användes för att generera rutnätet och ANSYS FLUENT användes för simuleringarna. Totalt simulerades 12 olika fall bestående av olika inflödeshastigheter och ventilinställningar. De beräknade resultaten användes sedan för att analysera luftflödet och partikelfördelningen i hela bilkabinen. Med högre inloppsflöde var det fler partiklar som transporterades till bakre delen av bilkabinen. Överlag var partikelkoncentrationen högre i framdelen av kabinen när partiklarna introducerades i inloppsventilerna, särskilt vid låga inloppshastigheter. Att öppna recirkulationsventilerna resulterade i en liten minskning av luftflödet till bakdelen av kabinen och även så partikelfördelningen. När rökpartiklar introducerades i baksätena, stannade de för det mesta i bakdelen av kabinen, särskilt vid låga inloppsflödeshastigheter då luften inte blandades tillräckligt. Överlag innebar en högre inloppsflödeshastighet reducerade mängden av partiklar som fastnade på fram- och baksätena, men ökade mängden partiklar som fastnade på taket, golvet och på väggarna.

This diploma thesis deals with comparing noise levels of three side vents of different constructions, which are used for distribution and directing of ventilation air in a cabin of an automobile. The fundamental knowledge of the physical and physiological acoustics is described in the introduction part of this study. Following the introduction part there is a brief explanation of the car air conditioning system (HVAC system) as well as are explained the acoustic properties of specific elements of this system. The study also deals with dividing ventilation vents and describes the vast traceable types of automobile vents. Prior to the description of the experiment, which was conducted as a part of this study, the procedures and results of the measurements carried out in other theses are explained. Measurement of noise levels of the compared vents was carried out in a semi-anechoic chamber under the ČSN ISO 3475 standardization. To clarify increase of noise generated by the vent in an interior of an automobile, additional measurement of noise was carried out in a cabin of Porsche Cayenne 2018. From the gathered results we can conclude that under the constant flow, (of 60 square meters per hour) louder vents are those with higher pressure loss. This pressure loss is dependant primarily on the speed of the flow in the vent, as well as on the number and the adjustment of the deflectors. In a cabin of an automobile, the noise produced by the vent is negligible in comparison with total noise in an interior of a car. However, in the area surrounding the air flowing out from the vent, (approximately 0,7 meters from it) the level of acoustic pressure increases significantly.

The thesis deals with car cabin environment and thermal comfort inside. A car cabin heat load model was developed in Dymola/Modelica to investigate influence of ambient environmental parameters. The model was validated on the data set of eight test cases measured in a climatic chamber and in a real traffic. The main objective of the thesis was to develop a human thermal comfort model suitable for non-homogenous environments and for a car cabin environment especially. The Coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. The model allows predicting an overall human thermal comfort from local boundary conditions representing ambient and personal factors. The model was validated by 16 test cases taken from experiments in literature. Moreover three test cases were created in Theseus-FE to consider an asymmetrical heat load from Sun rays inside a car cabin. Prediction of the Coupled model was compared with Fiala model and experimental data. The Coupled model predicted mean skin temperature for moderate activities in neutral and warm environment well. In cold environment a predicted core temperature was very affected by ambient temperature and during high activity exercises, the predicted mean skin temperature was too high.

The diploma thesis deals with CFD simulating the air flow inside the car using the numerical calculation program Star-CCM+. The aim of the thesis was to prepare 3D geometry, resp. realistic model of the real car, preparing boundary conditions including material properties, simulating the steady state of the environment and evaluating the speed and temperature of the car cabin. The paper presents the results of the temperature distribution and air velocities in the cabin during the winter, spring and summer conditions in HVAC on and HVAC off modes. The monitored air temperatures and surface temperatures of the car parts are compared with the measured data. The average difference between simulation and measurement was at air temperatures of 2.3 °C and surface temperatures of 3.4 °C.

The thesis deals with car cabin environment and thermal comfort inside. A car cabin heat load model was developed in Dymola/Modelica to investigate influence of ambient environmental parameters. The model was validated on the data set of eight test cases measured in a climatic chamber and in a real traffic. The main objective of the thesis was to develop a human thermal comfort model suitable for non-homogenous environments and for a car cabin environment especially. The Coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. The model allows predicting an overall human thermal comfort from local boundary conditions representing ambient and personal factors. The model was validated by 16 test cases taken from experiments in literature. Moreover three test cases were created in Theseus-FE to consider an asymmetrical heat load from Sun rays inside a car cabin. Prediction of the Coupled model was compared with Fiala model and experimental data. The Coupled model predicted mean skin temperature for moderate activities in neutral and warm environment well. In cold environment a predicted core temperature was very affected by ambient temperature and during high activity exercises, the predicted mean skin temperature was too high.