Conceptual Design of Propulsion Systems for Boundary Layer Ingestion

To reduce the climate impact of aviation new aircraft and engine concepts as well as improved design methods are needed. In this thesis, two fronts are explored. The first concerns improved methods for the conceptual design of the engine. A consistent conceptual design approach is presented, where calculated parameters such as stage loadings are used to update the component efficiency assumptions within the cycle optimization loop. The result is that the design space is fully explored, and that pressure ratio is optimally distributed between the components. A coupled analysis of a low pressure turbine and turbine rear structure has also been conducted, showing the importance of considering their coupled interaction when these components are designed.On the second front, concerning the application of the developed methods to new propulsion applications, a conceptual design of a propulsion system for a turbo-electric boundary layer ingesting aircraft concept is presented. The aircraft features and aft-mounted fuselage fan for boundary layer ingestion. Earlier studies have shown a theoretical potential of 10% in power savings compared to a conventional aircraft configuration. The fuselage fan is electrically powered and fed by power offtake from two under-wing mounted geared turbofan engines. To this end, a 5 MW-class generator is integrated into the geared turbofans. The generator is connected to a free power turbine that is introduced to facilitate an optimal generator design and to mechanically decouple the generator from the low pressure shaft. A system-level analysis of the designed propulsion system, including the effects of the boundary layer ingesting fuselage fan shows a fuel burn reduction of 0.6%-3.6%, depending on electric machinery technology, compared to a conventional aircraft in the 2050 time frame. The modest reduction, compared to the theoretical potential, is caused by the difficulty of obtaining a benefit from ingesting the outer part of the boundary layer. This benefit is more than offset by electric machinery losses and the reduced efficiency of the fuselage fan compared to the main engine fan

A Review on Expert System Applications in Power Plants

The control and monitoring of power generation plants is being complicated day by day, with the increase size and capacity of equipments involved in power generation process. This calls for the presence of experienced and well trained operators for decision making and management of various plant related activities. Scarcity of well trained and experienced plant operators is one of the major problems faced by modern power industry. Application of artificial intelligence techniques, especially expert systems whose main characteristics is to simulate expert plant operator’s actions is one of the actively researched areas in the field of plant automation. This paper presents an overview of various expert system applications in power generation plants. It points out technological advancement of expert system technology and its integration with various types of modern techniques such as fuzzy, neural network, machine vision and data acquisition systems. Expert system can significantly reduce the work load on plant operators and experts, and act as an expert for plant fault diagnosis and maintenance. Various other applications include data processing, alarm reduction, schedule optimisation, operator training and evaluation. The review point out that integration of modern techniques such as neural network, fuzzy, machine vision, data base, simulators etc. with conventional rule based methodologies have added greater dimensions to problem solving capabilities of an expert system.DOI:http://dx.doi.org/10.11591/ijece.v4i1.502

Design and modelling of innovative machinery systems for large ships

Eighty percent of the growing global merchandise trade is transported by sea. The shipping industry is required to reduce the pollution and increase the energy efficiency of ships in the near future. There is a relatively large potential for approaching these requirements by implementing waste heat recovery (WHR) systems.Studies of alternative WHR systems in other applications suggests that the Kalina cycle and the organic Rankine cycle (ORC) can provide significant advantages over the steam Rankine cycle, which is currently used for marine WHR.This thesis aims at creating a better understanding of the Kalina cycle and the ORC in the application on board large ships; the thermodynamic performances of the mentioned power cycles are compared. Recommendations of suitable system layouts and working fluids for the marine applications are provided along with methodologies useful for the design and optimisation of the main engine and WHR system combined cycle.Numerical models of a low-speed two-stroke diesel engine, turbochargers, and the mentioned types of WHR systems in various configurations, are used to achieve the mentioned objectives. The main engine is simulated using a zero-dimensional model consisting of a two-zone combustion and NOx emission model, a double Wiebe heat release model, the Redlich-Kwong equation of state and the Woschni heat loss correlation. A novel methodology is presented and used to determine the optimum organic Rankine cycle process layout, working fluid and process parameters for marine WHR. Using this mentioned methodology, regression models are derived for the prediction of the maximum obtainable thermal efficiency of ORCs. A unique configuration of the Kalina cycle, the Split-cycle, is analysed to evaluate the fullest potential of the Kalina cycle for the purpose. Integrated with three main engine waste heat streams, the Kalina cycle, the ORC and a dual-pressure steam cycle are compared with regards to the power outputs and other aspects. The part-load performances of four different WHR system configurations, including an exhaust gas recirculation system, are evaluated with regards to the fuel consumption and NOx emissions trade-off.The results of the calibration and validation of the engine model suggest that the main performance parameters can be predicted with adequate accuracies for the overall purpose. The results of the ORC and the Kalina cycle optimisation efforts indicate that both cycles can achieve higher power outputs than the steam cycle; however, the results suggest that for the Kalina cycle to achieve such high power outputs, a relatively complex process layout and high working pressures are required. Conversely, the ORC can achieve superior power outputs with a much simpler process layout in comparison. The toxic ammonia-water working fluid of the Kalina cycle is problematic for the use in marine machinery rooms, and so are the highly flammable ORC working fluids. Based on the analyses, no configuration of the Kalina cycle is recommended for marine WHR. An exhaust gas power turbine is recommended as an initial WHR system investment due its cost-effectiveness. For large ships, a dual-pressure steam cycle is recommended because it is well-known, proven, highly efficient and environmentally benign. The ORC is recommended for large and medium size ships and it is recommended to use the highly flammable working fluids and take the needed precautions. The main reasons are that the ORCs can achieve superior efficiencies with a simple process that can be operated fully automated. For the same reasons a WHR system consisting of a hybrid turbocharger and a recuperated ORC is recommended

Performance-based health monitoring, diagnostics and prognostics for condition-based maintenance of gas turbines: A review

With the privatization and intense competition that characterize the volatile energy sector, the gas turbine industry currently faces new challenges of increasing operational flexibility, reducing operating costs, improving reliability and availability while mitigating the environmental impact. In this complex, changing sector, the gas turbine community could address a set of these challenges by further development of high fidelity, more accurate and computationally efficient engine health assessment, diagnostic and prognostic systems. Recent studies have shown that engine gas-path performance monitoring still remains the cornerstone for making informed decisions in operation and maintenance of gas turbines. This paper offers a systematic review of recently developed engine performance monitoring, diagnostic and prognostic techniques. The inception of performance monitoring and its evolution over time, techniques used to establish a high-quality dataset using engine model performance adaptation, and effects of computationally intelligent techniques on promoting the implementation of engine fault diagnosis are reviewed. Moreover, recent developments in prognostics techniques designed to enhance the maintenance decision-making scheme and main causes of gas turbine performance deterioration are discussed to facilitate the fault identification module. The article aims to organize, evaluate and identify patterns and trends in the literature as well as recognize research gaps and recommend new research areas in the field of gas turbine performance-based monitoring. The presented insightful concepts provide experts, students or novice researchers and decision-makers working in the area of gas turbine engines with the state of the art for performance-based condition monitoring

Waste Heat Recovery from Marine Gas Turbines and Diesel Engines

The paper presents the main results of a research project directed to the development of mathematical models for the design and simulation of combined Gas Turbine-Steam or Diesel-Steam plants for marine applications. The goal is to increase the energy conversion efficiency of both gas turbines and diesel engines, adopted in ship propulsion systems, by recovering part of the thermal energy contained in the exhaust gases throughWaste Heat Recovery (WHR) dedicated installations. The developed models are used to identify the best configuration of the combined plants in order to optimize, for the different applications, the steam plant layout and the performance of WHR plant components. This research activity has allowed to obtain significant improvements in terms of energy conversion efficiency, but also on other important issues: dimensions and weights of the installations, ship load capacity, environmental compatibility, investment and operating costs. In particular, the main results of the present study can be summarized as follows: (a) the quantitative assessment of the advantages (and limits) deriving by the application of a Combined Gas And Steam (COGAS) propulsion system to a large container ship, in substitution of the traditional two-stroke diesel engine; (b) the proposal of optimized WHR propulsion and power systems for an oil tanker, for which a quantitative evaluation is given of the attainable advantages, in terms of fuel consumption and emissions reduction, in comparison with more traditional solutions

Progettazione multidisciplinare ottimizzata nelle microturbine a gas

Optimized multidisciplinary design in micro-gasturbine

Performance analysis and dynamics of innovative SOFC hybrid systems based on turbocharger-derived machinery

La crescente consapevolezza su temi quali il cambiamento climatico e l\u2019inquinamento atmosferico ha portato a politiche nazionali ed internazionali mirate allo sviluppo di sistemi energetici innovativi e sostenibili. Tra di essi, le fuel cell sono uno dei pi\uf9 promettenti, essendo caratterizzate da alte efficienze e basse emissioni. In particolare, i sistemi ibridi basati sull\u2019integrazione di fuel cell ad alta temperatura con dispositivi derivati da turbocompressori hanno attirato l\u2019attenzione del mondo accademico e dell\u2019industria negli ultimi decenni. Tuttavia, la complessit\ue0, la fragilit\ue0 e l\u2019alto costo di questi impianti ha rallentato il loro sviluppo, e solo poche grandi aziende sono state in grado di realizzare prototipi completi. Le difficolt\ue0 tecniche affrontate dalla comunit\ue0 scientifica hanno messo in luce l\u2019importanza delle simulazioni per progettare, testare, controllare e analizzare i sistemi ibridi a fuel cell. Sulla base di tale esperienza, questa tesi mira ad espandere la attuale conoscenza sui sistemi ibridi a fuel cell a ossidi solidi, ponendo una particolare attenzione su un innovativo sistema turbocompresso di piccola taglia, alimentato con biogas e recentemente introdotto all\u2019interno del progetto europeo Bio-HyPP. Lo scopo principale della tesi \ue8 determinare se questo tipo di sistema possa essere una valida alternativa ai sistemi basati su microturbine a gas, analizzando il suo comportamento in relazione a diversi scenari, sia stazionari, sia transitori. Per fare ci\uf2, \ue8 necessario definire i vincoli operativi del sistema e sviluppare un sistema di controllo in grado di rispettarli, ottimizzando al tempo stesso le prestazioni dell\u2019impianto. Inoltre, l\u2019affidabilit\ue0 dei sistemi ibridi pu\uf2 essere migliorata grazie all\u2019implementazione di strumenti diagnostici e di procedure per prevenire il pompaggio del compressore. La parte finale della tesi \ue8 mirata allo studio di tali strumenti, al loro sviluppo e alla loro integrazione con il sistema di controllo. Tutte le attivit\ue0 presentate in questa tesi sono state svolte facendo affidamento su strumenti di simulazione. Ci\uf2 \ue8 stato possibile grazie alla collaborazione tra il Laboratorio di Matematica Applicata, Simulazione e Modellistica Matematica e il Thermochemical Power Group dell\u2019Universit\ue0 degli Studi di Genova. Dopo aver presentato il layout del sistema a fuel cell con turbocompressore, un dettagliato modello stazionario dell\u2019impianto sviluppato in Matlab\uae-Simulink\uae \ue8 stato utilizzato per progettare una strategia, basata sul controllo di valvole installate sull\u2019impianto, in grado di rispettare tutti i suoi vincoli operativi. Successivamente, \ue8 stata svolta un\u2019analisi di prestazioni in off-design, considerando allo stesso tempo diverse condizioni di carico di potenza e di temperatura ambiente. Tale analisi \ue8 stata utilizzata per confermare l\u2019efficacia della strategia di controllo proposta, e per valutare le capacit\ue0 del sistema con turbocompressore. Successivamente \ue8 stato creato un modello dinamico utilizzando lo strumento TRANSEO, in modo da studiare il comportamento del sistema durante i transitori. Avendo adottato una strategia di controllo basata sulla valvola di cold bypass, \ue8 stata analizzata la risposta del sistema ad una sua apertura a gradino, al fine di progettare un sistema di controllo efficace e reattivo, in grado di mantenere la massima temperatura di cella costante e, allo stesso tempo, di rispettare i vincoli del sistema. Sono stati progettati quattro diversi controllori, che successivamente sono stati testati su due diversi scenari di variazione di carico e confrontati sulla base di vari parametri operativi. La parte finale della tesi ha riguardato lo sviluppo di innovativi strumenti che possano aumentare l\u2019affidabilit\ue0 dei sistemi ibridi a fuel cell a ossidi solidi, in particolare tecniche di prevenzione del pompaggio e sistemi di diagnostica basati su reti Bayesiane. Un modello semplificato del sistema con turbocompressore \ue8 stato sviluppato in TRANSEO e sono state testate diverse tecniche di prevenzione del pompaggio: condizionamento del flusso d\u2019aria, iniezione di acqua, ricircolo e bleed, installazione di un eiettore all\u2019imbocco del compressore. Le soluzioni pi\uf9 efficaci sono state integrate con il controllore del sistema ibrido e sono state testate durante un transitorio per evitare che il punto operativo del compressore si avvicinasse al pompaggio. Infine, grazie ad una collaborazione tra l\u2019Universit\ue0 degli Studi di Genova e la M\ue4lardalens H\uf6gskola di V\ue4ster\ue5s, in Svezia, sono state sviluppate delle reti Bayesiane per la diagnostica di sistemi ibridi a fuel cell a ossidi solidi con microturbina a gas. Questa attivit\ue0 \ue8 stata svolta simulando il sistema su Matlab\uae-Simulink\uae e creando le reti Bayesiane su Hugin Expert. Due sistemi di diagnostica, uno per la microturbina e uno per la fuel cell, sono stati sviluppati e testati in condizioni stazionarie. Il secondo \ue8 stato anche testato in condizioni dinamiche e integrato con il sistema di controllo per prevenire l\u2019usura della cella. In conclusione, questa tesi ha messo in luce il grande potenziale dei sistemi ibridi SOFC-turbocompressore, mostrando la loro alta efficienza in un ampio intervallo di condizioni operative in termini di carico elettrico e temperatura ambiente. La tesi ha anche dimostrato che \ue8 possibile garantire il corretto funzionamento di questi sistemi durante diversi scenari transitori, implementando controllori a cascata progettati per agire sulla valvola di bypass freddo per controllare la massima temperatura della cella. Per quanto riguarda la possibilit\ue0 di migliorare l\u2019affidabilit\ue0 di tali sistemi, le tecniche basate sul ricircolo del compressore sono risultate essere le pi\uf9 efficaci per allontanare il sistema da una condizione di pompaggio. I risultati delle simulazioni mostrano come la loro integrazione con strumenti di monitoraggio possa prevenire diverse situazioni di pericolo. La parte finale della tesi ha mostrato come il deterioramento dei sistemi ibridi a SOFC possa essere limitato grazie a reti Bayesiane, che sono state utilizzate per diagnosticare accuratamente le condizioni di un sistema SOFC-microturbina a gas, ma potrebbero ugualmente essere applicate su impianti con turbocompressore.The growing awareness on climate change and pollution has brought to national and international policies aimed at promoting the development of innovative and environmentally sustainable energy systems. Among these systems, fuel cells are one of the most promising technologies, characterized by high energy conversion efficiencies and low emissions. In particular, hybrid systems based on the integration of a high temperature fuel cell with turbocharger-derived machinery have drawn the interest of academia and industry over the past decades. However, the complexity, fragility and high cost of these plants have slowed down their development, and only a few big companies were able to build complete prototypes. The technological challenges faced by the scientific community have highlighted the importance of simulations to design, test, control and analyse fuel cell hybrid systems. Based on this experience, this thesis wants to expand the current knowledge on solid oxide fuel cell hybrid systems, with a particular focus on an innovative small-scale biofueled turbocharged layout, which was introduced recently within the Bio-HyPP European project. The main goal of this thesis is to determine if this kind of system can be a viable alternative to micro gas turbine-based systems, analysing its steady-state and transient behaviour in various operating conditions. To do this, it is necessary to define the system operative constraints, and to develop a control system capable of ensuring their compliance, while optimizing the plant performance. The possibility of increasing the reliability of solid oxide fuel cell hybrid systems is finally investigated, considering the implementation of surge prevention techniques and diagnostic tools. All these activities strongly relying on simulation tools. This was possible thanks to the collaboration between the Laboratory of Applied Mathematics, Simulation and Mathematical Modelling with the Thermochemical Power Group of the University of Genoa. After introducing the layout of the turbocharged fuel cell system, a detailed steady-state model of the plant is developed in Matlab\uae-Simulink\uae and used to design a strategy, based on the control of valves installed on the plant, able to comply with its many operative constraints. Then, an off-design performance analysis of the system is performed, considering simultaneously various conditions of power load and ambient temperature. This analysis is used to confirm the effectiveness of the proposed control strategy and to assess the capabilities of the turbocharged system. A dynamic model is created using the TRANSEO tool to study the transient behaviour of the system. Having adopted a control strategy based on the cold bypass valve, the response of the system to a valve opening step change is analysed in order to design an effective and responsive control system, able to keep the fuel cell maximum temperature constant while complying with the system constraints. Four different controllers are designed, tested on two different load variation scenarios and compared on the basis of many parameters. The final part of the thesis regards the development of innovative tools aimed at improving the reliability of solid oxide fuel cell hybrid system, in particular surge prevention techniques and Bayesian belief network-based diagnosis systems. A simplified dynamic model of the turbocharged SOFC system is developed in TRANSEO, and various surge prevention techniques are tested on it: intake air conditioning, water spray at compressor inlet, air bleed and recirculation, and installation of an ejector at the compressor intake. The most effective procedures are integrated with the controller of the hybrid system and tested during a transient scenario to prevent the compressor operative point from approaching a surge condition. Bayesian belief networks aimed at diagnosing the status of SOFC hybrid systems are developed thanks to a collaboration between the University of Genoa and the M\ue4lardalens H\uf6gskola of V\ue4ster\ue5s, Sweden. A micro gas turbine \u2013 solid oxide fuel cell system is considered for this study, but the methodology could be easily extended to turbocharged plants. The activity is carried out simulating the system on Matlab\uae-Simulink\uae and designing the Bayesian networks on Hugin Expert. Two different diagnosis systems, one for the turbomachinery and one for the fuel cell stack, are developed and tested on stationary conditions. The second one is also tested during transients and integrated with the control system to prevent degradation of the fuel cells. In conclusion, this thesis highlighted the great potential of turbocharged SOFC hybrid systems, showing high energy conversion efficiencies in a wide operative range in terms of load and ambient conditions. It also showed that the proper operation of the system is possible during various transient scenarios, implementing cascade controllers designed to act on a cold bypass valve to control the SOFC maximum temperature. Regarding the possibility of improving the reliability of these systems, surge prevention techniques based on compressor recirculation appeared as the most effective ones. Simulation results suggest that their integration with a surge precursors detection tool could avoid the occurrence of many potentially dangerous scenarios. The final part of this thesis showed that the durability of SOFC hybrid systems could be further improved thanks to Bayesian belief networks, which were proved to effectively diagnose the status of SOFC-MGT systems but could be applied to turbocharged plants as well

Profitability, reliability and condition based monitoring of LNG floating platforms: a review

The efficiency and profitability of Floating, Production, Storage and Offloading platform (FPSO) terminals depends on various factors such as LNG liquefaction process type, system reliability and maintenance approach. This review is organized along the following research questions: (i) what are the economic benefit of FPSO and how does the liquefaction process type affect its profitability profile?, (ii) how to improve the reliability of the liquefaction system as key section? and finally (iii) what are the major CBM techniques applied on FPSO. The paper concluded the literature and identified the research shortcomings in order to improve profitability, efficiency and availability of FPSOs

Waste heat driven turbo-compression cooling

2018 Spring.Includes bibliographical references.Waste heat recovery systems utilize exhaust heat from power generation systems to produce mechanical work, provide cooling, or create high temperature thermal energy. One waste heat recovery application is to use the exhaust heat from a Natural Gas Combined Cycle Power Plant (NGCC) to drive a heat activated cooling system that can offset a portion of the plant condenser load. There are several heat activated cooling systems available including absorption, adsorption, ORVC, and ejector, but each has disadvantages. One system that can overcome the disadvantages of typical heat activated cooling systems is a turbo-compression cooling system (TCCS). In this system, the exhaust heat enters an organic Rankine cycle at the boiler and vaporizes the fluid that passes through a turbine. The turbine power is directly transferred to a compressor via a hermetically sealed shaft that is made possible by a magnetic coupling. The compressor operates a vapor-compression system which provides a cooling effect in the evaporator. The hermetic seal between the turbine and compressor allows for two separate fluids on the power and cooling cycles, which maximizes the efficiency of the turbine and compressor simultaneously. This study presents a thermodynamic modeling approach that makes system performance predictions for the baseline design case, and for off-design performance conditions. The off-design modeling approach uses turbo-compressor performance maps and a heat exchanger UA scaling methodology to accurately simulate system operation for a broad range of temperatures and cooling loads. A 250 kWth cooling capacity TCCS was constructed and tested to validate the modeling approach. The test facility simulates a 138:1 scaled NGCC power plant configuration in which the TCCS extracts 106°C waste heat from the flue gases and produces a cooling effect that offsets a portion of the NGCC condenser load. The design target for the test facility was to achieve a COP of 2.1 while chilling water from 17.2°C to 16°C at an ambient temperature of 15°C. Although the final design point was not tested for this study due to facility limitations, the off-design performance methodology was utilized to predict the performance for an ambient condition of 27.5°C and power and cooling cycle mass flow rate range between 0.35 kg s-1 - 0.5 kg s-1 and 0.65 kg s-1 – 0.85 kg s-1, respectively. The comparison between the experimental and modeling data suggested strong correlation over the data range presented with a maximum error in COP of only 2.0% among the selected data points. Future experimental data over a larger range of ambient temperatures and system conditions is suggested to further validate the system modeling. Regardless, the results in the present study show that the TCCS compares favorably with other heat activated cooling systems

Direct solar air heating in linear concentrating collectors assisted by a turbocharger for industrial processes: theoretical analysis and experimental characterization

Mención Internacional en el título de doctorEnergy demand of industry has a relevant share of global energy consumption. The larger portion of industrial demand is heating, mainly provided from fossil fuels. The concerns about pollutant and greenhouse gas emissions, together with the fossil fuels scarcity encourage the research efforts toward environmentally sustainable energy sources and among them, solar energy is widely available. Among solar thermal technologies, linear concentrating collectors represent a suitable solution for providing industrial process heat in the medium temperature range. A heat transfer fluid, as thermal oil, or water, is generally adopted to evacuate heat from the solar receivers and to deliver it to thermal processes, contributing to complexity, cost, and even environmental impact. In this thesis the direct air heating inside concentrating solar collector is investigated as a promising solution for industrial processes requiring hot air in the medium temperature range, aiming at low installation and maintenance costs. Although uncommon, the theoretical analysis carried out revealed the feasibility of direct air heating at atmospheric pressure either in a parabolic trough and linear Fresnel collectors within a limited range of design and operating conditions. The high pumping power required to blow air through the receivers arises as one of the main constraints, becoming unsustainable at medium and large scale. To overcome this limitation, an innovative layout is proposed using an automotive turbocharger to configure an original open-to-atmosphere solar Brayton cycle with null power efficiency. The compressor increases the air pressure before solar heating inside the receivers, minimizing the pumping power consumption. The turbine placed at the receiver outlet recovers the compressing and the pumping power, releasing hot air at between 300 °C and 400 °C for its usage in the thermal process. The maximum allowable temperature of evacuated standard receivers, indicated as 600 °C by most of the manufacturers, limits the inlet turbine temperature. No substantial mechanical excess of power at the common turbine and compressor shaft is expected. Instead, turbocharger freewheeling enables to blow air through the solar receivers without auxiliary energy consumption, eventually delivering the hot air with an overpressure for pumping to the user. To support the proposal, a first small-scale experimental prototype of the turbo-assisted solar air heater is designed and installed, using Linear Fresnel collectors and a low-capacity turbocharger. The experimental results allow the thermal and mechanical characterization of the solar collector and the turbocharger, besides tuning and validating the numerical model implemented. They corroborate the practical viability of the concept and indicates relevant features and critical aspects for scaling up to industrial size. A detailed quasi-steady numerical model is developed, including technical features of commercial linear Fresnel collectors and off-the-shelf turbochargers. Daily and yearly assessments of several medium-scale facilities are obtained considering the typical meteorological year of the selected location. The results allow identifying the relevant design and operating parameters and their effect on the performances of the turbo-assisted solar air heater. By combining theoretical and experimental approaches this thesis establishes the framework for the development, design, optimization, and operation of the innovative technology proposed, opening the possibility to its application to several industrial sectors.La demanda energética de la industria tiene una participación relevante en el consumo energético mundial. La mayor parte de la demanda industrial es calor, principalmente obtenido a partir de combustibles fósiles. Las preocupaciones sobre las emisiones de gases contaminantes y de efecto invernadero, junto con la escasez de combustibles fósiles, fomentan los esfuerzos de investigación hacia fuentes de energía ambientalmente sostenibles, entre las cuales, la energía solar se encuentra ampliamente disponible. Entre las tecnologías solares térmicas, los colectores de concentración lineal representan una solución adecuada para proporcionar calor de proceso industrial en el rango de media temperatura. Generalmente se adopta un fluido caloportador, como aceite térmico o agua, para evacuar el calor de los receptores solares y entregarlo al proceso térmico, contribuyendo a la complejidad, costo, e incluso impacto ambiental. En esta tesis se investiga el calentamiento directo de aire en colectores solares de concentración como una solución prometedora para procesos industriales que requieran aire caliente en el rango de media temperatura, con el objetivo de reducir los costos de instalación y mantenimiento. Aunque poco común, el análisis teórico realizado revela la viabilidad del calentamiento directo del aire a presión atmosférica tanto en colectores cilindro-parabólicos como en colectores Fresnel lineales dentro de un rango limitado de condiciones de diseño y operación. La alta potencia de bombeo necesaria para soplar aire a través de los receptores es una de las principales limitaciones, volviéndose insostenible a mediana y gran escala. Para superar esta limitación, se propone un diseño innovador que utiliza un turbocompresor de automóvil para configurar un ciclo Brayton solar abierto a la atmósfera con una eficiencia energética nula. El compresor aumenta la presión del aire antes del calentamiento solar en los receptores, minimizando el consumo de energía de bombeo. La turbina, colocada en la salida del receptor, recupera la potencia de compresión y bombeo, liberando aire caliente entre 300 °C y 400 °C para su uso en el proceso térmico. La temperatura máxima permitida de los receptores estándar evacuados, indicada como 600 °C por la mayoría de los fabricantes, limita la temperatura de entrada de la turbina, por lo que no se espera un exceso mecánico de potencia sustancial en la turbina común y el eje del compresor. En cambio, el turbocompresor permite soplar aire a través de los receptores solares sin consumo de energía auxiliar de bombeo. Si existiera un exceso, estará disponible para el bombeo hasta el usuario. Para apoyar la propuesta, se diseña e instala un primer prototipo experimental de pequeña escala del calentador de aire solar turbo-asistido, utilizando colectores lineales Fresnel y un turbocompresor de baja capacidad. Los resultados experimentales permiten la caracterización térmica y mecánica del colector solar y el turbocompresor, además de ajustar y validar los modelos numéricos implementados. Los ensayos corroboran la viabilidad práctica del concepto e indican características relevantes y aspectos críticos para escalar al tamaño industrial. Se desarrolla un modelo numérico cuasi-estacionario detallado, que incluye las características técnicas de los colectores Fresnel lineales comerciales y los turbocompresores estándar. Se obtienen evaluaciones diarias y anuales de varias instalaciones de mediana escala considerando el año meteorológico típico de la ubicación seleccionada. Los resultados permiten identificar los parámetros de diseño y funcionamiento relevantes y su efecto sobre el rendimiento del calentador de aire solar turbo-asistido. Combinando enfoques teóricos y experimentales, esta tesis establece el marco para el desarrollo, diseño y operación de la tecnología innovadora propuesta, abriendo la posibilidad de su aplicación a varios sectores industriales, apuntando a la descarbonización y transición industrial sustentable.This research was supported by the Industrial Ph.D. project “Producción directa de aire a alta temperatura y a presión turboalimentada en colectores solares de concentración” (BOCM Reference IND2017/AMB7769) funded by “Comunidad de Madrid”, Spain (Orden 3779/2017 of October 17th 2017, by “Consejero de Educación e Investigación”, pubblished on “BOCM. 252, of October 23th 2017.)Programa de Doctorado en Ingeniería Mecánica y de Organización Industrial por la Universidad Carlos III de MadridPresidente: Eduardo A. Rincón Mejía.- Secretario: José Miguel Cardemil Iglesias.- Vocal: José González Aguilaré Migue