This thesis is focused on the design of steam boiler like a supplement for cogeneration unit of biogas plant. The main idea is to use a waste heat from the exhaust gasses to produce a technological steam of required parameters. The thesis contains of a calculation an amount of the heat in exhaust gasses and a heat exchange surface. An Aerodynamic loss and a wall thickness of the boilers are verified by strength calculation in the next parts of this thesis. At the end of this thesis are made projection drawings and diagram, which are made of the calculations.

[ES] Las regulaciones medioambientales imponen el uso de refrigerantes con cada vez menor Poder de Calentamiento Atmosférico (PCA), y obligan a que la búsqueda de refrigerantes alternativos a los actuales sea una necesidad real acorde a las tendencias del sector. El paso de los refrigerantes actuales a la utilización de refrigerantes alternativos no es inmediato ni mucho menos sencillo. La complejidad a nivel tecnológico es muy elevada, dado que el uso de un nuevo refrigerante exige diseñar y desarrollar de cero todos los componentes del circuito, puesto que poseen unas especificaciones y requerimientos de funcionamiento totalmente diferentes de los que poseen los refrigerantes actuales. La motivación principal de la tesis doctoral es la de plantear lo primeros pasos para el desarrollo de un equipo de bomba de calor para climatización que utilice un refrigerante con un bajo índice de PCA como el propano, en sustitución del que emplea la unidad actualmente (R410A), reduciendo así el impacto medioambiental del equipo y mejorando sus propiedades. Todo esto se encuentra incluido en los siguientes puntos: - Anticipar el cambio de tecnología necesario para el cumplimiento de la regulación F-GAS, asegurando menores emisiones para el medio ambiente y manteniendo la eficiencia energética actual mediante el desarrollo de equipos de bomba de calor con capacidad de modulación y con propano como fluido refrigerante. - Desarrollar herramientas de modelado y simulación para las diferentes plataformas objetivo. - Obtener conocimiento específico sobre el comportamiento de la bomba de calor mediante el análisis experimental con prototipos funcionales bajo las condiciones de trabajo especificadas, con la intención de conocer su funcionamiento, además de sus limitaciones, exigencias prácticas y sus necesidades de control. - Facilitar el diseño y desarrollo industrial de nuevos equipos de climatización mediante las herramientas de simulación y los datos experimentales obtenidos a través de prototipos funcionales. Motivada por este nuevo escenario, esta tesis se centra en estudiar qué posibilidades existen en medio-largo plazo en el desarrollo de bombas de calor para ajustarse a la regulación existente, no solo en cuanto a requerimientos ambientales sino también energéticos. Para ello, el primer paso ha sido el de realizar una sustitución directa del refrigerante original de la unidad aerotérmica, el R410A, por R290 para establecer el punto de referencia y poder conocer qué prestaciones es capaz de desarrollar esa misma unidad sin un rediseño del circuito de refrigerante. Tras esta primera evaluación, se ha llevado a cabo un estudio teórico de distintas configuraciones de circuito frigorífico con propano para evaluar las ventajas e inconvenientes entre ellas, con el objetivo de elegir la que mejor se ajuste al cumplimiento de los objetivos marcados. Este estudio se ha efectuado en tres ámbitos distintos: calefacción a baja temperatura, alta temperatura y condiciones de alta temperatura de impulsión de agua hasta 75ºC. En todos ellos, el resultado principal que se ha considerado ha sido el de eficiencia, lo que ha permitido obtener un orden de las tipologías estudiadas en función de los resultados obtenidos. A pesar de esto, esta evaluación también ha puesto de manifiesto otra característica intrínseca a cada uno de ellos como es su límite de funcionamiento en relación con la máxima temperatura de impulsión de calefacción. Tras ello, se ha construido un prototipo de bomba de calor funcional completo para ejecutar la fase experimental, que incluya hasta tres de las tipologías evaluadas en la fase teórica previa, para que, con todos los ensayos pertinentes, los resultados permitan seleccionar la tipología de circuito de refrigerante que se integre en un prototipo final. Este prototipo permitirá caracterizar el funcionamiento del sistema tanto para una plataforma aire-agua, como para una plataforma salm / [CA] Les regulacions mediambientals imposen l'ús de refrigerants amb cada vegada menor Poder d'Escalfament Atmosfèric (PCA), i obliguen a que la recerca de refrigerants alternatius als actuals sigui una necessitat real d'acord amb les tendències del sector. El pas dels refrigerants actuals a l'utilització de refrigerants alternatius no és immediat ni tampoc fàcil. La complexitat a nivell tecnològic és molt elevada, ja que l'ús d'un nou refrigerant exigeix dissenyar i desenvolupar de zero tots els components del circuit, tenint en conta que tenen unes especificacions i requeriments de funcionament totalment diferents dels que posseeixen els refrigerants actuals. La motivació principal de la tesi doctoral és la de plantejar el primers passos per al desenvolupament d'un equip de bomba de calor per a climatització que utilitzi un refrigerant amb un baix índex de PCA com el propà, en substitució del què empra la unitat actualment (R410A), reduint així l'impacte mediambiental de l'equip i millorant les seves propietats. Tot això es troba inclòs en els següents punts: - Anticipar el canvi de tecnologia necessari per al compliment de la regulació F-GAS, assegurant menors emissions per al medi ambient i mantenint l'eficiència energètica actual mitjançant el desenvolupament d'equips de bomba de calor amb capacitat de modulació i amb propà com a fluid refrigerant. - Desenvolupar ferramentes de modelatge i simulació per a les diferents plataformes objectiu. - Obtenir el coneixement específic sobre el comportament de la bomba de calor mitjançant l'anàlisi experimental amb prototips funcionals en les condicions de treball especificades, amb la intenció de conèixer el seu funcionament, a més de les seues limitacions i exigències pràctiques i les seues necessitats de control. - Facilitar el disseny i desenvolupament industrial de nous equips de climatització mitjançant les ferramentes de simulació i les dades experimentals obtingudes a través de prototips funcionals. Motivada per aquest nou escenari, aquesta tesi es centra a estudiar quines possibilitats hi ha al mitjá-llarg termini en el desenvolupament de bombes de calor per a ajustar-se a la regulació existent, no només en relació amb el requeriments ambientals sinó també energètics. Per això, el primer pas ha sigut el de fer una substitució directa del refrigerant original de la unitat aerotèrmica, el R410A, per R290 per establir el punt de referència i poder conèixer quines prestacions és capaç de desenvolupar aquesta mateixa unitat sense un redisseny del circuit de refrigerant. Després d'aquesta primera avaluació, s'ha dut a terme un estudi teòric de diferents configuracions de circuit frigorífic amb propà per avaluar els avantatges i inconvenients entre elles, amb l'objectiu de triar la que millor s'ajusti a l'acompliment dels objectius marcats. Aquest estudi s'ha efectuat en tres àmbits diferents: calefacció a baixa temperatura, alta temperatura i condicions d'alta temperatura d'impulsió d'aigua fins a 75ºC. En tots ells, el resultat principal que s'ha considerat ha sigut el d'eficiència, el que ha permès obtenir un ordre de les tipologies estudiades en funció dels resultats obtinguts. Tot i això, aquesta avaluació també ha posat de manifest una altra característica intrínseca a cada un d'ells com és el seu límit de funcionament en relació amb la màxima temperatura d'impulsió de calefacció. Després d'això, s'ha construït un prototip de bomba de calor funcional complet per executar la fase experimental, que inclogui fins a tres de les tipologies avaluades en la fase teòrica prèvia, perquè, amb tots els assajos pertinents, els resultats permeten seleccionar la tipologia de circuit de refrigerant que s'integri en un prototip final. Aquest prototip permetrà caracteritzar el funcionament de sistema tant per a una plataforma aire-aigua, com per a una plataforma salmorra-aigua, a través del canvi del bescanviador / [EN] Environmental regulations impose the use of refrigerants with less and less Global Warming Potential (GWP), and force that the search for alternative refrigerants in order to substitute the current ones is a real need according to the trends in the sector. The transition from current refrigerants to the use of alternative refrigerants is neither immediate nor simple. The complexity at the technological level is very high, since the use of a new refrigerant requires a new design and a new development for all the components along the refrigerant circuit, since they may have totally different specifications and operating requirements compared to the traditional refrigerants. The main motivation of this thesis is to present the initial stages concerning the development of a heat pump unit for space heating that uses a lo GWP refrigerant like propane, replacing the current refrigerant of the unit (R410A), leading to a reduction of the environmental impact of this equipment and improving its properties. All this has been included on the following points: - Anticipate the required technology change to be compliant with the F-GAS regulation, ensuring low-impact emissions to the atmosphere and keeping a similar energy efficiency through the development of heat pump units with heating capacity modulation and with propane as refrigerant. - Develop modelling and simulation tools for the different platforms approaches. - Obtain specific knowledge about the heat pump performance through experimental analysis with functional prototypes under the specified working conditions, with the aim of acquiring knowledge not only about its operation, but also about its limitations, practical requirements and its control needs. - Contribute to the industrial design and development of new space heating equipment using simulation tools and experimental data obtained through functional prototypes. Motivated by this new scenario, this thesis focuses on studying the available options in the medium-long term concerning the heat pump development in order to be compliant with the applicable regulations, not only in terms of environmental requirements but also energy requirements. To do this, the first step has been related to carry out a direct replacement of the original refrigerant of the aerothermal unit, R410A, with R290 to establish the reference point and to be able to know the performance of the original unit without considering a redesign of the refrigerant circuit. After this initial evaluation, a theoretical study of different refrigerant circuit configurations with propane has been carried out with the purpose of evaluating the advantages and disadvantages among them, in order to choose the one that fulfils the performance requirements the best. This study has been executed in three different areas: low heating temperature, high heating temperature and high water flow temperature conditions up to 75ºC. In all of them, the main result considered has been the efficiency, which has enabled to obtain a priority order based on the results obtained. Despite this, this evaluation has also revealed another attached feature, such as their operating limit in relation to the maximum heating flow temperature. After that, a complete functional heat pump prototype has been built to execute the experimental phase, which includes up to three of the typologies evaluated in the previous theoretical phase, so that, with all the corresponding tests, the results allow to select the typology of refrigerant circuit to be integrated into a final prototype. This prototype has also enabled the performance characterization for two different types of platforms, air-water and brine-water, by changing of the corresponding exchanger using cutting valves. In parallel to this, a certain phenomenon related to the behaviour of the refrigerant have been studied through different operating conditions for each typology as well as the proper measures to improve the system control. As / López Juárez, E. (2021). Desarrollo de una bomba de calor doméstica que usa propano como fluido de trabajo [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/174570 / TESIS

Thesis (MScEng)--Stellenbosch University, 2012 / ENGLISH ABSTRACT: Through many years of research, a number of production schemes have been developed for converting lignocellulosic biomass into transport fuels. These technologies have been assessed through a number of techno-economic studies for application in a particular context in terms of the technical and economic feasibility. However, previous studies using these methods have tended to lack vigour in various aspects. Either the energy efficiency of the processes were not maximised through adequate heat integration, or a competing technology which existed was not considered. From an economic perspective, the financial models would often lack the vigour to account for the risk and uncertainty that is inherent in the market prices of the commodities. This phenomenon is especially relevant for the biofuel industry that faces the full fledge of uncertainties experienced by the agricultural sector and the energy sector. Furthermore, from an environmental perspective, the techno-economic studies had often ignored the environmental impacts that are associated with biofuel production. Thus, a comparative study could have favoured an option due to its economic feasibility, while it could have had serious environmental consequences. The aim of this study was to address these issues in a South African context, where biofuels could be produced from sugarcane bagasse. The first step would be to modify an existing simulation model for a bioethanol scenario that operates with a Separate Hydrolysis and Fermentation (SHF process) configuration into a second processing scenario that operates with a Simultaneous Saccharification and Fermentation (SSF process) configuration using reliable experimental data. The second step was to ensure that the maximum energy efficiency of each scenario was realised by carrying out pinch point analysis as a heat integration step. In contrast to these biological models is the thermochemical model that converts bagasse to gasoline and diesel via gasification, Fischer-Tropsch synthesis and refining (GFT process). While there were no significant advances in technology concerning this type of process, the energy efficiency was to be maximised with pinch point analysis. The GFT process obtained the highest energy efficiency of 50.6%. Without the affects of pinch point technology, the efficiency dropped to 46%, which thus emphasises the importance of heat integration. The SSF had an efficiency of 42.8%, which was superior to that of the SHF at 39.3%. This resulted from a higher conversion of biomass to ethanol in the SSF scenario. Comparing the SHF model to an identical model found in literature that did not have pinch point retrofits, this study showed lower efficiency. This arose because the previous study did not account for the energy demands of the cold utility systems such as the cooling tower operation, which has been shown in this study to account for 40% of the electrical energy needs. The economic viability of all three processes was assessed with Monte Carlo Simulations to account for the risks that the fluctuations in commodity prices and financial indices pose. This was accomplished by projecting the fluctuations of these parameters from samples of a historical database that has been transformed into a probability distribution function. The consequences were measured in terms of the Net Present Value (NPV) and Internal Rate of Return (IRR) for a large number of simulations. The results of these variables were aggregated and were then assessed by testing the probability that the NPV<0, and that the IRR recedes below the interest rate of 12.64%. The investment was thus deemed unfeasible if these probabilities were greater than 20%. Both biological models were deemed profitable in terms of this standard. The probabilities were 13% for the SSF and 14% for the SHF. The GFT process however was deemed completely unfeasible because the probability that the NPV<0 was 78%. Given that the GFT process had the highest energy efficiency, this result arises mainly because the capital investment of 140,000USD/MWHHV of biomass energy input is to enormous for any payback to be expected. The environmental footprint of each process was measured using Life Cycle Assessments (LCAs). LCAs are a scientifically intricate way of quantifying and qualifying the effects of a product or process within a specified boundary. The impacts are assessed on a range of environmental issues, such as Global Warming, Acidification, Eutrophication and Human toxicity. Furthermore, if the project under concern has multiple output products, then the impacts are distributed between the output products in proportion to the revenue that each generates. The impacts were either relative to the flow of feedstock, which was 600MW of bagasse, or to the functional unit, which was the amount of fuel required to power a standard vehicle for a distance of 1 kilometre. In either case, the GFT scenario was the least burdening on the environmental. This was expected because the GFT process had the highest energy efficiency and the process itself lacked the use of processing chemicals. Relative to the feedstock flow, the SSF was the most environmentally burdening scenario due to the intensive use of processing chemicals. Relative to the functional unit, the SHF was the most severe due to its low energy efficiency. Thus, the following conclusions were drawn from the study:  The GFT is the most energy and environmentally efficient process, but it showed no sign of economic feasibility. iv  There is no significant difference in the economic and environmental evaluation of the SSF and SHF process, even though the SSF is considered to be a newer and more efficient process. The major cause of this is because the setup of the SSF model was not optimised. / AFRIKAANSE OPSOMMING: Deur baie jare van navorsing is ‘n aantal produksie-skemas vir die omskakeling van lignosellulose biomassa na vloeibarebrandstof ontwikkel. Hierdie tegnologië is geassesseer ten opsigte van die tegniese en ekonomiese haalbaarheid deur middel van tegno-ekonomiese studies in bepaalde tekste. Tog het hierdie vorige studies besliste beperkings gehad. Of die energie-doeltreffendheid van die proses is nie gemaksimeer deur voldoende hitte-integrasie nie, of 'n mededingende tegnologie wat bestaan is nie oorweeg nie. Vanuit 'n ekonomiese perspektief, was die finansiële modelle dikwels nie die omvattend genoeg om rekening te hou met die risiko en onsekerheid wat inherent is in die markpryse van die kommoditeite nie. Hierdie verskynsel is veral relevant vir die biobrandstof bedryf wat die volle omvang van onsekerhede ervaar waaraan die landbousektor en die energiesektoronderhewig is. Verder het die tegno-ekonomiese studies dikwels die omgewingsimpakte wat verband hou met biobrandstofproduksie geïgnoreer. Dus kon ‘n opsie deur die ekonomiese haalbaarheid bevoordeel word, ten spyte van die ernstige omgewingsimpakte wat dit kon inhou. Die doel van hierdie studie was om hierdie kwessies aan te spreek in 'n Suid-Afrikaanse konteks, waar biobrandstof uit suikerriet bagasse geproduseer kan word. Die eerste stap was om 'n bestaande simulasiemodel vir 'n bio-scenario wat met Afsonderlike Hidroliese en Fermentasie (SHF proses) stappe werk, te modifiseer vir 'n tweede verwerking scenario wat met 'n gelyktydige Versuikering en Fermentasie (SSF proses) konfigurasie werk. Die verandering is gedoen deur die gebruik van betroubare eksperimentele data. Die tweede stap was om te verseker dat elke scenario die maksimum energie-doeltreffendheid het, deur 'n hitte-integrasie stap, wat gebruik maak van “pinch-point” analise. In teenstelling met hierdie biologiese modelle, is daar die thermochemiese roete waar petrol en diesel van bagasse vervaardig word via vergassing, Fischer-Tropsch-sintese en rafinering (GFT proses). Daar was geen betekenisvolle vooruitgang in tegnologie vir hierdie proses nie, maar die energie-doeltreffendheid is gemaksimeer word deur energie-integrasie. Die GFT proses toon die hoogste energie-doeltreffendheid van 50,6%. Sonder die invloed van energie-integrasie het die doeltreffendheid gedaal tot 46%, wat dus die belangrikheid van hitte-integrasie beklemtoon. Die SSF het 'n effektiwiteit van 42,8% gehad, wat beter was as dié 39,3% van die SHF opsie. Hierdie hoër effektiwiteit wasas gevolg van die hoër omskakeling van biomassa na etanol in die SSF scenario. Die energie doeltreffendheid vir die SHF-model was laer as met 'n identiese model (sonder energie-integrasie) wat in die literatuur gevind wat is. Dit het ontstaan omdat die vorige studie nie 'n volledig voorsiening gemaak het met die energie-eise van die verkillingstelselsnie, wat tot 40% van die elektriese energie behoeftes kan uitmaak. Die ekonomiese lewensvatbaarheid van al drie prosesse is bepaal met Monte Carlo simulasies om die risiko's wat die fluktuasies in kommoditeitspryse en finansiële indekse inhou, in berekening te bring. Hierdie is bereik deur die projeksie van die fluktuasies van hierdie parameters aan die hand van 'n historiese databasis wat omskep is in 'n waarskynlikheid verspreiding funksie. Die gevolge is gemeet in terme van die netto huidige waarde (NHW) en Interne Opbrengskoers (IOK) vir 'n groot aantal simulasies. Die resultate van hierdie veranderlikes is saamgevoeg en daarna, deur die toets van die waarskynlikheid dat die NPV <0, en dat die IRR laer as die rentekoers van 12,64% daal, beoordeel. Die belegging is dus nie realiseerbaar geag as die waarskynlikhede meer as 20% was nie. Beide biologieseprosesse kan as winsgewend beskou word in terme van bostaande norme. Die waarskynlikhede was 13% vir die SSF en 14% vir die SHF. Aangesien die NHW van die GFT-proses onder 0 met ‘n waarskynlikheid van 78% is, is die opsie as nie-winsgewend beskou. Gegewe dat die GFT-proses die hoogste energie-doeltreffendheid het, is die resultaat hoofsaaklik omdat die kapitale belegging van 140,000 USD / MWHHV-biomassa energie-inset te groot is, om enige terugbetaling te verwag. Die omgewingsvoetspoor van elke proses is bepaal deur die gebruik van Lewens Siklus Analises (“Life Cycle Assessments”) (LCAS). LCAS is 'n wetenskaplike metodeom die effek van ‘n produk of proses binne bepaalde grense beide kwalitatief en kwantitatief te bepaal. Die impakte word beoordeel vir 'n verskeidenheid van omgewingskwessies, soos aardverwarming, versuring, eutrofikasie en menslike toksisiteit. Voorts, indien die projek onder die saak verskeie afvoer produkte het, word die impakte tussen die afvoer produkte verdeel, in verhouding tot die inkomste wat elkeen genereer. Die impak was met of relatief tot die vloei van roumateriaal (600MW van bagasse), of tot die funksionele eenheid, wat die hoeveelheid van brandstof is om 'n standaard voertuig aan te dryf oor 'n afstand van 1 kilometer. In al die gevalle het die GFT scenario die laagste belading op die omgewing geplaas. Hierdie is te verwagte omdat die GFT proses die hoogste energie-doeltreffendheid het en die proses self nie enige addisionele chemikalieë vereis nie. Relatief tot die roumateriaal vloei, het die SSF die grootse belading op die omgewing geplaas as gevolg van die intensiewe gebruik van verwerkte chemikalieë. Relatief tot die funksionele eenheid, was die SHF die swakste as gevolg van sy lae energie-doeltreffendheid.