Design and Operation of a Polygeneration System in Spanish Climate Buildings under an Exergetic Perspective

This work defines and analyzes the performance of a polygeneration system in five different locations in Spain to maintain the thermal comfort and air quality of an office building. The facility is based on a chiller and a CHP engine with PV panels that provide almost all the electricity demand of the chiller. According to the energy performance analysis results, the installation working in Bilbao is a full polygeneration system since no electricity needs to be imported from the grid in summer. To quantify the energy savings related to a separated production facility, polygeneration indicators (percentage of savings PES/PExS and equivalent electric efficiency EEE/EExE) have been calculated in energy and exergy terms. The main motivation for using exergy is based on the ambiguity that can arise from the point of view of the First Law. As expected, the exergetic indicators have lower values than the energetic ones. In addition, an in-depth analysis was conducted for the air-handling unit components. The study shows the behavior of components over the year and the efficiency values from both an energy and exergy point of view. From these facts, the need arises to develop methodologies based on exergy

Application of Thermoeconomics in HVAC Systems

In order to achieve a sustainable society, the energy consumption in buildings must be reduced. The first step toward achieving this goal is to detect their weak points and analyze the energy-saving potential. to detect the units with higher consumption and cost. Exergy is very useful for analyzing pieces of equipment, systems or entire buildings. It measures not only the quantity of energy but also its quality. If the exergy is combined with economic analysis, this gives rise to thermoeconomics, and the system can be checked systematically and optimized from the perspective of economics. In this work, exergy methods and thermoeconomic analysis were applied to a building thermal system. Due to its complexity, it is necessary to adapt some concepts to translate the exergy application from industry to buildings. The purpose of this work is to overcome these shortcomings and to deal with energy-saving actions for buildings. To this end, a thermoeconomic study of a facility that covers the heating and domestic hot water (DHW) demands of 176 dwellings in Vitoria-Gasteiz (Basque Country) using two boilers and two cogeneration engines was analyzed. The irreversibility associated with each piece of equipment was quantified, and the costs associated with resources, investment and maintenance were calculated for each flow and, consequently, for the final flows, that is, electricity (11.37 c€/kWh), heating (7.42 c€/kWh) and DHW (7.25 c€/kWh). The results prove that the boilers are the lesser efficient components (with an exergy efficiency of 15%). Moreover, it is demonstrated that micro-cogeneration engines not only save energy because they have higher exergy efficiency (36%), but they are also economically attractive, even if they require a relatively high investment. Additionally, thermoeconomic costs provide very interesting information and underscore the necessity to adapt the energy quality in between the generation and demand

Development of a tool based on thermoeconomics for control and diagnosis building thermal facilities

[EN] This work develops a software to control and diagnose building thermal facilities based on thermoe-conomics. It is tested with the data obtained from three building blocks in the Basque Country (northern Spain) with the aim of detecting the potential energy saving points and mitigating environmental im-pacts. Some obstacles, solved, are related to the insufficient number of probes and the inherent errors of sensors. Besides, new methodologies for performing a thermoeconomic dynamic analysis are described. Apart from this, the inefficiencies of components are quantified, a dynamic cost calculation of all fiows is done and different operation modes are discussed. The outcomes of operation modes are discussed and their exergetic, economic and environmental average unit cost are calculated. In such way, the inter-vention of the control system is analysed and the operation modes with lower and higher fuel con-sumption are detected. The results show that domestic hot water (DHW) production has an average value of 13.72 c euro /kWh and heating of 12.92 c euro /kWh; in addition, boilers have 1,587 MWh of real losses. Besides, the operating modes dynamic analysis opens a new research line for thermoeconomics appli-cations. This information is a key fact for control optimization searching the high performance of buildings.The authors appreciate the financial support provided for this work by the Basque Government through the ERAIKAL 2019 project. The authors also acknowledge the support provided by the Laboratory for the Quality Control in Buildings of the Basque Government

Eguzki-energia termikoa: etxebizitzen eskariak asetzeko erabilera anitzeko iturri-berriztagarria

The aim of this paper is to provide information on the current situation of solar collectors in the building sector. Solar thermal energy is a key for the energy transition, so it is necessary to know the technologies of exploitation of the source and its operating ranges, taking into account, especially, the current situation of solar energy in Spain and the specific installations in buildings. Although conventional solar systems are currently installed, there are other less common configurations. For this reason, the findings of recent years must be taken into account in order to introduce new materials, geometries and heating fluids for solar collectors. In addition, solar systems can be integrated into architectural elements and solar cooling applications and air conditioning networks can be promoted. Consequently, it is demonstrated that the thermal applications of solar energy are versatile and adaptable for any building thermal demand.; Lan honen helburua da eguzki-kolektoreen egungo egoeraren informazioa ematea, eraikuntza-sektorean. Energia-trantsiziorako giltzarri bat da eguzki-energia termikoa, eta, horregatik, iturria ustiatzeko teknologiak eta horien funtzionamendu-tarteak ezagutu behar dira, kontuan hartuz, batez ere, Espainiako eguzki-energiaren egungo egoera eta eraikinen instalazio espezifikoak. Egun, ohiko eguzki-sistemak instalatzen badira ere, hain ohikoak ez diren beste konfigurazio batzuk ere badaude. Hori dela eta, azken urteen aurkikuntzak aintzat hartu behar dira eguzki-kolektoreen material, geometria eta fluido bero-eramaile berriak ezagutarazteko. Gainera, eguzki-sistemak elementu arkitektonikoetan integra daitezke, eta eguzki bidezko hozte-sistemen aplikazioak eta klimatizazio-sareak ere bultza daitezke. Ondorioz, eguzki-energiaren aplikazio termikoak aldakorrak eta moldagarriak direla frogatzen da, eraikuntzako edozein eskari termikorako

Instalazio termiko hibrido baten energia- eta exergia-analisi dinamikoa

Climate change is modifying the energy demand everywhere. This influences the way in which energy demand supply systems are sized and how they work, especially in systems designed for the long term. Thus, it is urgent to know the sources of renewable energy to exploit them in a sustainable way and to do so with systems that adapt their exploitation to the requirements of climate change. The system that mixes these two requirements is the heat pump. The heat pump is capable of exploiting energy sources close to the surrounding temperature and is an ideal technology for meeting the energy needs of applications with low thermal requirements. The energy demand of buildings is high, but domestic hot water for buildings and heating have a low thermal demand. Thus, the use of heat pumps in the thermal facilities of buildings ensures the energy transition and the flexibility to adapt to the new climate change scenario. In order to reduce energy demand as much as possible, it is necessary to know the degradation mechanisms of energy resources. Energy and exergy analyses are very useful tools to know the exergy destruction and the energy and exergy efficiency of a system. This paper presents a real hybrid facility containing in the generation block a ground-coupled heat pump and a gas boiler. The facility supplies a building with domestic hot water and heating. The dynamic simulation of the facility has been carried out with TRNSYS software and data for the application of energy and exergy analysis have been obtained. For the first time, a dynamic exergy analysis has been applied to a system consisting of a ground source heat pump and a gas boiler. The results obtained indicate that 71% of the exergy destruction occurs in the boiler and the exergy efficiency of the heat pump is 6%. The results obtained allow to improve the energy performance of this thermal facility.; Klima-aldaketaren eraginez, tokian tokiko energia-eskaria aldatzen ari da. Horrek energia-eskaria asetzeko sistemen dimentsionamenduan eta operazio-moduan eragiten du; batez ere, epe luzerako proiektatzen diren sistemetan. Hala, premiazkoa da jatorri berriztagarria duten energia-iturriak ezagutzea, modu jasangarrian ustiatzea eta ustiaketa klima-aldaketaren eskakizunetara egokituko diren sistemekin egitea. Bero-ponpak bi baldintza horiek bateratzen ditu. Bero-ponpa inguru-tenperaturatik gertu dauden energia-iturriak ustiatzeko gai da eta eskakizun termiko baxua duten aplikazioen energia-beharrak asetzeko aproposa den teknologia da. Eraikinen energia-eskaria handia da, baina eraikinetarako ur bero sanitarioak eta berokuntzak eskakizun termiko baxua dute. Horrela, eraikinen instalazio termikoetan bero-ponpa edukitzeak, energia- trantsizioa eta klima-aldaketaren agertoki berrira egokitzeko malgutasuna bermatzen ditu. Energia-eskaria ahalik eta gehien murrizteko, energia-baliabideen degradatze-mekanismoak ezagutu behar dira. Energia- eta exergia-analisiak oso tresna erabilgarriak dira sistema baten exergia-suntsiketa eta energia- eta exergia-efizientzia ezagutzeko. Lan honetan, sorkuntza-sisteman lurzorura akoplatutako bero-ponpa bat eta gas-galdara bat dauzkan instalazio hibrido erreal bat aurkezten da. Instalazioak ur bero sanitarioz eta berokuntzaz hornitzen du eraikin bat. TRNSYS softwarearen bitartez, instalazioaren simulazio dinamikoa burutu da eta energia- eta exergia-analisia aplikatzeko datuak lortu dira. Lehen aldiz, exergia-analisi dinamikoa aplikatu da. Lortutako emaitzen arabera, exergia-suntsiketaren % 78 galdaran gertatzen da, eta bero-ponparen exergia-efizientzia % 46koa da. Lortutako emaitzek zabaldu egiten dute instalazio termiko honen energia-portaera hobetzeko bidea

Termoekonomia. Eraikinen sistema termikoetan energia eta ekonomia ebaluatrzeko tresna.

210 p.One of the current main objectives of the European Union is focused on primary energy conservation, as a consequence of the enduring climate change the world is undergoing. Buildings are responsible for almost 40 % of the final energy used in the EU while in Spain, the built environment accounts for 28 % of the final energy consumption. Therefore, such sector plays an important role in the total energy consumption and many specialists are working for the improvement of buildings energetic efficiency.The benefits obtained through the application of exergy concept in buildings are currently known, since they contribute to the proper use of energy as well as to a better adequacy of the different energy qualities taking part in a facility. This is especially useful in buildings where low quality energy demands are required, such as heating, cooling and domestic hot water.The aim of Chapter A is to show the enormous possibilities for the energy efficiency improvement that still exist, which cannot be assessed through a common energetic analysis; in both, new and retrofit buildings.Because buildings are permanently changing over the time, dynamic models are imperative. In Chapter B two innovative methods are developed for their transient representations.Besides, an exergy analysis supports the identification of the economic cost formation in every phase of the energy transformation chain, which is, precisely, the objective of Chapter C. Such study is the base of Thermoeconomics that, among other applications, enables the exergetic and exergoeconomic costs of all the flows along the system. For that, Symbolic Thermoeconomic is used to obtain general equations, which relate the thermoeconomic variables of every component. The pioneering point is related to the dynamism incorporation, which is, in addition, seconded by a ground breaking dynamic software in the Annex.Furthermore, thermoeconomic diagnosis attempts to identify the components affected by any anomaly by analyzing its symptoms according to the exergetic efficiency variations and quantifying the energy recovery potential; unfortunately, it limps in certain aspects. Chapter D overcomes the essential issues of the application and succeed in the direct dynamic diagnosis problem resolution.In Chapter E, by contrast, a Dynamic Advanced Exergy Analysis is applied for the first time in buildings. Therefore, the corresponding dynamic challenges are solved.The overall research purpose it to stand out the advantages and disadvantages of the Second Law analyses in buildings dynamic systems. After all, a critical judgment is the base of any application and the only way forward to achieve the goal of energy and economic savings in buildings

Termoekonomia. Eraikinen sistema termikoetan energia eta ekonomia ebaluatrzeko tresna.

210 p.One of the current main objectives of the European Union is focused on primary energy conservation, as a consequence of the enduring climate change the world is undergoing. Buildings are responsible for almost 40 % of the final energy used in the EU while in Spain, the built environment accounts for 28 % of the final energy consumption. Therefore, such sector plays an important role in the total energy consumption and many specialists are working for the improvement of buildings energetic efficiency.The benefits obtained through the application of exergy concept in buildings are currently known, since they contribute to the proper use of energy as well as to a better adequacy of the different energy qualities taking part in a facility. This is especially useful in buildings where low quality energy demands are required, such as heating, cooling and domestic hot water.The aim of Chapter A is to show the enormous possibilities for the energy efficiency improvement that still exist, which cannot be assessed through a common energetic analysis; in both, new and retrofit buildings.Because buildings are permanently changing over the time, dynamic models are imperative. In Chapter B two innovative methods are developed for their transient representations.Besides, an exergy analysis supports the identification of the economic cost formation in every phase of the energy transformation chain, which is, precisely, the objective of Chapter C. Such study is the base of Thermoeconomics that, among other applications, enables the exergetic and exergoeconomic costs of all the flows along the system. For that, Symbolic Thermoeconomic is used to obtain general equations, which relate the thermoeconomic variables of every component. The pioneering point is related to the dynamism incorporation, which is, in addition, seconded by a ground breaking dynamic software in the Annex.Furthermore, thermoeconomic diagnosis attempts to identify the components affected by any anomaly by analyzing its symptoms according to the exergetic efficiency variations and quantifying the energy recovery potential; unfortunately, it limps in certain aspects. Chapter D overcomes the essential issues of the application and succeed in the direct dynamic diagnosis problem resolution.In Chapter E, by contrast, a Dynamic Advanced Exergy Analysis is applied for the first time in buildings. Therefore, the corresponding dynamic challenges are solved.The overall research purpose it to stand out the advantages and disadvantages of the Second Law analyses in buildings dynamic systems. After all, a critical judgment is the base of any application and the only way forward to achieve the goal of energy and economic savings in buildings

Termoekonomia. Eraikinen sistema termikoetan energia eta ekonomia ebaluatrzeko tresna.

210 p.One of the current main objectives of the European Union is focused on primary energy conservation, as a consequence of the enduring climate change the world is undergoing. Buildings are responsible for almost 40 % of the final energy used in the EU while in Spain, the built environment accounts for 28 % of the final energy consumption. Therefore, such sector plays an important role in the total energy consumption and many specialists are working for the improvement of buildings energetic efficiency.The benefits obtained through the application of exergy concept in buildings are currently known, since they contribute to the proper use of energy as well as to a better adequacy of the different energy qualities taking part in a facility. This is especially useful in buildings where low quality energy demands are required, such as heating, cooling and domestic hot water.The aim of Chapter A is to show the enormous possibilities for the energy efficiency improvement that still exist, which cannot be assessed through a common energetic analysis; in both, new and retrofit buildings.Because buildings are permanently changing over the time, dynamic models are imperative. In Chapter B two innovative methods are developed for their transient representations.Besides, an exergy analysis supports the identification of the economic cost formation in every phase of the energy transformation chain, which is, precisely, the objective of Chapter C. Such study is the base of Thermoeconomics that, among other applications, enables the exergetic and exergoeconomic costs of all the flows along the system. For that, Symbolic Thermoeconomic is used to obtain general equations, which relate the thermoeconomic variables of every component. The pioneering point is related to the dynamism incorporation, which is, in addition, seconded by a ground breaking dynamic software in the Annex.Furthermore, thermoeconomic diagnosis attempts to identify the components affected by any anomaly by analyzing its symptoms according to the exergetic efficiency variations and quantifying the energy recovery potential; unfortunately, it limps in certain aspects. Chapter D overcomes the essential issues of the application and succeed in the direct dynamic diagnosis problem resolution.In Chapter E, by contrast, a Dynamic Advanced Exergy Analysis is applied for the first time in buildings. Therefore, the corresponding dynamic challenges are solved.The overall research purpose it to stand out the advantages and disadvantages of the Second Law analyses in buildings dynamic systems. After all, a critical judgment is the base of any application and the only way forward to achieve the goal of energy and economic savings in buildings

Energy and exergy analysis of an experimental ventilated façade

This work, analyzes ventilated façades through the first and second law of thermodynamics. In addition to the energy-balances, it presents the exergy-balances on the interior and exterior surface of a façade, taking into account the different mechanisms of heat exchange. It proposes two new indexes (EQC and ExQC) to characterize the behavior of ventilated façades, by comparing their behavior with a reference façade and considering the energy balance in one case and the exergy balance in the other. An experimental test of a forced ventilated façade serves as the case study, using the test-methodology based on Paslink cells. The test data serve to characterize the behavior of the façade, both from an energy and exergy point of view. Overall, 53.05 kWh of heat is lost to the outside through the façade during 6 days of November, which corresponds to 0.31 kWh of exergy-loss. The internal energy change of the façade is decomposed according to its layers, showing that in terms of energy the sandwich insulation layer influences the most (99.45 % of the total change) but in terms of exergy, on the contrary, the metal sheet affects the most (83.66 %). The values obtained for the two indexes show that, under the test conditions, although the ventilated façade and the reference façade present similar values from the energy point of view, when the exergy is used, it is clearly seen that the behavior of the ventilated façade is 44 % better.The authors wish to express their gratitude for the support provided by the Building Quality Control Laboratory (LCCE) of the Basque Government, especially to JM. Hidalgo, C. Garcia-Gáfaro and D. Pérez for the help given throughout the test

Aplicación de una herramienta avanzada de análisis de datos en el entorno de la construcción = Application of advanced data analysis tool in building environment.

Los sistemas de monitorización de edificios proporcionan grandes volúmenes de información y existen herramientas avanzadas de análisis de datos. Un problema de detección y diagnóstico de fallos (FDD) en los sistemas energéticos de los edificios también puede considerarse un problema de aprendizaje automático puro. El objetivo de este trabajo es promover la FDD con aplicaciones de aprendizaje automático en el entorno de los edificios. Como contribución, en este trabajo se procesan series de datos temporales brutos, obtenidos de un SCADA, para la posterior construcción de patrones de una instalación térmica de un edificio. La instalación térmica abastece las demandas de ACS y calefacción de un edificio residencial, compuesto por 26 viviendas sociales y situado en Durango (norte de España). Los datos registrados cada 24 horas en valores acumulados se incluyen en el software R para el cálculo de gráficos estadísticos. Para los valores de los contadores de consumo de ACS y calefacción se obtienen 229 puntos de datos válidos y los rangos de consumo diario están comprendidos entre 1,94 - 5,90 m3 y 0 - 547,63 kWh.AbstractBuilding monitoring systems deliver large volumes of information and advanced data analysis tools are available. A fault detection and diagnosis (FDD) problem in building energy systems can also be regarded as a pure machine learning problem. The aim of this work is to promote FDD with machine learning applications in building environment. As a contribution, in this work raw time data series, obtained from a SCADA, are processed for further pattern construction of a building thermal facility. The thermal facility supplies the DHW, and heating demands of a residential building, consisting of 26 social dwelling units and located at Durango (northern Spain). Data recorded every 24 hours in cumulative values is included in the R software for computing statistical graphs. For DHW and heating consumption meter values, 229 valid data points are obtained, and the daily consumption ranges are between 1.94 - 5.90 m3 and 0 - 547.63 kWh respectively