scholarly journals A methodological approach for energy demand assessment: theoretical analysis on solar thermal collector energy contribution

2021 ◽  
Vol 312 ◽  
pp. 02002
Author(s):  
Domenico Palladino ◽  
Carmen Lavinia ◽  
Francesca Margiotta ◽  
Francesca Pagliaro

Solar thermal collector system is a widely used solution involving renewable energy source to cover the energy demand for domestic hot water production. At Italian level, the UNI TS 11300 provides a calculation methodology based on two approaches: the asset rating, which is easy to be applied but provides approximated results, and the tailored rating, which is more reliable but requires several detailed information. In this context, the present work proposes a new methodological approach to develop a simplified calculation method in order to obtain accurate energy performance results with no-additional cost for assessors and final users. Different case studies were analysed carrying out parametric simulations. The obtained results have led to the definition of the new simplified calculation methodology to predict the thermal energy supplied by solar thermal collectors; it allows also calculating the domestic hot water volume to be covered by other technical building systems, becoming a useful tool for their pre-dimensioning. Besides, the results open to new scenarios of interest, such as the application of the same approach to other energy services in order to integrate the outcomes of the asset rating provided by the UNI TS 11300.

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4057
Author(s):  
Mohammad Emamjome Kashan ◽  
Alan S. Fung ◽  
John Swift

In Canada, more than 80% of energy in the residential sector is used for space heating and domestic hot water (DHW) production. This study aimed to model and compare the performance of four different systems, using solar energy as a renewable energy source for DHW production. A novel microchannel (MC) solar thermal collector and a microchannel-based hybrid photovoltaic/thermal collector (PVT) were fabricated (utilizing a microchannel heat exchanger in both cases), mathematical models were created, and performance was simulated in TRNSYS software. A water-to-water heat pump (HP) was integrated with these two collector-based solar systems, namely MCPVT-HP and MCST-HP, to improve the total solar fraction. System performance was then compared with that of a conventional solar-thermal-collector-based system and that of a PV-resistance (PV-R) system, using a monocrystalline PV collector. The heat pump was added to the systems to improve the systems’ efficiency and provide the required DHW temperatures when solar irradiance was insufficient. Comparisons were performed based on the temperature of the preheated water storage tank, the PV panel efficiency, overall system efficiency, and the achieved solar fraction. The microchannel PVT-heat pump (MCPVT-HP) system has the highest annual solar fraction among all the compared systems, at 76.7%. It was observed that this system had 10% to 35% higher solar fraction than the conventional single-tank solar-thermal-collector-based system during the wintertime in a cold climate. The performance of the two proposed MC-based systems is less sensitive than the two conventional systems to collector tilt angle in the range of 45 degrees to 90 degrees. If roof space is limited, the MCPVT-HP system is the best choice, as the MCPVT collector can perform effectively when mounted vertically on the facades of high-rise residential and commercial buildings. A comparison among five Canadian cities was also performed, and we found that direct beam radiation has a great effect on overall system solar faction.


Designs ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 44
Author(s):  
Jordi Roviras Miñana ◽  
Vicente Sarrablo Moreno

The work presented here aims to demonstrate the technical, architectural, and energy viability of solar thermal collectors made with ceramic materials and their suitability for domestic hot water (DHW) and building heating systems in the Mediterranean climate. The proposal is for the design of a ceramic shell, formed by collector and non-collecting panels, which forms part of the building system itself, and is capable of responding to the basic requirements of a building envelope and harnessing solar energy. Ceramics considerably reduce the final cost of the collector system and offer the new system a variety of compositional and chromatic finishes, occupying the entire building surface and achieving a high degree of architectural integration, although less energy-efficient compared to a conventional metallic collector.


2018 ◽  
Vol 4 (3) ◽  
pp. 25 ◽  
Author(s):  
Daniel Ferrández ◽  
Carlos Moron ◽  
Jorge Pablo Díaz ◽  
Pablo Saiz

ResumenEl actual Código Técnico de la Edificación (CTE) pone de manifiesto la necesidad de cubrir parte de la demanda energética requerida para el abastecimiento de agua caliente sanitaria y climatización de piscinas cubiertas mediante sistemas de aprovechamiento de la energía solar térmica. En este artículo se presenta una comparativa entre las dos principales tipologías de captadores solares térmicos que existen en el mercado: el captador de placa plana y el captador de tubo de vacío, atendiendo a criterios de fracción solar, diseño e integración arquitectónica. Todo ello a fin de discernir en qué circunstancias es más favorable el uso de uno u otro sistema, comparando los resultados obtenidos mediante programas de simulación con la toma de medidas in situ.AbstractThe current Technical Building Code (CTE) highlights the need to cover part of the energy demand required for the supply of hot water and heating of indoor swimming pools using solar thermal systems. This article presents a comparison between the two main types of solar thermal collectors that exist in the market: the flat plate solar collector and the vacuum tube solar collector, according to criteria of solar fraction, design and architectural integration. All of this in order to discern in what circumstances the use of one or the other system is more favourable, comparing the results obtained through simulation programs with the taking of measurements in situ.


2021 ◽  
Author(s):  
Kamyar Tanha

This thesis is focused on the performance of the two SDHW systems of the sustainable Archetype houses in Vaughan, Ontario with daily hot water consumption of 225 litres. The first system consists of a flat plate solar thermal collector in conjunction with a gas boiler and a DWHR. The second SDHW system consists of an evacuated tube collector, an electric tank and a DWHR. The experimental results showed that the DWHRs were capable of an annual heat recovery of 789 kWh. The flat plate and evacuated tube collectors had an annual thermal energy output of 2038 kWh and 1383 kWh. The systems were also modeled in TRNSYS and validated with the experimental results. The simulated results showed that Edmonton has the highest annual energy consumption of 3763.4 kWh and 2852.9 kWh by gas boiler and electric tank and that the solar thermal collectors and DWHRs are most beneficial in Edmonton.


2016 ◽  
Vol 861 ◽  
pp. 198-205
Author(s):  
Anton Pitonak ◽  
Martin Lopusniak

In the members states of the European Union, portion of buildings in the total consumption of energy represents 40%, and their portion in CO2 emissions fluctuates around 35%. The European Union is trying to protect the environment by reducing energy demand and releasing CO2 emissions into the air. Energy performance is the quantity of energy, which is necessary for heating and domestic hot water production, for cooling and ventilation and for lighting. Based on results of energy performance, individual buildings are classified into energy classes A to G. A global indicator (primary energy) is the decisive factor for final evaluation of the building. The new building must meet minimum requirements for energy performance, i.e. it must be classified to energy class A1 since 2016, and to energy class A0 since 2020. The paper analyses effect of the use of different resources of heat in a family house designed according to requirements valid since 2020, and its subsequent classification into an energy class.


Author(s):  
Radu Radoi ◽  
Ioan Pavel ◽  
Corneliu Cristescu ◽  
Liliana Dumitrescu

Fossil fuels are an exhaustible resource on Earth, and their use pollutes the environment massively. The population of the planet has grown a lot, and for the production of domestic hot water, to ensure a decent standard of living, it is necessary to consume increasing quantities of fossil fuels. The very high level of greenhouse gases released into the atmosphere leads to an increase in average of annual temperature and climate change. Climate change is manifested by the melting of the ice caps, which has the consequence of increasing the level of the seas and oceans. Climate change also leads to extreme weather events such as floods, heat waves or the appearance of arid areas. Risks to human health have increased through deaths caused by heat or by changing the way some diseases are spread. Risks also exist for flora and wildlife due to rapid climate change.Many species of animals migrate, and other species of animals and plants are likely to disappear. Climate change also leads to costs for society and the economy due to damage to property and infrastructure, which have been more than 90 billion euros in the last 30 years, just because of the floods. In order to reduce the effects of environmental pollution, ecological energy production solutions need to be expanded. The article presents the creation of an experimental stand of a Solar - TLUD stove combined system for the production of domestic hot water in a sustainable way. TLUD is the acronym for "Top-Lit UpDraft". The advantage of the combined heat system is that it can provide thermal energy both during the day and at night. If the atmospheric conditions are unfavorable (clouds, fog) and do not allow the water to be heated only with the solar panel, TLUD gas stove can be used to supplement the energy. The TLUD stove has low Carbon Monoxide (CO) and Particulate Matter (PM) emissions. After gasification, about 10% of the carbon contained in the biomass is thermally stabilized and can be used as a "biochar" in agriculture or it can be burnt completely, resulting in very little ash. The stand is composed of a solar thermal panel, a TLUD stove, a boiler for hot water storage and an automation system with circulation pumps and temperature sensors. To record the experimental results, a data acquisition board was used, with which data were recorded from a series of temperature and flow transducers located in the installation. Experimental results include diagrams for temperature variation, available energy and heat accumulated in the boiler. Keywords: combined thermal system, TLUD stove, domestic hot water, solar thermal panel, data aquisition system


Author(s):  
Gonzalo Sánchez-Barroso ◽  
Jaime González-Domínguez ◽  
Justo García-Sanz-Calcedo

Hospitals need to prepare large amounts of domestic hot water (DHW) to develop their healthcare activity. The aim of this work was to analyse potential savings that can be achieved by installing solar thermal energy for production of domestic hot water in the hospitals of Extremadura (Spain). For this purpose, 25 hospitals between 533 and 87,118 m2 and between 15 and 529 beds were studied, three solar factor scenarios were simulated (0.70, 0.75 and 0.80) and the necessary investment and corresponding economic and environmental savings were calculated. Better economic results and energy ratios for 70% of solar contribution were obtained. These results show an average payback of 4.74 years (SD = 0.26) reaching 4.29 kWh/€ per year (SD = 0.20). Undertaking an investment of 674,423 €, 2,895,416 kWh/year of thermal energy could be generated with which to save both 145,933 € and 638 tons of CO2 per year. It was statistically demonstrated the priority of carrying out an installation with a solar factor of 70%, investing preferably in hospitals in Cáceres over those in Badajoz, especially in the public sector with more than 300 beds. These findings will provide hospital managers with useful information to make decisions on future investments.


2020 ◽  
Vol 160 ◽  
pp. 01004 ◽  
Author(s):  
Stanislav Chicherin ◽  
Lyazzat Junussova ◽  
Timur Junussov

Proper adjustment of domestic hot water (DHW) load structure can balance energy demand with the supply. Inefficiency in primary energy use prompted Omsk DH company to be a strong proponent of a flow controller at each substation. Here the return temperature is fixed to the lowest possible value and the supply temperature is solved. Thirty-five design scenarios are defined for each load deviation index with equally distributed outdoor temperature ranging from +8 for the start of a heating season towards extreme load at temperature of -26°C. All the calculation results are listed. If a flow controller is installed, the customers might find it suitable to switch to this type of DHW supply. Considering an option with direct hot water extraction as usual and a flow controller installed, the result indicates that the annual heat consumption will be lower once network temperatures during the fall or spring months are higher. The heat load profiles obtained here may be used as input for a simulation of a DH substation, including a heat pump and a tank for thermal energy storage. This design approach offers a quantitative way of sizing temperature levels in each DH system according to the listed methodology and the designer's preference.


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