Energy efficiency of a solar domestic hot water system (original) (raw)
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Zbornik radova pisanih za 5. Međunarodnu konferenciju o obnovljivim izvorima električne energije, 2017
Srbiji se najčešće električna energija koristi za zagrevanje sanitarne vode (SV). Kako je oko 70% električne energije dobija korišćenjem uglja koji oslobađa veliki broj gasova sa efektom staklene bašte, korišćenje solarne energije za zagrevanje sanitarne vode u solarnim sistemima za zagrevanje sanitarne vode (STV) ima povoljan uticaj na očuvanje život-ne sredine. Tokom rada solarni sistem za grejanje sanitarne tople vode generiše različite količine toplote iz solarne energije, dobijaju se različite količine izbegnute elekrične energije. U istraživanjma je primenjen softver EnergyPlus. Korišćeni vremenski podaci su iz ovlašćenih meteoroloških stanica. U ovom radu pokazana je energetska optimizacija solarnog sistema za zagrevanje STV sa solarnim prijemnikom koji funkcioniše tako što koristi ugao nagiba 37.5° i 12 različitih vrednosti ugla azimuta, po jedan za svaki mesec u toku godine. Ovom prilikom je za svaki solarni sistem za grejanje STV izračunat solarni udeo u funkciji ugla nagiba i ugla azimuta i predstavljen odgovarajućim krivama. Takođe je prikazan i mesečni deficit solarnog udela za odstupanja ugla azimuta, kada on u nekim mesecima nije optimalan. Korišćene su odgovarajuće simulacione i optimizacione rutine sa modifikovanom metodologijom Hooke Jeeves algoritma. Solarni sistemi su poboljšani, tako što je dobijena minimalna potrošnja fosilne energije, smanjena upotreba energetskih resursa, maksimizirana energetska sigurnost, kao minimiziran uticaj na životnu sredinu. Ključne reči: Optimizacija; solarni sistem za zagrevanje STV; solarni udeo; simulacija; solarni prijemnik; In Serbia, it is usually to use electrical energy for domestic hot water (DHW) heating. About 70% of electrical energy is produced by using coal with high greenhouse emission, so it is beneficial to environment to use solar energy for heating of DHW in solar DHW system (SDHWS). During SDHWS operation, different SDHWSs generate different amounts of heat from solar energy, and different amounts of avoided electrical energy are obtained. These investigations use computer software EnergyPlus. The used weather data are from the meteorological station. In this peper, it is analyzed energy optimization of the solar system for DHW heating with solar collector, which works by using the angle slope 37.5° and 12 different azimuth angle values, for each month during the year. In this occasion, it has been calculated solar fraction for each SDHWS as a function of number of optimum positions of the solar collector in SDHWS during year, for the city of Belgrade, Serbia and represented by the corresponding curves. It is also shown the monthly deficit of solar fraction for deviations the azimuth angle, when it is not optimal. It was used appropriate simulation and optimization routines with the modified methodology of the Hooke Jeeves algorithm. Solar energy systems have been improved, due to obtaining of minimum fossil energy consumption, reduction of the energy resources use, maximizing energy security, as well as the minimum impact on the environment.
Energies, 2021
According to the authors of this paper, the mathematical point of view allows us to see what sometimes cannot be seen from the designer’s point of view. The aim of this study was to estimate the influence of the most important parameters (volume of heat storage tanks, daily consumption of domestic hot water, optical efficiency, heat loss coefficient, and total area of a solar collector) on the thermal power output of solar domestic hot water (SDHW) system in European climatic conditions. Three deterministic mathematical models of these relationships for Madrid, Budapest, and Helsinki were created. The database for the development of these models was carried out using computer simulations made in the TRNSYS software environment. The SDHW system located at the Bialystok University of Technology (Poland) was the source of the measurement results used to validate the simulation model. The mathematical optimization procedure showed that the maximum annual useful energy output that can be...
Aspects regarding using solar energy in heating systems and sanitary hot water
Selection and sizing of heating and sanitary hot water solar system for a building always involves determining the optimal rate of heat provided by solar energy conversion. As this rate is higher, a greater amount of fossil fuels is saved and the pollutant emission and greenhouse gases emission decreases. But this may involve, during the summer, the producing of a quantity of heat, greater than heat demand of the building, resulting an excess of heat that involves additional energy management costs with negative impact on the annual energy efficiency of solar thermal system. In the final part of this article, it was presented a case study on the use of an solar system for indirect preparation of sanitary hot water and for supporting the space heating for a building for tourism.
E3S Web of Conferences
The systems using solar energy, popular in Poland, can be used to supply hot water for the installation used by employees of industrial halls. In manufacturing plants, employing a large number of people, the demand for hot water is practically constant throughout the year and is characterized by periodic use at the end of each work shift. Dynamics of the hot water consumption depends on the number of shifts as well as working days and holidays. Additionally the maximum hot tap water demand occurs in the whole period of installation operation. In polish climatic conditions the solar collectors’ systems have the largest capacity in the summer, while in winter they need to be assisted. Beside that the supply of renewable energy is uneven and depends on weather conditions. In the paper the one-hour step analysis concerning the dependence of the load pattern of the hot tap water preparation system on the energy yield from solar collectors had been performed.
Lifecycle and ecomonical study of selected thermal solar installations
Selected Scientific Papers - Journal of Civil Engineering, 2020
Creating a scheme of solar thermal installations is a mighty move forward to develop a suitable energy standards of residential buildings. In recent years were done many studies, which did a several energy simulations for residence buildings. If design of thermal installation is false, it can lead to rise in the expensive overall energy costs and unsatisfactory thermal comfort in the building. Nowdays, in Slovakia using solar thermal installations are increasing more than in recent years. This research investigates twelve modern solar water heating systems, formed on the roof of the family house. We tried to make analysis, where designed solar energy systems were appropriate and fulfill energy requirements of DHW and heating. The study deals with the best financial alternative of the prepared installations of the house. According to overall prices of installation, energy production of additional source for heating and total system efficiency and lifespan, we found out the best possi...
Techno-Economic Analysis Solar Energy Use for Sanitary Water Heating in Institute "Drin Fojnica
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The paper analyses the impact of installation of the solar heat system in the building of the Institute for Care of Mental Disabled Persons "Drin Fojnica" on its energy consumption, energy costs and air emissions. During 2019, solar collectors were installed on the roof of the Institute's main building, as a support for heating of hot sanitary water (HSW). Heating of HSW before installation of solar heat system was performed by the electric boilers out of heating season and by heat from the coal boiler during heating season. This way of HSW heating caused high energy costs for the Institute. Since there was no data on baseline energy consumption for HSW heating, the calculation of heat demand for HSW was performed based on the number of users and water consumption per user. Based on the calculation of heat production from the solar collectors and secondary heat sources for HSW (out of heating season the electric boilers, during the heating seasons the coal boiler) the annual energy balance of the system for HSW was obtained. The energy balance was the basis for calculation of decrease of coal and electricity consumption, annual cost savings for heating of HSW, financial indicators of investment in the solar system (payback period, net present value and internal return rate), reduction of air pollutant emissions (sulphur dioxide, nitrogen oxide and particulate matter) and carbon dioxide. Financial savings achieved by the solar system amount is about 8,500 BAM per year. Direct emissions of air pollutants were reduced by 27.12% and indirect by 29.02%. The payback period is 5.8 years.
Optimisation of solar domestic hot water systems
Proceedings of Eurosun, 1998
ABSTRACT. The plant under consideration in this paper is a Solar Domestic Hot Water System (SDHWS). The heat exchanger is a mantle, which surrounds the entire storage tank. Optimization of both the components and the operation of this system have been carried out. As a result, the overall performances have been improved simultaneously from an energy and a reliability perspective. On the components side, a magnetic-driven pump with a PV-cells supply and a segmented auxiliary heater have been introduced. On the operation side, a combined ...
Solar heating/cooling and domestic hot-water systems
2011
Increasing awareness of global warming forces policy makers and industries to face two challenges: reducing greenhouse gas emissions and securing stable energy supply against ever-increasing world energy consumption, which is projected to increase by 71% from 2003 to 2030. In addressing these two issues simultaneously, renewable energies prove themselve attractive, as they are independent from the fossil fuel supply and do not contribute to greenhouse gas emissions. Therefore, providing heating and cooling by utilizing renewable energy such as solar energy is a key solution to the energy and environmental issues. This paper makes references to the solar generation of thermal energy and its use for buildings and domestic water heating, describing both different types of solar equipment and system, and developing a mathematical model for energetical analysis of the solar heating systems. Also, this paper provides a review of the available cooling technologies assisted by solar energy ...
Journal of Renewable and Sustainable Energy, 2016
Here, we evaluated the efficiency of a solar domestic hot water system in a dormitory in Rzeszow. Radiance exposure was analyzed based on information obtained from an online database (the meteorological station in Rzeszow-Jasionka). The mean seasonal and annual solar irradiation of a flat surface and surfaces inclined at 30 , 45 , and 60 from the horizontal plane in Rzeszow were determined. The mean monthly irradiation was compared with that in selected European cities based on the Photovoltaic Geographical Information System meteorological database. The thermal solar panel area and final consumption of solar energy in Poland from 2005 to 2014 are also presented. The characteristics of the analyzed building, distribution of the inhabitants, and consumption of hot water from 2009 to 2014 are described. The heat demand was determined by hot water consumption per day per person based on hot water consumption metering and heat metering. The solar energy conversion efficiency was determined after the solar thermal collectors were installed in the building. The relation of the heat demand calculated based on the thermal energy utilized to heat water per person and heat metering for heating water was also analyzed. We also present a method of calculating the annual (stratified by month) ratio of solar energy utilization. Energy savings for the building were calculated. Improvements that could further increase the solar energy efficiency and shorten the investment payback period are proposed.
Applied Energy, 2013
The use of different materials for the same solar system component (collector, water tank, etc) 16 affects both the efficiency and the amount of conventional energy substituted by the system 17 and hence the overall environmental impact of a Domestic Solar Hot Water System 18 (DSHWS). The net environmental gain achieved by the use of DSHWS therefore is 19 influenced, among others, by the materials and techniques used, up to 20% in some cases. In 20 this paper, Life Cycle Analysis (LCA) of a variety of typical, for the Greek Market, DSHWS 21 is performed. Their environmental impact, as well as the influence from the use of different 22 materials or/and manufacturing techniques on their impact, is identified. In all cases Corresponding Author examined, the environmental impact of the solar systems is significantly lower compared to 24 that of the energy conserved. As thermal efficiency differs from system to system, their 25 environmental performance is influenced mainly by the conventional energy substituted and 26 to a lesser extent by the materials used for their production. 27