scholarly journals Thermal loss analysis of a solar flat collector using numerical simulation

2020 ◽  
Author(s):  
Timur Merembayev ◽  
Yedilkhan Amirgaliyev ◽  
Murat Kunelbayev ◽  
Abdumauvlen Berdyshev

In this paper, we studied theoretically and numerically heat losses of a flat solar collector for the subsequent modelling of the solar water heating system for the Kazakhstan climate condition. For different climatic zones with a growing cost for energy or lack of central heating systems, promising is to find ways to improve the energy efficiency of the solar system. The solar system is simulated by the mathematical model (ODE model) of energy. To bridge the results of modelling and real values, our research investigated the important physical parameters such as loss coefficient, Nu, Ra, Pr values, which are impacting on the efficiency of solar flat collector and for heat losses of system. The developed mathematical models, the design and composition of the software and hardware complex, automated control and monitoring systems allow solar hot water heating system to increase the energy efficiency of a life support systems and heat supply of buildings, by reducing energy consumption for heat supply.

2018 ◽  
Vol 210 ◽  
pp. 02023
Author(s):  
Jan Skovajsa ◽  
Martin Zálešák

The article deals with the economic evaluation of investment and optimization of the solar water heating system for family houses. From the point of view of solar systems, the optimal solution is based on the specific application of it. The design is dependent on the location of solar thermal collectors and ration between active aperture area and real daytime consumption. Common calculations according to actual standards often give overstated results, which also reflected in the value of the investments. The article presents the research of optimal parameters of the thermal solar system for preparing of domestic hot water. A combination of related standards and software TRNSYS are used to find optimal parameters. Thanks to created and verified simulation models, it is possible to design parameters so as to avoid under-dimensioning or over-dimensioning of the solar system. Energy price is another factor affects the payback period of investments. This is affected by the used energy sources and their combination. For example, buildings that use electricity to heat water or heating have different energy charges than a building that uses natural gas. So, the aim is to find technically and economically efficient solution.


2010 ◽  
Vol 171-172 ◽  
pp. 215-218
Author(s):  
Hai Ying Wang ◽  
Song Tao Hu ◽  
Jia Ping Liu

Solar water heating system is used to supply hot water all-year-round for a new dormitory building. Flat solar energy collectors are mounted on the roof. The hot water tank and pumps are installed together with the air conditioning equipments in the plant room. Air cooled heat pump is used to provide cooling in summer, and high temperature water from boiler room (in old building) is used as heat source in winter. Usually auxiliary heating is necessary to improve the stability and reliability of solar water heating system. In this case, we take full use of the equipment of air conditioning system instead of electricity as auxiliary heating resources. In this paper, we introduced the design of the solar water heating system and the auxiliary heating method by air conditioning systems. The control strategies to fulfill all the functions and switch between different conditions are also introduced.


1983 ◽  
Vol 105 (4) ◽  
pp. 430-439 ◽  
Author(s):  
S. A. Klein ◽  
A. H. Fanney

A rating procedure for solar domestic hot water systems is described which combines the advantages of short-term system tests and correlations of long-term thermal performance. The testing procedure consists of two indoor tests which are in accordance with ASHRAE Standard 95-1981, except for one additional measurement needed only for systems employing a heat exchanger between the collector fluid and the potable water. The test results are plotted in a manner in which they can be used to estimate the long-term performance of the solar water heating system for any location where site-specific, monthly-average meterological data are available. The annual solar function obtained in this manner provides the recommended rating indicator. The validity of this rating procedure is first demonstrated by simulations. Further support is provided by experiments conducted at the National Bureau of Standards.


2013 ◽  
Vol 724-725 ◽  
pp. 163-170
Author(s):  
Zhang Yuan Wang ◽  
Xiang Mei Zhang ◽  
Wan Sheng Yang ◽  
Zhi Wu Chen

In this paper, a novel solar water heating system will be proposed by applying the loop heat pipe to a conventional split solar hot water system, which will have the characteristics of high efficiency, low cost, appearance appealing and building integration. Three types of the system, i.e., the system with evacuated tubes, with single flat-plate glazing cover, and without glazing, will be experimentally investigated and compared on the influence to the dynamic performance of the system. It was found that the system’s operating temperature increased significantly during the start-up stage and gently after until reach relatively constant. The instantaneous efficiency was found to be fluctuated, although it reached stable eventually during the operations for all three types. By using the moving average calculating method, every 10 minutes were applied for the calculation of the average efficiency which had a negative linear relation with the combined factor of (Tmean-Tamb)/I. In general, the solar system with evacuated tubes performed the best with the highest water temperature output, highest system efficiency and lowest heat loss coefficient among the three systems.


Author(s):  
Najat Abdeljebbar ◽  
Abdelwahab Haddaoui

The preservation of natural water and electricity resources is essential for the development of smart cities. Indeed, water and electricity are highly dependent and must be analyzed together to improve the energy efficiency. This article is about the study of the integration of renewable energy and smart solutions in a water heating system. The existing system uses mainly heat pumps to cover the most of the hot water needs. The purpose of this work is to explore possible solutions to optimize the electricity and the water consumption of the installation.


Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1536
Author(s):  
Xilian Han ◽  
Chao Li ◽  
Hongqiang Ma

This paper proposed an experimental test: the solar water-heating system was been monitored for a whole year to analyze collector performance in an actual operation process. Heat-collecting efficiency, heating capacity, power consumption, and heat required were analyzed theoretically. Results showed that solar irradiance and ambient temperature were positively correlated with heat collection efficiency, and the daily average heat collection efficiency was up to 56.63%. In winter, the auxiliary heat source consumed the most power, almost all of which bears the heat of users. The heat collection in summer met the demand for hot water, and the guarantee rate of solar energy could reach 100%. The energy saving properties and CO2 emission reduction were analyzed. This system had a significant effect on the energy-saving effect and environmental protection. The analysis showed that the hot-water system can fully meet the design requirements under the condition of relatively sufficient solar energy, and can operate stably, which has a certain guiding significance for the design and application of large-scale solar hot-water systems.


2019 ◽  
Vol 18 (2) ◽  
pp. 26
Author(s):  
R. R. Barbosa ◽  
M. Carvalho

A clear and direct guide for the design of a solar heating system is presented herein, focused on industrial applications. This guide focuses on the design of solar water heating systems for nonresidential applications. The importance of considering climatic conditions throughout the year is highlighted herein, along with reliable solar radiation data. Solar heating water systems are essential for the diversification of the Brazilian energy matrix and rationalization of the energy resources available. The system is initially dimensioned without the consideration of losses. Then, the required procedure to calculate thermal losses is described, and it is verified that the main losses occur in solar collectors and storage. After careful consideration of the hot water consumption profile and the results obtained in the calculation of the main thermal losses, the storage volume was doubled to guarantee the satisfaction of energy demands.


2011 ◽  
Vol 224 ◽  
pp. 42-49
Author(s):  
Xiao Hui Du ◽  
Hai Shan Xia ◽  
Zhong Yi

During the integrated design of solar hot water system into high-rise residences, economy of solar hot water system directly effects its popularization and application. Combining with the concentrated solar water heating system on one high-rise residences, This paper tidies up the testing data on the June to October, and calculates solar insuring rate, auxiliary heat source heating rate and hot water cost at the different weather conditions, analyzes on the causes and provides some improvement advice, which will put forward the reference for architects to make the integrated design on the solar water heating system on high-rise residences.


Solar Energy ◽  
2006 ◽  
Author(s):  
Peter E. Zemke ◽  
Byard D. Wood

Hybrid solar lighting (HSL) has been successfully demonstrated as a means of collecting sunlight and transferring it through optical fibers into a building. The collected solar energy is primarily intended for illumination purposes. However, this technology may have an application in solar water heating. For a traditional solar water heating system, energy is required to pump the water to the roof and collected solar energy is lost to the environment through the collector and plumbing. If such a system is to be used in climates where the temperature falls below freezing, complexity is added resulting in lower system efficiencies. If, rather than pumping water to the roof to absorb solar energy, the solar radiation is “piped” into the hot water store, a solar water heating system may be much less complex and potentially more efficient. HSL technology can be used to collect solar radiation and transport it through optical fibers into a hot water store. Since the water remains in the tank, it is not exposed to freezing temperatures and heat loss through plumbing. The efficiency of the system would not be dependent on the outside temperature or the temperature of the water as traditional systems are, but solely on the efficiency in which solar radiation is transferred into the water. This paper will outline the major advantages of using HSL technology for solar water heating over traditional systems. The approximate efficiencies of a flat-plate collector, 2-axis solar tracking collector, and a system using HSL technology are compared using F-Chart for locations in the Southwestern and Northeastern United States. It is shown that improvements in efficiency are obtained using HSL technology if the system is capable of collecting and transferring the visible and infrared spectrum of solar radiation.


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