scholarly journals INFLUENCE OF SOLAR COLLECTOR SURFACE ON ITS THERMAL ENERGY EFFICIENCY

2021 ◽  
Vol 177 (27) ◽  
pp. 165-171
Author(s):  
Sławomir Morel ◽  
◽  
Magdalena Skrzyniarz ◽  
Keyword(s):  
Energy Efficiency ◽  
Thermal Energy ◽  
Solar Collector

The AQUASOL System: Solar Collector Field Efficiency and Solar-Only Mode Performance

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
Julián Blanco ◽  
Diego Alarcón ◽  
Elena Guillén ◽  
Wolfgang Gernjak
Keyword(s):  
Energy Efficiency ◽  
Heat Pump ◽  
Thermal Energy ◽  
Solar Collector ◽  
Performance Ratio ◽  
Inlet Temperature ◽  
Renewable Energy Resources ◽  
Seawater Desalination ◽  
Operating Modes ◽  
Solar Desalination

Water scarcity is a global problem that will be of capital importance during the first half of this century, when seawater desalination will often be the only way to achieve sustainable development. Despite significant energy efficiency improvements during recent years, seawater desalination is still an intensive energy consumer; therefore, in the current instability of oil prices and environmental requirements, the sustainability of this technological solution inevitably passes through continued improvement of energy efficiency of the physical processes involved, as well as the use of renewable energy resources such as solar energy. In 2006, the “Enhanced Zero Discharge Seawater Desalination Using Hybrid Solar Technology” Project (AQUASOL) concluded with the erection of a complete solar desalination facility at the Plataforma Solar de Almeria (Spain) for the main purpose of developing an improved-cost, energy-efficient multi-effect distillation (MED) solar desalination technology. The system was designed to make the following three desalination operating modes feasible: (a) solar-only: the energy to the first distillation effect comes exclusively from thermal energy from the solar collector field, (b) fossil-only: a double-effect absorption heat pump powered by gas supplies all of the heat required by the distillation plant, and (c) hybrid: the energy comes from both the heat pump and the solar field. In this paper, solar-only mode system performance is presented and discussed. Optimum working conditions achieved in the solar-only mode were in the range of 64–67°C of MED first cell inlet temperature, which implies specific thermal energy consumption from around 58 kW hth/m3 to 62 kW hth/m3 and a performance ratio of 11.1–10.4, respectively.

scholarly journals Overall Efficiency of On-Site Production and Storage of Solar Thermal Energy

2021 ◽  
Vol 13 (3) ◽  
pp. 1360
Author(s):  
Teodora M. Șoimoșan ◽  
Ligia M. Moga ◽  
Livia Anastasiu ◽  
Daniela L. Manea ◽  
Aurica Căzilă ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Thermal Energy ◽  
Urban Areas ◽  
Renewable Energy Sources ◽  
Multicriteria Analysis ◽  
High Energy ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
The Impact ◽  
And Storage

Harnessing renewable energy sources (RES) using hybrid systems for buildings is almost a deontological obligation for engineers and researchers in the energy field, and increasing the percentage of renewables within the energy mix represents an important target. In crowded urban areas, on-site energy production and storage from renewables can be a real challenge from a technical point of view. The main objectives of this paper are quantification of the impact of the consumer’s profile on overall energy efficiency for on-site storage and final use of solar thermal energy, as well as developing a multicriteria assessment in order to provide a methodology for selection in prioritizing investments. Buildings with various consumption profiles lead to achieving different values of performance indicators in similar configurations of storage and energy supply. In this regard, an analysis of the consumption profile’s impact on overall energy efficiency, achieved in the case of on-site generation and storage of solar thermal energy, was performed. The obtained results validate the following conclusion: On-site integration of solar systems allowed the consumers to use RES at the desired coverage rates, while restricted by on-site available mounting areas for solar fields and thermal storage, under conditions of high energy efficiencies. In order to segregate the results and support optimal selection, a multicriteria analysis was carried out, having as the main criteria the energy efficiency indicators achieved by hybrid heating systems.

scholarly journals THE INFLUENCE OF THE METHOD OF LAYING PIPELINES ON THE ENERGY EFFICIENCY OF THE HEATING NETWORK

2019 ◽  
Vol 10 (2) ◽  
pp. 59-66
Author(s):  
E. A Biryuzova ◽  
A. S Glukhanov
Keyword(s):  
Energy Efficiency ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Thermal Energy ◽  
Great Influence ◽  
Temperature Fields ◽  
Insulation Material ◽  
Design Work ◽  
Heat Networks ◽  
Insulation Thickness

Through pipelines of heat networks, due to their large length, a large amount of thermal energy is lost. Identification of technical solutions related to improving the energy efficiency of heating networks is an urgent task at present. The article is devoted to the consideration of options for laying pipelines of heat networks during design work. In the conducted studies, two main methods of underground laying of pipelines of heat networks with the choice of the most energy-efficient, with minimal losses of thermal energy are considered. Channel and channelless laying methods are investigated with the same design features and technological conditions of operation of pipelines of heat networks using the same thermal insulation material. For each option, the required thickness of the thermal insulation is determined by the normalized density of the heat flow, thermal calculations are performed to determine the heat loss and the value of the temperature fields generated around the operating pipelines of the heat networks. The obtained values of the thermal insulation thickness in the channel method of laying pipelines are 30-50 % lower than those in channelless laying. The heat loss values, according to the results of the heat calculation for the options under consideration, in the channel method of laying are reduced by 47-65 %. The temperature fields formed around the pipelines of thermal networks with channelless laying significantly exceed the natural value of the soil temperature at the depth of the pipeline. What has a great influence on the determination of the distance to adjacent pipelines and other utilities, laid underground, in the zone of the thermal network. A comparative analysis of the results obtained makes it possible to single out the choice of the method of laying the pipeline into a group of measures aimed at energy saving and increasing energy efficiency in heating systems.

Designing a novel solar-assisted heat pump system with modification of a thermal energy storage unit

2019 ◽  
Vol 233 (5) ◽  
pp. 588-603 ◽  
Author(s):  
Mustafa Aktaş ◽  
Meltem Koşan ◽  
Erhan Arslan ◽  
Azim Doğuş Tuncer
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Collector ◽  
Working Fluid ◽  
Storage Unit ◽  
Heating Systems ◽  
Energy Storage Unit

The integrated usage of solar energy systems, heat pump applications, and thermal energy storage units is an effective way for heating systems due to their sustainability and stability in operations. In this study, a novel direct solar-assisted heat pump with thermal energy system has been designed which uses the solar collector as the evaporator of the heat pump. Besides, two-dimensional transient numeric analyses have been conducted for the thermal energy storage unit using the ANSYS Fluent 16.2 commercial software package. With this direct system, the heat required for heating systems is supplied from the condenser with the heat received from the solar collector of the working fluid. For an effective and high performance system, the solar collector is designed as a double-pass which provided superheating of the working fluid. It is aimed to store the surplus energy from the solar energy in the thermal energy storage unit and to operate the system continuously and efficiently in both sunny and overcast weather conditions. Furthermore, the system has been analyzed theoretically and the results show that coefficient of performance may improve. As a result, this newly designed system can be successfully applied for thermal applications.

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