An Average Slope Factor for Solar Insolation

1980 ◽  
Vol 102 (3) ◽  
pp. 223-226
Author(s):  
R. L. Field
Keyword(s):  
Tilt Angle ◽  
Solar Collector ◽  
Hot Water ◽  
Space Heating ◽  
Solar Insolation ◽  
Average Slope ◽  
Slope Factor ◽  
The Given ◽  
Single Set ◽  
Haze Factor

Design methods for solar collector sizing (such as f-chart) usually require a multiplying factor (the slope factor) to correct insolation data taken on the horizontal for the tilt angle of the solar collector. The slope factor is a function of the haze factor (KT) at each location which varies month to month. A simplification (with attendant error) can be made for space heating by taking the 6 month average winter haze factor as a constant to get a single set of slope factor curves. For hot water heating a 12 month average of the haze factor is used to find the correct slope factor chart. Available slope factor equations using average haze factors were plotted to result in a chart whose parameters are latitude and month of year. Correction charts for off-average locations are presented. The error in the given slope factor charts is estimated to be accurate ± 7 percent for most cities.

Architecture Design of Building Integrated Solar Collector

2014 ◽  
Vol 889-890 ◽  
pp. 1333-1336
Author(s):  
Yu Fu ◽  
Kai Chen ◽  
Fei Ying Fu ◽  
Xin Bin Wang
Keyword(s):  
Water Supply ◽  
Solar Collector ◽  
Residential Buildings ◽  
Radiation Energy ◽  
Hot Water ◽  
Space Heating ◽  
Solar Collectors ◽  
Domestic Hot Water ◽  
Heating And Cooling ◽  
Hot Water Supply

Solar thermal collector converts solar radiation energy into useful thermal energy and transfers to a transport fluid flowing through the system. The collected energy can be used either direct to space or water heating equipment, or to a thermal storage for later use. Along with fast development, not only domestic hot water supply is needed, but also space heating and cooling are required. Also, limited roof space is another key barrier that should be considered. Furthermore, most of the building integration with solar collectors are mounted on the roof top by flat or tilt angle at present. It is considered to be a failure of low level architectural quality because the collector is used only for application and seems as an independent technical element of the building. With the consideration of the above, novel type of solar collector has been proposed to realize the utilization and offset the barriers. This novel solar collectors is especially suitable to supply domestic hot water, and combines with ASHP for multi-function, space heating and cooling as well as domestic hot water supply. Additionally, it is well integrated with high-rise residential buildings, which is good for aesthetic.

scholarly journals Analysis of the Solar Collectors Installation on a Roof of the Small Public Building in Poland, Lithuania and Spain—A Case Study

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1272 ◽  
Author(s):  
Dorota Anna Krawczyk ◽  
Mirosław Żukowski ◽  
Antonio Rodero ◽  
Ruta Bilinskiene
Keyword(s):  
Solar Radiation ◽  
Tilt Angle ◽  
Solar Collector ◽  
Simulation Software ◽  
Hot Water ◽  
Government Support ◽  
Office Building ◽  
Radiation Balance ◽  
Solar Collectors

A solar collector market is most European countries is at the stage of continuous development, however its expansion rate differs. It shows that much more factors than only the local solar radiation is important, including a technology progress, costs, local manufactures’ engagement, an economic government support or an environmentally consciousness raising relevant to a mitigating climate change. We conducted the analysis for a public office building, with a few toilets and a social room, used by 54 people. As a primary heat source for HVAC and DHW systems an oil boiler was used, whereas solar collectors were considered as an energy source for hot water preparation. The analysis was conducted for three locations of the building: Bialystok (Poland), Cordoba (Spain) and Kaunas (Lithuania), using a simulation software delivered within the framework of VIPSKILLS project. Theoretical hot water consumption was considered as 3–7 dm3/(day person) in compliance with national recommendations. It was found that beam solar radiation share in a total radiation balance was nearly twice higher in Cordoba than in Bialystok or Kaunas. The highest efficiency (44%) was estimated in Cordoba for solar collectors installed with the tilt angle between 45–50°. In case of Bialystok and Kaunas the efficiency was lower than in Cordoba and nearly equal 40–41% and the recommended tilt angle was in a range 30– 45°.

Optimization Position and Tilt Angle for Automatic Tracking Solar Collector in Solar Thermal Cooling System of Building MRC FTUI

2015 ◽  
Vol 780 ◽  
pp. 75-80 ◽  
Author(s):  
Nasruddin ◽  
Aldi Suyana ◽  
Budihardjo ◽  
Arnas
Keyword(s):  
Tilt Angle ◽  
Solar Collector ◽  
Cooling System ◽  
Hot Water ◽  
Solar Thermal ◽  
Parameter Study ◽  
Power Efficient ◽  
System Utilization ◽  
Solar Thermal Cooling ◽  
Thermal Cooling

The solar thermal cooling system is expected to replace the utilization of conventional cooling system, particularly the vapour compression system. This cooling system is power-efficient, refrigerant environmentally friendly and able to use the abundant potential of solar energy. Hence, the optimization of this cooling system is necessary in order to obtain the best performance. For that purpose, this study focus on the simulation phase of the solar thermal cooling system utilization in MRC FTUI building as well as the optimization of solar collector applying EnergyPlus and GenOpt software. The position and the tilt angle of solar collector set as parameter study to gain the best performance of solar collector to produce hot water, which will be used as energy source in the absorption chiller. Finally, the optimum position and the optimum tilt angle every month in a year were obtained from this study.

scholarly journals Numerical and Experimental Study of an Asymmetric CPC-PVT Solar Collector

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1669 ◽  
Author(s):  
Pouriya Nasseriyan ◽  
Hossein Afzali Gorouh ◽  
João Gomes ◽  
Diogo Cabral ◽  
Mazyar Salmanzadeh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Solar Cells ◽  
Flow Rate ◽  
Tilt Angle ◽  
Solar Collector ◽  
Hot Water ◽  
Back Side ◽  
Cell Temperature ◽  
Compound Parabolic Concentrator ◽  
Operating Cell

Photovoltaic (PV) panels and thermal collectors are commonly known as mature technologies to capture solar energy. The efficiency of PV cells decreases as operating cell temperature increases. Photovoltaic Thermal Collectors (PVT) offer a way to mitigate this performance reduction by coupling solar cells with a thermal absorber that can actively remove the excess heat from the solar cells to the Heat Transfer Fluid (HTF). In order for PVT collectors to effectively counter the negative effects of increased operating cell temperature, it is fundamental to have an adequate heat transfer from the cells to the HTF. This paper analyzes the operating temperature of the cells in a low concentrating PVT solar collector, by means of both experimental and Computational Fluid Dynamics (CFD) simulation results on the Solarus asymmetric Compound Parabolic Concentrator (CPC) PowerCollector (PC). The PC solar collector features a Compound Parabolic Concentrator (CPC) reflector geometry called the Maximum Reflector Concentration (MaReCo) geometry. This collector is suited for applications such as Domestic Hot Water (DHW). An experimental setup was installed in the outdoor testing laboratory at Gävle University (Sweden) with the ability to measure ambient, cell and HTF temperature, flow rate and solar radiation. The experimental results were validated by means of an in-house developed CFD model. Based on the validated model, the effect of collector tilt angle, HTF, insulation (on the back side of the reflector), receiver material and front glass on the collector performance were considered. The impact of tilt angle is more pronounced on the thermal production than the electrical one. Furthermore, the HTF recirculation with an average temperature of 35.1 °C and 2.2 L/min flow rate showed that the electrical yield can increase by 25%. On the other hand, by using insulation, the thermal yield increases up to 3% when working at a temperature of 23 °C above ambient.

scholarly journals Life Cycle Assessment of the Use of Phase Change Material in an Evacuated Solar Tube Collector

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4146
Author(s):  
Agnieszka Jachura ◽  
Robert Sekret
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impact ◽  
Phase Change ◽  
Phase Change Material ◽  
Solar Collector ◽  
Hot Water ◽  
Production Operation ◽  
Management Scenarios ◽  
Change Material

This paper presents an environmental impact assessment of the entire cycle of existence of the tube-vacuum solar collector prototype. The innovativeness of the solution involved using a phase change material as a heat-storing material, which was placed inside the collector’s tubes-vacuum. The PCM used in this study was paraffin. The system boundaries contained three phases: production, operation (use phase), and disposal. An ecological life cycle assessment was carried out using the SimaPro software. To compare the environmental impact of heat storage, the amount of heat generated for 15 years, starting from the beginning of a solar installation for preparing domestic hot water for a single-family residential building, was considered the functional unit. Assuming comparable production methods for individual elements of the ETC and waste management scenarios, the reduction in harmful effects on the environment by introducing a PCM that stores heat inside the ETC ranges from 17 to 24%. The performed analyses have also shown that the method itself of manufacturing the materials used for the construction of the solar collector and the choice of the scenario of the disposal of waste during decommissioning the solar collector all play an important role in its environmental assessment. With an increase in the application of the advanced technologies of materials manufacturing and an increase in the amount of waste subjected to recycling, the degree of the solar collector’s environmental impact decreased by 82% compared to its standard manufacture and disposal.

scholarly journals Experimental Comparison of Innovative Composite Sorbents for Space Heating and Domestic Hot Water Storage

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 476
Author(s):  
Vincenza Brancato ◽  
Larisa G. Gordeeva ◽  
Angela Caprì ◽  
Alexandra D. Grekova ◽  
Andrea Frazzica
Keyword(s):  
Silica Gel ◽  
Xrd Analysis ◽  
Complete Characterization ◽  
Operating Conditions ◽  
Hot Water ◽  
Experimental Comparison ◽  
Space Heating ◽  
Calorimetric Analysis ◽  
Domestic Hot Water ◽  
Composite Sorbents

In this study, the development and comparative characterization of different composite sorbents for thermal energy storage applications is reported. Two different applications were targeted, namely, low-temperature space heating (SH) and domestic hot water (DHW) provision. From a literature analysis, the most promising hygroscopic salts were selected for these conditions, being LiCl for SH and LiBr for DHW. Furthermore, two mesoporous silica gel matrixes and a macroporous vermiculite were acquired to prepare the composites. A complete characterization was performed by investigating the porous structure of the composites before and after impregnation, through N2 physisorption, as well as checking the phase composition of the composites at different temperatures through X-ray powder diffraction (XRD) analysis. Furthermore, sorption equilibrium curves were measured in water vapor atmosphere to evaluate the adsorption capacity of the samples and a detailed calorimetric analysis was carried out to evaluate the reaction evolution under real operating conditions as well as the sorption heat of each sample. The results demonstrated a slower reaction kinetic in the vermiculite-based composites, due to the larger size of salt grains embedded in the pores, while promising volumetric storage densities of 0.7 GJ/m3 and 0.4 GJ/m3 in silica gel-based composites were achieved for SH and DHW applications, respectively.

scholarly journals Overview of Solutions for the Low-Temperature Operation of Domestic Hot-Water Systems with a Circulation Loop

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3350
Author(s):  
Theofanis Benakopoulos ◽  
William Vergo ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Svend Svendsen
Keyword(s):  
Low Temperature ◽  
Heat Loss ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Heating Power ◽  
Circulation Loop ◽  
Space Heating ◽  
District Heating System ◽  
Domestic Hot Water

The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.

scholarly journals ANALISYS OF THERMAL EFFICIENCY OF A MODIFIED SOLAR COLLECTOR TYPE EVACUATED TUBE

2014 ◽  
Vol 13 (1) ◽  
pp. 03
Author(s):  
E. Avallone ◽  
A. I. Sato ◽  
V. L. Scalon ◽  
A. Padilha
Keyword(s):  
Solar Collector ◽  
Renewable Energy Sources ◽  
Experimental Tests ◽  
Clean Energy ◽  
Hot Water ◽  
Energy Sources ◽  
Transient Heat Flow ◽  
Important Approach ◽  
Experimental Problem ◽  
Evacuated Tube

The need of renewable energy sources due to climate change and thus the search for clean energy sources, justify the growing investment on new types of solar collectors. The research has contributed to this expansion in the scope of solar concentrator collectors, with the efficiency as the main goal. Many works have been developed in order to optimize the thermal stratification of the fluid inside the tubes and heat reservoirs, as well as mathematical modeling considering the problem as transient heat flow as boundary condition. In this work is studied experimentally, the heating of the water by solar collector modified from the conventional evacuated tube, focusing on efficiency. With the help of CFD software, a theoretical analysis is done to visualize the phenomenon, assuming the same boundary conditions and geometric experimental problem. An important approach concerns the physical separation of the flows of both cold and hot water inside the evacuated tube. The system performance was analyzed using experimental tests performed outdoors with sunlight.

Solar Water Heater Design for Houses in Arid Zones

2013 ◽  
Author(s):  
Ramses Vega ◽  
Hector E. Campbell ◽  
Juan de Dios Ocampo ◽  
Diego R. Bonilla G.
Keyword(s):  
Solar Collector ◽  
Extreme Temperature ◽  
Hot Water ◽  
Arid Zones ◽  
Water Heater ◽  
Collector System ◽  
End Use ◽  
Flat Plate Solar Collector ◽  
Demand Profile ◽  
Heater Design

This paper shows the simulation and design of a flat plate solar collector system, used to feed hot water to a typical home located in the city of Mexicali, Baja California, México. The system consists of a solar collector, a storage tank, a water pump and accessories and special tools that allow its proper operation. Analyzing the consumption and end use of water in a typical House, a demand profile is established, which combined with the weather information of the region, constitutes the input parameters required for the simulation of the system, which is performed with the software package TRNSYS. Mexicali, due to its location (latitude 32 °, longitude 114 °) and semi-desert condition presents high temperatures in the summer and low in winter, so the design and operation of such systems require special features, not always considered in the conventional ratings. This paper presents methods for simulation and design oriented to optimize the dimensioning and operation of this type of solar heaters in regions with extreme temperature conditions.

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