scholarly journals Optimal forecasting of thermal conductivity and storage in parabolic trough collector using phase change materials

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
P. Muruganantham ◽  
◽  
Balaji Dhanapal ◽  
Keyword(s):  
Solar Energy ◽  
Phase Change ◽  
Heat Loss ◽  
Thermal Efficiency ◽  
Phase Change Materials ◽  
Storage System ◽  
Solar Collectors ◽  
Parabolic Trough ◽  
Fluid Medium ◽  
Parabolic Trough Collector

Renewable energy is one of the cleaner energy generation strategies practiced all over the world to reduce environmental impacts and waste based on current sustainability in economic practices. Solar energy is one kind of renewable sources of energy practiced for different application. The thermal storage system in solar energy is one of the least practiced methods in research, and the utilization of solar energy in the thermal application is attaining higher responses and is quite possible. In this paper, solar heat generation is attained by solar parabolic trough collector using phase change materials. The ideology behind this research is to develop a thermal energy storage system using solar collectors and phase change materials. A composition mixture of MgCl2. 6H2O phase change materials used as the fluid medium in trough collector and thermal efficiency of the material is evaluated. For effective optimization, an imperialist competitive algorithm is used for optimizing the thermal efficiency of the solar collectors. The thermal efficiency of the collector is numerically experimented in the running platform of Mat Lab and executed in terms of heat gain, heat loss, and thermal efficiency of the parabolic trough collector, respectively. The efficiency of the proposed framework is 85%, and the current framework just has 80% efficiency. The heat loss in the proposed framework is lower than that of the current system, distinguished as 4200 W and 4520 W, respectively. It is shown from the research study that the proposed PCM composition is an optimal method for generating heat energy in solar parabolic trough collectors.

Experimental Study of Thermal Energy Storage in Solar System Using PCM

2012 ◽  
Vol 433-440 ◽  
pp. 1027-1032 ◽  
Author(s):  
B. Kanimozhi ◽  
B.R. Ramesh Bapu
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Storage System ◽  
Hot Water ◽  
Copper Tube

This paper summary the investigation and analysis of thermal energy storage extracted from solar heater and use for domestic purpose. Choosing a suitable phase change materials paraffin wax used for storing thermal energy in insulation tank. The tank carries minimum of 45 liters capacity of water and 50 numbers copper tubes each copper tube carries minimum of 100 grams PCM materials. Inside the tank phase change materials are receiving hot water from solar panel. This solar energy is stored in Copper tubes each copper tube contains PCM Materials as latent heat energy. Latent heat is absorbed and stored in Copper tubes .Large quantity of solar energy can be stored in a day time and same heat can be retrieved for later use. The tank was instrumented to measure inlet and outlet water temperature. The differences of temperature of the water is measured in a definite interval of time have been noted then calculating heat transfer rate and system effectiveness. The heat storage system is to be applied to store solar energy and the stored heat is used for domestic hot water supply system.

scholarly journals POTENTIAL USE OF PHASE CHANGE MATERIALS IN GREENHOUSES HEATING: COMPARISON WITH A TRADITIONAL SYSTEM

2009 ◽  
Vol 40 (3) ◽  
pp. 25
Author(s):  
Claudio Caprara ◽  
Giovanni Stoppiello
Keyword(s):  
Heat Exchange ◽  
Low Temperature ◽  
Phase Change ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Storage System ◽  
Inlet Temperature ◽  
Water Tank ◽  
Sensible Heat ◽  
Solar Collectors

In order to use solar radiation as thermal energy source, heat storage equipments result necessary in each application where continuous supply is required, because of the natural unsteady intensity of radiation during the day. Thermal solar collectors are especially suitable for low temperature applications, since their efficiency decreases when an high inlet temperature of fluid flowing through them is established. On the other hand, low temperatures and low temperature gaps, above all, make very difficult to use traditional sensible heat storing units (water tanks), because of the very large amounts of material required. In this work, a traditional sensible heat storage system is compared with a latent heat storing unit based on phase change materials (PCMs). As a case study, a 840 m3 greenhouse heating application was considered with an inside constant temperature of 18°C. It is thought to be heated by using single layer plate thermal solar collectors as energy source. Inlet temperature of the collectors fluid (HTF) was fixed at 35°C (little higher than melting temperature of PCMs) and a constant flux of 12 l/m2 hour was established as technical usual value. At these conditions, 215m2 solar panels exposed surface resulted necessary. The sensible heat storage system considered here is a traditional water tank storing unit equipped with two pipe coils, respectively for heat exchanges with HTF from collectors and water flux for greenhouse heating. Available DT for heat exchange is estimated as the difference of minimum HTF temperature (in outlet from the collectors) and the required water temperature for greenhouse heating. The latent heat storing unit is instead a series of copper rectangular plate shells which a phase change material is filled in (Na2SO4⋅10H2O). Heat transfer fluids flow through thin channels between adjacent plates, so that a large heat exchange available surface is achieved. The developed computational model (Labview software) permits to superimpose heat exchanges daily curves between heat storing materials and heat transport fluids (for both of the fluids and the heat storing equipments) on the energy supply/demand ones, respectively calculated on the basis of greenhouse energy demand and solar collectors dimensions, characteristics and efficiency. In this manner, units design is achieved by changing thermal energy storing units dimensions, in order that the corresponding heat exchange curves coincide with the previously calculated ones. Successively, among all the possible configurations, the ones showing lower units volumes and less amount of storing materials are chosen as the optimal design solutions. It has been proven that PCMs materials are much more suitable for low temperature applications than sensible heat storing materials (water). In the case of water tank, an about 15.8m3 total volume is required while for PCMs equipment the total volume of storing unit is reduced to about 2.2 m3, such as about seven times total volume less. Besides, according to the simplified and steady state model calculations, PCMs unit shows a better response to the hourly energy fluctuations of solar collectors and greenhouse demand than water tank unit. This is especially due to the high available exchange surface achieved in proposed arrangement.

Experimental Study on Thermal Efficiency of Parabolic Trough Collector (PTC) Using Al2O3/H2O Nanofluid

2015 ◽  
Vol 787 ◽  
pp. 192-196
Author(s):  
E. Siva Reddy ◽  
R. Meenakshi Reddy ◽  
K. Krishna Reddy
Keyword(s):  
Experimental Study ◽  
Solar Energy ◽  
Thermal Efficiency ◽  
Base Fluid ◽  
Concentration Ratio ◽  
Volume Fraction ◽  
Nano Particles ◽  
Parabolic Trough ◽  
Flow Rates ◽  
Parabolic Trough Collector

Dispersing small amounts of solid nano particles into base-fluid has a significant impact on the thermo-physical properties of the base-fluid. These properties are utilized for effective capture and transportation of solar energy. This paper attempts key idea for harvesting solar energy by using alumina nanofluid in concentrating parabolic trough collectors. An experimental study is carried out to investigate the performance of a parabolic trough collector using Al2O3-H2O based nanofluid. Results clearly indicate that at same ambient, inlet temperatures, flow rate, concentration ratio etc. hike in thermal efficiency is around 5-10 % compared to the conventional Parabolic Trough Collector (PTC). Further, the effect of various parameters such as concentration ratio, receiver length, fluid velocity, volume fraction of nano particles has been studied. The different flow rates employed in the experiment are 2 ml/s, 4 ml/s and 6 ml/s. Volumetric concentration of 0.02%, 0.04% and 0.06% has been studied in the experiment. Surfactants are not introduced to avoid bubble formation. Tracking mode of parabolic trough collector is manual. Results also reveal that Al2O3-H2O based nanofluid has higher efficiency at higher flow rates.

Solar energy based thermal energy storage system using phase change materials

2012 ◽  
Vol 3 (1) ◽  
pp. 11 ◽  
Author(s):  
R. Meenakshi Reddy ◽  
N. Nallusamy ◽  
T. Hariprasad ◽  
K. Hemachandra Reddy ◽  
G. Ramachandra Reddy
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Storage System ◽  
Energy Storage System ◽  
Thermal Energy Storage System

scholarly journals Generation of a Parabolic Trough Collector Efficiency Curve From Separate Measurements of Outdoor Optical Efficiency and Indoor Receiver Heat Loss

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Charles Kutscher ◽  
Frank Burkholder ◽  
J. Kathleen Stynes
Keyword(s):  
Ambient Temperature ◽  
Heat Loss ◽  
Thermal Efficiency ◽  
Operating Temperature ◽  
Efficiency Curve ◽  
Parabolic Trough ◽  
Optical Efficiency ◽  
Parabolic Trough Collector ◽  
Collector Efficiency ◽  
The Difference

The thermal efficiency of a parabolic trough collector is a function of both the fraction of direct normal radiation absorbed by the receiver (the optical efficiency) and the heat lost to the environment when the receiver is at operating temperature. The thermal efficiency can be determined by testing the collector under actual operating conditions or by separately measuring these two components. This paper describes how outdoor measurement of the optical efficiency is combined with laboratory measurements of receiver heat loss to obtain the thermal efficiency curve. This paper describes this approach and also makes the case that there are advantages to plotting collector efficiency versus the difference between the operating temperature and the ambient temperature at which the receiver heat loss was measured divided by radiation to a fractional power (on the order of 1/3 but obtained via data regression)—as opposed to the difference between operating and ambient temperatures divided by the radiation. The results are shown to be robust over wide ranges of ambient temperature, sky temperature, and wind speed.

Improving the thermal efficiency of a solar dryer using phase change materials at different position in the collector

Solar Energy ◽  
2021 ◽  
Vol 220 ◽  
pp. 535-551
Author(s):  
Hana Ebrahimi ◽  
Hadi Samimi Akhijahani ◽  
Payman Salami
Keyword(s):  
Phase Change ◽  
Thermal Efficiency ◽  
Phase Change Materials ◽  
Solar Dryer

Experimental investigation of transpired solar collectors with/without phase change materials

Solar Energy ◽  
2021 ◽  
Vol 214 ◽  
pp. 478-490
Author(s):  
A.S. Bejan ◽  
C. Teodosiu ◽  
C.V. Croitoru ◽  
T. Catalina ◽  
I. Nastase
Keyword(s):  
Experimental Investigation ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solar Collectors
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