Numerical Study of Nanofluid-Based Solar Collector for Humidification-Dehumidification (HDH) Desalination

2018 ◽  
Author(s):  
Kapil Garg ◽  
Vikrant Khullar ◽  
Sarit K. Das ◽  
Himanshu Tyagi
Keyword(s):  
Solar Collector ◽  
Numerical Study ◽  
Open Water ◽  
Operating Conditions ◽  
Small Scale ◽  
Outlet Temperature ◽  
Direct Absorption ◽  
Output Ratio ◽  
Direct Absorption Solar Collector ◽  
Desalination Technology

Humidification-dehumidification (HDH) desalination technology is one such technology (based on thermal desalination technology) which has been found to be ideal for small scale water productions (1–100 m3/day). It requires less maintenance and can be combined with renewable energy sources such as solar or geothermal due to lower temperature operation. In this paper, nanofluid-based direct absorption solar collector (DASC) has been coupled with the one of the versions of HDH desalination system (closed air open water - CAOW) with the help of a counter-flow heat exchanger. These collectors (DASCs) have high thermal efficiency (10% higher) as compared to conventional surface absorption based collectors. Numerical model is prepared for a closed air open water HDH system, working together with a direct absorption solar collector. The aim of the present study is to evaluate the thermal performance of the system in terms of gained output ratio (GOR) against the various influencing parameters related to the solar collector such as, height (H) and length (L) of the collector, nanoparticle volume fraction (fv), and incident solar radiation on the collector (q) and the effect of the aforementioned parameters on the collector outlet temperature (Tout) have also been analyzed in detail. Solar weighted absorptivity (Sab) for different nanofluids has also been calculated which helps in choosing the suitable nanoparticle material for preparing the nanofluid. The gained output ratio of the proposed system was found to be around 16% higher, compared to conventional CAOW-HDH desalination systems under certain operating conditions. Finally, the model proposed in this study has been validated with the data available in literature.

Numerical Simulation on the Performance of Nanofluid-Based Direct Absorption Solar Collector With Parabolic Trough Concentrator

2016 ◽  
Author(s):  
Wei Chen ◽  
Guoying Xu ◽  
Sainan Zhao ◽  
Xiaosong Zhang
Keyword(s):  
Heat Transfer ◽  
Solar Collector ◽  
Numerical Study ◽  
Radiation Absorption ◽  
Transfer Model ◽  
Direct Absorption ◽  
Operating Characteristics ◽  
Parabolic Trough ◽  
Weight Concentration ◽  
Direct Absorption Solar Collector

Nanofluids obtain high stability, improved heat transfer capability and excellent optical properties, the low-temperature nanofluid-based direct absorption solar collector (NDASC) has been previously investigated. However, the detailed radiation absorption and heat transfer mechanism for a NDASC with a solar concentrator operated on medium-temperature conditions were seldom researched. Therefore, this paper presents a numerical study on the solar collection characteristics of NDASC with a parabolic trough concentrator. CuO/oil nanofluids with various weight concentration from 0.05% to 0.1% were prepared, and used as working fluids of NDASCs, respectively. Using the developed heat transfer model, operating characteristics of NDASCs were simulated. Furthermore, the influences of weight concentration of nanofluids on the heat transfer characteristics in the NDASCs were analyzed and optimum weight concentration used for the designed NDASC obtained.

Predicted Efficiency of a Low-Temperature Nanofluid-Based Direct Absorption Solar Collector

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Himanshu Tyagi ◽  
Patrick Phelan ◽  
Ravi Prasher
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Pure Water ◽  
Operating Conditions ◽  
Heat Transfer Analysis ◽  
Working Fluid ◽  
Direct Absorption ◽  
Direct Absorption Solar Collector ◽  
Low Efficiency ◽  
Flat Plate Collector

Due to its renewable and nonpolluting nature, solar energy is often used in applications such as electricity generation, thermal heating, and chemical processing. The most cost-effective solar heaters are of the “flat-plate” type, but these suffer from relatively low efficiency and outlet temperatures. The present study theoretically investigates the feasibility of using a nonconcentrating direct absorption solar collector (DAC) and compares its performance with that of a typical flat-plate collector. Here a nanofluid—a mixture of water and aluminum nanoparticles—is used as the absorbing medium. A two-dimensional heat transfer analysis was developed in which direct sunlight was incident on a thin flowing film of nanofluid. The effects of absorption and scattering within the nanofluid were accounted for. In order to evaluate the temperature profile and intensity distribution within the nanofluid, the energy balance equation and heat transport equation were solved numerically. It was observed that the presence of nanoparticles increases the absorption of incident radiation by more than nine times over that of pure water. According to the results obtained from this study, under similar operating conditions, the efficiency of a DAC using nanofluid as the working fluid is found to be up to 10% higher (on an absolute basis) than that of a flat-plate collector. Generally a DAC using nanofluids as the working fluid performs better than a flat-plate collector, however, much better designed flat-plate collectors might be able to match or outperform a nanofluids based DAC under certain conditions.

Experimental Study of Water-Based Al2O3Nanofluid Flow in Direct Absorption Solar Collector

2015 ◽  
Vol 357 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Hemant Kumar Gupta ◽  
Ghanshyam Das Agrawal ◽  
Jyotirmay Mathur
Keyword(s):  
Experimental Study ◽  
Solar Collector ◽  
Direct Absorption ◽  
Water Based ◽  
Direct Absorption Solar Collector

Performance of a tubular direct absorption solar collector with a carbon-based nanofluid

2021 ◽  
Vol 179 ◽  
pp. 121717
Author(s):  
P.G. Struchalin ◽  
V.S. Yunin ◽  
K.V. Kutsenko ◽  
O.V. Nikolaev ◽  
A.A. Vologzhannikova ◽  
...  
Keyword(s):  
Solar Collector ◽  
Direct Absorption ◽  
Direct Absorption Solar Collector ◽  
Carbon Based

Experimental Study on the Desalination System Using Humidification-Dehumidification Technology

2020 ◽  
Vol 1008 ◽  
pp. 177-185
Author(s):  
Hamed Abbady ◽  
Mahmoud Salem Ahmed ◽  
Hamdy Hassan ◽  
A.S.A. Mohamed
Keyword(s):  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Major Objective ◽  
Cooling Water Flow Rate ◽  
Output Ratio

In this paper, an experimental work studies the principal operating parameters of a proposed desalination process using air humidification-dehumidification method. The major objective of this work is to determine the humid air behavior through the desalination system. Different operating conditions including the effect of the water temperature at the entry to the humidifier, the ratio of the mass of water to the air, the air/water flow rate, and cooling water at entry the dehumidifier on the desalination performance were studied. The results show that the freshwater increases with increasing the water temperature at the inlet of the humidifier, the ratio of the mass of water to air, and cooling water flow rate in the dehumidifier. Cooling water outlet temperature at the condenser increases with increasing the water temperature at humidifier inlet. Also, it decreases as increasing cooling water flow rate while the ratio of the mass of water to air achieves the highest productivity and gained output ratio (GOR). The achieved mass ratio (MR) is 4.5 and the mass flow rate of air is 0.8 kg/min.

scholarly journals Performance Investigation of High Temperature Application of Molten Solar Salt Nanofluid in a Direct Absorption Solar Collector

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 285 ◽  
Author(s):  
M. Karim ◽  
Owen Arthur ◽  
Prasad Yarlagadda ◽  
Majedul Islam ◽  
Md Mahiuddin
Keyword(s):  
High Temperature ◽  
Molten Salt ◽  
Solar Collector ◽  
Volume Fraction ◽  
Heat Transfer Fluid ◽  
Total Efficiency ◽  
Total System ◽  
Direct Absorption ◽  
Wide Range ◽  
Direct Absorption Solar Collector

Nanofluids have great potential in a wide range of fields including solar thermal applications, where molten salt nanofluids have shown great potential as a heat transfer fluid (HTF) for use in high temperature solar applications. However, no study has investigated the use of molten salt nanofluids as the HTF in direct absorption solar collector systems (DAC). In this study, a two dimensional CFD model of a direct absorption high temperature molten salt nanofluid concentrating solar receiver has been developed to investigate the effects design and operating variables on receiver performance. It has been found that the Carnot efficiency increases with increasing receiver length, solar concentration, increasing height and decreasing inlet velocity. When coupled to a power generation cycle, it is predicted that total system efficiency can exceed 40% when solar concentrations are greater than 100×. To impart more emphasis on the temperature rise of the receiver, an adjusted Carnot efficiency has been used in conjunction with the upper temperature limit of the nanofluid. The adjusted total efficiency also resulted in a peak efficiency for solar concentration, which decreased with decreasing volume fraction, implying that each receiver configuration has an optimal solar concentration.

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