CFD and comparative study on the dual-function solar collectors with and without tile-shaped covers in water heating mode

He, Wei; Hong, Xiaoqiang; Luo, Bingqing; Chen, Hongbing; Ji, Jie

doi:10.1016/j.renene.2015.09.053

Cited by 29 publications

(10 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In agreement with the values of temperature gradient, the energy harvested by the collector increases with the flow rate (although it does it in a non-linear manner), thus resulting in higher performances as the flow rate grows (Figure 7). Similar trends of temperature gradient and thermal performance were obtained by Wu [5] and He [34], respectively, in spite of the different specific results achieved by them due to the different magnitudes considered. As seen in Figure 7, negligible differences have been obtained in terms of the average temperature reached by the collector's surface for the three values of flow rate studied.…”

Section: Influence Of the Water Flow Rate And Validation Of The Numersupporting

confidence: 81%

“…In order to calculate the heat transfer occurring by radiation, the model S2S (Surface to Surface) was used. This radiation model has been previously used by other researchers for the numerical analysis of the performance of different conventional solar collectors [34]. The S2S model assumes that the surfaces are grey and diffuse, and therefore the amount of radiation reaching a surface (q) can be reflected (q•ρ), absorbed (q•α) or transmitted (q•τ).…”

Section: Mathematical Approach and Energy Balancementioning

confidence: 99%

See 1 more Smart Citation

3D numerical modelling and experimental validation of an asphalt solar collector

Alonso-Estébanez

Pascual-Muñoz

Sampedro-García

et al. 2017

Applied Thermal Engineering

View full text Add to dashboard Cite

Research about renewable technologies for thermal energy collection is crucial when critical problems such as climate change, global warming or environmental pollution are concerned. Transforming solar energy into thermal energy by means of asphalt solar collectors might help to reduce greenhouse gas emissions and fossil fuel consumption. In this paper, a laboratory-scale asphalt solar collector formed by different slabs has been characterized by applying numerical techniques. An experimental test where the thermal performance of the collector was determined for three values of heat exchange fluid flow rate was carried out for the validation of the numerical model. Then, the CFD model was used to analyse the thermal response of the collector according to the following parameters: flow rate, solar irradiance, size and thickness. Results show that increasing values of heat exchange fluid flow rate result in better thermal performances. Likewise, increasing values of irradiance and size of the collector lead to higher values of thermal performance, although other parameters should also be considered for the final design of the system. Finally, under the conditions here considered, the thickness of the collector turned out not to be as significant as expected in relation to its thermal response. The combination of experimental tests and CFD codes can be considered a powerful tool for the characterization of asphalt solar collectors without incurring significant costs related to experimental field tests.

show abstract

Section: Influence Of the Water Flow Rate And Validation Of The Numersupporting

confidence: 81%

Section: Mathematical Approach and Energy Balancementioning

confidence: 99%

3D numerical modelling and experimental validation of an asphalt solar collector

Alonso-Estébanez

Pascual-Muñoz

Sampedro-García

et al. 2017

Applied Thermal Engineering

View full text Add to dashboard Cite

show abstract

“…Adiabatic and non-slippage was set as boundary conditions of the pipe. The Scalable function which could promote convergence and accuracy of simulation was used as the near wall face function [17][18][19][20]. Solution with applying FLUENT software is equivalent to a residual error comparison process.…”

Section: Computational Models Of a Variety Of Pipesmentioning

confidence: 99%

Numerical investigation on impacts of leakage sizes and pressures of fluid conveying pipes on aerodynamic behaviors

Mu¹,

Zhang²

2017

J. vibroeng.

View full text Add to dashboard Cite

Small hole leakage of pipes caused by erosion and perforation is the major form leading to the leakage. The leakage rate is an important premise and foundation for consequence computation and risk evaluation. Those published papers fail to systematically study impacts of initial pressures and leakage sizes of a pipe on the leakage rate. More numerical simulation results are not verified by experimental test. This paper applies numerical simulation technology to establish the model of small hole leakage in pipes, designs and processes different leakage modules to simulate different leakage scenes, and then experimentally validates the model correctness. On this basis, this paper studies impacts of initial pressures and leakage sizes on leakage rates and obtains fluid dynamic characteristics around the leakage hole, including velocity distribution and pressure distribution. However, in actual engineering, the position of leakage hole could not be predicted and changed in general. Therefore, this paper further studies impacts of leakage hole positions on the pipe leakage rate. In this way, this research is refined and could provide a theoretical basis for emergency rescue and accident survey of pipe leakage accidents.

show abstract

“…The convection heat transfer coefficient on the top and bottom side of the collector used in this study can be expressed by equation (2), (3) for considering heat loss [8],…”

Section: B Simulation Methodsmentioning

confidence: 99%

Numerical Analysis on Thermal Efficiency of Hybrid Solar Collector with Fin-and-Tube Heat Exchanger

Choi¹,

Rokhman²,

Son³

et al. 2018

JOCET

View full text Add to dashboard Cite

A solar assisted heat pump system uses solar thermal energy as a heat source for evaporator in the heat pump by applying solar collector. The COP (coefficient of performance) of the heat pump can be increased when the evaporating temperature increases. The efficiency of the solar collector can be increased because it has lower operating temperature compare to traditional solar collector. Thus, as a part of these researches, a hybrid solar collector that has fin-and-tube heat exchanger has been developed. This collector is flat plat solar collector that can get thermal energy from ambient air for heating the circulating water in the collector by heat exchanging between the air and water side in fin-and-tube heat exchanger. This heated water can be used as heat source of the evaporator in the heat pump even if the solar energy is not enough. So, in this study, an numerical analysis was conducted for confirming the heat gain and pressure drop of water in the collector when the solar energy was provided. As a result, lower thermal efficiency and higher overall heat loss coefficient were obtained when the air channel of the fin-and-tube heat exchanger was opened. But, in case of the closed air channel type, similar maximum thermal efficiency and slightly higher overall heat loss coefficient was obtained. Thus, the significant effect of open and close of the air channel on thermal efficiency was confirmed, and the lower pressure drop of the water side was confirmed with similar thermal efficiency on two row distribution type tube compared to the traditional series type tube. So, it is confirmed that the closed air channel with two row distribution tube can be regarded as proper type.

show abstract

CFD and comparative study on the dual-function solar collectors with and without tile-shaped covers in water heating mode

Cited by 29 publications

References 18 publications

3D numerical modelling and experimental validation of an asphalt solar collector

3D numerical modelling and experimental validation of an asphalt solar collector

Numerical investigation on impacts of leakage sizes and pressures of fluid conveying pipes on aerodynamic behaviors

Numerical Analysis on Thermal Efficiency of Hybrid Solar Collector with Fin-and-Tube Heat Exchanger

Contact Info

Product

Resources

About