Experimental investigation and analysis of new design solar flat plate collector

Rahul Sonkar 12-1-2-071Isuru Walpora 12-1-2-098Rakesh Mazumdar 12-1-2-095Abhishek Bharti 12-1-2-079Shashi Kumar 12-1-2-055

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Under the guidance of

Mr. JagadishAsst. Professor,

Mechanical Dept.

Outline

Introduction

Literature Review

Research Gap

Methodology

Work done till now

Work to be done

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Introduction

• Solar Flat plate Collector (FPC) is a heat exchanger which consists of metal box with a glass cover on top and a absorber plate inside. The sides and bottom of the collector are insulated to minimize heat loss.

• Most commonly used FPC is fin and tube type,

• A new type of collector consisting of rectangular ducts has been theorized in 1996.

• Theoritically, this type of absorber would yield higher efficiency due to the overall lower temperature.

• The motivation for this project is to test whether this hypothesis is valid.

• This will be accomplished by a CFD Flow and Heat Transfer study of the above mentioned designs, followed by experimental analysis.

Literature Review

Title Author Research Area

Flat Plate CollectorsY.R. Sekhar, K.V Sharma, M.B. Rao

Experimental determination the top loss coefficients of a fin and tube design absorber under known heat flux conditions.

M. Rommel, W. MoockAnalyltical study of rectgular duct based absorber.

Raj Thundil Karuppa , Pavan and Reddy Rajeev

experimented on a sandwich type collector which is made of GI sheet

Title Author Research Area

Flat Plate CollectorsA. Alvarez , O. Cabeza , M.C. Muñiz , L.M. Varela

Comparison of the heating curves of a sandwich-like serpentine ducts serpentine ducts, to those of a fin-tube type collector with parallel ducts

M.A. Oyinlola, G.S.F. Shire, R.W. Moss

conducted an experiment using fluid micro-channels experimentally and analytically evaluate the heat transfer characteristic of this particular duct geometry

Research Gap

From the previous studies following are the research gaps have

been identified:

The higher efficiency of rectangular ducts of varying heights has

been analytically theorized. However, numerical and experimental

analysis have not been performed.

The conditions for optimal efficiency of a duct based collector of

optimum channel height has not been suggested.

Design goal (of achieving greater efficiency than fin and tube

design) has not been validated experimentally.

Research Gap

Experimental Analysis

Experimental Setup

Identification of Input / Output parameters

Thermal Analysis Optimal Analysis

Literature review

Comparative Analysis

Methodology

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CFD ANALYSIS OF RECTANGULAR DUCTS

Step-1: Geometrical modeling

First the geometry of the models were created in a standard CAD software of wall thickness 0.8mm, width 100mm,length of 1000mm. 10 different model is generated by varying duct height from 1 to 10 mm

Step-2: Meshing & Named Selections

Initially, a mesh consisting of hexahedral elements was used to test whether the solution converges with the initial boundary conditions.

Afterwards, mesh refinement of degree 3 was performed on the fluid inlet and outlet, as well as the sides of the channel, to obtain more simulation details. The resulting fluid mesh after refinement was a structured mesh consisting of triangular prismatic cells having triangular and quadrilateral faces at the boundaries. In this, the edges and regions of high temperature gradients are finely meshed.

Different sections are named according to their use:

Inlet

Outlet

Top surface

Bottom surface

Step 3: Solution Problem Setup

The mesh was checked. The analysis type was changed to pressure based type because the flows in this problem are well below supersonic levels, and the velocity formulation was changed to absolute. Time was changed to steady state.

Models

Energy equation was enabled, and viscous model was selected as “laminar model”.

The flow in all the test ducts were all considered to be laminar, as the Reynold’s numbers of all the flows are well below the transition threshold value of 2300.

Table 1: Reynold’s Number for duct heights 1-6mm

Materials

Water-liquid as fluid and aluminum as solid was selected from the fluent database by clicking change/create.

Cell zone conditions

Different parts were assigned as solid or fluid accordingly.

Name Type Values

InletMass flow –rate ,

Fixed inlet temperature

Low mass flow:0.000625 kg/s

High mass-flow:0.0010417 kg/s

Top-surfaceMixed thermal

boundary conditions

Convective heat transfer co-efficient : 3.3W/m2K

Free stream temperature : 305K

Emissivity of the surface : 0.3

Bottom-surface Convective Convective heat transfer co-efficient :0.7W/m2k

Free stream temperature : 305K

Boundary Conditions :

Work done till now

Literature Review

Identification of research gaps

Identification of Input and Output parameters.

Preparation of experimental set-up.

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Work to be done

Conducting the experiments on SFPC by varying the identified

input parameters.

Analyze the experimental data and its Simulation using ANSYS.

Comparative analysis.

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References

 •Rommel M., Moock W. (1996). Collector Efficiency Factor F’ for Absorbers with Rectangular Fluid Ducts Contacting the Entire Surface. Solar Energy Vol. 60, 199-207, Elsevier Science Ltd., 1997.•Oyinlola, M.A., Shire, G.S.F., Moss, R.W (2014). Thermal Analysis of a Solar Collector Absorber Plate with Microchannels. Experimental Thermal and Fluid Science Vol. 67, 102-109, 2014.•Sekhar, Y.R., Sharma, K.V., Rao, M.B (2009), Evaluation of Heat loss Coefficients in Solar Flat Plate Collectors. ARPN Journal of Engineering and Applied Sciences Vol. 4, 2009.•Karuppa, R.T.R, Pavan, P., Reddy, R.D. (2012), Experimental Investigation of a New Solar Flat Plate Collector. Research Journal of Engineering Sciences Vol. 1, 2012.•Alvarez, A., Cabeza, O., Muniz, M.C., Varela, L.M. (2010), Experimental and Numerical Investigation of a Flat-Plate Solar Collector. Journal of Energy Vol. 35, 3707-3716, Elsevier Science Ltd., 2010.•Rojas, D., Beerman, J., Klein, S.A., Reindl, D.T. (2007), Thermal Performance Testing of Solar Flat Plate Collectors. Solar Energy Vol. 82, 746-757, Elsevier Science Ltd., 2008.•Selmi, M. Mohammed, J. Marafia, A. (2006), Validation of CFD Simulation for Flat Plate Solar Energy Collector. Renewable Energy Vol. 33, 383-387, Elsevier Science Ltd., 2007.