Flat Plate Solar Collector, Conjugated Heat Transfer (CHT)

Flat Plate Solar Collector Conjugated Heat Transfer (CHT), ANSYS Fluent CFD Training

Introduction

Flat Plate Solar Collectors (FPSC) are widely used in the solar industry to convert solar radiation into thermal energy. The efficiency of FPSCs depends on various factors, including the design of the collector, the materials used, and the collector’s location.

In this simulation, we investigate radiation’s effects on the water’s temperature passing through pipes in an FPSC located in Doha with a 15-degree tilt angle at three different hours during a day in August using ANSYS Fluent software.

The simulation was conducted for three different hours on August 10th: 12:00 pm, 3:00 pm, and 5:30 pm. The solar radiation intensity at these times is different due to changes in sun angle and atmospheric conditions.

The geometry of the FPSC was designed using SpaceClaim software and meshed using Fluent Meshing software in Polyhedra type. It must be noted that the whole number of elements created is 2,871,429.

The model consists of a Rockwool insulator, an Aluminum Frame, a Glass cover, and water inside the pipes.

Flat Plate Solar Collectors Methodology

The simulation was conducted by solving Navier-Stokes equations for fluid flow and energy equations for heat transfer. The boundary conditions were set as follows:

– Inlet temperature of water = 298k
– Inlet mass flow rate of water = 0.1 kg/s
– Outlet pressure = atmospheric pressure
– Solar radiation intensity = obtained from weather data

The Discrete Ordinate (DO) Radiation Model simulates radiation behavior on the FPSC. Also, the Solar Ray Tracing sub-model has been used for Solar Load.

Conclusion

The simulation results showed that solar radiation significantly affects the temperature of the water passing through pipes in an FPSC. When solar radiation is highest at noon, the water inside pipes reaches up to 301.676k. At 3:00 pm and 5:30 pm, when solar radiation intensity is lower than at noon. But still significant enough to heat the water. The water temperature inside pipes reached 300.599k and 298.593k, respectively.

The simulation also showed that the Rockwool insulator, Aluminum Frame, and Glass cover are important in reducing heat loss from the FPSC. The Rockwool insulator reduces heat loss from the bottom of the collector, while the Aluminum Frame and Glass cover reduce heat loss from the top and sides of the collector.

It’s easily apparent that the pressure amount of water fluid decreases as it flows upward through the pipes.

In conclusion, this simulation provides valuable insights into how solar radiation affects the temperature of the water passing through pipes in an FPSC. It also highlights the importance of using appropriate materials and design features to maximize efficiency and minimize heat loss in FPSCs.