Underfloor Heating System with Spiral Pipe

Description

Underfloor Heating System with Spiral Pipe, ANSYS Fluent CFD Simulation Training

The present problem simulates the process of heat transfer through the underfloor heating system by spiral pipe using ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

The heat source inside this model is the spiral tubes placed at the bottom of the room. Due to the buoyancy effect, the air near the spiral tubes becomes warmer and starts to move upward, creating a rotating flow inside the room.

The present model is designed in three dimensions using the Design Modeler software.

The calculation area of the present model is related to a room with a length of 3.6 m, a width of 2.6 m, and a height of 2.6 m, and a layer of concrete with a thickness of 0.12 m is designed as a solid area in the lower part of this room.

Inside this concrete layer, a 0.04 m diameter spiral pipe is designed to be inserted circumferentially, and after, a spiral path across the floor of the room is led out of the room.

The meshing of the model was done using ANSYS Meshing software. The element number is equal to 2936179.

Underfloor Heating Methodology

In this project, a room is designed in cold winter conditions, and a floor heating system is installed to heat the air inside the room. The underfloor heating system is in the form of a spiral tube that carries the flow of hot water.

The hot water pipe is placed inside a layer of concrete and transfers its heat to the concrete layer of the floor. Then, heat transfer inside the concrete layer occurs in conduction, and finally, heat transfer or convection from the ground floor leads to heating the air inside the room.

Air is defined as the ideal gas for the occurrence of free convection heat transfer in the room’s interior. Hot water flows with a flow rate of 0.5 kg/s and a temperature of 303.15 K enter the pipe to perform the heating process.

This is while for the ceiling and walls of the room, a layer of bricks is defined that transfers heat with the cold air of the surrounding environment; So the ambient temperature is defined as 278.15 K, and the heat transfer coefficient is defined as 20 W/m2K.

Moreover, the RNG k-epsilon model and energy equation are enabled to solve the turbulent fluid equations and calculate the temperature change within the domain.

Underfloor Heating Conclusion

At the end of the solution process, three-dimensional contours related to changes in indoor air temperature and water flow inside the pipe, two-dimensional contours related to changes in temperature and velocity on a vertical plane passing through the middle of the room, and velocity vectors on the same plate Two-dimensional are obtained.

Two-dimensional and three-dimensional temperature-related meters well indicate the increase in indoor air temperature and the positive performance of the heating system in heating the indoor air. Also, velocity contours and vectors indicate natural heat transfer and the effect of buoyancy.