What Is Forced Convection?

The three basic methods of heat transfer are heat transfer, convective heat transfer and radiant heat transfer.

In addition, our common examples of convection, such as covering a quilt when sleeping in the winter, are mainly to prevent the convection of air inside and outside the quilt and maintain the body temperature. When drinking hot water, if you think it is too hot, you often blow in your mouth. This is because When blowing air, convection occurs in the vicinity of the air, and the hot water is taken away from the tropics, so that the hot water is easy to cool. Where there is a fire, there is often wind to help the fire. In coastal areas, sea breeze is often blown during the day in summer and land wind is often blown at night. Is an example of thermal convection. ^[1]

Convection is the movement of molecules inside a fluid and is one of the main modes of heat and mass transfer. Thermal convection is one of the three main modes of heat transfer, which usually occurs in fluids with temperature differences, because the difference in temperature will cause different densities between the fluids. Examples of mass transfer, such as different salt densities or the application of external forces to cause uneven density, can also cause convection. Convection also occurs in the atmosphere, in the ocean, and in the ground function of planets.

In the naturally occurring heat exchange process, heat is transmitted from high to low temperatures. This phenomenon is called heat transmission. There are three types of heat transmission: thermal conduction, thermal convection, and thermal radiation. The cause of thermal convection is that when a part of a liquid or gaseous substance is heated, its volume expands, its density decreases, and it gradually rises. Its position is supplemented by a substance with a lower ambient temperature and a higher density. This substance is heated and rises, and the surrounding substance returns. In addition, this cycle is endless, and then heat is transmitted from the flowing fluid to everywhere.

For other applications of heat convection, in terms of air convection, we usually place the indoor air-conditioning device on the upper part and the heater on the lower part of the room, mainly because the cold air drops and the hot air rises. Convection will occur between the rooms. Chimneys are set up to help convection of gas. When hot air is passed up the chimney, fresh cold air can be continuously replenished to make the combustion in the furnace better.

Common forced convection in life:

1. Electric fan;

2. The liquid in the pot tumbles while cooking;

3. Stir the soup. ^[2]