The role and principle of heat exchange tubes in heat exchangers
ASTM A179 standard requires that tubular heat exchangers, condensers and similar heat transfer equipment use seamless cold-drawn mild steel tubes with minimum wall thickness.
The role of heat exchanger tubes
A heat exchanger is a device that can transfer heat from a heat source to a cold source, and the heat exchange tubes in it are the main pipes for transferring heat. Heat exchanger tubes are important components for heat exchange, and their function is to transfer heat from one medium (usually liquid or gas) to another medium. Specifically, the role of heat exchanger tubes in heat exchangers has the following aspects:
1. Improve energy utilization
Heat exchange tubes play a key role in heat transfer. Because the outer area of the tube is much larger than the inner area of the tube, when the fluid passes through the heat exchange tube in the heat exchanger, it can transfer heat to the surface of the tube, and then move to the other end through the wall layer of the tube, and then transfer the heat to the cold source on the other side. Therefore, the heat transfer capacity of the heat exchange tube directly determines the heat transfer efficiency of the heat exchanger. Using heat exchanger tubes for heat exchange can convert waste heat into reusable heat energy, improve energy utilization and reduce energy consumption.
2. Maintain temperature balance
In many industrial production processes, a certain temperature needs to be maintained to ensure production efficiency and product quality. Heat exchanger tubes can transfer heat between different media to maintain temperature balance.
3. Improve equipment efficiency
In order for the fluid to flow normally, it is necessary to ensure that its flow in the heat exchange tube is stable and unobstructed. If the pipeline is too thin or too long, it is easy to cause the fluid flow rate to decrease, resulting in a drop in pressure. In this case, the heat exchange tube plays a role in regulating the fluid flow rate, thereby reducing adverse effects such as flow resistance and pressure drop. In some equipment, such as steam turbines, there are high-temperature and high-pressure media inside, which need to be cooled and reduced by heat exchangers to improve the efficiency of the equipment and extend its service life.
4. Withstand high temperature and high pressure and other conditions
In the heat exchanger, the temperature and pressure of the fluid may be higher than normal temperature and pressure, and the external environment is often different. Only with sufficient strength and tolerance can it operate normally and function in such a high temperature and high pressure environment, and the heat exchange tube is the main component that withstands such conditions.
Principle of heat exchanger heat exchange tube
The heat exchange principle of heat exchanger heat exchange tube is based on three ways of heat transfer: heat conduction, convection and radiation. The heat source and the cold source flow through the pipe respectively, and then the heat energy is transferred through the heat exchange tube. Specifically, the principle of heat exchanger heat exchange tube has the following aspects:
1. Heat conduction transfer
When two media are in contact with each other, the temperature difference between them will cause heat transfer, which is called heat conduction transfer. The tube wall in the heat exchanger heat exchange tube transfers heat from the hot medium side to the cold medium side.
2. Convection transfer
Convection transfer refers to the transfer of heat through the flow of fluid. In the heat exchanger heat exchange tube, the hot medium and the cold medium flow through the tube, and the heat is transferred to the cold medium side by the convection of the fluid.
3. Radiation transfer
Radiation transfer refers to the transfer of heat through electromagnetic radiation between objects. In the heat exchanger tube, there is a temperature difference between the two media, so the heat radiation transfer phenomenon occurs.
In short, through the combination of the above three heat transfer methods, the heat exchanger tube can efficiently exchange heat.
Summary