A heat exchanger is a universal device that enables heat exchange between cold and hot fluids to meet different industrial production needs. As a universal heat exchange device, heat exchangers are widely used in many fields such as chemical engineering, aerospace, microelectronics, metallurgy, communication, and power.
In 1774, Watt completed the transformation of the steam engine, separated the condensation process from the body, and manufactured the first heat exchanger used for condensation. The development of heat exchangers has a history of more than 240 years! With the advancement of theoretical technology and manufacturing processes, heat exchangers have evolved from the earliest few cast iron tubes to plate heat exchangers, shell and tube heat exchangers, microchannel heat exchangers, printed circuit board heat exchangers, heat pipe heat exchangers, and other structurally diverse heat exchange devices suitable for different application scenarios.
According to the working principle, heat exchangers can usually be divided into three types: one is the partition type heat exchanger, where cold and hot fluids flow on both sides of the solid medium without contact, and heat is transferred between the cold and hot fluids through the solid, also known as surface heat exchanger. Shell and tube heat exchangers and plate heat exchangers are this form of heat transfer; The second type is a hybrid heat exchanger, which involves the contact and mixing of cold and hot fluids to achieve heat transfer. It is also known as a contact heat exchanger and is commonly used in cooling towers and deaerators in power generation systems; The third type is a regenerative heat exchanger, which achieves heat transfer by periodically flowing cold and hot fluids through a thermal storage body. It is also known as a regenerative heat exchanger, such as a rotary air preheater.
In recent decades, the world's energy consumption has increased sharply, and enhanced heat transfer technology for heat exchangers has gradually become a hot research field, playing an important role in energy conservation, environmental protection, and cost reduction. The enhanced heat transfer technology of heat exchangers can be divided into two types: active enhanced heat transfer and passive enhanced heat transfer. Active enhancement refers to the application of additional energy input to a heat transfer system to achieve enhanced heat transfer, such as applying periodic vibrations to the device, applying static electric or magnetic fields to the system, etc. Active heat transfer increases system complexity, reduces reliability, and limits applicability due to the need for additional equipment. Passive enhanced heat transfer refers to achieving enhanced heat transfer effect by modifying the structure of the heat exchanger to change the flow state without relying on external energy. Passive enhanced heat transfer can achieve heat transfer enhancement without the need for external forces, relying only on partial structural modifications, making it a key direction for subsequent research on enhanced heat transfer