Heat exchanger, a device that transfers part of the heat from a hot fluid to a cold fluid, is also known as a heat exchanger. Heat exchanger occupies an important position in chemical, petroleum, power, food and many other industrial production, its heat exchanger in chemical production can be used as a heater, cooler, condenser, evaporator and reboiler, etc., widely used. For example, low-temperature power plant with PTFE heat exchanger is a new device to reduce the exhaust temperature of power plants for waste heat recovery equipment. Using fluorine plastic heat exchanger, it can prevent acid corrosion and reduce the flue gas temperature to within 100 degrees.
Applicable to different media, different working conditions, different temperatures, different pressures of the heat exchanger, structure type is also different, the specific classification of heat exchangers are as follows：
According to the classification of heat transfer principle
1, Inter-wall heat exchanger
Inter-wall heat exchanger is a temperature difference between the two fluids in the space separated by the wall flow, through the thermal conductivity of the wall and fluid convection on the wall surface, heat transfer between the two fluids. There are shell and tube type heat exchangers, casing type heat exchangers and other types of heat exchangers. Inter-wall heat exchanger is currently the most widely used heat exchanger.
2, Heat storage heat exchanger
Heat storage heat exchanger through the solid material constituted by the heat storage body, the heat from the high-temperature fluid to the low-temperature fluid, the hot medium first by heating the solid material to a certain temperature, the cold medium and then through the solid material is heated, so that it achieves the purpose of heat transfer. The heat storage heat exchanger has a rotary type, valve switching type, etc.
3、Fluid connection indirect heat exchanger
Fluid connected indirect heat exchanger, is the two surface heat exchanger connected by the heat carrier circulating in it heat exchanger, heat carrier in the high-temperature fluid heat exchanger and low-temperature fluid circulation between the high-temperature fluid to receive heat, in the low-temperature fluid heat exchanger to release heat to the low-temperature fluid.
4、Direct contact heat exchanger
Also known as a hybrid heat exchanger, this heat exchanger is a direct contact between two fluids, mixed with each other for heat transfer equipment, for example, cold water towers, gas condensers, etc.
5、Compound heat exchanger
Both the vapor surface type indirect heat transfer and water-water direct mixed flow heat transfer two kinds of heat transfer equipment. Compared with the vapor surface indirect heat transfer, with higher heat transfer efficiency; with the direct mixing of steam and water heat transfer compared to the higher stability and lower unit noise.