Following the fundamental laws of thermodynamics, heat spontaneously flows from a hotter object to a colder object; heat transfer occurs as long as a temperature difference exists. In plate heat exchangers, this process is particularly pronounced when two liquids flow across opposite sides of the plates. The liquid on the high-temperature side (usually on the primary side of the heat exchanger) exchanges heat with the liquid on the low-temperature side (usually on the secondary side) through the plates. Due to the unique corrugated structure design of the plates, the heat transfer efficiency reaches approximately 92%, ensuring efficient heat transfer from the high-temperature side to the low-temperature side.
Specifically, the inlet and outlet of the high-temperature side are marked with dark red and pink arrows, respectively, while the inlet and outlet of the low-temperature side are marked with dark blue and sky blue arrows. When the liquid on the high-temperature side enters through the dark red inlet, its temperature gradually decreases due to convective heat exchange with the liquid on the low-temperature side through the plates, and then flows out through the pink outlet. Simultaneously, the liquid on the low-temperature side enters through the dark blue inlet, absorbs heat from the liquid on the high-temperature side, and its temperature rises, eventually flowing out through the sky blue outlet. At this point, the liquid has completed the entire heat exchange process.
Plate heat exchangers are widely used in various fields, including power, petroleum, chemical, metallurgy, machinery, food, pharmaceutical, shipbuilding, and household applications, due to their compact structure, high heat exchange efficiency, convenient installation, small footprint, and low maintenance costs.
