In the overall structure of a plate heat exchanger, the heat transfer plate is the core component that determines heat exchange efficiency, operational stability, and applicable scenarios. Like the "heart" of the heat exchanger, it achieves efficient heat transfer between cold and hot fluids through precise structural design and suitable material selection, widely supporting heat exchange needs in various industries such as chemical engineering, food processing, heating, ventilation, air conditioning (HVAC), and pharmaceuticals. Compared with the heat transfer components of traditional heat exchangers, heat transfer plates have become a key part of modern high-efficiency heat exchange equipment due to their compact structure and flexible combination methods.

The selection of plate materials is directly related to the applicable medium, operating temperature, and pressure of the heat exchanger, and is the foundation for ensuring the safe operation of the equipment. Currently, the mainstream plate materials are mainly metals, which are divided into several categories according to different operating conditions. Stainless steel, with its excellent corrosion resistance, high thermal conductivity, and mechanical strength, has become the most widely used basic material, suitable for neutral or weakly corrosive fluids and conventional operating conditions with temperatures not exceeding 300°C. For scenarios involving strongly corrosive media such as acids and alkalis, titanium and titanium alloys are mostly used due to their extremely high corrosion resistance, especially suitable for harsh working conditions like chemical engineering and seawater desalination, but the cost is relatively high. In addition, copper alloys, due to their excellent thermal conductivity, are often used in low-temperature fluid heat exchange scenarios with high heat exchange efficiency requirements, such as refrigeration systems; however, their corrosion resistance is weak, so the medium characteristics need to be strictly controlled. Besides metal materials, polymer material plates are used in a few special working conditions to meet specific corrosion resistance or hygiene requirements.

Structural design is the core of achieving efficient heat exchange in plates. The key lies in strengthening fluid disturbance, increasing heat transfer area, and reducing flow resistance through reasonable corrugation design. The basic structure of a heat transfer plate includes the plate body, gasket groove, flow guide area, and heat transfer area. The gasket groove is located at the edge of the plate for placing gaskets to ensure that cold and hot fluids do not leak or mix. The flow guide area is set at the inlet and outlet of the plate to guide the fluid smoothly into the heat transfer area and avoid energy loss caused by excessively high local flow velocity. The heat transfer area is the core region of the plate, covered with elaborately designed concave-convex corrugations. These corrugations not only increase the heat transfer area but also break the fluid boundary layer, transforming the fluid from laminar flow to turbulent flow, thereby greatly improving the heat transfer coefficient. Common corrugation types include corrugated, herringbone, and mesh types. Among them, herringbone corrugations are widely used in the industrial field due to their good fluid disturbance effect and high heat transfer efficiency; corrugated corrugations, with the advantage of low flow resistance and pressure loss, are suitable for scenarios with strict requirements on pressure drop.

According to different heat exchange requirements, heat transfer plates can be divided into various types to adapt to different working conditions and fluid characteristics. Classified by function, they can be divided into ordinary heat transfer plates, turbulence-promoting plates, seal-enhanced plates, and heat exchange adjustment plates. Ordinary heat transfer plates are the most basic type, mainly undertaking the heat transfer function. Turbulence-promoting plates further strengthen fluid disturbance through special corrugation design, improving heat transfer efficiency, and are suitable for scenarios with high heat exchange requirements. Seal-enhanced plates optimize the gasket groove structure to enhance sealing performance, suitable for high-pressure and high-temperature working conditions. Heat exchange adjustment plates can adjust the heat transfer area and efficiency by changing the corrugation density or thickness to achieve flexible adaptation. Classified by fluid flow direction, they can be divided into counterflow plates and parallel flow plates. Counterflow plates, where the flow directions of cold and hot fluids are opposite, have a larger heat transfer temperature difference and higher efficiency, making them the mainstream type. Parallel flow plates are suitable for scenarios with special temperature control requirements.

The performance of heat transfer plates directly affects the overall operational effect of the plate heat exchanger. In addition to materials and structure, the thickness, dimensional accuracy, and surface quality of the plates are also crucial. The plate thickness needs to be reasonably selected according to the working pressure and mechanical strength requirements; excessively thin plates will lead to insufficient pressure resistance, while excessively thick plates will increase heat transfer resistance and reduce heat exchange efficiency. Dimensional accuracy includes the length and width of the plate, corrugation depth, and gasket groove position accuracy; insufficient accuracy will cause uneven gaps between assembled plates, affecting sealing performance and heat transfer efficiency. Surface quality requires the plate surface to be smooth, free of burrs and scratches, to avoid corrosion hazards caused by surface defects and reduce fluid flow resistance.

In practical applications, the maintenance of heat transfer plates is also directly related to the service life and heat exchange effect of the heat exchanger. After long-term operation, dirt, scale, or impurities will accumulate on the plate surface, forming a fouling layer. This layer significantly increases heat transfer resistance and reduces heat exchange efficiency. Therefore, regular cleaning of the plates is necessary. Cleaning methods include chemical cleaning and physical cleaning; the specific method should be selected according to the type of fouling and plate material to avoid damage to the plates during cleaning. At the same time, it is necessary to regularly inspect the gasket groove and surface condition of the plates. If problems such as gasket groove wear, plate deformation, or corrosion are found, they should be replaced or repaired in a timely manner to ensure the stable operation of the heat exchanger.

As the core component of plate heat exchangers, the design, material selection, and maintenance of heat transfer plates jointly determine the heat exchange efficiency, operational stability, and service life of the heat exchanger. With the continuous development of industrial technology, the design of heat transfer plates is moving towards higher efficiency, better corrosion resistance, and lighter weight. New materials and optimized structure plates are constantly emerging, providing support for the application of plate heat exchangers in a wider range of fields and promoting the continuous improvement of heat energy utilization efficiency.