In the family of industrial heat transfer equipment, plate heat exchangers hold a crucial position due to their high efficiency and energy-saving properties. However, the traditional dichotomy between fully welded and detachable types once left many enterprises caught in a dilemma: either facing "sealing challenges" or "maintenance troubles". The emergence of semi-welded plate heat exchangers, however, acts as an innovator breaking this deadlock — with its unique structure of "partial welding + partial sealing", it has opened up a new path that better meets the practical needs of industry, balancing the stability required for high-pressure working conditions and the flexibility of later maintenance.

Unlike fully welded plate heat exchangers, which completely weld the edges of all plates and sacrifice the possibility of disassembly to achieve high-pressure resistance, and different from detachable plate heat exchangers that rely on gasket sealing (which is prone to aging and leakage in high-temperature and high-pressure environments), semi-welded plate heat exchangers adopt a hybrid design of "welded core flow channels + sealed end plates". The plates in the core heat transfer area form closed flow channels through laser welding or resistance welding, easily withstanding working pressures above 10MPa and medium temperatures above 300℃. This makes them well-suited for heat transfer scenarios with strong corrosiveness and harsh working conditions in fields such as petrochemicals and energy power. Meanwhile, the two ends of the equipment retain detachable end plates and sealing gaskets. When it is necessary to clean the plates or replace vulnerable parts, there is no need to disassemble the entire welded structure; only the end plates need to be opened for operation, significantly reducing maintenance costs and downtime.

This "combination of rigidity and flexibility" in structure also enables semi-welded plate heat exchangers to achieve dual advantages in heat transfer efficiency. On one hand, the flow channels formed by welding have no gasket obstruction, resulting in a more complete medium flow cross-section and reduced local resistance loss, allowing heat exchange to proceed more smoothly. On the other hand, the plates still retain the corrugated design of traditional plate heat exchangers. The medium forms intense turbulence in the flow channels, disrupting the boundary layer on the heat transfer surface. Compared with shell-and-tube heat exchangers, the heat transfer coefficient is increased by 3 to 5 times. For the same heat transfer requirement, the equipment volume can be reduced by more than 40%, saving valuable space resources in industrial plants.

What is more noteworthy is the strong adaptability of semi-welded plate heat exchangers. By adjusting the plate material (such as 316L stainless steel, titanium alloy, Hastelloy, etc.) and welding process, they can handle high-viscosity crude oil and syrup, tolerate strong acid and alkali chemical media, and even play a role in battery coolant heat transfer in the new energy field and heat recovery systems in hydrogen energy production, relying on their "high-pressure resistance + easy maintenance" characteristics. Under the current context where the dual carbon goals are driving the upgrading of industrial energy conservation, they not only reduce energy loss during heat transfer but also feature a modular design that allows flexible adjustment of the number of plates according to changes in production load, avoiding energy waste caused by "using a large machine for a small task".

From solving the "dilemma" of traditional heat exchangers to becoming a "suitable solution" for heat transfer scenarios in multiple fields, the innovative value of semi-welded plate heat exchangers lies precisely in their accurate response to the practical needs of industry — they neither compromise on the stability requirements of harsh working conditions nor ignore the economic needs of later operation and maintenance. Ultimately, they have found their unique position between efficiency, reliability, and flexibility.