Simulation and Test of Titanium Tube-Tube Sheet Explosive Welding of High Pressure Heat Exchanger

The use of explosive welding technology to realize the welding of thin-walled metal titanium tubes and tube sheets not only improves production efficiency, reduces processing costs, but also improves the service life and safe production of heat exchangers, so it has important industrial application value. At the same time, through the optimization and precise control of the test charge parameters, it is expected that an explosive welding molding workshop will be built inside the factory, which will greatly reduce production costs.

Compared with the above-mentioned various tube expansion technologies, the explosive welding forming process has the following outstanding advantages:

• (1) Because explosive welding is a special type of pressure welding, it can realize welding between zirconium and titanium pipes and steel and other special-shaped metals that cannot be achieved by conventional welding and tube expansion methods;
• (2) Because the explosive welding interface belongs to the solid phase bond between atoms, the welding strength between the heat exchanger tube and the tube sheet is high, which not only ensures the safety of the heat exchanger, but also greatly improves the heat exchanger The service life;
• (3) Since explosive welding can achieve simultaneous detonation at multiple points, the productivity is high, and all tubes and tube sheets of a heat exchanger can be welded and formed at a time.

Explosive welding of titanium tube-tube sheet involves multiple simultaneous explosive welding of rare metal thin-walled long pipe fittings and tube sheet and microscopic analysis of the interface.

Titanium tube-tube sheet explosive welding has the following key technologies to be solved:

• (1) When titanium/steel is explosively welded, if the charge parameters are not well controlled, it is easy to cause high temperature at the interface and produce intermetallic compounds at the interface, which will greatly reduce the heat transfer effect of the composite pipe. Therefore, the explosive welding charge process of the internal heat exchange titanium tube or zirconium tube is one of the keys to successful explosive welding.
• (2) Generally speaking, the wall thickness of the outer tube and inner tube of the composite pipe is only 1~2mm. However, ultra-thin metal composite materials, especially ultra-thin pipes, are prone to cracks or even breaks during explosive welding. Therefore, the explosive speed and the thickness of the charge must be accurately controlled.
• (3) The seawater corrosion-resistant high-efficiency composite pipe must not only save rare metal materials, but also achieve efficient heat transfer. The key to efficient heat transfer is that the bonding interface of the composite pipe must be an excellent micro-wave interface, and the formation of the micro-wave interface Accurate optimization and design of charging parameters are required.