Research and application of composite titanium heat exchangers

It is known that the extraction cost of titanium is high, which results in its relatively high price. Although it has the characteristics of light weight and high strength, its use is also one of the important factors affecting manufacturing costs. Therefore, in product design, how to reduce the usage of titanium materials becomes a relatively important design requirement.

In heat exchangers, the embedded tube sheet is an important component. The existing titanium heat exchangers with both tube sheets and flanges have the following shortcomings:
1. Due to the characteristic that titanium cannot be welded with other materials, both the flange and the tube plate require titanium. As a result, the usage of titanium has significantly increased.

II. Since the thickness of the titanium material has a significant impact on the design pressure, when the design pressure increases, the thickness of the flange and the tube plate will increase simultaneously.

Therefore, the researchers have developed an embedded tube titanium heat exchanger that can adapt to different design pressures and also adopts a liner ring live coupling flange structure.

The structure of this three-layer composite tube plate titanium heat exchanger includes the tube plate, spacer tubes, tie rods, nuts, anti-loosening ears, support plates, U-shaped heat exchange tubes. The U-shaped heat exchange tubes are multiple in number, and after overlapping, they pass through the tube plate. The U-shaped heat exchange tubes are fixed on the support plate through the anti-loosening ears. The anti-loosening ears are multiple in number and are evenly spaced. Between the anti-loosening ears, spacer tubes are set. One end of the tie rod is connected to the tube plate, and the other end passes through the spacer tubes and anti-loosening ears and is pressed tightly by the nut. The tube plate is made of three-layer composite materials. The anti-loosening ears are five in number. The connection between the anti-loosening ears and the support plate is fixed. A buffer sleeve is set between the U-shaped heat exchange tubes and the tube plate. The buffer sleeve for the U-shaped heat exchange tubes and the tube plate is made of steel. After the U-shaped heat exchange tubes pass through the tube plate, they are welded to the tube plate. Each layer of the tube plate is made of TA9 + Q345R + TA9.

Since the U-shaped heat exchange tubes are welded to the tube plate after being passed through it, and a buffer sleeve is set between the U-shaped heat exchange tubes and the tube plate, the U-shaped heat exchange tubes are welded again after passing through the tube plate. Moreover, the U-shaped heat exchange tubes are welded to the tube plate by means of titanium layer welding with the tube plate. The buffer sleeve between the U-shaped heat exchange tubes and the tube plate is welded to the intermediate layer of the tube plate. Under the same strength conditions, the thinner the thickness of the tube plate required, the lower the cost will be, and it can be freely welded with other material pipelines. The new titanium heat exchanger has a simple structure, a compact shape and is easy to use.