Performance Enhancement of the Vertical Double Pipe Heat Exchanger by Applying of Bubbling Generation on the Shell Side

The performance of a vertical double pipe heat exchanger was analyzed experimentally under effect of bubble generation by air injection through an air diffuser has many hundreds of very small holes placed at the bottom of the vertical heat exchanger around the (inner) hot tube. The air is supplied by using a small compressor with an air flow meter, and a small boiler with a temperature controller which used for heating the hot fluid, the inlet and outlet temperatures are measured by using digital thermocouples, the tests are performed for parallel and counter flow configurations with different flow rates of cold fluid and air injection. The results show that the exergy loss was affected significantly by bubble generation with positive effects on (Heat Transfer Rate, Effectiveness, Number of Transfer Units and Overall Heat Transfer Coefficient).