Research On Heat Exchange Enhancement Of Heat Exchanger Tube With Helical Spring Inserts Of Different Cross-sections

As a kind of efficient technology, Tube of the built-in spiral spring heat transfer enhancement could effectively solve the problem of low heat transfer efficiency of heat exchanger. In this paper, in order to study the different wire cross-section of the spring tube built-enhanced heat transfer efficiency, the method was taken to study comparative experiments and CFD numerical simulation method of combining contrast. It was analysed the effects of various parameters on the spring structure of enhanced heat transfer performance systematic.Built on the tube spring conditions, it was analyzed in three areas which was the average Nusselt number ratio( Nu’), the average friction factor ratio(’f) and the thermal enhancement efficiency(η) of the fluid tube. Experimental study on the use of contrast methods to build a canal built-in coil spring experimental platform enhanced heat transfer tubes, each tube section built different wire springs, wire diameter sizes of different springs and different pitch sizes spring tubes and fluorescent tubes within tubes fluid flow and heat transfer characteristics for comparison analysis, analyzed the impact of different wire cross section of pipe built-in spring for heat transfer efficiency. Experimental results showed that the tube with the square-wire inserts of the fluid of the average Nusselt number ratio Nu’ was 2.4, the average friction factor ratio’f was 8 and the thermal enhancement efficiency η was 1.18 and the tube with the coil-wire inserts of the fluid of the average Nusselt number ratio Nu’ was 2.2,the average friction factor ratio’f was 7.5 and the thermal enhancement efficiency η was 1.1.In this paper, it was used CFD numerical simulation software to build better reliability of the numerical simulation model, different models were meshed grid independent verification to ensure the reliability of the simulation experiments. Then The impact of different the built-in wire-section tube for enhanced heat transfer efficiency of the spring was analyzed by using the field synergy principle of Zeng-Yuan Guo academician as theory verification of the simulation results. The experiment results showed that Numerical simulation method could be more intuitive flow field characteristics showing the distribution of, and under the same conditions, the built-in square tube section of the spring wire and triangular cross-section of the spring wire were enhanced heat transfer efficiency( η) compared to a circular cross-section of the spring wire enhanced heat transfer efficiency was higher than 11%-20%.