Effect of annular ribs in heat exchanger tubes on the performance of phase‐change regenerative heat exchangers

Optimizing the efficiency of conventional heat exchangers is critical for improving the performance of various processes. This study proposed increasing the heat dissipation buffer space of heat exchangers by filling the gap between the heat exchanger and the shell with phase‐change materials for optimizing phase‐change heat exchangers. Comparative simulation analyses were performed by investigating the difference between the internal and external diameters of the inner ring ribs of the heat exchanger, the flow rate of the cooling liquid, the spacing distance, and the number of the inner ring ribs as independent variables. The results revealed that the heat transfer efficiency of heat exchangers can be improved by adding the inner ring rib structure to the heat exchange copper tube. The difference between the inner and outer diameters of the inner ring rib considerably influences heat dissipation. Furthermore, a sensitivity coefficient of 0.2457 can be obtained. The distance and number of inner ring ribs and the flow rate of cooling liquid exhibit certain effects on the heat transfer efficiency of the heat exchanger. The sensitivity coefficients were 0.1477 and 0.0935. The heat dissipation efficiency of the coil heat exchanger was improved by 3.8% by adding inner ring ribs in the coil heat exchanger channel. During the simulation, the cooling liquid inlet and outlet were set to ensure the flow of the cooling liquid. The real‐time temperature at the inlet and outlet was obtained by inserting temperature probes at the inlet and outlet, and the temperature difference at the inlet and outlet reflects the heat dissipation of the heat exchanger laterally. If the temperature difference at the inlet and outlet can reach a high peak in a short time, then the heat dissipation effect of this parameter improved. Therefore, according to the simulation results, the factor of the difference between the inner and outer diameters of the inner ring rib was considered for analyzing the time when the inlet and outlet reach the peak temperature difference and the peak temperature difference, and Figure 7 is drawn. The peak time and peak temperature difference were recorded as presented in the table. According to Figure 7 and Table 2, when the difference between the inner diameter and the outer diameter was 3 mm, the temperature difference at the inlet and outlet reached the peak value of 11.65 K, and the time required was the shortest, 0.53054 s, which indicated, consistent wi