Introduction  In this paper, the thermal performance of a parabolic trough direct steam generation system (DSGS) is investigated. With the considerations of the stratified flow phenomenon and real flow patterns in the complex two-phase flow, the heat transfer progress in the DSG system is numerically studied, and the thermodynamic performances are revealed.

  Method  Based on the flow pattern inside the trough collector, the two-phase heat transfer model in the trough-type heat collecting region was established, and the DSG process in the trough collector was simulated by MatLab programming.

  Result  The variation of heat transfer characteristics of DSG technology along the length of the tube is revealed. The stratification phenomenon occurs in the two-phase flow region where the dryness is between 0.7 and 0.8. The occurrence of delamination reduces the heat transfer between the working medium and metal tube, which weakens the heat transfer effect.

  Conclusion  This study provides a reference for the design and operation of DSG power stations, and verifies that the optimal arrangement of DSG collectors is recirculating.