| 摘要 |
A fuel nozzle 110 having a plurality of swirl vane 130 on an outer peripheral surface thereof is installed within a burner tube 120 , with a clearance 121 being provided. Each swirl vane 130 progressively curves from an upstream side toward a downstream side (inclines along a circumferential direction) in order to swirl compressed air A flowing through an air passage 111 to form a swirl air flow a. Here, curvature of each swirl vane 130 is greater on its outer peripheral side than on its inner peripheral side. By suppressing occurrence of an air streamline heading from the inner peripheral side toward the outer peripheral side, therefore, flow velocity on the inner peripheral side and flow velocity on the outer peripheral side become equal, thus preventing flashback on the inner peripheral side. Moreover, a swirl imparting force in the circumferential direction per unit length on the inner peripheral side and that on the outer peripheral side become equal, equalizing the fuel concentration on the inner peripheral side and the fuel concentration on the outer peripheral side. Furthermore, a leakage flow, which passes from the vane dorsal surface side through the clearance 121 and leaks to the vane ventral surface side, generates a vortex air flow, promoting mixing of fuel and air.
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