With micro turbine Capstone C30 flue gas as the heat source, the characteristics of boiling heat transfer inside tubes including vortex tubes, dimple tubes and plain tubes were investigated experimentally. The results reveal that boiling heat transfer coefficient of vortex tubes is about 1.6 to 2.1 times that of the plain tubes, external surface heat transfer coefficient is about 1.3 to 1.5 times that of the plain tube, and the overall heat transfer coefficient is about 1.3 to 1.6 times that of the plain tubes; boiling heat transfer coefficient of dimpled tubes is about 2.1 to 2.5 times that of the plain tubes, external surface heat transfer coefficient is about 1.8 to 2.0 times that of the plain tube, and the overall heat transfer coefficient is about 1.9 to 2.1 times that of the plain tubes. And the reason why the heat transfer performance of vortex tubes and dimple tubes is better than that of the plain tubes is analyzed.