Three-level flow equalizing, diffusion and transition flue of heat recovery boiler of gas turbine

Abstract

The invention discloses a transition flue used in a heat recovery boiler of a gas turbine, wherein the transition flue is in a three-level diffusion flow guiding design. The transition flue comprises a gradually-expanding type guiding flue body (2), a round-square conversion horizontal flue body (3), a gradually-expanding spray nozzle type diffusion flue body (4) and a linear type diffusion flue body (5), wherein the gradually-expanding type guiding flue body (2), the round-square conversion horizontal flue body (3), the gradually-expanding spray nozzle type diffusion flue body (4) and the linear type diffusion flue body (5) are connected in sequence. An outlet (1) of the flue of the gas turbine is connected with an inlet of the gradually-expanding type guiding flue body (2), a smoke inlet (6) of the heat recovery boiler is connected with an outlet of the linear type diffusion flue body (5), and the inlet of the linear type diffusion flue body (5) is provided with a central flowing guiding plate (7) arranged in the airflow direction. According to the transition flue, peripheral diffusion of high-speed smoke at the outlet of the gas turbine can be achieved in the transition flue, step-by-step guiding is achieved, separation of a boundary layer and generation of a backflow area are reduced, and accordingly the flowing uniformity of the smoke in the transition flue and the cross section of the inlet of the heat recovery boiler is improved.

Description

technical field [0001] The invention is applied in the field of waste heat boilers of gas turbines, and in particular relates to a transitional flue that can effectively improve the uniformity of the plane velocity at the inlet of the waste heat boiler. Background technique [0002] The outlet of the gas turbine and the heating surface of the waste heat boiler often need to be connected by a transitional flue. There is a big difference in size between the outlet of the gas turbine and the inlet of the heating surface of the waste heat boiler, and the former is at an unfavorable position relative to the lower end of the latter. The structure of the traditional transitional flue is designed so that the upper surface is two elevation sections, and the lower surface is a plane with a certain inclination angle, which completes the space expansion from the entrance to the exit. The above structure leads to poor flue gas flow in the flue. The flue gas generally enters the inlet pl...

AI Technical Summary

Problems solved by technology

However, deflectors in this area still have deficiencies: compared with other areas, the flue gas velocity in the lowermost part of the flue is relatively large, and it is easy to concentrate on the bottom tube bundle; bigger

The grid baffle is composed of large-diameter pipes, which has a complex structure and is difficult to maintain. Moreover, the grid is also prone to impact and wear

In addition, the installation of the grid baffle increases the flow resistance of the flue gas, which increases the outlet pressure of the gas turbine and reduces the power generation of the gas turbine.

[0007] In short, in the existing transitional flue design, the high-speed airflow mostly enters from the lower end relative to the heating surface of the waste heat boiler inlet, which hinders the diffusion of the airflow. At the waste heat boiler inlet, the high-speed airflow is still concentrated at the bottom, resulting in extremely uneven velocity distribution. Uniform; or significantly increase the resistance of the flue gas to evenly transition the flue gas flow in the upper and lower areas of the flue, reducing the power generation of the gas turbine

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