US-20260126175-A1 - LOW-EMISSION COMBUSTOR HEAD STRUCTURE WITH V-SHAPED TRAILING EDGE VANE

US20260126175A1US 20260126175 A1US20260126175 A1US 20260126175A1US-20260126175-A1

Abstract

A low-emission combustor head structure with a V-shaped trailing edge vane solves the problems of a combustor head structure with short service life and uneven outlet air flow leading to poor combustion stability. The low-emission combustor head structure includes a pilot stage and a main stage, where the pilot stage includes a swirler, a venturi, and a centrifugal nozzle. The main stage includes an oblique radial swirler, a swirler vane, a V-shaped trailing edge vane, an annular fuel manifold, and direct injection nozzles. The oblique radial swirler of the main stage ensures swirl intensity while reducing the axial length of the swirler head. The discrete multi-point direct injection nozzles of the main stage enable the initial pressure atomization, and the V-shaped trailing edge structure enhances fuel droplet breakup and mixing. Thus, the fuel is fully premixed in the swirling passage, greatly reducing pollutant emissions, thereby achieving ultra-low emissions.

Inventors

Ningbo ZHAO
Honghao XU
Liyao PANG
Zhongmin FENG
Zongfu LI
Ren Yang
Honglei YANG
Hongtao Zheng

Assignees

HARBIN ENGINEERING UNIVERSITY

Dates

Publication Date: 20260507
Application Date: 20251031
Priority Date: 20241106

Claims (6)

1 . A low-emission combustor head structure with a V-shaped trailing edge vane, comprising: a main stage, a pilot stage, a heat shield, and a flame tube, wherein the main stage and the pilot stage are arranged coaxially; the pilot stage is connected to a middle portion of a front end of the main stage; an outer edge of a rear end of the main stage is connected to the flame tube through the heat shield; the rear end of the main stage, the heat shield, and the flame tube enclose to form a combustor; and the main stage is configured to inject fuel into the combustor; the low-emission combustor head structure further comprises: fuel conduits, comprising one fuel conduit configured to deliver the fuel to the pilot stage and the other fuel conduit configured to deliver the fuel to the main stage; the main stage comprises: a main stage outer ring and a main stage inner ring; the main stage outer ring and the main stage inner ring are arranged coaxially; an outer edge of a rear end of the main stage outer ring is connected to the flame tube through the heat shield; a main stage annular fuel manifold is disposed inside the main stage inner ring; and the other fuel conduit communicates with the main stage annular fuel manifold; the main stage further comprises: main stage swirler vanes and main stage V-shaped trailing edge vanes; an outer wall of the main stage inner ring and an inner wall of the main stage outer ring are connected by the plurality of main stage swirler vanes and the plurality of main stage V-shaped trailing edge vanes; the plurality of main stage swirler vanes are arranged circumferentially at equal intervals around an axis of a pilot stage swirler inner ring; the plurality of main stage V-shaped trailing edge vanes are arranged circumferentially at equal intervals around the axis of the pilot stage swirler inner ring; and one main stage V-shaped trailing edge vane is disposed between any two adjacent main stage swirler vanes; and the main stage V-shaped trailing edge vane is provided with at least one main stage fuel injection hole; a third flow passage communicates with the combustor through the main stage fuel injection hole; and the main stage fuel injection hole is located inside a V-shaped groove of the main stage V-shaped trailing edge vane and is supplied with fuel through the main stage annular fuel manifold.
2 . The low-emission combustor head structure with the V-shaped trailing edge vane according to claim 1 , wherein the pilot stage comprises: the pilot stage swirler inner ring and a centrifugal nozzle; the centrifugal nozzle is disposed inside a rear end of the pilot stage swirler inner ring; and the one fuel conduit communicates with a front end of the pilot stage swirler inner ring.
3 . The low-emission combustor head structure with the V-shaped trailing edge vane according to claim 2 , wherein the front end of the pilot stage swirler inner ring is circumferentially provided with a plurality of purge flow passages; and the plurality of purge flow passages all communicate with the combustor.
4 . The low-emission combustor head structure with the V-shaped trailing edge vane according to claim 3 , wherein the pilot stage further comprises: swirler vanes; an inner wall of the main stage inner ring and an outer wall of the rear end of the pilot stage swirler inner ring are connected by the plurality of swirler vanes; and the plurality of swirler vanes are arranged circumferentially at equal intervals around the axis of the pilot stage swirler inner ring.
5 . The low-emission combustor head structure with the V-shaped trailing edge vane according to claim 4 , wherein each of the swirler vanes is internally provided with a first swirling flow passage; and one end of the first swirling flow passage communicates with an interior of the pilot stage swirler inner ring, and the other end of the first swirling flow passage communicates with the main stage annular fuel manifold.
6 . The low-emission combustor head structure with the V-shaped trailing edge vane according to claim 1 , wherein the heat shield is provided with a plurality of cooling orifices distributed circumferentially; an axis of each of the cooling orifices and an axis of the pilot stage form an angle of 0-30°; the cooling orifices each have a diameter of 0.4-0.6 mm; and there are 150-300 cooling orifices.

Description

CROSS REFERENCE TO THE RELATED APPLICATIONS This application is based upon and claims priority to Chinese Patent Application No. 202411577361.2, filed on Nov. 6, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to the technical field of staged low-emission combustors for gas turbines, and in particular to a low-emission combustor head structure with a V-shaped trailing edge vane. BACKGROUND The pollutant emissions of gas turbines originate from the combustor. Therefore, developing low-emission combustion technology is a key to reducing the pollutant emissions of gas turbines. The main pollutants from the combustor include nitrogen oxides (NOx), carbon monoxide (CO), and unburned hydrocarbons (UHC), among which reducing NOx emissions is of paramount importance. The generation mechanism of thermal NOx plays a dominant role in the combustor, so reducing the combustion temperature in the combustion zone is one of the effective means to reduce NOx emissions. Lean combustion technology can effectively lower the combustion temperature in the combustion zone, thereby reducing NOx emissions. The ability of advanced low-emission combustors to reduce pollutant emissions is largely attributed to the advanced head design for combustion management. For lean low-emission combustors, due to the need for air staging and fuel staging combustion, most advanced low-emission combustor nozzles primarily include a pilot stage nozzle (centrifugal type) and a main stage nozzle (direct injection type). For lean combustion technology, foreign researchers have proposed lean premixed prevaporized (LPP) combustion technology and conducted extensive research on it. This technology can effectively control the combustion temperature in the main combustion zone and has great potential in reducing NOx emissions. General Electric (GE) has already filed many United States (US) patents for twin annular premixing swirler (TAPS) combustors. The technical solutions proposed in low-emission combustor head patents, such as U.S. Pat. Nos. 6,453,660B1, 6,381,964B1, and 6,389,815B1, are as follows. The pilot stage includes a centrifugal nozzle, a two-stage axial swirler, a venturi, and a sleeve. The main stage includes a direct injection nozzle and a one-or two-stage radial swirler. The large head nozzle includes a pilot stage single-fuel-circuit centrifugal nozzle and a main stage direct injection nozzle. Beihang University and China Gas Turbine Establishment (CGTE) have also filed patents for various LPP combustors, such as CN101169252A, CN101275751A, CN101275750A, CN202032612U, CN202032613U, and CN202082953U. NOx is one of the pollutants that gas turbine combustor designers need to focus on. In the combustor, NOx is primarily determined by the flame temperature in the combustion zone and the gas residence time. Existing low-emission combustors adopt centrally-staged LPP combustion technology to reduce the pollutant emissions. The head of the low-emission combustor is divided into a pilot stage and a main stage surrounding the pilot stage. The head requires good mixing of fuel and air to achieve good low-emission effects. The fuel and air need to mix within a limited spatial distance. In the prior art, transverse fuel jet injection is often used to achieve desired atomization and mixing effects. However, the transverse jet penetration depth is greatly related to the fuel-air momentum ratio. The transverse jet penetration depth varies under different operating conditions of the gas turbine. This causes uneven radial fuel distribution and deviation of fuel atomization effects from design requirements, leading to issues such as high pollutant emissions and incomplete combustion. SUMMARY In view of the aforementioned problems of existing combustors, such as uneven radial fuel distribution, poor fuel atomization, high pollutant emissions, and incomplete combustion, an objective of the present disclosure is to provide a low-emission combustor head structure with a V-shaped trailing edge vane. To achieve the above objective, the present disclosure adopts the following technical solution. A low-emission combustor head structure with a V-shaped trailing edge vane includes: a main stage, a pilot stage, a heat shield 12, and a flame tube 13, where the main stage and the pilot stage are arranged coaxially; the pilot stage is connected to a middle portion of a front end of the main stage; an outer edge of a rear end of the main stage is connected to the flame tube 13 through the heat shield 12; the rear end of the main stage, the heat shield 12, and the flame tube 13 enclose to form a combustor; and the main stage is configured to inject fuel into the combustor. The aforementioned low-emission combustor head structure with a V-shaped trailing edge vane further includes: fuel conduits 11, including one fuel conduit 11 configured to deliver the fuel to the pilot stage and the other fuel conduit