RU2823422C1 - Counterflow burner module - Google Patents

Abstract

FIELD: engines.

SUBSTANCE: invention is intended for formation and combustion of fuel-air mixture in combustion chambers of gas turbine engines. Counterflow burner module comprises primary confined mixing chamber shaped as diffuser-confuser channel, secondary direct-flow mixing chamber, tangential swirling device with inter-blade channels, axial swirling device and fuel injector. In the fuel injector there is a circumferentially distributed fuel injection system, in the axial part of the secondary direct-flow mixing chamber there is a truncated cone-fairing with a fan system of fuel channels located at an angle to its axis, which provides supply of pilot gas to the combustion zone of the fuel-depleted, partially mixed fuel-air mixture. An annular air supply channel with an axial vane swirler is made coaxially to the fuel injector.

EFFECT: invention increases mass rate of combustion, completeness of fuel combustion, reduces concentration of carbon monoxide and nitrogen oxides in the combustion zone.

1 cl, 3 dwg

Description

The invention is intended for the formation and combustion of a fuel-air mixture in the combustion chambers of gas turbine engines.

A known vortex nozzle-burner premixing module RU 2775105 C1 MPK F23R 3/34 (2006.01), F23R (2022.02), publ. 06/28/2022, designed for organizing and burning the air-fuel mixture in the combustion chambers of gas turbine engines for power applications. The invention contains a nozzle, a swirler, a bushing, a central nozzle, nozzle holes, a hollow body, a gas supply channel, and gas supply holes.

The disadvantage of the vortex nozzle-burner premixing module is the narrow range of operating modes.

The closest in technical essence to the proposed device is the counter-flow premix burner module RU 2750176 C1 MPK F23D 14/62 (2021.02), publ. 06/23/2021, which refers to devices designed for the formation and combustion of the air-fuel mixture in the combustion chambers of gas turbine engines. The invention contains a primary limited mixing chamber, which is profiled in the form of a diffuser-confuser channel, a secondary direct-flow semi-limited mixing chamber, a tangential swirling device with inter-blade channels, an axial swirling device, and a fuel injector.

The disadvantages of the design that is closest in technical essence are the low completeness of fuel combustion, the unevenness of the temperature field in the combustion zone, the high concentration of carbon monoxide and nitrogen oxides in the combustion zone, the low mass combustion rate, the high probability of developing thermoacoustic instability and the operation of the chamber in vibration combustion modes.

The technical result of the invention is to increase the completeness of fuel combustion, increase the uniformity of the temperature field in the combustion zone, reduce the concentration of carbon monoxide and nitrogen oxides in the combustion zone, increase the mass combustion rate, reduce the likelihood of developing thermoacoustic instability and eliminate vibration combustion in the counterflow burner module.

The technical result is achieved by the fact that a counterflow burner module containing a primary limited mixing chamber, which is profiled in the form of a diffuser-confuser channel, a secondary direct-flow mixing chamber, a tangential swirling device with inter-blade channels, an axial swirling device, a fuel injector, wherein the fuel injector has a fuel injection system distributed around the circumference , in the axial part of the secondary direct-flow mixing chamber there is a truncated cone-fairing with a fan-shaped system of fuel channels located at an angle to its axis, ensuring the supply of pilot gas to the combustion zone of a fuel-depleted, partially mixed air-fuel mixture; An annular air supply channel with an axial blade swirler is made coaxially with the fuel injector.

In order to increase the completeness of fuel combustion, an annular air supply channel with an axial blade swirler is made coaxially with the fuel injector; increasing the uniformity of the temperature field in the combustion zone and reducing the concentration of carbon monoxide and nitrogen oxides in the combustion zone is achieved by the fact that the fuel injection system is distributed around the circumference in the fuel injector; an increase in the mass combustion rate is achieved by the fact that the counterflow burner module contains a cone fairing; reducing the likelihood of developing thermoacoustic instability and eliminating vibration combustion in the counterflow burner module is ensured by the fact that the cone-fairing has a fan-shaped system of fuel channels located at an angle to its axis, ensuring the supply of pilot gas to the combustion zone of a fuel-depleted, partially mixed fuel-air mixture.

The invention is illustrated by figures.

Fig. 1 - Longitudinal section of the counter-flow burner module;

Fig. 2 - Section A-A from the longitudinal section of Fig. 1, which shows a tangential twisting device;

Fig. 3 - Section B-B - cross section from Fig. 1, made in the area of the cone-fairing;

The counterflow burner module contains a fuel injector 1 located in the end part of the primary limited mixing chamber 2. Coaxially with the fuel injector 1 in the primary limited combustion chamber 2, there is an annular air supply channel 3 with an axial blade swirler 4. The primary limited mixing chamber 2 is shaped like diffuser-confuser channel formed by diffuser 5 and confuser 6 sections. At the beginning of the diffuser section 5 of the primary limited mixing chamber 2 there is a tangential twisting device 7 having inter-blade channels 8 for air supply. On the opposite side, the tangential twisting device 7 is attached to the secondary direct-flow mixing chamber 9. The secondary direct-flow mixing chamber 9 has external 10 and internal 11 walls that form a profiled hollow expanding channel 12 with a distributed fuel supply system 13. In the end part of the profiled hollow expanding channel 12 there is an axial twisting device 14. The axial twisting device 14 is limited by a conical section 15 of the profiled nozzle nozzle 16 and a profiled hollow expanding channel 12, forming a channel for supplying tertiary air 17. The fuel injector 1 contains a system of fuel injection holes 18 distributed around the circumference. The outlet section 19 of the profiled nozzle nozzle 16 has the shape of a spherical segment. In the axial part of the secondary direct-flow mixing chamber 9 there is a truncated cone-fairing 20 with a fan-shaped system of fuel channels 21.

The counterflow burner module operates as follows. Compressed air from the compressor, passing through the interblade channels 8 formed by the tangential twisting device 7, enters the diffuser section 5 of the primary limited combustion chamber 2 with a high peripheral speed, after which it moves along the periphery towards the confuser section 6 of the primary limited combustion chamber 2, where it forms a toroidal vortex structure and interacts with the fuel flow supplied from the circumferentially distributed system of fuel injection holes 18 of fuel injector 1. The distribution of fuel supply through the system of fuel injection holes 18 ensures an increase in the uniformity of the temperature field in the combustion zone and a decrease in the concentration of carbon monoxide and nitrogen oxides in the combustion zone . A fuel-air mixture is formed, which has a composition based on the excess air coefficient outside the boundaries of the concentration ignition limits. Air from the annular air supply channel 3 enters the confuser section 6 of the primary limited mixing chamber 2 with a high value of the circumferential velocity component, which is imparted to the flow in the axial blade swirler 4. In the confuser section 6 of the primary limited mixing chamber 2, the air flow is mixed with the air-fuel mixture , thereby impoverishing it. Next, the flow of the lean fuel-air mixture moves in the axial vortex towards the secondary direct-flow mixing chamber 9. Getting into the secondary direct-flow mixing chamber 9, the flow of components moves between the inner wall 11 of the profiled hollow expanding channel 12 and the truncated cone-fairing 20 into the area of the outlet section 19 of the profiled nozzle nozzle 16. Installation of a truncated cone-fairing 20 ensures the directed movement of the flow of a lean fuel-air mixture into the combustion zone, thereby achieving an increase in the mass combustion rate. In order to reduce the likelihood of developing thermoacoustic instability and eliminate vibration combustion in the truncated cone-fairing 20, a fan-shaped system of fuel channels 21 is made, located at an angle to its axis, ensuring the supply of pilot gas to the combustion zone of a fuel-depleted, partially mixed fuel-air mixture. From the profiled hollow expanding channel 12, through a distributed fuel supply system 13, single- or multi-component fuel enters the tertiary air supply channel 17, where it is partially mixed with air. Thus, through the tertiary air supply channel 17 with a high degree of swirl, which is communicated to the flow in the axial swirling device 14, a flow of a fuel-poor mixture enters the area of the outlet section 19 of the profiled nozzle 16. At the exit, a combustion zone of a fuel-depleted, partially mixed fuel-air mixture is formed.

The organization of a uniform air-fuel mixture in terms of the excess air ratio in the primary limited combustion chamber is ensured by installing an axial blade swirler in the annular air supply channel. As a result, a large area of flame front is formed in the combustion zone, which ensures complete combustion of the fuel.

Claims (2)

1. A counterflow burner module containing a primary limited mixing chamber, which is profiled in the form of a diffuser-confuser channel, a secondary direct-flow mixing chamber, a tangential swirling device with inter-blade channels, an axial swirling device, a fuel injector, characterized in that the fuel injector has a distributed circumference of the fuel injection system, in the axial part of the secondary direct-flow mixing chamber there is a truncated cone-fairing with a fan-shaped system of fuel channels located at an angle to its axis, ensuring the supply of pilot gas to the combustion zone of a fuel-depleted, partially mixed air-fuel mixture. 2. A counter-flow burner module according to claim 1, characterized in that an annular air supply channel with an axial blade swirler is made coaxially with the fuel injector.