RU2289065C1 - Mixer of fuel components - Google Patents

Abstract

FIELD: devices for mixing of fuel components including gaseous and liquid fuel, water vapor and air before their supply to the combustion chamber.

SUBSTANCE: the mixer of fuel components has a fuel supply manifold and a system for preparation of the fuel-containing mixture including a device of multi-point fuel injection. The system for preparation of the fuel-containing mixture is made in the form of a single Venturi tube, the device of multi-point fuel injection installed in the Venturi tube up to its critical section is made in the form of a tore-shaped stream-lined manifold with openings on the outer and inner surfaces. The tore-shaped manifold of multi-point injection is tear-shaped.

EFFECT: simplified and lightened construction of the mixer, reduced friction loss.

2 cl, 2 dwg

Description

The present invention relates to devices for mixing fuel components, such as gaseous or liquid fuel, with air or water vapor, before being fed into the combustion chamber.

Industrial gas turbine plants (GTUs) used to generate electricity or as industrial power plants must comply with strict rules regarding the content of harmful gases in the exhaust, primarily nitrogen oxides (NOx), carbon monoxide (CO) and unburned hydrocarbons. To minimize unwanted emissions, industrial gas turbines are equipped with pre-mixed nozzles in which fuel and air are completely mixed before being fed into the combustion chamber for combustion. Complete preliminary mixing of fuel and air provides a uniformly low flame temperature, which is a prerequisite for suppressing the formation of NOx and contributes to the complete combustion of fuel.

A decrease in the temperature of the flame, and therefore the level of nitrogen oxides NOx in the exhaust gases, is also provided by supplying fuel mixed with water vapor to the combustion chamber.

Known mixing device for the preparation of the air-fuel mixture (FA), supplying fuel to the air passing through special channels.

Closest to the proposed invention is a mixing device for preparing a fuel-air mixture [Touchton, Shema, Katrok and others. Design of a catalytic combustion chamber for a high power gas turbine. Energy machines, t. 105, No. 4, 1983. Pages 82-91], containing the manifolds for supplying fuel components and a system for preparing the air-fuel mixture, including a multi-point fuel injection device, which is a series of jet or centrifugal injectors, and parallel to the supply manifold fuel venturi, as well as a mixing chamber for mixing the individual flows of the air-fuel mixture. In this case, the nozzles of the multipoint injection device are installed in the venturi so that the fuel is sprayed before the critical section of the venturi. The fuel in individual venturi tubes is mixed in the air stream, and after the flows merge, it continues to mix in the mixing chamber.

The disadvantage of this device is its structural complexity (a large number of pipes), and therefore, the complexity of manufacturing and maintenance, and high weight (especially for high-capacity gas turbines). The disadvantages also include significant frictional pressure losses due to the large contact surface of the air-fuel mixture with the walls in the venturi tubes.

The present invention is aimed at obtaining a technical result, which consists in simplifying and facilitating the design of the fuel component mixer and reducing friction pressure losses.

To achieve the specified technical result in a fuel component mixer containing a fuel supply manifold and a fuel-containing mixture preparation system including a multi-point fuel injection device, unlike the known one, the fuel-containing mixture preparation system is made in the form of a single Venturi pipe, while installed in the Venturi pipe to of its critical section, the device of multipoint fuel injection is made in the form of a toroidal streamlined collector with holes on the external and internal surfaces.

In particular, the toroidal manifold of the multi-point fuel injection may have a teardrop shape.

The invention is illustrated by drawings, which depict:

figure 1 is a General view of the design of the mixer of fuel components,

figure 2 is a projection view in the direction of arrow A.

The fuel component mixer contains a Venturi pipe 1 with an inlet pipe 2, on the outer casing of which there is a fuel manifold 3, and inside, in a high-speed flow of medium (air or water vapor), a multi-point fuel injection device 5 in the form of a toroidal manifold with streamlined, for example, a teardrop-shaped profile, in which numerous holes 6 are made normal to the outer and inner surfaces.

Means for supplying fuel, air or water vapor are located at a distance from the fuel component mixer.

The device operates as follows.

Air or water vapor from remote sources through special channels (not shown) is supplied to the fuel component mixer through the nozzle 2, passing through the venturi 1, accelerates to a maximum speed in critical section 7 and then slows down while passing through the diffuser part 8.

Fuel from the fuel manifold 3 through the pylons 4 enters the multi-point injection device 5, is injected through multiple openings 6 into a high-speed flow of medium (air or water vapor) before the critical section 7 of the Venturi 1, undergoes a large shear and turbulence, which leads to complete mixing fuel and air or steam at the outlet of the diffuser part 8 of the venturi 1.

Thus, due to the implementation of a multi-point fuel injection device in the form of a toroidal collector with a streamlined profile, with holes on its internal and external surfaces instead of individual nozzles installed in separate parallel Vsnturi pipes, it is possible to organize complete mixing of the fuel-containing mixture in one larger diameter Venturi pipe . This allows you to significantly simplify and facilitate the device.

Since the degree of mixing of the fuel jets from nozzles or manifold openings with air or steam is determined by the ratio of the length of the diffuser part of the venturi to the diameter of the outlet of the jets, the proposed mixing device has a length equal to the length of the multi-tube mixer. Moreover, the contact area of the fuel mixture with the walls of one Venturi pipe is √n times smaller than in a multi-tube mixer, therefore, hydraulic friction losses also decrease by √n times, where n is the number of parallel venturi pipes in a multi-pipe mixer.

Claims (2)

1. A fuel component mixer comprising a fuel supply manifold and a fuel-containing mixture preparation system including a multi-point fuel injection device, characterized in that the fuel-containing mixture preparation system is made in the form of a single Venturi pipe, with a multi-point injection device installed in the Venturi pipe to its critical section fuel is made in the form of a toroidal streamlined collector with holes on the outer and inner surfaces. 2. The mixer according to claim 1, characterized in that the toroidal manifold of multipoint injection has a teardrop shape.

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