CN100368667C - Gas Turbine Dilution Diffusion Combustion Nozzles - Google Patents

Abstract

A dilution diffusion combustion nozzle for a gas turbine, comprising three cone-shaped nozzles set concentrically in sequence, wherein the outermost nozzle is fixed on an end cover; a small end cover is fixed on one side of the end cover; the middle layer nozzle is coaxially It is sleeved in the outermost nozzle, and its cone and the cone of the outermost nozzle form an air passage; the bottom of the middle nozzle is fixed on a hollow connecting rod through a fuel collecting pipe, and the connecting rod is a gas fuel pipeline, which has The external thread is matched with the internal thread of the adjustment sleeve inlaid on the small end cap; the innermost nozzle is coaxially sleeved in the middle nozzle, and its cone forms a fuel channel with the cone of the middle nozzle; the innermost The layer nozzle is fixed on a hollow connecting rod with external thread. The connecting rod is a liquid fuel pipe with external thread, which matches the internal thread of the adjustment sleeve embedded in the small end cap; adjust the adjustment sleeve to drive the middle The layer nozzle and the innermost layer nozzle move axially to adjust the outlet cross-sectional area of the air channel and the fuel channel.

Description

Gas Turbine Dilution Diffusion Combustion Nozzles

technical field

The invention relates to the field of gas turbines and other gas-phase combustion systems. It is a method to adjust the outlet geometric cross-sectional area of the air and fuel of the burner according to different dilution methods, different diluents and different dilution amounts during operation, so as to achieve high efficiency, stability and A gas turbine dilution diffusion combustion nozzle with low pollution.

Background technique

Gas turbine technology is a major direction of energy utilization. In China's energy structure, coal is the main energy source. Therefore, integrated gasification combined cycle (IGCC) and integrated gasification wet air turbine (IGHAT) cycle are more suitable for China's energy utilization. . The combustor is a key component in the gas turbine cycle, which is related to the efficiency of the system and the emission of pollutants. Therefore, it is required that the combustor can adapt to the combustion of syngas and different dilution amounts, and achieve stable, high-efficiency and low-pollutant emission combustion, with low cost and long service life.

On the one hand, the dilution diffusion combustion technology is suitable for some advanced gas turbine cycles (HAT cycle and ISTG cycle, etc.), because the system itself determines that its combustion method must be dilution diffusion combustion. Diluted diffusion combustion technology can improve the system efficiency and specific power of the wet air turbine (HAT) cycle and steam injection turbine (ISTG) cycle, and can greatly reduce _NOx emissions. On the other hand, for the combustion of syngas in integrated gasification combined cycle (IGCC), due to the large change of its composition, diffusion combustion must be used, and dilution combustion technology must be used in order to reduce NO _x emissions. Diluted diffusion combustion can be divided into fuel dilution and air dilution. The diluent can be water, water vapor, nitrogen, etc. The range of dilution is also very wide, and the diluent can account for 1%-40% of the air volume.

The existing dilution combustion technology is to inject water, water vapor or nitrogen into the combustion chamber of a common gas turbine, so as to achieve the purpose of reducing pollutant emissions by reducing the flame temperature. It cannot adjust the combustion situation according to different dilution conditions. Therefore, under different dilution conditions, the combustion stability, efficiency and pollutants cannot reach the optimal value, and even cannot burn stably under certain working conditions. Therefore, it is necessary to do further work to dynamically organize the flow field according to the components of the syngas and the diluted components, so that the entire combustion chamber can burn stably, efficiently and with low pollution under different working conditions.

Contents of the invention

The object of the present invention is to provide a kind of gas turbine dilution diffusion combustion nozzle, the present invention under different working conditions (synthesis gas component, dilution component, dilution amount), all can stable, efficient, the dilution diffusion combustion technology of low-pollution combustion. Its innovative point is that it can dynamically adjust the outlet geometric area of the burner according to the composition of the syngas, the dilution component and the dilution amount, so as to adjust the flow field so that the combustion nozzle can burn stably, efficiently and with low pollution under different working conditions. In addition, the present invention can also be adopted in a gas boiler.

In order to achieve the above object, the gas turbine dilution and diffusion combustion nozzle provided by the present invention includes three cone-shaped nozzles that are concentrically arranged sequentially, wherein:

The outermost nozzle is fixed on the end cover; a small end cover is fixed on one side of the end cover;

The middle layer nozzle is coaxially sleeved in the outermost layer nozzle, and its cone part and the cone part of the outermost layer nozzle form an air channel; the bottom of the middle layer nozzle is fixed on a hollow connecting rod through a fuel collecting pipe, and the connecting rod is The gas fuel pipe has an external thread that matches the internal thread of the adjustment sleeve embedded on the small end cap;

The innermost nozzle is coaxially sleeved in the middle nozzle, and its cone and the cone of the middle nozzle form a fuel channel; the innermost nozzle is fixed on a hollow connecting rod with external threads, and the connecting rod is The liquid fuel pipeline has an external thread that matches the internal thread of the adjusting sleeve embedded on the small end cap;

Turn the two adjustment sleeves respectively to drive the middle layer nozzle and the innermost layer nozzle to move axially, and adjust the outlet cross-sectional area of the air channel and the fuel channel.

In the gas turbine dilution and diffusion combustion nozzle, an air swirler is arranged in the ring between the outermost layer nozzle and the second layer nozzle.

In the gas turbine dilution and diffusion combustion nozzle, a fuel swirler is arranged around the nozzle in the middle layer and the nozzle in the innermost layer.

In the gas turbine dilution and diffusion combustion nozzle, the air swirler and the fuel swirler are vane swirlers or tangential inlet swirlers.

In the gas turbine dilution and diffusion combustion nozzle, the adjustment sleeve is driven manually or by a motor.

Said gas turbine dilution diffusion combustion nozzle, wherein the liquid fuel is diesel oil, heavy oil or methanol.

In a nutshell, the gas turbine dilution diffusion combustion nozzle provided by the present invention includes a fixed cone structure and two movable cone structures, wherein the outermost fixed channel and the middle movable cone structure form a ring The air channel with variable outlet cross-section, and the innermost movable conical structure and the middle movable conical structure also constitute an annular gas fuel channel with variable outlet cross-sectional area, and the middle movable structure has Liquid fuel nozzles. The two movable structures are respectively connected through two externally threaded pipes and the internally threaded structure on the end cap, and the axial distance between the two movable conical structures can be adjusted by turning the internally threaded part on the end cap, thus changing the air flow rate. and fuel outlet cross-sectional area, adjust its outlet velocity to achieve stable, efficient, and low-pollution combustion under different combustion conditions.

When the combustion nozzle of the present invention operates under non-dilution conditions, the two movable cone structures are adjusted to ensure that the outlet cross-sectional area of air and fuel is at a smaller position, and the flame is stable at a design condition. . When the air is diluted, due to the increase of the diluted air volume, the outlet velocity increases, making the working condition deviate from the design working condition. At this time, the internal thread adjustment mechanism on the end cover is adjusted to make the two movable cone structures move along the axial direction. Moving backward, the air outlet area increases, so that the air outlet velocity becomes the same as the air outlet velocity under non-dilution conditions, so that the flame can burn stably under different air dilution conditions. When the fuel is diluted, similar to the air dilution, the movable mechanism is adjusted to increase the outlet cross-sectional area of the fuel passage, so that the fuel outlet velocity remains approximately constant, thereby ensuring a stable combustion flow field condition.

In addition, the present invention is also applicable to the combustion of syngas with different components in the gas turbine. When the composition of the syngas changes, the outlet cross-sectional area of the fuel channel can be changed by adjusting the two internal thread adjustment mechanisms on the end cover to see the distance between the fuel outlet and the air outlet. distance, so as to achieve stable, efficient and low-pollution combustion of different components of syngas.

Description of drawings

Fig. 1 is a schematic diagram of an extreme adjustment position of the present invention

Fig. 2 is another extreme adjustment position schematic diagram of the present invention

Detailed ways

Accompanying drawing is a schematic diagram of a specific embodiment of the present invention. Wherein accompanying drawing 1 and accompanying drawing 2 are two extreme adjustment positions of the present invention respectively. Referring to the accompanying drawing 1, it can be seen that the combustion nozzle of the present invention mainly includes three coaxially sleeved and conical nozzles 1, 2 and 3, in which the middle layer nozzle 2 and the innermost layer nozzle 3 can move axially. The outermost nozzle is fixed on the end cover 6 by a fixing structure 7 (such as a bracket, etc.). The nozzle 2 between the middle layers is coaxially sleeved in the nozzle 1 of the outermost layer, and an air channel 14 is formed at the nozzles of the two nozzles 1 and 2 . The middle layer nozzle 2 is fixed on a connecting rod 10 through a fuel collecting pipe 8 . The connecting rod 10 is a hollow gas fuel channel with external threads. The gas fuel can enter the fuel collecting pipe 8 through the connecting rod 10 . Two rotatable adjustment sleeves 12, 13 are inlaid side by side on the small end cap 9, and the adjustment sleeves 12, 13 have an internal thread structure, wherein the connecting rod 10 and the adjustment sleeve 12 are threadedly matched (the adjustment sleeve 13 and the later-described connecting rod 11). By turning the adjustment sleeve 12, the middle layer nozzle 2 can move axially, thereby changing the cross-sectional area of the air channel 14, that is, changing the throughput of air and fuel (as shown in FIG. 2 ). An air swirler 4 is also arranged between the above-mentioned two layers of nozzles, which is fixed on the outermost nozzle 1. The air swirler can be a vane swirler or a tangential inlet swirler.

Similar to the outermost nozzle 1 and the middle nozzle 2 , the innermost nozzle 3 is coaxially sleeved in the middle nozzle 2 , and fuel channels 15 are formed at the nozzles of the two nozzles 2 , 3 . The innermost nozzle 3 is connected to a connecting rod 11 with an external thread, and the connecting rod 11 is a hollow fuel channel through which liquid fuel, diesel oil, heavy oil, methanol, etc. flow. The connecting rod 11 cooperates with the internal thread of the adjustment sleeve 13 on the small end cap 9, and the innermost nozzle 3 can be moved axially by rotating the adjustment sleeve 13, thereby changing the cross-sectional area of the fuel passage 15 (as shown in Figure 2 Show). A fuel swirler 5 is arranged between the middle nozzle 2 and the innermost nozzle 3, and the fuel swirler 5 is fixed on the middle nozzle 2. The air swirler can be a vane swirler or a tangential air inlet swirler. streamer etc.

The adjustment sleeves 12 and 13 can be controlled manually, or can be connected with a stepper motor.

When the air is diluted, due to the increase of the amount of diluted air, the outlet velocity of the air increases, and the flame deviates from the design condition, so it cannot burn well. The present invention is according to different diluents and dilution amount, and described diluent comprises water, water vapour, nitrogen and carbon dioxide etc., adjusts adjustment cover 12 and 13, makes middle layer nozzle 2 and innermost layer nozzle 3 move backward, like this The outlet cross-sectional area of the air passage 14 increases, and although the amount of diluted air increases, the outlet velocity remains unchanged. Generally, after the air is diluted, in order to ensure that the turbine efficiency of the gas turbine remains unchanged, the amount of fuel needs to be increased. At this time, the adjustment sleeve 13 is adjusted accordingly so that the outlet cross-sectional area of the fuel channel 15 is also increased to adapt to the increased fuel amount. In this way, under different working conditions, the flame can be burned stably, efficiently and with low pollution.

Similarly, when the fuel is diluted, the amount of fuel increases due to the diluent and the need to increase the amount of fuel to ensure the turbine efficiency of the gas turbine. Therefore, in order to stabilize combustion, the adjusting sleeve 13 is adjusted so that the innermost nozzle 3 moves backward, thereby increasing The outlet cross-sectional area of the fuel channel 15 is kept constant while the outlet velocity of the fuel is kept constant. In this way, it can ensure stable flame, high-efficiency and low-pollution combustion under different fuel dilution conditions.

When the fuel is syngas, since the composition of the syngas may change during the operation of the gas turbine, and in different applications, the composition of the syngas changes, if the on-site adjustment cannot be realized, it will not be possible Stable combustion. When the composition of the syngas fuel changes, the present invention changes the outlet cross-sectional area and the relative position of the fuel channel 15 and the air channel 14 by adjusting the adjustment sleeves 12 and 13, thereby ensuring that the syngas fuel of different components can be This nozzle achieves stable, efficient, and low-pollution combustion.

Claims (6)

1. A gas turbine dilution and diffusion combustion nozzle, comprising three cone-shaped nozzles that are successively sheathed concentrically, wherein the innermost nozzle is coaxially sleeved in the middle layer nozzle, and its cone and the cone of the middle layer nozzle form a fuel channel; the innermost nozzle is fixed on a hollow connecting rod provided with external thread, the connecting rod is a liquid fuel pipeline with external thread, which is matched with the internal thread of the adjustment sleeve embedded on the small end cap; Rotate the two adjusting sleeves respectively to drive the middle layer nozzle and the innermost layer nozzle to move axially, and adjust the outlet cross-sectional area of the air channel and the fuel channel; Its characteristics are: the outermost nozzle is fixed on the end cover; a small end cover is fixed on one side of the end cover; The middle layer nozzle is coaxially sleeved in the outermost layer nozzle, and its cone part and the cone part of the outermost layer nozzle form an air channel; the bottom of the middle layer nozzle is fixed on a hollow connecting rod through a fuel collecting pipe, and the connecting rod is The gas fuel pipe has an external thread, which is matched with the internal thread of the adjusting sleeve embedded on the small end cap. 2. The gas turbine dilution diffusion combustion nozzle according to claim 1, wherein an air swirler is arranged in the ring between the outermost layer nozzle and the second layer nozzle. 3. The gas turbine dilution and diffusion combustion nozzle according to claim 1, wherein a fuel swirler is arranged in the ring between the middle layer nozzle and the innermost layer nozzle. 4. The gas turbine dilution diffusion combustion nozzle according to claim 2 or 3, wherein the air swirler and the fuel swirler are vane swirlers or tangential inlet swirlers. 5. The gas turbine dilution and diffusion combustion nozzle according to claim 1, wherein the adjustment sleeve is driven manually or by a motor. 6. The gas turbine dilution diffusion combustion nozzle according to claim 1, wherein the liquid fuel is diesel oil, heavy oil or methanol.

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