CN110822482A

CN110822482A - Medium-low calorific value gas and liquid dual-fuel nozzle and fuel switching method

Info

Publication number: CN110822482A
Application number: CN201911186946.0A
Authority: CN
Inventors: 王巍龙; 王邦赛; 吕晶; 董丽丽; 蓝天霞
Original assignee: AECC Shenyang Liming Aero Engine Co Ltd
Current assignee: AECC Shenyang Liming Aero Engine Co Ltd
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2020-02-21
Anticipated expiration: 2039-11-28
Also published as: CN110822482B

Abstract

The invention relates to a gas and liquid dual-fuel nozzle with medium and low calorific value and a fuel switching method, and specifically comprises a nozzle shell, a core and a compression nut: the nozzle shell comprises a main oil passage, an auxiliary oil passage, a fuel gas passage, a distributor, a head shell and a mounting flange; the mold core is assembled into the nozzle shell and comprises a main nozzle, an inner nozzle, an auxiliary nozzle, a sleeve, a swirler and a sealing ring, the front end of the compression nut tightly props against the sealing ring, and the compression nut is connected onto the head shell through threads. Under the condition that the quality of the medium-low calorific value gas fuel is not high, the unit is ignited by the liquid fuel, the unit starts to switch from liquid to gas when reaching a certain stable operation state, and when the fuel pressure is insufficient during the operation of the unit for combusting the medium-low calorific value gas fuel, the unit needs to switch from gas to liquid. The invention expands the fuel application range of the gas turbine, enhances the fuel adaptability and improves the market competitiveness of the gas turbine.

Description

Medium-low calorific value gas and liquid dual-fuel nozzle and fuel switching method

Technical Field

The invention relates to the technical field of gas turbines, in particular to a gas and liquid dual-fuel nozzle with medium and low heat values and a fuel switching method.

Background

Natural gas is a high-quality fuel for gas turbine power generation as a high-calorific-value fuel, but as the price of natural gas increases, gas turbines using natural gas as a fuel gradually come out of the mainstream of market competition. Many industrial departments such as petroleum, chemical industry and the like produce a large amount of gas fuels with medium and low calorific value, such as coke oven gas, blast furnace gas, chemical industry tail gas and the like, while producing main products thereof, and become another good resource for enterprises to actively utilize the gas fuels to generate electricity and create benefits. However, due to the quality problems of low calorific value gas fuel in by-products and unstable gas production, the gas turbine needs to rely on liquid fuel (such as diesel oil) for ignition and maintain normal operation. However, most of the gas turbines present a single fuel combustion state and insufficient fuel applicability, the market requirements are not met for diversified energy structures at present, the fuel switching technology is not mature for dual fuel units, the market development of the gas turbines is restricted, and meanwhile, most of nozzles in the prior art adopt a casting or forging process to form a complex structure and then perform mechanical processing, the process is complex, and the casting and forging production cost is high.

Disclosure of Invention

In order to solve the problems, the invention provides the gas and liquid dual-fuel nozzle with the medium and low heat values and the fuel switching method, so that the application range of the fuel of the gas turbine is expanded, the fuel adaptability is enhanced, and the market competitiveness of the gas turbine is improved.

The technical scheme of the invention is as follows:

a gas and liquid dual-fuel nozzle with medium and low heat value comprises a nozzle shell, a core and a compression nut:

the nozzle shell comprises a main oil passage, an auxiliary oil passage, a fuel gas passage, a distributor, a head shell and a mounting flange: the main oil path is formed by welding a main oil path connector to one side of the distributor through elbow switching and then connecting a main fuel oil pipeline; the auxiliary oil path is formed by welding an auxiliary oil path connector with an oil filter in the middle to the other side of the distributor and then connecting an auxiliary fuel oil pipeline; the gas passage is formed by welding a gas nozzle to the top end of the distributor and then connecting a gas pipeline; the mounting flange is welded at the tail end of the distributor and used for fixing the nozzle on the combustion chamber casing; outlets of the main fuel pipeline, the auxiliary fuel passage and the fuel gas passage are welded on the head shell, and a closing-in is arranged on the front end face of the head shell;

the core is assembled in the nozzle shell, and comprises a main nozzle, an inner nozzle, an auxiliary nozzle, a sleeve, a swirler and a sealing ring: the front end of the main nozzle is in contact fit with the closing-up, the rear end of the main nozzle is matched with the front end of the inner nozzle, the front end of the sleeve is connected with the annular end face of the rear end of the inner nozzle, the head of the cyclone is inserted into the inner nozzle and the sleeve, the end face of the head of the cyclone is welded with the auxiliary nozzle, the front end face of the cylindrical structure at the rear end of the cyclone is matched with the rear end of the sleeve, the sealing ring is assembled on the rear end face of the cyclone, the front end of the compression nut tightly supports the sealing ring, and the.

Furthermore, the outlets of the main oil passage, the auxiliary oil passage and the fuel gas passage are in annular coaxial layout, the inner part and the outer part of the main oil passage are respectively provided with the auxiliary oil passage and the main oil passage, and the fuel gas passage is arranged between the auxiliary oil passage and the main oil passage.

Further, the main nozzle is provided with a tangential groove.

Furthermore, the outer profile of the cyclone is provided with a cyclone groove structure, and an auxiliary vortex cone is arranged in the cyclone groove structure.

A switching method of a gas and liquid dual-fuel nozzle with a medium-low heating value comprises the following steps:

a. under the condition that the quality of the medium-low calorific value gas fuel is not high, the unit is ignited by the liquid fuel, and the unit starts to switch from liquid to gas when reaching a certain stable operation state:

(1) the gas fuel is supplied to ensure that the unit state is slightly promoted, and the gas fuel is reliably ignited and stably burnt;

(2) under the condition of keeping the stable state of the unit, uniformly increasing the supply amount of gas fuel and simultaneously uniformly reducing the supply amount of liquid fuel;

(3) after the supply amount of the liquid fuel is reduced to zero, the main oil passage and the auxiliary oil passage supply compressed air for cleaning and blowing protection;

(4) finishing fuel switching, increasing the amount of gas fuel, and increasing the load of the unit to a required working condition;

b. when the fuel pressure is insufficient during the operation of the unit using the medium-low heat value gas fuel, the switching step from gas to liquid needs to be carried out:

(1) the unit reduces the load to a certain stable operation state, and liquid fuel is fed to ensure that the state of the unit is slightly improved, so that the liquid fuel is reliably ignited and stably combusted;

(2) under the condition of keeping the stable state of the unit, the supply quantity of liquid fuel is uniformly increased, and the supply quantity of gas fuel is uniformly reduced;

(3) when the supply quantity of the gas fuel is reduced to zero, the fuel gas channel supplies compressed air, which is beneficial to combustion and blowing protection;

(4) and finishing fuel switching, increasing the liquid fuel amount, and increasing the load of the unit to the required working condition.

The working principle of the medium-low heating value gas and liquid dual-fuel nozzle is as follows:

the main oil passage and the auxiliary oil passage are in a pressure atomization type, a swirler is arranged at the position of an auxiliary nozzle, fuel oil is centrifugally rotated by the aid of fuel oil pressure, and a fuel oil fog cone is formed at the position of a spraying hole to start ignition; the tangential groove is designed at the position of the main nozzle, the main nozzle rotates by the pressure of fuel oil, a layer of oil film is formed on the inner surface of the main nozzle, meanwhile, air is screwed out from the inner nozzle through an air passage and a swirler in the middle of the nozzle, and the screwed air flow meets the oil film sprayed out from the main nozzle to form an oil-gas mixed fog cone; the fuel gas channel is a nozzle direct-injection type, and fuel flows through the nozzle by the gas supply pressure to form a fuel gas cone which enters the combustion chamber for stable combustion.

The main oil passageway, vice oil passageway and gas passageway are each other the circulation air auxiliary passage among the steady operation process, and the fuel switches the in-process and is the explicit reliable switching of state: (1) when the nozzle burns by taking fuel gas as fuel, compressed air is supplied to the primary oil path and the secondary oil path, so that the carbon deposit prevention and blowing protection function at the nozzle is achieved; (2) when the nozzle burns by taking fuel oil as fuel, compressed air is supplied to the fuel gas passage and forms a mixed oil-gas fog cone with the fuel oil of the main oil passage, so that the full combustion is facilitated, the combustion efficiency is improved, the pollutant emission is reduced, and the carbon deposit prevention and blowing protection effect at the nozzle is achieved; (3) when fuel is switched, the pre-combustion fuel is fed in first to improve the state of the unit, the pre-combustion fuel is ensured to be reliably ignited and stably combusted, then the pre-combustion fuel is uniformly added, the pre-removal fuel is reduced, and after the switching is finished, compressed air is introduced into a fuel-free supply passage for protection.

The invention has the beneficial effects that:

(1) the liquid fuel can be combusted, and the gas fuel with medium and low heat value can also be combusted, so that the application range of the gas turbine fuel is expanded, the fuel adaptability is enhanced, and the market competitiveness of the gas turbine is improved;

(2) in the process of burning with liquid fuel or gas fuel, a small stream of compressed air is fed into a channel without fuel supply, so that the nozzles can be cleaned and blown to be protected, carbon deposit is effectively prevented, meanwhile, full burning is facilitated, the burning efficiency is improved, and the pollutant emission is reduced;

(3) when the fuel is switched, the pre-combustion fuel is fed firstly to improve the unit state, and then the fuel supply quantity is increased and decreased and the subsequent compressed air is supplied, so that the pre-combustion fuel can be reliably ignited and stably combusted, and the fuel switching process is stable and reliable;

(4) the structure of each part provided by the invention adopts a modular part structure, and each part is assembled in a welding mode, so that the production cost is reduced, and the economic benefit is improved.

Drawings

FIG. 1 is a cross-sectional view of a medium to low heating value gas and liquid dual fuel nozzle;

FIG. 2 is a cross-sectional view of a nozzle housing

FIG. 3 is a cross-sectional view of the core

FIG. 4 is a partial view of a closure

FIG. 5 is a cross-sectional view of a main nozzle

FIG. 6 is a schematic view of a tangential groove at the primary nozzle

FIG. 7 is a cross-sectional view of a cyclone

FIG. 8 is a cross-sectional view taken along line C of FIG. 7

FIG. 9 is a schematic view of a swirl channel of the outer swirler profile

In the figure: 1-a gas nozzle; 2-main oil way connection mouth; 3-bending the pipe; 4-a distributor; 5-auxiliary oil way connection mouth; 6-oil filtration; 7-secondary fuel line; 8, mounting a flange; 9-gas pipeline; 10-a primary fuel line; 11-a head housing; 12-a compression nut; 13-a sealing ring; 14-a sleeve; 15-a swirler; 16-secondary vortex cone; 17-secondary nozzle; 18-a primary orifice; 19-inner spout; 20-closing up; 21-tangential grooves; 22-swirl groove

Detailed Description

A medium to low heating value gas and liquid dual fuel nozzle comprising a nozzle housing as shown in fig. 2, a core as shown in fig. 3, and a compression nut 12 as shown in fig. 1:

as shown in fig. 1 to 4, the nozzle housing includes a main oil passage, an auxiliary oil passage, a fuel gas passage, a distributor 4, a head case 11, and a mounting flange 8:

the main oil path is formed by connecting and welding a main oil path connector 2 to one side of a distributor 4 through an elbow 3 and then connecting a main fuel oil pipeline 10; the auxiliary oil path is formed by welding an auxiliary oil path connector 5 with an oil filter 6 in the middle to the other side of the distributor 4 and then connecting an auxiliary fuel oil line 7; the gas passage is formed by welding a gas nozzle 1 to the top end of the distributor 4 and then connecting a gas pipeline 9; the mounting flange 8 is welded at the tail end of the distributor 4 and is used for fixing the nozzle on the combustion chamber casing; outlets of the main fuel pipeline, the auxiliary fuel passage and the fuel gas passage are welded on the head shell 11, and a closing-in 20 is arranged on the front end face of the head shell 11; the outlets of the main oil passage, the auxiliary oil passage and the fuel gas passage are in annular coaxial layout, the inner part and the outer part of the main oil passage are respectively provided with the auxiliary oil passage and the main oil passage, and the fuel gas passage is arranged between the auxiliary oil passage and the main oil passage.

The core is fitted into the nozzle housing, the core comprising a primary nozzle 18, an inner nozzle 19, a secondary nozzle 17, a sleeve 14, a swirler 15 and a sealing ring 13: the front end of the main nozzle 18 is in contact fit with the closing-in 20, the rear end of the main nozzle 18 is matched with the front end of the inner nozzle 19, the front end of the sleeve 14 is connected with the annular end face of the rear end of the inner nozzle 18, the head of the swirler 15 is inserted into the inner nozzle 19 and the sleeve 14, the end face of the head of the swirler 15 is welded with the auxiliary nozzle 17, the front end face of the cylindrical structure of the rear end of the swirler 15 is matched with the rear end of the sleeve 14, the sealing ring 13 is assembled on the rear end face of the swirler 15, the front end of the compression nut 12 tightly supports the sealing ring 13, and the compression nut.

As shown in FIGS. 5-6, the primary nozzles 18 are provided with tangential slots 21.

As shown in fig. 3 and 7 to 9, the cyclone 15 has a cyclone groove 22 on its outer surface and an auxiliary vortex 16 inside.

Claims

1. The utility model provides a gaseous and liquid dual fuel nozzle of well low calorific value which characterized in that, includes nozzle shell, core and gland nut:

the nozzle shell comprises a main oil passage, an auxiliary oil passage, a fuel gas passage, a distributor, a head shell and a mounting flange: the main oil path is formed by welding a main oil path connector to one side of the distributor through a bent pipe in a switching and parallel mode and then connecting a main fuel oil pipeline; the auxiliary oil path is formed by welding an auxiliary oil path connector with an oil filter in the middle to the other side of the distributor and then connecting an auxiliary fuel oil pipeline; the gas passage is formed by welding a gas nozzle to the top end of the distributor and then connecting a gas pipeline; the mounting flange is welded at the tail end of the distributor and used for fixing the nozzle on the combustion chamber casing; outlets of the main fuel pipeline, the auxiliary fuel passage and the fuel gas passage are welded on the head shell, and a closing-in is arranged on the front end face of the head shell;

the core is assembled into a nozzle housing, the core including a primary nozzle, an inner nozzle, a secondary nozzle, a sleeve, a swirler, and a sealing ring: the front end of the main nozzle is in contact fit with the closing-up, the rear end of the main nozzle is matched with the front end of the inner nozzle, the front end of the sleeve is connected with the annular end face of the rear end of the inner nozzle, the head of the cyclone is inserted into the inner nozzle and the sleeve, the end face of the head of the cyclone is welded with the auxiliary nozzle, the front end face of the cylindrical structure at the rear end of the cyclone is matched with the rear end of the sleeve, the sealing ring is assembled on the rear end face of the cyclone, the front end of the compression nut tightly supports the sealing ring, and the.

2. The dual fuel nozzle for gas and liquid with medium and low heating value as claimed in claim 1, wherein the outlets of the main oil passage, the auxiliary oil passage and the fuel gas passage are arranged in an annular coaxial manner, the inner part and the outer part of the main oil passage are respectively the auxiliary oil passage and the main oil passage, and the fuel gas passage is arranged between the auxiliary oil passage and the main oil passage.

3. A medium to low heating value gas and liquid dual fuel nozzle as claimed in claim 1, wherein the primary orifice is provided with tangential slots.

4. A medium to low heating value gas and liquid dual fuel nozzle as claimed in claim 1, wherein the swirler outer profile is provided with a swirl groove structure and a secondary swirl cone is mounted therein.

5. A switching method of a gas and liquid dual-fuel nozzle with a medium-low heat value is characterized by comprising the following steps:

a. switching from liquid to gas:

b. switching from gas to liquid: