LU503079B1 - Low-emission nozzle, low-emission dual-fuel combustion chamber and gas turbine generator set - Google Patents

Abstract

A low-emission nozzle, a low-emission dual-fuel combustion chamber and a gas turbine generator set, which relate to a generator set. The present invention aims to solve the problem that the existing technology is prone to high-temperature carbon deposits. In the present invention, liquid fuel diffusion combustion and gas fuel premix combustion are combined through the integrated design of a dual-fuel low-emission nozzle; when the gas turbine uses gas fuel, the gas fuel are injected through small holes in a low-emission nozzle swirler for good mixing with air, and pollutant emissions are reduced by means of premix combustion; when the gas turbine uses liquid fuel, the problem of poor atomization effect of liquid fuel at low working conditions of the gas turbine is solved by the air-assisted atomization low-emission nozzle in the center of the low-emission nozzle; and a low-emission dual-fuel combustion control system is proposed to supply gas fuel or liquid fuel for the gas turbine machine, and adjust the fuel, and online smooth switching of gas/liquid fuel can also be realized without stopping the machine. The present invention is used for power generation.

Description

BL-5590 1

LOW-EMISSION NOZZLE, LOW-EMISSION DUAL-FUEL COMBUSTION LUS503079

CHAMBER AND GAS TURBINE GENERATOR SET

Technical field

The present invention relates to a low-emission nozzle, a low-emission dual-fuel combustion chamber and a fuel control system for a gas turbine generator set. It belongs to the field of thermal energy and power engineering.

Technical background

With the continuous advancement of China's marine strategy, the exploration and extraction of marine crude oil have been continuously increased, and the output of marine crude oil has increased rapidly. In the process of extracting crude oil, a large amount of oil-associated gas is often produced. Such associated gas is flammable, explosive, and difficult to store and transport. For safety reasons, it will be directly burned from the beginning of extraction, resulting in a serious waste of energy. The national marine strategy has put forward an urgent need to solve this problem.

Dual-fuel gas turbines are a kind of power equipment that can effectively solve this problem. It can not only provide power for extraction of crude oil, but also use oil-associated gas as gas fuel for working. In the case of non-stop, the undisturbed online switching between the raw liquid fuel and the oil-associated gas is realized, which improves the adaptability of the gas turbine to the fuel, effectively utilizes the oil-associated gas, and solves various fuel requirements in different states during the crude oil extraction process.

Dual-fuel combustion chambers and dual-fuel control systems are the most important core components of dual-fuel gas turbines. With the increasing demand for high-power, low-emission, dual-fuel gas turbines in the marine strategy, higher requirements are also placed on the design of combustion chambers. In addition, gas associated gas is used for 95% of the time during an overhaul cycle of dual-fuel gas turbines, and liquid fuel is only required for occasional failures or adjustments to the gas supply, so the functional need to achieve low emissions when using gas fuel is extremely urgent.

BL-5590 2

LU503079

In order to meet the requirements of low emission when dual-fuel gas turbines use associated gas, at present, the most commonly used solution is nozzle water spray technology. By spraying water in the combustion chamber to reduce the temperature of the combustion zone, the purpose of reducing the emission of nitrogen oxides and other pollutants is achieved. However, this also brings increased supporting equipment and complicated auxiliary systems, which seriously affects the inherent advantages of small size and light weight of gas turbines, and brings limitations to the application of dual-fuel gas turbines.

Multi-stage lean-burn premixing technology is used to fully mix the fuel and air evenly, eliminate the fuel-enriched zone, and make the outlet temperature distribution of the combustion chamber uniform. Also, a low gas/air ratio makes the outlet temperature of the combustion chamber not greater than a rated value, which removes the high temperature distortion point while efficiently and stably burning. As a result, it is possible to effectively achieve low emissions while addressing the above limitation. In Announcement No. CN102393028B, a low-emission combustion chamber was invented in this way, and a good low-emission effect was achieved.

In an invention patent Announcement No. CN103486617B entitled "dual-fuel low-emission burner for gas turbine”, the use of dual fuels is realized by feeding gas fuel and liquid fuel separately, and at the same time, the emission of nitrogen oxides is reduced by means of lean oil premixing. When the main fuel burner is working, a small amount of cooling air is introduced to cool and protect the end face of the auxiliary burner. However, due to the poor cooling effect of a small amount of cooling air, the auxiliary burner has a problem of high-temperature carbon deposits.

Summary of the invention

An objective of the present invention is to solve the problem that the auxiliary burner in the existing dual-fuel low-emission burner is prone to high-temperature carbon deposits. Thus, a low-emission nozzle, a low-emission dual-fuel combustion chamber and a gas turbine generator set are provided.

BL-5590 3

The technical solutions of the present invention are as follows: LU503079

Solution 1: A low-emission nozzle, comprising a first fuel gas path, a second fuel gas path, an atomizing air path, a liquid fuel path, a purging air path and a nozzle body; wherein the first fuel gas path, the second fuel gas path, the atomizing air path and the liquid fuel path are mounted on the nozzle body in the form of internal oil and external gas and staggered oil and gas paths; and wherein the atomizing air path, the first fuel gas path and the liquid fuel path ensure that a set enters a slow working condition and share a first-path air swirler of the first fuel gas path, the atomizing air path, the second fuel gas path and the liquid fuel path ensure that the set enters a fast working condition and share a second-path air swirler of the second fuel gas path, the purging air path is mounted on a fuel ejection side of the nozzle body, and the purging air path prevents carbon deposits at the spout by means of impingement convection cooling, air film cooling and thermal insulation cooling.

Solution 2: A low-emission dual-fuel combustion chamber, comprising a combustion chamber outer shell, a combustion chamber inner shell and a flame tube, a front load-bearing shell, a rear support shell, a combustion chamber outlet, a diffuser, a combustion chamber inlet, a positioner and a low-emission nozzle, wherein the combustion chamber outer shell is sealed and connected with the front load-bearing shell and the rear support shell through front and rear annular flanges, respectively, the combustion chamber inner shell is connected to the front load-bearing shell through the front annular flange and forms a three-dimensional annular working space together with the combustion chamber outer shell, the diffuser is connected to the rear of the combustion chamber inner shell, an end of the diffuser is the combustion chamber inlet, and the combustion chamber outlet is provided in the rear support shell; and wherein the flame tube is mounted in the three-dimensional annular working space, the low-emission nozzle is inserted into an insertion hole of the head of the flame tube through a mounting hole of a front annular cone surface of the front load-bearing shell, a main combustion hole is provided in the middle of the flame tube, there are two positioners connected to the head of the flame tube, and a tail mounting seat of the flame tube is mounted on the rear support shell with three-point support.

BL-5590 4

LU503079

Solution 3: A gas turbine generator set, comprising the above-mentioned low-emission dual-fuel combustion chamber, a low-emission dual-fuel control system, a compressor, a turbine and a generator, wherein the low-emission dual-fuel combustion chamber is connected to a low-emission nozzle annular pipe system of the low-emission dual-fuel control system; high-temperature and high-pressure air from the compressor enters a diffuser from an inlet of the combustion chamber for deceleration and diffusion, and then flows into an annular cavity of the combustion chamber, and then the air is distributed to a low-emission nozzle and mixed with liquid fuel or gas fuel to form a combustible mixture, which is efficiently and stably combusted in a flame tube, and is discharged from an outlet of the combustion chamber to push the turbine to output work for achieving power generation of the generator; wherein the low-emission dual-fuel control system comprises a liquid fuel system, a gas fuel system, a liquid fuel purging system, a gas fuel purging system, an auxiliary atomizing air system and the low-emission nozzle annular pipe system; wherein the low-emission nozzle annular pipe system comprises a liquid fuel annular pipe, an auxiliary atomizing air annular pipe, a gas fuel path-1 annular pipe and a gas fuel path-2 annular pipe, and the liquid fuel annular pipe, the auxiliary atomizing air annular pipe, the gas fuel path-1 annular pipe and the gas fuel path-2 annular pipe are connected to a liquid fuel path inlet pipe, an auxiliary atomizing air path inlet pipe, a first gas fuel inlet pipe and a second gas fuel inlet pipe on the low-emission nozzle through branch pipes, respectively; during combustion of liquid fuel: when under ignition and below slow working conditions: the liquid fuel system is put into operation, the gas fuel system is not in operation, the liquid fuel purging system is not in operation, the gas fuel purging system is put into operation, and the auxiliary atomizing air system is put into operation,

BL-5590 5 and at this time, the liquid fuel system enters the liquid fuel annular pipe of the LU503079 low-emission nozzle annular pipe system through the liquid fuel flow path, and then enters the liquid fuel path of the low-emission nozzle;

the auxiliary atomizing air system enters the auxiliary atomizing air annular pipe through the auxiliary atomizing air flow path, and then enters the atomizing air path of the low-emission nozzle for auxiliary atomization of liquid fuel; the gas fuel purging system is divided into two flow paths, i.e., a first gas fuel flow path purging branch and a second gas fuel flow path purging branch, for cleaning and purging the gas fuel annular pipe in a non-operation state and the internal passages of the low-emission nozzle; when above the slow working condition: a purging air source of the atomizing air path is adjusted from the auxiliary atomizing air system to be supplied from the atomizing air purging path of the liquid fuel path purging system, that is, the auxiliary atomizing air source is supplied by the compressed air in the annular cavity space formed by the combustion chamber outer shell and the flame tube of the low-emission dual-fuel combustion chamber, and the rest of the system remains unchanged; during combustion of gas fuel: the liquid fuel system is closed, the gas fuel system is put into operation, and the liquid fuel purging system is put into operation; when under the ignition and below slow working conditions: the compressed air in the annular cavity space of the low-emission dual-fuel combustion chamber enters the liquid fuel path of the liquid fuel system A, the second gas fuel flow path purging branch of the gas fuel purging system, and the auxiliary atomizing air path of the auxiliary atomizing air system; the gas fuel enters the gas fuel path-1 annular pipe of the low-emission nozzle annular pipe system

BL-5590 6 through the gas fuel system, and then enters the first gas fuel inlet pipe of the LU503079 low-emission nozzle; the liquid fuel purging system is in a purging working state, and the auxiliary atomizing air path inlet pipe and the liquid fuel path inlet pipe are both supplied by the compressed air in the annular cavity space formed by the combustion chamber outer shell and the flame tube of the low-emission dual-fuel combustion chamber to purge and cool each passage; when above the slow working condition: the gas fuel purging system is closed, and the gas fuel simultaneously enters the gas fuel path-1 annular pipe and the gas fuel path-2 annular pipe of the low-emission nozzle annular pipe system through the gas fuel system, and then enters the first fuel gas path and the second fuel gas path of the low-emission nozzle separately; and when the gas fuel and liquid fuel are switched, both the liquid fuel purging system and the gas fuel purging system are closed, and both the liquid fuel system and the gas fuel system are put into operation.

Compared with the prior art, the present invention has the following effects: 1. The low-emission nozzle of the present invention adopts a purging air path, and the purging air path of the present invention prevents carbon deposits at the spout by means of impingement convection cooling, air film cooling and thermal insulation cooling, which effectively reduces the temperature of the core working components, and extends the service life of the low-emission nozzle. 2. In the low-emission dual-fuel combustion chamber of the present invention, the multi-stage lean-burn premix low-emission technology is effectively incorporated to the dual-fuel low-emission nozzle. When gas fuel is used in the combustion chamber, the gas fuel is injected through the small holes in the low-emission nozzle swirler for good and uniform mixing with air, and the pollutant emission value is

BL-5590 7 reduced by means of premix combustion. When liquid fuel is used in the LUS03079 combustion chamber, The air-assisted atomization low-emission nozzle in the center of the low-emission nozzle solves the problem of liquid fuel atomization under the same distribution structure. On the basis that the low-emission nozzle meets the requirements of dual-fuel use, the purpose of using the lean-burn premix combustion technology to reduce the pollutant emission of the gas turbine under the condition of gas fuel can be realized. In order to cooperate with the low-emission dual-fuel combustion chamber proposed by the present invention to operate effectively, the present invention also proposes a dual-fuel control system.

The dual-fuel control system can supply gas fuel or liquid fuel for the whole machine according to the requirements of use, and adjust the fuel, and can also realize the online smooth switching of gas/liquid fuel without stopping the machine.

Also, in order to prevent the high-temperature carbon deposit of the other fuel path when one fuel is working, a purging system is designed in the dual-fuel control system. The present invention can ensure that the gas turbine burns gas fuel and liquid fuel at the same time to reduces the emission and realize the low-carbon, environment-friendly and high-efficiency operation of the gas turbine. 3. When the gas turbine of the present invention uses liquid fuel to start and operate under low working conditions, the liquid low-emission nozzle air path actively supplies auxiliary atomizing air to improve the ignition performance and combustion efficiency at this time. Under high working conditions, by using the compressed air in the annular cavity in the combustion chamber, the air in the combustion chamber is pressed into the low-emission nozzle air path under the action of the pressure difference, which strengthens the atomization of the liquid fuel, further improves the combustion efficiency, and can easily and effectively solve the problem of poor atomization effect under the ignition and slow working conditions under the condition of a single liquid fuel path while meeting the requirement of dual-fuel use. 4. When the gas fuel is used for working, the uniform mixing degree of gas fuel and air is improved by two-stage lean-burn premixing, wherein the air ratio of the first air swirler 2-5 to the second air swirler 2-9 is 1:7, which is matched with the fuel supplied by the first gas fuel branch B0O-1 and the second gas fuel branch B0-2; an

BL-5590 8 equivalence ratio of two stages of combustion zones is controlled to be the same LU503079 and within the low emission range of 2.5 to 4.5 so as to ensure that the temperature of the combustion zones is within the low-emission combustion temperature control range of 1700°C to 1900°C, thus achieving efficient and stable combustion, thereby achieving efficient and stable combustion; and at the same time, the emission value of NOx is controlled within the low emission range, and the middle of the flame tube is also designed with a main combustion hole, which provides further mixing of air and fuel, reducing the temperature of the main combustion zone, enhancing the effect of reducing emission, and finally meeting or being better than the emission standard of GB13223-2011. 5. The gas turbine of the present invention uses gas fuel during startup and low working conditions, and only the first air swirler 2-5 and the first gas fuel branch

BO-1 are used to supply assemblies; and during high working conditions, the second air swirler 2-9 and the second gas fuel branch BO-2 operate together with the first gas fuel branch BO-1, which can ensure the sufficient mixing of gas fuel and air, and lower pollutant emissions. Through the effective combination of good atomization of liquid fuel during slow working and high working conditions, and the overall design that takes into account the use of low-emission gas fuels, the gas turbine can operate efficiently with multiple fuels in all working conditions, which maintains the inherent advantages of small size and light weight of gas turbines, broadens the application fuel range of gas turbines, reduces nitrogen oxide emissions, and achieves efficient energy utilization. 6. The low-emission dual-fuel combustion control system of the present invention can supply gas fuel or liquid fuel for the whole machine according to the requirements of use, and adjust the fuel, and can also realize the online smooth switching of gas/liquid fuel without stopping the machine. Also, in order to prevent the high-temperature carbon deposit of the other fuel path when one fuel is working, a purging system is designed in the dual-fuel control system for preventing carbon deposit of the fuel path. 7. The present invention combines liquid fuel diffusion combustion and gas fuel premix combustion through the integrated design of the dual-fuel low-emission

BL-5590 9 nozzle, and solves the technical problems of forming of complex structural parts LU503079 and precision machining of core parts through the combination of additive manufacturing and machining, and realize the good work of the dual-fuel low-emission nozzle under different working conditions of gas turbines. When the gas turbine uses gas fuel, the gas fuel is injected through the small holes in the low-emission nozzle swirler for good mixing with air, and pollutant emissions are reduced by means of premix combustion. When the gas turbine uses liquid fuel, the problem of poor atomization effect of liquid fuel at low working conditions of the gas turbine is solved by the air-assisted atomization low-emission nozzle in the center of the low-emission nozzle. On the basis of meeting the requirement of dual-fuel use for the low-emission nozzle, the purpose of using lean-burn premix combustion technology to reduce pollutant emissions of the gas turbine under the gas fuel condition is realized. Also, a low-emission dual-fuel control system is proposed.

The dual-fuel control system can supply gas fuel or liquid fuel for the gas turbine according to the requirements of use, and adjust the fuel, and can also realize the online smooth switching of gas/liquid fuel without stopping the machine. Also, in order to prevent the high-temperature carbon deposit of the other fuel path when one fuel is working, a purging system is designed in the dual-fuel control system to achieve the purpose of preventing carbon deposit of the fuel path.

Brief description of the drawings

FIG. 1 is a schematic structural view of a gas turbine generator set of the present invention;

FIG. 2 is a schematic view of the internal structure of a low-emission nozzle of the present invention;

FIG. 3 is a front view of the low-emission nozzle of the present invention;

FIG. 4 is a right side view of FIG. 3;

FIG. 5 is a left side view of FIG. 3; and

BL-5590 10

FIG. 6 is a schematic structural view of a sealing assembly. LU503079

Detailed description of the embodiments

Embodiment 1: This embodiment will be described with reference to FIGS. 1 to 6. A low-emission nozzle of this embodiment comprises a first fuel gas path, a second fuel gas path, an atomizing air path, a liquid fuel path, a purging air path and a nozzle body. The first fuel gas path, the second fuel gas path, the atomizing air path and the liquid fuel path are mounted on the nozzle body in the form of internal oll and external gas and staggered oil and gas paths. The atomizing air path, the first fuel gas path and the liquid fuel path ensure that a set enters a slow working condition and share a first-path air swirler 2-5 of the first fuel gas path. The atomizing air path, the second fuel gas path and the liquid fuel path ensure that the set enters a fast working condition and share a second-path air swirler 2-9 of the second fuel gas path. The purging air path is mounted on a fuel ejection side of the nozzle body, and the purging air path prevents carbon deposits at the spout by means of impingement convection cooling, air film cooling and thermal insulation cooling.

The nozzle of this embodiment is a low-emission dual-fuel low-emission nozzle, which adopts an integrated design idea of two fuel paths. The low-emission nozzle shell and the swirler adopt an additive manufacturing process and are integrally formed. The core components of the low-emission nozzle oil path are independently processed by fine machining, and the core components are detachable. The combination of additive manufacturing and machining is used to ensure the effective molding of complex structural parts and the machining accuracy requirements of precision parts.

Embodiment 2: This embodiment will be described with reference to FIG. 2. The nozzle body of this embodiment comprises a low-emission nozzle shell 5-1 and a combustion chamber cover plate 5-2, and the combustion chamber cover plate 5-2 is mounted on a fuel inlet of the low-emission nozzle shell 5-1. This arrangement is convenient to connect and cooperate with the flame tube of the combustion

BL-5590 11 chamber to realize the ignition function. Other components and connections are the LU503079 same as in Embodiment 1.

Embodiment 3: This embodiment will be described with reference to FIG. 2. A liquid fuel path of this embodiment comprises a liquid fuel swirler 1-1, a screw plug 1-4, a sealing cover 1-17, a sealing assembly, a rotating plug 1-14, a liquid fuel thermal insulation pipe 1-13, a liquid fuel path inlet pipe 1-9, a liquid fuel path connecting cap 1-10, a liquid fuel path connecting conical pipe 1-11 and a liquid fuel filter assembly 1-12. The liquid fuel path connecting conical pipe 1-11 is inserted on a combustion chamber cover plate 5-2. The liquid fuel filter assembly 1-12 is mounted in the liquid fuel path connecting conical pipe 1-11. The liquid fuel path inlet pipe 1-9 is mounted on the liquid fuel path connecting conical pipe 1-11 through the liquid fuel path connecting cap 1-10. The liquid fuel swirler 1-1 and the screw plug 1-4 are coaxially mounted in the low-emission nozzle shell 5-1. The sealing cover 1-17 seals the screw plug 1-4 through the sealing assembly, the screw plug 1-14 is screwed on the sealing cover 1-17, and both ends of the liquid fuel heat insulation pipe 1-13 are communicated with the liquid fuel swirler 1-1 and the liquid fuel path connecting conical pipe 1-11, respectively. With this arrangement, in this embodiment, the liquid fuel thermal insulation pipe 1-13 is designed on the outside of the oil path (referring to the liquid fuel path) to prevent carbon deposits of fuel in the pipeline, and a purging air path for preventing carbon deposit is designed at the spout of the low-emission nozzle, which can effectively prevent high-temperature carbon deposit at the fuel spout of the nozzle. The liquid fuel path inlet pipes 1-9 is an insulation inlet pipe, and other components and connections are the same as those in Embodiment 1 or 2.

Embodiment 4: This embodiment will be described with reference to FIG. 6. The sealing assembly of this embodiment comprises a circular ring 1-15, a sealing ring 1-16 and a steel ring 1-18. The sealing ring 1-16 is an annular sealing ring, and the upper part of the sealing ring 1-16 is provided with a tapered stepped groove 1-16-1. The steel ring 1-18 is sealed and embedded in the sealing ring 1-16, and the outer side of the lower part of the circular ring 1-15 is a tapered step. The circular ring 1-15 is inserted into a stepped groove 1-16-1 of the sealing ring 1-16,

BL-5590 12 and the upper end surface of the circular ring 1-15 is lower than the upper end LU503079 surface of the sealing ring 1-16.

With this arrangement, the circular ring 1-15, the sealing ring 1-16 and the steel ring 1-18 in this embodiment are an integrally formed structure, wherein the upper part of the sealing ring wraps the circular ring 1-15. When the sealing ring is located in the sealing cover 1-17 and the injection slot hole of the low-emission nozzle shell 5-1, it can achieve a more tightly connected purpose. At the same time, when the sealing ring 1-16 and the steel ring 1-18 are used for a long time, especially under the influence of high temperature environment, thermal expansion may occur.

Under the action of the steel ring, the sealing effect can be further improved to avoid sealing failure.

In addition, in this embodiment, the upper end surface of the circular ring 1-15 is also lower than the upper end surface of the sealing ring 1-16. At this time, when the rotating plug 1-14 is screwed, there is still a pressing force on the sealing assembly, and the gap between the rotating plug 1-14 and the sealing cover 1-17 is sealed to prevent sealing ring failure or oil leakage or oil seepage, so as to ensure the smooth operation of the low-emission nozzle.

Other components and connections are the same as those in Embodiment 1, 2 or 3.

Embodiment 5: This embodiment will be described with reference to FIG. 2. An atomizing air path of this embodiment comprises an atomizing air swirler 1-2, a cap 1-3, an auxiliary atomizing air path inlet pipe 1-6, an auxiliary atomizing air path connecting cap 1-7 and an auxiliary atomizing air path conical pipe 1-8. The atomizing air swirler 1-2 is sleeved on the liquid fuel swirler 1-1 and the screw plug 1-4. The cap 1-3 is sleeved on the atomizing air swirler 1-2 and is located on the side of the liquid fuel swirler 1-1. The auxiliary atomizing air path inlet pipe 1-6 is mounted on the combustion chamber cover plate 5-2. The auxiliary atomizing air path inlet pipe 1-6 is connected to the auxiliary atomizing air path conical pipe 1-8 through the auxiliary atomizing air path connecting cap 1-7. The bottom of the auxiliary atomizing air path conical pipe 1-8 is communicated with the atomizing air

BL-5590 13 swirler 1-2 through an auxiliary atomizing air passage 1-5. The atomizing air path of LU503079 the present embodiment can effectively atomize and eject the oil in the liquid fuel path, thereby promoting ignition. Other components and connections are the same as those in any one of Embodiments 1 to 4.

Embodiment 6: This embodiment will be described with reference to FIG. 2. A first fuel gas path of this embodiment comprises a first gas fuel inlet pipe 2-1, a first gas fuel connecting cap 2-2, a first gas fuel connecting conical pipe 2-3, a bow clip 2-4, a first-path air swirler 2-5, a premix first-path compression member 2-6, a first cup assembly 2-7 and a second cup assembly 2-8.

The first gas fuel connecting conical pipe 2-3 is mounted on the combustion chamber cover plate 5-2, and the first gas fuel inlet pipe 2-1 is mounted on the first gas fuel connecting conical pipe 2-3 through the first gas fuel connecting cap 2-2.

The bow clip 2-4 is mounted on the end of the low-emission nozzle shell 5-1 on the fuel injection side. The first-path air swirler 2-5 is mounted at the rear end of the bow clip 2-4, and the premix first-path compression member 2-6 is inserted at the tail of the first-path air swirler 2-5 coaxially with the first-path air swirler 2-5. The first cup assembly 2-7 and the second cup assembly 2-8 are sleeved on the premix — first-path compression member 2-6 from the inside to the outside. The bottom of the first gas fuel connecting conical pipe 2-3 is communicated with the first-path air swirler 2-5 through a first gas passage. This arrangement facilitates the realization of gas combustion, and can also provide convenience for the purging system to prevent the occurrence of carbon deposits in the low-emission nozzle. Other components and connections are the same as those in any one of Embodiments 1 to 5.

Embodiment 7: This embodiment will be described with reference to FIG. 2. The second fuel gas path in this embodiment comprises a second-path air swirler 2-9, a second-path swirler shell 2-10, a second gas fuel inlet pipe 3-1, a second gas fuel connecting cap 3-2, a second gas fuel connecting conical pipe 3-3, a sealing cover 3-4, a ferrule 3-5 and a premix second-path compression member 3-6.

BL-5590 14

The second-path swirler shell 2-10 is mounted on a first-path air swirler 2-5 through LU503079 the sealing cover 3-4. The second-path air swirler 2-9 is mounted on the second-path swirler shell 2-10. The premix second-path compression member 3-6 is mounted on the second-path swirler shell 2-10 through the ferrule 3-5, and the second gas fuel connecting conical pipe 3-3 is mounted on the combustion chamber cover plate 5-2. The second gas fuel inlet pipe 3-1 is connected to the second gas fuel connecting conical pipe 3-3 through the second gas fuel connecting cap 3-2, and the second gas fuel connecting conical pipe 3-3 is communicated with the second-path air swirler 2-9 through a second gas passage.

This arrangement facilitates the realization of gas combustion, and can also provide convenience for the purging system to prevent the occurrence of carbon deposits in the low-emission nozzle. Other components and connections are the same as those in any one of Embodiments 1 to 5.

Embodiment 8: This embodiment will be described with reference to FIGS. 2 to 4. A purging air path of this embodiment comprises an impingement convection cooling air path, a film cooling air path and a thermal insulation cooling air path, wherein: the impingement convection cooling air path is as follows: a second-path swirler shell 2-10 is provided with a plurality of path-2 anti-carbon deposit cold-state purging holes 6-3, and external cold air flows in from the plurality of path-2 anti-carbon deposit cold-state purging holes 6-3, flows in an internal cooling passage formed by the second-path swirler shell 2-10, a premix first-path compression member 2-6 and a first cup assembly 2-7, and performs impingement cooling of the premix first-path compression member 2-6 through multiple rows of holes in the first cup assembly 2-7 under the action of the gas pressure difference, cold air of an external purging system is ejected to a combustion space through a first path-2 anti-carbon deposit cold-state purging spout 6-4 and a second path-2 anti-carbon deposit cold-state purging spout 6-5 to form a thermal insulation protective air film, finally reducing the temperature of the premix first-path compression member 2-6 by means of a combination of impingement convection cooling and air film cooling;

BL-5590 15 the film cooling air path is as follows: a first-path air swirler 2-5 is provided with a LU503079 plurality of path-1 anti-carbon deposit cold-state purging holes 6-1, and cold air of an external purging system enters from the plurality of path-1 anti-carbon deposit cold-state purging holes 6-1, and flows in a cooling passage inside the cap 1-3, and is finally ejected from an anti-carbon deposit cold-state purging path-1 spout 6-2 to a combustion space, so as to form a thermal insulation protective air film and reduce the temperature of the cap 1-3; and the thermal insulation cooling air path is as follows: the ferrule 3-5 is provided with a plurality of path-3 cooling anti-carbon deposit cold-state purging holes 6-6, and the cold air of the external purging system enters from the plurality of path-3 cooling anti-carbon deposit cold-state purging holes 6-6, flows in an internal cooling passage formed by a second-path swirler shell 2-10, the ferrule 3-5 and the premix second-path compression member 3-6, and is finally ejected from a plurality of holes in the premix second-path compression member 3-6 to the combustion space, so as to form a thermal insulation protective air film and reduce the temperature of the premix second-path compression member 3-6.

The purging air path of this embodiment is provided with 3 air cooling passages, which are an oil path anti-carbon deposit purging path (film cooling air path), a cooling and purging path (impingement convection cooling air path) for the premix first-path compression member 2-6, and a cooling and purging path (thermal insulation cooling air path) for the premix second-path compression member 3-6;

One stream of cooling air flows into the low-emission nozzle from the path-1 anti-carbon deposit cold-state purging holes 6-1, and flows in the cooling passage inside the cap 1-3, and is finally ejected from the anti-carbon deposit cold-state purging path-1 hole 6-2 to the combustion space, so as to form a thermal insulation protective air film, reduce the temperature of the cap 1-3, and prevent the formation of carbon deposits; another stream of cooling air flows from the cooling purging path 6-3 into the low-emission nozzle, flows in an internal cooling passage formed by the second-path swirler shell 2-10, the premix first-path compression member 2-6 and

BL-5590 16 the first cup assembly 2-7, performs impingement cooling of the premix first-path LU503079 compression member 2-6 through multiple rows of holes in the first cup assembly 2-7 under the action of the pressure difference, and is finally ejected from the first path-2 anti-carbon deposit cold-state purging spout 6-4 and the second path-2 anti-carbon deposit cold-state purging spout 6-5 into the combustion space to form a thermal insulation protective air film, and the temperature of the premix first-path compression member 2-6 is reduced by means of a combination of impingement convection cooling and air film cooling to protect the premix first-path compression member 2-6; a third stream of cooling air flows from the path-3 cooling anti-carbon deposit cold-state purging holes 6-6 into the low-emission nozzle, flows in an internal cooling passage formed by the second-path swirler shell 2-10, the ferrule 3-5 and the premix second-path compression member 3-6, and is finally ejected from a plurality of small holes in the premix second-path compression member 3-6 to the combustion space, so as to form a thermal insulation protective air film and reduce the temperature of the premix second-path compression member 3-6. Other components and connections are the same as those in any one of Embodiments 1 to 7.

Embodiment 9: This embodiment will be described with reference to FIG. 4. The first path-2 anti-carbon deposit cold-state purging spout 6-4 and the second path-2 anti-carbon deposit cold-state purging spout 6-5 of this embodiment are provided in the premix first-path compression member 2-6 in the form of an annular array. This arrangement facilitates the formation of an annular gas film for cooling, and other components and connections are the same as those in any one of Embodiments 1 to 8.

Embodiment 10: This embodiment will be described with reference to FIG. 4. The first path-2 anti-carbon deposit cold-state purging spout 6-4 of this embodiment is an elliptical spout, and a plurality of first path-2 anti-carbon deposit cold-state purging spouts 6-4 are arranged in a circular array in a clockwise inclined manner.

This arrangement facilitates the formation of an annular air film with a swirl angle.

Such an air film is firmer. Moreover, within a unit length, the swirl area of the airflow

BL-5590 17 in contact with the outside world is large, and the cooling effect is good. Other LU503079 components and connections are the same as those in any one of Embodiments 1 to 9.

Embodiment 11: This embodiment will be described with reference to FIG. 4. The second path-2 anti-carbon deposit cold-state purging spout 6-5 in this embodiment is a rectangular spout. With this arrangement, the directly ejected cold air can quickly cool down corresponding components. Other components and connections are the same as those in any one of Embodiments 1 to 10.

As a whole structure, the low-emission nozzle in the present invention mainly comprises a first fuel gas path, a second fuel gas path, an atomizing air path, a liquid fuel path and a purging air path for preventing carbon deposits.

The two fuel paths (referring to the liquid fuel path and the fuel gas path) adopt an integrated design idea. The low-emission nozzle shell and the swirler adopt an additive manufacturing process and are integrally formed. The core components of the low-emission nozzle oil path are independently processed by fine machining, and the core components are detachable. The combination of additive manufacturing and machining is used to ensure the effective molding of complex structural parts and the machining accuracy requirements of precision parts. The entire low-emission nozzle has two gas fuel paths (referring to the fuel gas path), one liquid fuel path and one atomizing air path. The inner side is the liquid fuel path, the outer side is the gas fuel path, and the liquid and gas fuel paths are staggered.

The atomizing air path, the liquid fuel path and the first fuel gas path can ensure that the gas turbine generator set (hereinafter referred to as the set) enters the slow working condition, and the liquid fuel path and the first fuel gas path share the first-path air swirler 2-5. The atomizing air path, the liquid fuel path and the second fuel gas path ensure that the set enters the maximum working condition, and the liquid fuel path and the second fuel gas path share the second-path air swirler 2-9.

On the upstream side of the liquid fuel path, a liquid fuel thermal insulation pipe is designed to prevent carbon deposits of the liquid fuel in the pipeline. An anti-carbon deposit purging air path is designed at the spout of the low-emission nozzle, which can effectively prevent the high temperature carbon deposit at the liquid fuel spout.

BL-5590 18

The first fuel gas path and the second fuel gas path are provided with a gas fuel LU503079 passage. The passage is connected to the cap. The end face of the cap is evenly distributed with air outlet holes. The cap is located in a radial air swirler, and there is an annular cavity on the swirler in the outer periphery of the cap. The shell is provided with a fuel intake passage communicated with the annular cavity, and the swirler is provided with a fuel outflow passage communicated with the annular cavity. The liquid fuel swirling atomizing assembly comprises a liquid fuel passage, a liquid fuel swirler, a liquid fuel spout and an anti-carbon deposit air cooling device.

The liquid fuel auxiliary atomizing assembly comprises an auxiliary atomizing air passage, an auxiliary atomizing air swirler and an auxiliary atomizing air spout. The liquid fuel swirler is embedded in the inner cavity of the atomizing air swirler in the form of plugging, and the two are fixed in the low-emission nozzle shell by a detachable pressing and fixing assembly according to a rated torque. The detachable pressing and fixing assembly is connected to the low-emission nozzle shell by a sealing cover, a gasket and a screw plug by means of threads, which facilitates the trimming, cleaning and replacement of the core working components, shortens the development cycle of the low-emission nozzle, and prolongs the service life of the low -emission nozzle. A liquid fuel spout anti-carbon deposit air cooling assembly introduces air from the front normal air inlet of the first-path air swirler 2-5 to the outer ring of the central liquid fuel nozzle, so as to form an air cooling passage, which effectively reduces the temperature of the core working components. A compression member anti-carbon deposit air cooling assembly introduces air from the air inlet of the inclined hole between the first-path air swirler 2-5 and the second-path air swirler 2-9 to the outlet edge of the compression member so that the air is ejected out in two directions. The temperature of the compression member is reduced by means of impingement cooling and air film cooling.

Embodiment 12: This embodiment will be described with reference to FIG. 1. A low-emission dual-fuel combustion chamber of this embodiment comprises a combustion chamber outer shell 8-1, a combustion chamber inner shell 8-2 and a flame tube 8-3. It further comprises a front load-bearing shell 8-4, a rear support shell 8-5, a combustion chamber outlet 8-5A, a diffuser 8-6, a combustion chamber inlet 8-6A, a positioner 8-7 and a low-emission nozzle. The combustion chamber

BL-5590 19 outer shell 8-1 is sealed and connected with the front load-bearing shell 8-4 and the LU503079 rear support shell 8-5 through front and rear annular flanges, respectively. The combustion chamber inner shell 8-2 is connected to the front load-bearing shell 8-4 through the front annular flange, and forms a three-dimensional combustion chamber annular cavity 8A together with the combustion chamber outer shell 8-1.

The diffuser 8-6 is connected to the rear of the combustion chamber inner shell 8-2.

The end of the diffuser 8-6 is the combustion chamber inlet 8-6A, and the combustion chamber outlet 8-5A is provided in the rear support shell 8-5. The flame tube 8-3 is mounted in the three-dimensional annular working space. The low-emission nozzle is inserted into the insertion hole of the head of the flame tube 8-3 through a front annular cone surface mounting hole of the front load-bearing shell 8-4. The middle of the flame tube 8-3 is provided with a main combustion hole 8-3A, the head of the flame tube 8-3 is connected with two positioners 8-7, and the tail mounting seat of the flame tube 8-3 is mounted on the rear support shell 8-5 with three-point support.

The low-emission nozzle is inserted into the insertion hole of the head of the flame tube through the front annular cone surface mounting hole of the front load-bearing shell, and is fixed and sealed by the mounting flange of the low-emission nozzle.

The middle of the tube of the flame tube is provided with a main combustion hole, which is supported and fixed at three points, two positioners at the head and a mounting seat at the tail. The combustion chamber outer shell is connected to the front load-bearing shell and the rear support shell through the front and rear annular flanges, respectively, so as to ensure sealing. The combustion chamber inner shell is connected to the front load-bearing shell through the front annular flange, and forms a three-dimensional annular working space together with the combustion chamber outer shell. The diffuser is connected to the rear of the combustion chamber inner shell. The rear support shell of the combustion chamber is used to provide the mounting seat for the flame tube and the combustion chamber outlet.

Other components and connections are the same as those in any one of

Embodiments 1 to 11.

BL-5590 20

Embodiment 13: This embodiment will be described with reference to FIGS. 1 to 6. LU503079

A low-emission nozzle of this embodiment is the low-emission nozzle described in any one of Embodiments 1 to 11. Other components and connections are the same as those in any one of Embodiments 1 to 12.

Embodiment 14: This embodiment will be described with reference to FIGS. 1 to 6.

A gas turbine generator set of this embodiment comprises the low-emission dual-fuel combustion chamber 8 as described in Embodiments 12-13, a low-emission dual-fuel control system, a compressor 7, a turbine 9 and a generator 10, and the low-emission dual-fuel combustion chamber 8 is connected to an annular pipe system F of the low-emission nozzle of the low-emission dual-fuel control system, high-temperature and high-pressure air from the compressor 7 enters a diffuser 8-6 through a combustion chamber inlet 8-6A for deceleration and diffusion, and then flows into a combustion chamber annular cavity 8A, and then the air is distributed to a low-emission nozzle 11 and mixed with liquid fuel or gas fuel to form a combustible mixture, which is efficiently and stably combusted in a flame tube 8-3, and is discharged from a combustion chamber outlet 8-5A to push the turbine 9 to output work for achieving power generation of the generator 10; wherein the low-emission dual-fuel control system comprises a liquid fuel system A, a gas fuel system B, a liquid fuel purging system C, a gas fuel purging system D, an auxiliary atomizing air system E and the annular pipe system F of the low-emission nozzle; wherein the annular pipe system F of the low-emission nozzle comprises a liquid fuel annular pipe 1-9H, an auxiliary atomizing air annular pipe 4-1H, a gas fuel path-1 annular pipe 2-1H and a gas fuel path-2 annular pipe 3-1H, and the liquid fuel annular pipe 1-9H, the auxiliary atomizing air annular pipe 4-1H, the gas fuel path-1 annular pipe 2-1H and the gas fuel path-2 annular pipe 3-1H are connected to a liquid fuel path inlet pipe 1-9, an auxiliary atomizing air path inlet pipe 1-6, a first gas fuel inlet pipe 2-1 and a second gas fuel inlet pipe 3-1 on the low-emission nozzle through branch pipes, respectively;

BL-5590 21

LU503079 during combustion of liquid fuel: when under ignition and below slow working conditions: the liquid fuel system A is put into operation, the gas fuel system B is not in operation, the liquid fuel purging system C is not in operation, the gas fuel purging system D is put into operation, and the auxiliary atomizing air system E is put into operation, and at this time, the liquid fuel system A enters the liquid fuel annular pipe 1-9H of the annular pipe system F of the low-emission nozzle through the liquid fuel flow path AO, and then enters the liquid fuel path of the low-emission nozzle; the auxiliary atomizing air system E enters the auxiliary atomizing air annular pipe 4-1H through the auxiliary atomizing air flow path EO, and then enters the atomizing air path of the low-emission nozzle for auxiliary atomization of liquid fuel; the gas fuel purging system D is divided into two flow paths, i.e., a first gas fuel flow path purging branch D0-1 and a second gas fuel flow path purging branch DO-2, for cleaning and purging the gas fuel annular pipe in a non-operation state and the internal passages of the low-emission nozzle; when above the slow working condition: a purging air source of the atomizing air path is adjusted from the auxiliary atomizing air system E to be supplied from the atomizing air purging path CO-2 of the liquid fuel path purging system C, that is, the auxiliary atomizing air source is supplied by the compressed air in the annular cavity space formed by the combustion chamber outer shell and the flame tube of the low-emission dual-fuel combustion chamber, and the rest of the system remains unchanged; during combustion of gas fuel: the liquid fuel system is A closed, the gas fuel system B is put into operation, and the liquid fuel purging system C is put into operation;

BL-5590 22 when under the ignition and below slow working conditions: LU503079 the compressed air in the annular cavity space of the low-emission dual-fuel combustion chamber enters the liquid fuel path AO of the liquid fuel system A, the second gas fuel flow path purging branch DO-2 of the gas fuel purging system D, and the auxiliary atomizing air path EO of the auxiliary atomizing air system E; the gas fuel enters the gas fuel path-1 annular pipe 2-1H of the annular pipe system

F of the low-emission nozzle through the gas fuel system B, and then enters the first gas fuel inlet pipe 2-1 of the low-emission nozzle; the liquid fuel purging system C is in a purging working state, and the auxiliary atomizing air path inlet pipe 1-6 and the liquid fuel path inlet pipe 1-9 are both supplied by the compressed air in the annular cavity space formed by the combustion chamber outer shell and the flame tube of the low-emission dual-fuel combustion chamber to purge and cool each passage; when above the slow working condition: the gas fuel purging system D is closed, and the gas fuel simultaneously enters the gas fuel path-1 annular pipe 2-1H and the gas fuel path-2 annular pipe 3-1H of the annular pipe system F of the low-emission nozzle through the gas fuel system B, and then enters the first fuel gas path and the second fuel gas path of the low-emission nozzle separately; and when the gas fuel and liquid fuel are switched, both the liquid fuel purging system C and the gas fuel purging system D are closed, and both the liquid fuel system and A the gas fuel system B are put into operation.

The combustion chamber and the fuel control system enable the gas turbine to achieve low pollutant emissions when using gas fuel during high working conditions, and online stable switching can also be performed between gas fuel and liquid fuel without stopping, which can meet the purposes of stable combustion of dual fuel, smooth online switching and pollutant emission reduction of the gas turbine.

BL-5590 23

LU503079

Other components and connections are the same as those in any one of

Embodiments 1 to 13.

Low-emission dual-fuel control system: During combustion of liquid fuel, when under the slow working condition, the liquid fuel system A is put into operation, the gas fuel system B is not in operation, the liquid fuel purging system C is not in operation, the gas fuel purging system D is put into operation, the auxiliary atomizing air system E is put into operation; at this time, the liquid fuel enters the liquid fuel annular pipe of the annular pipe system F of the low-emission nozzle, and then enters the liquid fuel path of the low-emission dual-fuel nozzle; the auxiliary atomizing air and the combustion chamber annular cavity bleed air enter the auxiliary atomizing air annular pipe of the annular pipe system F of the low-emission nozzle separately, and then enters the atomizing air path of the low-emission dual-fuel nozzle for liquid fuel auxiliary atomizing; and the combustion chamber annular cavity bleed air enters the first fuel gas path and the second fuel gas path, and then enters the low-emission nozzle gas fuel passage for purging; when above the slow working condition, the purging of the auxiliary atomizing air flow path is adjusted from the auxiliary atomizing air system E to the atomizing air purging flow path of the liquid fuel path purging system C, that is, it is all switched to the compressed air of the combustion chamber annular cavity, and the rest of the system remains unchanged;

During burning of gas fuel, the liquid fuel system A is closed, the gas fuel system B is put into operation, and the liquid fuel purging system C is put into operation; when under the slow working condition, the compressed air of the combustion chamber annular cavity enters the liquid fuel path of the liquid fuel system A, the second gas fuel flow path purging branch DO-2 of the gas fuel purging system D, and the auxiliary atomizing air path of the auxiliary atomizing air system E; the gas fuel enters the gas fuel path-1 annular pipe 2-1H of the annular pipe system F of the low-emission nozzle through the gas fuel system B, and then enters the first fuel gas path of the low-emission nozzle, and the compressed air of the combustion chamber annular cavity enters the second gas fuel branch path BO-2, and then

BL-5590 24 enters the second fuel gas path of the low-emission nozzle for purging; when above LU503079 the slow working condition, the gas fuel purging system D is closed, and the gas fuel simultaneously enters the gas fuel path-1 annular pipe 2-1H and the gas fuel path-2 annular pipe 3-1H of the annular pipe system F of the low-emission nozzle through the gas fuel system B, and then enter the first fuel gas path and the second fuel gas path of the low-emission nozzle separately.

During fuel switching combustion: neither the liquid fuel purging system C nor the gas fuel purging system D is in operation, and both the liquid fuel system A and the gas fuel system B are put into operation; when switching from the gas fuel operation to the liquid fuel operation, the opening degree of the regulating valve of the gas fuel system B gradually decreases, the gas fuel flow gradually decreases, the opening degree of the regulating valve of the liquid fuel system gradually increases, and the liquid fuel flow gradually increases; when switching from liquid fuel operation to gas fuel operation, the opening degree of the regulating valve of the liquid fuel system A gradually decreases, the liquid fuel flow gradually decreases, the opening degree of the regulating valve of the gas fuel system B gradually increases, and the gas fuel flow gradually increases; the rate of increase and decrease of the two is matched according to the calorific value, that is, it is ensured that the product of the increase rate of liquid fuel and its calorific value and the product of the rate of decrease of gas fuel and its calorific value are equal, or the product of the rate of decrease of liquid fuel and its calorific value and the product of the rate of increase of gas fuel and its calorific value are equal; when fuel switching is performed, the rate of increase and decrease of the two should be strictly controlled to achieve the shortest switching time (switching time refers to the time it takes to completely switch from the current working fuel to another fuel for work when a switching instruction is given and timing is started) and the most stable power fluctuation of the set (the power fluctuation of the set refers to the ratio of the difference between the maximum and minimum power of the set to the power of the set in stable operation during the switching process, and in order to ensure the stable operation of the power grid, the power fluctuation range of the set is generally required to be no more than 10%).

BL-5590 25

Liquid fuel supply and air-assisted atomizing: During combustion of liquid fuel, from LU503079 start-up to slow working, the auxiliary atomizing air system E is put into operation to perform auxiliary atomizing of liquid fuel; the auxiliary atomizing air system E is equipped with a throttle orifice plate, which can be used to adjust the pressure and flow of the auxiliary atomizing air during operation to prevent the liquid fuel atomization from being deteriorated due to the too high or low pressure of the auxiliary atomizing air, resulting in the incomplete combustion of liquid fuel, and thereby leading to the thermal suspension of the set (thermal suspension generally refers to the phenomenon that no matter how much fuel is added to the gas turbine during the startup process, the rotating speed of the set cannot be increased normally); when it is higher than the slow working condition, the atomizing air purging path of the liquid fuel purging system is put into operation, and the auxiliary atomizing air is adjusted to the compressed air in the combustion chamber annular cavity, which further improves the atomizing effect of the liquid fuel under the slow working condition or above; during combustion of liquid fuel, from start-up to slow working condition, the auxiliary atomizing air system E is put into operation to perform auxiliary atomizing of liquid fuel; when it is higher than slow working condition, the auxiliary atomizing air is switched to the compressed air in the combustion chamber annular cavity, further improving the atomizing effect of liquid fuel above the slow working condition; during combustion of gas fuel, the combustion chamber bleed air is used to purge the oil path, and from start-up to slow working condition, only the first gas fuel branch path (referring to the first gas fuel branch path BO-1) operates; when it is higher than slow working, the second gas fuel branch path (referring to the second gas fuel branch path BO-2) stops purging, the gas fuel is put into operation, and with the increase of working conditions, the gas fuel amounts of the first gas fuel branch path and the second gas fuel branch path increase at the same time; when reaching a certain intermediate working condition, the fuel of the first gas fuel branch path begins to decrease, and the fuel of the second gas fuel branch path continues to increase until a rated working condition where the combustion zone equivalence ratios a corresponding to the two fuel paths are the same.

BL-5590 26

During combustion of gaseous fuel, from start-up to slow working condition, the fuel LU503079 amount is related to the exponential function of the high-pressure rotating speed of the gas turbine, and the opening degree of the fuel regulating valve of the first gas fuel branch path is controlled in real time through the equivalence ratio to ensure the stability of combustion, and prevent flameout during start-up.

During combustion of liquid fuel, from start-up to slow working condition, the auxiliary atomizing air system E is equipped with a throttle orifice plate to adjust the pressure and flow of the auxiliary atomizing air to prevent the atomizing effect of fuel oil from being deteriorated by the too high or low pressure of the auxiliary atomizing air, resulting in the incomplete combustion of fuel oil, and thereby leading to the thermal suspension of the set.

For the combustion zone equivalence ratio a, the range to achieve low emissions is 2.5<a<4.5, thereby ensuring that the combustion zone temperature is within the low-emission combustion temperature control range, and finally meeting or being better than the emission standard of GB13223-2011.

Regulation of gaseous fuel: During combustion of gas fuel, the combustion chamber bleed air is used to purge the liquid fuel path; from start-up to slow working condition, only the first fuel gas path is in operation, and the fuel amount is related to the function of the high-pressure rotating speed of the gas turbine, and the opening degree of the first gas fuel regulating valve is controlled in real time through the equivalence ratio to ensure the stability of combustion, thereby preventing the combustion chamber from flameout during the start-up process; when it is higher than the slow working condition, the second gas fuel path stops purging, and at the same time, the gas fuel is put into operation, and with the further increase of the working conditions, the fuel amounts of the first gas fuel path (referring to the first fuel gas path) and the second gas fuel path (referring to the second fuel gas path) increases simultaneously; when a certain intermediate working condition is reached (the intermediate working condition is generally selected according to the characteristics of the gas turbine), the fuel of the first gas fuel path begins to decrease, and the fuel of the second gas fuel path continues to increase until the rated working condition where the combustion zone equivalence

BL-5590 27 ratios corresponding to the two gas paths are substantially the same, so that the LU503079 gas turbine can achieve the lowest pollutant emission target.

The flame tube of this embodiment is provided with 8 main combustion holes, which are located in the middle of the tube, and are symmetrically distributed along a middle section. On the one hand, they provide supplementary air mixed with fuel, reduce the temperature of the main combustion zone, and enhance the emission reduction effect. On the other hand, they adjust the uniformity of the temperature distribution at the combustion chamber outlet to prolong the overall overhaul period of the set.

Both the liquid fuel system and the gas fuel system of this embodiment are provided with filters to ensure the cleanliness of the fuel. The liquid fuel swirler atomizing assembly is provided with an inlet filter assembly, which can effectively remove impurities in the incoming medium, improve the reliability and service life of the low-emission nozzle. Moreover, it is fixed by a detachable stop ring, which is convenient for replacement and cleaning.

Both the first gas fuel supply assembly and the second gas fuel supply assembly of this embodiment are provided with throttle assemblies, which can be used to precisely adjust the gas fuel flow, thereby ensuring the flow consistency of multiple low-emission nozzles when the gas turbine is assembled as a whole.

The dual-fuel control system of this embodiment is provided with a gas fuel vent valve and a liquid fuel relief valve to discharge unused gas fuel and waste liquid fuel in the pipeline to ensure the safety of the set operation.

The dual-fuel control system pipeline of this embodiment is provided with a one-way check valve to prevent the high pressure suddenly generated downstream, so that the fuel is returned to the upstream pipeline to ensure the safety of the fuel system and the operation of the set.

The dual-fuel control system of this embodiment is provided with a water bath heater for gas fuel to prevent the fuel temperature from dropping sharply due to

BL-5590 28 pressure drop, causing the fuel to reach the dew point temperature and causing the LU503079 pipelines and valves to freeze, thereby ensuring the stability of the fuel system.

The dual-fuel control system of this embodiment has a total of 8 flow paths (the 8 flow paths are the liquid fuel path, the first gas fuel branch path and the second gas fuel branch path of the gas fuel system, the liquid fuel purging path and the auxiliary atomizing air purging path of the liquid fuel purging system, the auxiliary atomizing air path of the auxiliary atomizing air system, and the first gas fuel purging branch path and the second gas fuel purging branch path of the gas fuel purging system, respectively), which are each optionally provided with a flow sensor to effectively monitor the actual flow of the medium and facilitate the corresponding control of the opening degree of the regulating valve, thereby ensuring the stable operation of the gas turbine generator set.

The liquid fuel in this embodiment comprises, but is not limited to, light diesel oil, and the gas fuel comprises, but is not limited to, natural gas.

Embodiment 15: This embodiment will be described with reference to FIG. 1. The liquid fuel system A of this embodiment comprises a liquid fuel source A1, a liquid fuel pipeline AO, a pump A2, a first filter A3, a first regulating valve A4, a first shut-off valve A5, a first flow sensor A6, a relief valve A7 and a first check valve A8; one end of the liquid fuel pipeline AO is connected to the liquid fuel source A1, and the other end of the liquid fuel pipeline AO is sequentially connected in series with the pump A2, the first filter A3, the first regulating valve A4, the first shut-off valve

AS, the first flow sensor A6 and the first check valve A8, and then connected to the liquid fuel annular pipe 1-9H; and the relief valve A7 is connected in parallel with the liquid fuel pipeline AO between the first flow sensor A6 and the first check valve

AB.

This arrangement facilitates supplying liquid fuel to the combustion chamber, and also facilitates switching between liquid fuel and gas fuel. Other components and connections are the same as those in any one of Embodiments 1 to 14.

BL-5590 29

Embodiment 16: The present embodiment will be described with reference to FIG. LU503079 1. A gas fuel system B of the present embodiment comprises a gas fuel source B1, a gas fuel path BO, a water bath heater B2, a second filter B3, a second shut-off valve B95, a relief valve B7, a second regulating valve B4-1, a third regulating valve

B4-2, a third shut-off valve B5-1, a fourth shut-off valve B5-2, a second flow sensor

B6-1, a third flow sensor B6 -2, a second check valve B8-1 and a third check valve

B8-2.

One end of the gas fuel path BO is connected to the gas fuel source B1, and the other end of the gas fuel path BO is sequentially connected in series with the water bath heater B2, the second filter B3 and the second shut-off valve B5, and then divided into a first gas fuel branch path BO-1 and a second gas fuel branch path

BO-2. The first gas fuel branch path BO-1 is sequentially connected in series with the second regulating valve B4-1, the third shut-off valve B5-1, the second flow sensor B6-1 and the second check valve B8-1 and then connected to a gas fuel path-1 annular pipe 2-1H. The second gas fuel branch path BO-2 is sequentially connected in series with the third regulating valve B4-2, the fourth shut-off valve

B5-2, the third flow sensor B6-2 and the third check valve B8-2 and then connected to a gas fuel path-2 annular pipe 3-1H. It is convenient to provide gas fuel for the combustion chamber, and at the same time, it is also convenient to switch between liquid fuel and gas fuel. Other components and connections are the same as those in any one of Embodiments 1 to 15.

Embodiment 17: This embodiment will be described with reference to FIG. 1. An auxiliary atomizing air system E of this embodiment comprises a compressed air source E1, an auxiliary atomizing air path EO, a throttle orifice plate E2, a fifth shut-off valve E5, an eighth flow sensor E6 and an eighth check valve ES.

One end of the auxiliary atomizing air path EO is connected to the compressed air source E1, and the other end of the auxiliary atomizing air path EO is sequentially connected to the throttle orifice plate E2, the fifth shut-off valve ES, the eighth flow sensor E6 and the eighth check valve E8, and then connected to an auxiliary atomizing air annular pipe 4-1H. This arrangement is convenient to provide

BL-5590 30 atomizing for the liquid fuel and ensure the combustion effect. Other components LU503079 and connections are the same as those in any one of Embodiments 1 to 16.

Embodiment 18: This embodiment will be described with reference to FIG. 1. A liquid fuel purging system C of this embodiment comprises a combustion chamber bleed air path CDO, a liquid fuel purging path CO-1, an atomizing air purging path

CO-2, a fourth regulating valve C4-1, a fifth regulating valve C4-2, a fourth flow sensor C6-1, a fifth flow sensor C6-2, a fourth check valve C8-1 and a fifth check valve C8-2.

The liquid fuel purging path CO-1 and the atomizing air purging path CO-2 are connected in parallel and share the combustion chamber bleed air path CDO. The liquid fuel purging path CO-1 is sequentially connected in series with the fourth regulating valve C4-1, the fourth flow sensor C6-1 and the fourth check valve C8-1 and then connected to the liquid fuel pipeline AO. The atomizing air purging path

CO-2 is sequentially connected in series with the fifth regulating valve C4-2, the fifth flow sensor C6-2 and the fifth check valve C8-2, and then connected to the auxiliary atomizing air circuit EO. This arrangement facilitates purging of the liquid fuel when gas fuel is used to prevent carbon deposits. Other components and connections are the same as those in any one of Embodiments 1 to 17.

Embodiment 19: This embodiment will be described with reference to FIG. 1. A gas fuel purging system D of this embodiment comprises a first gas fuel flow path purging branch DO-1, a second gas fuel flow path purging branch DO-2, a sixth regulating valve D4-1, a seventh regulating valve D4-2, a sixth flow sensor D6-1, a seventh flow sensor D6-2, a sixth check valve D8-1 and a seventh check valve

D8-2.

The first gas fuel flow path purging branch D0-1 and the second gas fuel flow path purging branch DO-2 are connected in parallel and share the combustion chamber bleed air path CDO. The first gas fuel flow path purging branch DO-1 is sequentially connected in series with the sixth regulating valve D4-1, the sixth flow sensor D6-1 and the sixth check valve D8-1 and then connected to a first gas fuel branch path

BO-1. The second gas fuel flow path purging branch DO-2 is sequentially connected

BL-5590 31 in series with the seventh regulating valve D4-2, the seventh flow sensor D6-2 and LU503079 the seventh check valve D8-2, and then connected to a second gas fuel branch path BO-2. This arrangement facilitates purging of the air path when fuel is switched.

Other components and connections are the same as those in any one of

Embodiments 1 to 18.

The working principle of the present invention will be described with reference to

FIGS. 1 to 6:

As shown in FIG. 1, a main body of a gas turbine is composed of a compressor 7, a combustion chamber 8, a low-emission dual-fuel control system, and a turbine 9, and a gas turbine generator set is formed by driving a generator 10 to generate electricity. An annular pipe is mounted at the head of the combustion chamber 8 to facilitate the fuel distribution work. For example, a annular pipe system F of the low-emission nozzle in partial enlarged view G specifically comprises a liquid fuel annular pipe 1-9H, an auxiliary atomizing air annular pipe 4- 1H, a gas fuel path-1 annular pipe 2-1H and a gas fuel path-2 annular pipe 3-1H, which are connected to the corresponding liquid fuel inlet pipe 1-9, auxiliary atomizing air inlet 4-1, gas fuel first-path inlet 2-1 and gas fuel second-path inlet 3-1 of the low-emission nozzle 11 through branch pipes, respectively (view G).

The liquid fuel system A is connected to the liquid fuel annular pipe 1-9H through the liquid fuel flow path AO, and the connection point is located in the lower half ring of the annular pipe. The gas fuel system B is divided into the first gas fuel branch path BO-1 and the second gas fuel branch path BO-2 through the gas fuel flow path

BO, which are connected with the gas fuel path-1 annular pipe 2-1H and the gas fuel path-2 annular pipe 3-1H, respectively. The two branch paths share the gas fuel source B1, the water bath heater B2, the filter B3, the shut-off valve B5 and the relief valve B7, and are separately designed with the regulating valve, the shut-off valve, the flow meter and the check valve at the same time. The auxiliary atomizing air system E is connected to auxiliary atomizing air annular pipe 4-1H through the auxiliary atomizing air flow path EO, and mainly assists the liquid fuel to carry out droplet breakup, strengthens the combustion and improves the efficiency. The liquid fuel purging system C is divided into two flow paths, i.e., the liquid fuel

BL-5590 32 purging path CO-1 and the atomizing air purging path C0-2, which are connected to LU503079 the downstream of the check valves A8 and E8 in the liquid fuel flow path AO and the auxiliary atomizing air flow path EO respectively, and clean and purge the liquid fuel path annular pipe in the non-working state and the internal passage of the low-emission nozzle to prevent carbon deposits and assist in atomizing. The gas fuel purging system D is also divided into two flow paths, i.e., the first gas fuel flow path purging branch D0-1 and the second gas fuel flow path purging branch DO -2, which clean and purge the gas fuel path annular pipe in the non-working state and the internal passage of the low-emission nozzle while preventing backfire and self-ignition. In addition, the liquid fuel system A, the gas fuel system B and the auxiliary atomizing air system E each have an independent medium source, i.e. a liquid fuel source A1, a gas fuel source B1 and a compressed air source E1, and the purging gas of the liquid fuel purging system C and the gas fuel purging system

D comes from the high-pressure gas of the annular cavity 8A of the combustion chamber B, and is supplied to the purging systems C and D through the combustion chamber bleed air passage CDO, wherein the upper bleed air point of the combustion chamber is located on the outer wall of the combustion chamber casing. The five systems in the present invention each adopt an independent modular design, which can be separately molded to facilitate transportation and installation, and are especially suitable for places with limited space such as offshore platforms.

As shown in FIG. 1, in view G, the low-emission dual-fuel combustion chamber 8 is composed of a combustion chamber outer shell 8-1, a combustion chamber inner shell 8-2, a front load-bearing shell 8-4, a rear support shell 8-5, a low-emission dual-fuel low-emission nozzle 11, a flame tube 8-3, a diffuser 8-6 and a positioner 8-7. The low-emission dual-fuel low-emission nozzle 11 passes through the mounting hole of the front annular cone surface of the front load-bearing shell 8-4, is inserted into the head insertion hole of the flame tube 8-3, and is fixed and sealed through the low-emission nozzle mounting flange. The flame tube 8-3 is a cylindrical structure, and the middle of the tube is provided with a cross-flame tube, a main combustion hole 8-3A and an air film cooling hole, wherein on the one hand, the main combustion hole provides supplementary air to be mixed with fuel, reducing the temperature of the main combustion zone, and enhancing the

BL-5590 33 emission reduction effect; and on the other hand, it adjusts the uniformity of the LU503079 temperature distribution at the combustion chamber outlet to improve the overall overhaul period of the set. The head of the flame tube 8-3 is provided with a low-emission nozzle insertion mounting hole and the tail is provided with a mounting seat, and it is supported and fixed at three points, two positioners 8-7 at the head and the mounting seat at the tail, providing a stable and efficient high-temperature flame working space. The combustion chamber outer shell 8-1 is connected to the front load-bearing shell 8-4 and the rear support shell 8-5 through front and rear annular flanges, respectively, to ensure sealing. The combustion chamber inner shell 8-2 is connected to the front load-bearing shell 8-4 through the front annular flange and forms a three-dimensional annular working space 8A (i.e., a high-temperature and high-pressure air circulation annular cavity) together with the combustion chamber outer shell 8-1. The diffuser 8-6 is connected to the rear of the combustion chamber inner shell 8-2, and is used to provide a high-temperature and high-pressure intake passage of the combustion chamber. The combustion chamber rear support shell 8-5 is used to provide a mounting seat for mounting the flame tube and a high-temperature combustion chamber outlet 8-5A, so that the high temperature gas impinges on the working blades of the turbine 9.

When the combustion chamber is working, the high-temperature and high-pressure air from the compressor 7 enters the diffuser 8-6 from the combustion chamber inlet 8-6A for deceleration and diffusion, and then flows into the combustion chamber annular cavity 8A. Then, the air is distributed to the first-stage air swirler and the second-stage air swirler of the low-emission dual-fuel nozzle 11 and the main combustion holes and air film cooling holes of the flame tube 8-3, etc. The former is mixed with liquid fuel or gas fuel to form a combustible mixture, which is efficiently and stably combusted in the flame tube 8-3. The latter forms supplementary combustion air to further reduce emissions and cooling air to protect the material of flame tube 8-3 from exceeding the temperature resistance limit. The finally formed high-temperature gas is discharged from the combustion chamber outlet 8-5A to drive the turbine 9 to output work for electricity generation.

When the combustion chamber 8 uses the gas fuel for working, the uniform mixing of gas fuel and air is realized by means of two-stage lean-burn premixing, wherein

BL-5590 34 the air ratio of the first-stage air swirler to the second-stage air swirler is 1:7, which LU503079 is matched with the fuel supplied by the first gas fuel path and the second gas fuel path. The equivalence ratio of two stages of combustion zones is controlled to be within the low emission range of 2.5 to 4.5, so as to ensure that the temperature of the combustion zones is within the low-emission combustion temperature control range of 1700°C to 1900°C, thus achieving efficient and stable combustion while controlling the emission value of NOx within the low emission range.

As shown in FIG. 2, the liquid fuel swirler 1-1 is mounted in the inner cavity of the atomizing air swirler 1-2 by means of insertion, and forms a liquid fuel passage together with its inner wall surface. The screw plug 1-4 is fixed to the atomizing air swirler 1-2 by means of threaded connection, and then the liquid fuel swirler 1-1 is compressed and fixed by squeezing to ensure good sealing and installation concentricity. The atomizing air swirler 1-2 is also mounted in the inner cavity of the cap 1-3 by means of insertion, and is simultaneously inserted and assembled with the shell 5-1. The rotating plug 1-14 is fixed to the shell 5-1 by means of threaded connection and rotates to apply a rated torque, so that the circular ring 1-15 and the sealing ring 1-16 squeeze the sealing cover 1-17 to ensure the sealing of the shell 5-1 and the rotating plug 1-14 and fix the atomizing air swirler 1-2. (1) When the liquid fuel is used for working: the liquid fuel in the liquid fuel source

A1 is pressurized through a pump A2, filtered through the first filter A3 to remove impurities, and passes through the first regulating valve A4 with a suitable opening degree and the fully opened first shut-off valve AS. The liquid fuel is transported to the liquid fuel annular pipe 1-9H under the metered condition of the first flow sensor

AB, and is finally supplied to the low-emission nozzle 11 through the branch pipe.

During this process, the relief valve A7 remains closed (FIG. 1). The liquid fuel passes through the liquid fuel inlet pipe 1-9, is filtered through the liquid fuel filter assembly 1-12, enters the liquid fuel thermal insulation pipe 1-13, and then flows through the passage formed by the sealing cover 1-17 and the screw plug 1-4 to the liquid fuel swirler 1-1, achieving a swirling state. Finally, it is ejected by the liquid fuel spout in the inner cavity of the atomizing air swirler 1-2 to form an atomizing cone, which enters the combustion space and is mixed with the compressed air for combustion. During this process, the gas fuel purging system D is in a flow-through

BL-5590 35 open state, the sixth regulating valve D4-1 and the seventh regulating valve D4-2 LU503079 are at appropriate opening degrees to control the amount of purging gas (Fig. 1), and the gas fuel first-path inlet 2-1 (referring to the first gas fuel inlet pipe 2-1) and the gas fuel second-path inlet 3-1 (referring to the second gas fuel inlet pipe 3-1) supply compressed air to purge and cool the gas fuel passage, and prevent the backflow of high-temperature gas when the low-emission nozzle is working.

According to the different working conditions of the gas turbine, the auxiliary atomizing air path will have two different working states. (2) When the liquid fuel is used for working under low working conditions: when the gas turbine uses the liquid fuel and operates under ignition and slow working conditions, the auxiliary atomizing air from the air compressor, namely, part of the gas from the compressed air source E1, is adjusted to an appropriate flow through the throttling orifice plate E2, and in a state in which the fifth shut-off valve ES is fully opened, it enters the auxiliary atomizing air annular pipe 4-1H and branch pipes through the eighth flow sensor E6 and the eighth check valve E8, and is finally supplied to the atomizing air passage of the low-emission nozzle 11. That is, the air is actively supplied by the atomizing air inlet 4-1, wherein an atomizing air interface is sealed and connected through an atomizing air connecting nut 4-2 and an atomizing air connecting conical pipe 4-3; the air enters the auxiliary atomizing air passage 1-5, then passes through the swirl passage space formed by the low-emission nozzle shell 5-1, the atomizing air swirler 1-2 and the cap 1-3, and a swirl groove to achieve a swirl state, and is finally ejected through the atomizing air spout formed by the atomizing air swirler 1-2 and the cap 1-3 to rotate and shear a liquid fuel atomizing cone liquid film for assisting in droplet breakage, which achieves a good atomizing effect and solves the problem of poor atomizing quality of the liquid fuel when operating under the slow and ignition working conditions of the gas turbine. (3) When the liquid fuel is used for working under high working conditions: when the gas turbine uses the liquid fuel and operates above slow working condition, the auxiliary atomizing air system E closes the shut-off valve E5 when the slow working condition arrives, and stops the supply of the external auxiliary atomizing air, the atomizing air supply of the atomizing air annular pipe 4-1H, the branch pipes and

BL-5590 36 the low-emission nozzle atomizing air passage is adjusted to be supplied by the LU503079 atomizing air purging path CO-2 of the atomizing air purging system C, and the regulating valve C4-2 is opened to an appropriate opening degree.

That is, the auxiliary atomizing air source is supplied by the compressed air in the annular cavity space formed by the combustion chamber outer shell of the gas turbine and the combustion chamber flame tube.

At this time, the air compressor can stop working, and only the high-pressure air brought by the rotary compression of the gas turbine compressor is used for auxiliary atomizing.

(4) When the gas fuel is used for working under low working conditions: when the gas turbine uses the gas fuel and operates under ignition and slow working conditions, the gas fuel system B is in the working state, and the gas fuel in the gas fuel source B1 is filtered to remove impurities through the completely opened third shut-off valve B5-1 and the second filter B3, and then enters the first gas fuel branch path BO-1 after being heated by the water bath heater B2. At this time, the third regulating valve B4-2 and the fourth shut-off valve B5-2 of the second gas fuel flow branch path all remain in the completely closed state.

After passing through the second regulating valve B4-1 with an appropriate opening degree and the fourth shut-off valve B5-2 completely opened, the gas fuel is delivered to the annular pipe 2-1H under a condition metered by the flow sensor B6-2, and finally supplied to the low-emission nozzle 11 via the branch pipes.

During this process, the relief valve B7 remains closed. (Fig. 1) The gas fuel is supplied from the gas fuel first-path inlet 2-1, wherein a gas fuel first-path interface is sealed through the gas fuel first-path connecting nut 2-2 and the gas fuel first-path connecting conical pipe 2-3. The gas fuel is delivered to a fuel passage formed by the low-emission nozzle shell 5-1 and the bow clip 2-4 2-4 through the holes in the low-emission nozzle shell 5-1, and spayed out through fuel small holes of the first-path air swirler 2-5. After mixed with air, the gas fuel enters the combustion space for premix combustion, effectively reducing pollutant emissions.

During this process, the second gas fuel flow path purging branch DO-2 of the gas fuel purging system D is in a flow-through open state, and the third regulating valve B4-2 is in an appropriate opening degree to control the amount of purging gas to the gas fuel path-2 annular pipe 3-1H (FIG. 1) and further enter the gas fuel second-path inlet pipe 3-1 of the low-emission nozzle 11. Similarly, the liquid fuel purging system C is in a purging

BL-5590 37 working state, and the atomizing air inlet 4-1 and the liquid fuel path inlet 1-9 are LU503079 both supplied by the compressed air in the annular cavity space formed by the combustion chamber shell and the combustion chamber flame tube of the gas turbine to purge and cool each passage and prevent the backflow of high-temperature gas when the low-emission nozzle is working. Optionally, the liquid fuel purging path CO-1 and the atomizing air purging path CO-2 include a fourth regulating valve C4-1 and a fifth regulating valve C4-2 for controlling the flow, and a fourth flow sensor C6-1 and a fifth flow sensor C6-2 for metering the actual purging flow. At the same time, the eighth check valve E8 and the first check valve

A8 can prevent the backflow of the purging gas to the auxiliary atomizing air system

E and the liquid fuel system A, thereby damaging the equipment. (5) When the gas fuel is used for working under high working conditions: when the gas turbine uses the gas fuel and operates above the slow working condition, the gas fuel supply is large. When the idle point is reached, the gas fuel path-2 annular pipe is adjusted from a purging state to a fuel supply state, that is, the seventh regulating valve D4-2 is adjusted from an open state to a closed state. At the same time, the seventh regulating valve D4-2 is adjusted to an appropriate opening degree, and the fourth shut-off valve B5-2 is adjusted to be completely open. The two branch paths of the gas fuel system B are both in the working state of fuel supply. Specifically, the gas fuel in the gas fuel source B1 is filtered to remove impurities through the completely opened second shut-off valve BS and the second filter B3, and then enters the first gas fuel branch path BO-1 and the second gas fuel branch path BO-2 after being heated by the water bath heater B2. After passing through the regulating valve with an appropriate opening degree and the shut-off valve completely opened, the gas fuel is delivered to the gas fuel path-1 annular pipe 2-1H and the gas fuel path-2 annular pipe 3-1H under a condition metered by respective flow sensors, and finally supplied to the low-emission nozzle 11 via the branch pipes. During this process, the relief valve B7 remains closed. When the working conditions continue to rise, this is achieved by controlling the opening degrees of the second regulating valve B4-1 and the third regulating valve B4-2. (Fig. 1) At this time, the gas fuel is supplied from the gas fuel first-path inlet 2-1 and the gas fuel first-path inlet 3-1 at the same time. Except for the gas fuel path |, the gas fuel second-path interface is sealed and connected through the gas fuel

BL-5590 38 second-path connecting nut 3-2 and the gas fuel second-path p connecting conical LU503079 pipe 3-3. The gas fuel is delivered to a fuel passage formed by the second-stage swirler 2-9 and the sealing cover 3-4 through the holes in the shell 5-1 and the first path air swirler 2-5, then enters the fuel small hole in the second-stage swirler 2-9 and is ejected.

After mixed with air, the gas fuel enters the combustion space, and is pre-heated together with the gas fuel path | for premix combustion.

During this process, the working state is the same as when the gas turbine uses the gas fuel to operate under low working conditions, the liquid fuel purging system C is in the purging working state, and the atomizing air inlet 4-1 and the liquid fuel path inlet 1-9 are both supplied by the compressed air in the annular cavity space formed by the combustion chamber outer shell and the combustion chamber flame tube of the gas turbine to purge and cool each passage and prevent the backflow of high-temperature gas when the low-emission nozzle is working. (6) During the process of switching from gas fuel to liquid fuel under a certain working condition, optionally, the following steps are performed: (1) Before switching starts, the gas fuel system B keeps working, that is, the gas fuel is supplied from the first gas fuel branch path BO-1 and the second gas fuel branch path BO-2 to the gas fuel path-1 annular pipe 2-1H and the gas fuel path-2 annular pipe and enters the gas low-emission nozzle 11 for combustion.

The liquid fuel purging system C keeps working, that is, the bleed air from the combustion chamber 8 enters the liquid fuel purging flow path CO-1 and the atomizing air purging path CO-2 through the flow path CDO, then enters the liquid fuel annular pipe 1-9H and the auxiliary atomizing air annular pipe 4-1H separately, and effectively purges the liquid fuel passage and the auxiliary atomizing air passage of the low-emission nozzle 11 to prevent carbon deposits.

The liquid fuel system A, the gas fuel purging system D and the auxiliary atomizing air system E do not work, and the bleed air, purging gas and gas fuel of the combustion chamber 8 are effectively checked through respective first check valve A8, sixth check valve D8-1 and seventh check valve D8-2, and the eighth check valve E8 to prevent the gas turbine from malfunctioning due to fuel backflow.

BL-5590 39 (2) When switching starts, on the basis of the state of step (1), the liquid fuel LU503079 purging flow path CO-1 of the liquid fuel purging system C stops working. That is, the fourth regulating valve C4-1 is adjusted to the closed state, the liquid fuel system A starts working, the pump A2 is started, the first shut-off valve AS is opened, the first regulating valve A4 is adjusted to the minimum opening degree of the valve, the working medium in the liquid fuel annular pipe 1-9H is changed from the bleed air of the combustion chamber 8 to the liquid fuel with a suitable flow G1 supplied by the liquid fuel flow path AQ, finally enters the liquid fuel passage of the low-emission nozzle 11, and enters the combustion chamber under the auxiliary atomizing of the purging gas under the condition of the bleed air of the combustion chamber 8 to participate in the combustion. At the same time, in order to ensure that the power fluctuation of the gas turbine generator set is within 5%, the second regulating valve B4-1 and the third regulating valve B4-2 of the gas fuel system are reduced by a certain opening degree to reduce the gas fuel amount Gg corresponding to the calorific value of G1. With the advancement of the fuel switching process, the opening degree of the first shut-off valve A5 gradually increases, and the opening degrees of the third shut-off valve B5-1 and the fourth shut-off valve B5-2 gradually decrease. During this process, it is ensured that the power fluctuation of the gas turbine generator set is within 5%. When a certain time is reached, the second regulating valve B4-1 and the third regulating valve B4-2 are completely closed while the third shut-off valve B5-1 and the fourth shut-off valve

B5-2 are also adjusted to the closed state, so as to ensure that the gas fuel is effectively shut off. The first shut-off valve AS is adjusted to a suitable opening degree to complete the fuel switching. During the maintenance of this working state of the gas turbine generator set, there is continuous power output, and the generator 10 is always in a stable working state. (3) After the switching is over, on the basis of step (2), the liquid fuel system A remains in the working state, the gas system B is in the closed state, the second shut-off valve B5, the third shut-off valve B5-1 and the fourth shut-off valve B5-2 all remain closed, and the fuel gas purging system D starts to work. That is, the sixth regulating valve D4-1 and the seventh regulating valve D4-2 are opened to an appropriate opening degree, and the bleed air of the combustion chamber 8 is introduced into the gas fuel path-1 annular pipe 2-1H and the gas fuel path-2

BL-5590 40 annular pipe separately to purge and clean the two gas fuel passages of the LUS03079 low-emission nozzle 11 to prevent carbon deposits and backfire. At the same time, the second check valve B8-1 and the third check valve B8-2 of the first gas fuel flow path branch and the second gas fuel flow path branch of the gas fuel system B can effectively prevent the purging gas from flowing back into the gas fuel system B, resulting in flammable mixtures and affecting the re-use of the gas fuel. In addition, the relief valve B7 of the gas fuel system B is optionally opened, and the residual gas fuel in the gas fuel flow path is safely evacuated through the relief port to prevent the formation of flammable mixtures and ensure the safety of the set. After evacuation, the relief valve B7 is adjusted to be closed to restore the system standby state. (7) During the process of switching from liquid fuel to gas fuel under a certain working condition, optionally, the following steps are performed: (1)Before the switching starts, the liquid fuel system A maintains the working state.

That is, the liquid fuel is supplied from the liquid fuel source A1 to the liquid fuel annular pipe 1-9H through the liquid fuel flow path AO, and finally enters the liquid fuel passage of the low-emission nozzle 11 for injection, atomizing and combustion.

The gas fuel system B is in the closed state, and the gas fuel purging system D is in the working state. That is, the sixth regulating valve D4-1 and the seventh regulating valve D4-2 are opened to an appropriate opening degree, and the bleed air of the combustion chamber 8 is introduced into the gas fuel path-1 annular pipe 2-1H and the gas fuel path-2 annular pipe separately through the first gas fuel flow path purging branch DO-1 and the second gas fuel flow path purging branch DO-2 to purge and clean the two gas fuel passages of the low-emission nozzle 11, so as to prevent carbon deposits and backfire. At the same time, the second check valve

B8-1 and the third check valve B8-2 of the first gas fuel flow path branch and the second gas fuel flow path branch of the gas fuel system B can effectively prevent the purging gas from flowing back into the gas fuel system B, resulting in flammable mixtures and affecting the re-use of the gas fuel. The liquid fuel purging system C remains in the semi-working state. That is, the liquid fuel purging flow path CO-1 is in the closed state, but the auxiliary atomizing air flow path CO-2 is in the open state.

The bleed air from the combustion chamber 8 passes through the flow path CDO,

BL-5590 41 enters the atomizing air purging path CO-2, further enters the auxiliary atomizing air LU503079 annular pipe 4-1H, and finally effectively purges the auxiliary atomizing air passage of the low-emission nozzle 11. After the bleed air is ejected from the passage outlet, it assists the efficient atomization of the liquid fuel, strengthens the combustion, and improves the combustion efficiency. The auxiliary atomizing air system E is not in operation, and the bleed air and purge gas of the combustion chamber 8 are effectively checked through the check valve E8 to prevent the purge gas from flowing back into the auxiliary atomizing air system to damage the equipment. @)At the start of switching, on the basis of the state of step (1), the first gas fuel flow path purging branch DO-1 and the second gas fuel flow path purging branch

DO-2 of the gas fuel purging system D stop working. That is, the sixth regulating valve D4-1 and the seventh regulating valve D4-2 are adjusted to the closed state, and the purging is stopped to prepare for switching. Further, the second shut-off valve B5 on the gas fuel flow path BO is opened, and the water bath heater B2 starts to heat the gas fuel supplied by the gas fuel source B1 to prevent the gas fuel hydrocarbon precipitation caused by the low fuel temperature. The second regulating valve B4-1 of the first gas fuel branch BO-1 is opened to the minimum opening degree, and the third shut-off valve B5-1 is adjusted to the open state.

Then, the gas fuel is supplied to the gas fuel path-1 annular pipe 2-1H through the flow path, the gas fuel flow is controlled to Gg, and the gas fuel further enters the first gas fuel passage of the low-emission nozzle 11 to participate in the combustion.

At the same time, the first regulating valve A4 on the liquid fuel flow path AO reduces the opening degree to reduce the liquid fuel flow GI, and the calorific values of Gl and Gg are the same, so that the power of the gas turbine generator set can be stabilized within 5%. With the advancement of the switching process, when the second regulating valve B4-1 is adjusted to a certain opening degree, the opening degree remains unchanged, the fourth shut-off valve B5-2 is adjusted to open, and the third regulating valve B4-2 is adjusted to the minimum opening degree. At the same time, the opening degree of the first regulating valve A4 of the liquid fuel system A continues to decrease until it is closed, and the gas fuel system

B is fully put into a stable working state to complete the fuel switching. During this process, the working state of the gas turbine generator set remains stable, there is continuous power output, the generator 10 is always in a stable working state.

BL-5590 42

LU503079 (3) After the switching is over, on the basis of step (2), the liquid fuel system A has stopped working, that is, the pump A2, the first regulating valve A4 and the first shut-off valve AS all remain in the closed state, the gas fuel system B is in an open and stable operation state. The liquid fuel purging system C starts to work, that is, the fourth regulating valve C4-1 is opened to an appropriate opening degree, and the bleed air of the combustion chamber 8 is separately introduced into the liquid fuel annular pipe 1-9H to purge and clean the liquid fuel passage of the low-emission nozzle 11, so as to prevent carbon deposits. At the same time, the check valve A8 on the liquid fuel flow path AO of the liquid fuel system A can effectively prevent the purge gas from flowing back into the liquid fuel system A, resulting in flammable mixtures and affecting the re-use of the liquid fuel. Further, the relief valve A7 in the liquid fuel system A is optionally opened, and the residual liquid fuel in the liquid fuel flow path is released through the relief port to ensure the safety of the set and then adjusted to be closed to restore the system standby state. (8) In order to prevent high-temperature carbon deposit in the dual-fuel low-emission nozzle, three air cooling passages for anti-carbon deposit are provided, and their specific compositions are as follows:

In order to reduce the temperature of the cap 1-3 and prevent carbon deposits, when the dual-fuel low-emission nozzle is working, a plurality of holes are provided in the swirler shell 2-10. The unburned compressed air from the annular cavity space between the combustion chamber outer shell and the flame tube flows into the low-emission nozzle from the path-1 anti-carbon deposit cold-state purging hole 6-1, flows in the cooling passage inside the cap 1-3, and is finally ejected from the anti-carbon deposit cold-state purging path-1 spout 6-2 to the combustion space, so as to form a thermal insulation protective air film, reduce the temperature, and prevent the formation of carbon deposits. In order to reduce the temperature of the premix first-path compression member 2-6 and prevent carbon deposits, when the dual-fuel low-emission nozzle is working, a plurality of holes are provided in the swirler shell 2-10. The unburned compressed air from the annular cavity space between the combustion chamber outer shell and the flame tube flows into the

BL-5590 43 low-emission nozzle from the path-2 anti-carbon deposit cold-state purging hole LU503079 6-13, flows in the internal cooling passage formed by the swirler shell 2-10, the premix first-path compression member 2-6 and the first cup assembly 2-7, and under the action of the pressure difference, performs impingement cooling of the premix first-path compression member 2-6 through multiple rows of holes in the first cup assembly 2-7. Finally, the compressed air is ejected from the first path-2 anti-carbon deposit cold-state purging spout 6-4 and the second path-2 anti-carbon deposit cold-state purging spout 6-5 to the combustion space, so as to form a thermal insulation protective air film, reduce the temperature, and prevent the formation of carbon deposits. In order to reduce the temperature of the premix second-path compression member 3-6 and prevent carbon deposits, when the dual-fuel low-emission nozzle is working, a plurality of holes are provided in the ferrule 3-5. The unburned compressed air from the annular cavity space between the combustion chamber outer shell and the flame tube flows into the low-emission nozzle from the path-3 cooling anti-carbon deposit cold-state purging hole 6-6, flows in the internal cooling passage formed by the swirler shell 2-10, the ferrule 3-5 and the premix second-path compression member 3-6, and is finally ejected from the plurality of small holes in the premix second-path compression member 3-6 to the combustion space, so as to form a thermal insulation protective air film, reduce the temperature and prevent the formation of carbon deposits.

Only preferred embodiments of the present invention are described above, but the present invention is not limited to the above-mentioned specific embodiments.

Various modifications or equivalent substitutions made by those skilled in the art to the features and embodiments of the present invention for adapting to specific situations under the inspiration of the present invention without departing from the spirit of the present invention, all will not depart from the spirit of the present invention and the protection scope of the claims.

Claims (19)

BL-5590 44 Claims LU503079

1. À low-emission nozzle, characterized in that it comprises a first fuel gas path, a second fuel gas path, an atomizing air path, a liquid fuel path, a purging air path and a nozzle body; wherein the first fuel gas path, the second fuel gas path, the atomizing air path and the liquid fuel path are mounted on the nozzle body in the form of internal oil and external gas and staggered oil and gas paths; and wherein the atomizing air path, the first fuel gas path and the liquid fuel path ensure that a set enters a slow working condition and share a first-path air swirler (2-5) of the first fuel gas path, wherein the atomizing air path, the second fuel gas path and the liquid fuel path ensure that the set enters a fast working condition and share a second-path air swirler (2-9) of the second fuel gas path, wherein the purging air path is mounted on a fuel ejection side of the nozzle body, and the purging air path prevents carbon deposits at a spout by means of impingement convection cooling, air film cooling and thermal insulation cooling.

2. The low-emission nozzle according to claim 1, characterized in that the low-emission nozzle comprises a low-emission nozzle shell (5-1) and a combustion chamber cover plate (5-2), and the combustion chamber cover plate (5-2) is mounted on a fuel inlet of the low-emission nozzle shell (5-1).

3. The low-emission nozzle according to claim 2, characterized in that the liquid fuel path comprises a liquid fuel swirler (1-1), a screw plug (1-4), a sealing cover (1-17), a sealing assembly, a rotating plug (1-14), a liquid fuel thermal insulation pipe (1-13), a liquid fuel path inlet pipe (1-9), a liquid fuel path connecting cap (1-10), a liquid fuel path connecting conical pipe (1-11) and a liquid fuel filter assembly (1-12); the liquid fuel path connecting conical pipe (1-11) is inserted on a combustion chamber cover plate (5-2); the liquid fuel filter assembly (1-12) is mounted in the liquid fuel path connecting conical pipe (1-11); the liquid fuel path inlet pipe (1-9) is mounted on the liquid fuel path connecting conical pipe (1-11) through the liquid fuel path connecting cap (1-10); the liquid fuel swirler (1-1) and the screw plug (1-4) are coaxially mounted in the low-emission nozzle shell (5-1); and the sealing cover

BL-5590 45 (1-17) seals the screw plug (1-4) through the sealing assembly, the screw plug LU503079 (1-14) is screwed on the sealing cover (1-17), and both ends of the liquid fuel heat insulation pipe (1-13) are communicated with the liquid fuel swirler (1-1) and the liquid fuel path connecting conical pipe (1-11), respectively.

4. The low-emission nozzle according to claim 3, characterized in that the sealing assembly comprises a circular ring (1-15), a sealing ring (1-16) and a steel ring (1-18); the sealing ring (1-16) is an annular sealing ring, and the upper part of the sealing ring (1-16) is provided with a tapered stepped groove (1-16-1); the steel ring (1-18) is sealed and embedded in the sealing ring (1-16), and the outer side of the lower part of the circular ring (1-15) is a tapered step; the circular ring (1-15) is inserted into a stepped groove (1-16-1) of the sealing ring (1-16), and the upper end surface of the circular ring (1-15) is lower than the upper end surface of the sealing ring (1-16).

5. The low-emission nozzle according to claim 1, 2, 3 or 4, characterized in that the atomizing air path comprises an atomizing air swirler (1-2), a cap (1-3), an auxiliary atomizing air path inlet pipe (1-6), an auxiliary atomizing air path connecting cap (1-7) and an auxiliary atomizing air path conical pipe (1-8); the atomizing air swirler (1-2) is sleeved on the liquid fuel swirler (1-1) and the screw plug (1-4); the cap (1-3) is sleeved on the atomizing air swirler (1-2) and is located on the side of the liquid fuel swirler (1-1); the auxiliary atomizing air path inlet pipe (1-6) is mounted on the combustion chamber cover plate (5-2); the auxiliary atomizing air path inlet pipe (1-6) is connected to the auxiliary atomizing air path conical pipe (1-8) through the auxiliary atomizing air path connecting cap (1-7); and the bottom of the auxiliary atomizing air path conical pipe (1-8) is communicated with the atomizing air swirler (1-2) through an auxiliary atomizing air passage (1-5).

6. The low-emission nozzle according to claim 5, characterized in that the first fuel gas path comprises a first gas fuel inlet pipe (2-1), a first gas fuel connecting cap (2-2), a first gas fuel connecting conical pipe (2-3), a bow clip (2-4), a first-path air swirler (2-5), a premix first-path compression member (2-6), a first cup assembly (2-7) and a second cup assembly (2-8); and

BL-5590 46 the first gas fuel connecting conical pipe (2-3) is mounted on the combustion LU503079 chamber cover plate (5-2), and the first gas fuel inlet pipe (2-1) is mounted on the first gas fuel connecting conical pipe (2-3) through the first gas fuel connecting cap (2-2); the bow clip (2-4) is mounted on the end of the low-emission nozzle shell (5-1) on the fuel injection side; the first-path air swirler (2-5) is mounted at the rear end of the bow clip (2-4), and the premix first-path compression member (2-6) are inserted at the tail of the first-path air swirler (2-5) coaxially with the first-path air swirler (2-5); the first cup assembly (2-7) and the second cup assembly (2-8) are sleeved on the premix first-path compression member (2-6) from the inside to the outside; and the bottom of the first gas fuel connecting conical pipe (2-3) is communicated with the first-path air swirler (2-5) through a first gas passage.

7. The low-emission nozzle according to claim 6, characterized in that the second fuel gas path comprises a second-path air swirler (2-9), a second-path swirler shell (2-10), a second gas fuel inlet pipe (3-1), a second gas fuel connecting cap (3-2), a second gas fuel connecting conical pipe (3-3), a sealing cover (3-4), a ferrule (3-5) and a premix second-path compression member (3-6); and the second-path swirler shell (2-10) is mounted on a first-path air swirler (2-5) through the sealing cover (3-4); the second-path air swirler (2-9) is mounted on the second-path swirler shell (2-10); the premix second-path compression member (3-6) is mounted on the second-path swirler shell (2-10) through the ferrule (3-5), and the second gas fuel connecting conical pipe (3-3) is mounted on the combustion chamber cover plate (5-2); and the second gas fuel inlet pipe (3-1) is connected to the second gas fuel connecting conical pipe (3-3) through the second gas fuel connecting cap (3-2), and the second gas fuel connecting conical pipe (3-3) is communicated with the second-path air swirler (2-9) through a second gas passage.

8. The low-emission nozzle according to claim 1, 2, 3, 4, 6 or 7, characterized in that the purging air path comprises an impingement convection cooling air path, a film cooling air path and a thermal insulation cooling air path, wherein: the impingement convection cooling air path is as follows: a second-path swirler

BL-5590 47 shell (2-10) is provided with a plurality of path-2 anti-carbon deposit cold-state LU503079 purging holes (6-3), and external cold air flows in from the plurality of path-2 anti-carbon deposit cold-state purging holes (6-3), flows in an internal cooling passage formed by the second-path swirler shell (2-10), a premix first-path compression member (2-6) and a first cup assembly (2-7), and performs impingement cooling of the premix first-path compression member (2-6) through multiple rows of holes in the first cup assembly (2-7) under the action of the gas pressure difference, wherein cold air of an external purging system is ejected to a combustion space through a first path-2 anti-carbon deposit cold-state purging spout (6-4) and a second path-2 anti-carbon deposit cold-state purging spout (6-5), so as to form a thermal insulation protective air film, finally reducing the temperature of the premix first-path compression member (2-6) by means of a combination of impingement convection cooling and air film cooling; the film cooling air path is as follows: a first-path air swirler (2-5) is provided with a plurality of path-1 anti-carbon deposit cold-state purging holes (6-1), and cold air of an external purging system enters from the plurality of path-1 anti-carbon deposit cold-state purging holes (6-1), and flows in a cooling passage inside the cap (1-3), and is finally ejected from an path-1 anti-carbon deposit cold-state purging spout (6-2) to a combustion space, so as to form a thermal insulation protective air film and reduce the temperature of the cap (1-3); and the thermal insulation cooling air path is as follows: the ferrule (3-5) is provided with a plurality of path-3 cooling anti-carbon deposit cold-state purging holes (6-6), and the cold air of the external purging system enters from the plurality of path-3 cooling anti-carbon deposit cold-state purging holes (6-6), flows in an internal cooling passage formed by a second-path swirler shell (2-10), the ferrule (3-5) and the premix second-path compression member (3-6), and is finally ejected from a plurality of holes in the premix second-path compression member (3-6) to the combustion space, so as to form a thermal insulation protective air film and reduce the temperature of the premix second-path compression member (3-6).

9. The low-emission nozzle according to claim 8, characterized in that the first path-2 anti-carbon deposit cold-state purging spout (6-4) and the second path-2

BL-5590 48 anti-carbon deposit cold-state purging spout (6-5) are provided in the premix LU503079 first-path compression member (2-6) in the form of an annular array.

10. The low-emission nozzle according to claim 9, characterized in that the first path-2 anti-carbon deposit cold-state purging spout (6-4) is an elliptical spout, and a plurality of first path-2 anti-carbon deposit cold-state purging spouts (6-4) are arranged in a circular array in a clockwise inclined manner.

11. The low-emission nozzle according to claim 10, characterized in that the second path-2 anti-carbon deposit cold-state purging spout (6-5) is a rectangular spout.

12. A low-emission dual-fuel combustion chamber, comprising a combustion chamber outer shell (8-1), a combustion chamber inner shell (8-2) and a flame tube (8-3), characterized in that the low-emission dual-fuel combustion chamber further comprises a front load-bearing shell (8-4), a rear support shell (8-5), a combustion chamber outlet (8-5A), a diffuser (8-6), a combustion chamber inlet (8-6A), a positioner (8-7) and a low-emission nozzle, the combustion chamber outer shell (8-1) is sealed and connected with the front load-bearing shell (8-4) and the rear support shell (8-5) through front and rear annular flanges, respectively, the combustion chamber inner shell (8-2) is connected to the front load-bearing shell (8-4) through the front annular flange and forms a three-dimensional combustion chamber annular cavity (8A) together with the combustion chamber outer shell (8-1), wherein the diffuser (8-6) is connected to the rear of the combustion chamber inner shell (8-2), an end of the diffuser (8-6) is the combustion chamber inlet (8-6A), and the combustion chamber outlet (8-5A) is provided in the rear support shell (8-5); and the flame tube (8-3) is mounted in the three-dimensional annular working space, wherein the low-emission nozzle is inserted into an insertion hole of the head of the flame tube (8-3) through a mounting hole of a front annular cone surface of the front load-bearing shell (8-4), wherein a main combustion hole (8-3A) is provided in the middle of the flame tube (8-3), there are two positioners (8-7) connected to the

BL-5590 49 head of the flame tube (8-3), and a tail mount of the flame tube is mounted on the LU503079 rear support shell (8-5) with three-point support.

13. The low-emission dual-fuel combustion chamber according to claim 12, characterized in that the low-emission nozzle is the low-emission nozzle according to any one of claims 1 to 11.

14. A gas turbine generator set, characterized in that the gas turbine generator set comprises the low-emission dual-fuel combustion chamber (8) according to any one of claims 12-13, a low-emission dual-fuel control system, a compressor (7), a turbine (9) and a generator (10), wherein the low-emission dual-fuel combustion chamber (8) is connected to an annular pipe system (F) of the low-emission nozzle of the low-emission dual-fuel control system, high-temperature and high-pressure air from the compressor (7) enters a diffuser (8-6) through a combustion chamber inlet (8-6A) for deceleration and diffusion, and then flows into a combustion chamber annular cavity (8A), and then the air is distributed to a low-emission nozzle (11) and mixed with liquid fuel or gas fuel to form a combustible mixture, which is efficiently and stably combusted in a flame tube (8-3), and is discharged from a combustion chamber outlet (8-5A) to push the turbine (9) to output work for achieving power generation of the generator (10); wherein the low-emission dual-fuel control system comprises a liquid fuel system (A), a gas fuel system (B), a liquid fuel purging system (C), a gas fuel purging system (D), an auxiliary atomizing air system (E) and the annular pipe system (F) of the low-emission nozzle; wherein the annular pipe system (F) of the low-emission nozzle comprises a liquid fuel annular pipe (1-9H), an auxiliary atomizing air annular pipe (4-1H), a gas fuel path-1 annular pipe (2-1H) and a gas fuel path-2 annular pipe (3-1H), wherein the liquid fuel annular pipe (1-9H), the auxiliary atomizing air annular pipe (4-1H), the gas fuel path-1 annular pipe (2-1H) and the gas fuel path-2 annular pipe (3-1H) are connected to a liquid fuel path inlet pipe (1-9), an auxiliary atomizing air path inlet pipe (1-6), a first gas fuel inlet pipe (2-1) and a second gas fuel inlet pipe (3-1) on

BL-5590 50 the low-emission nozzle through branch pipes, respectively; LU503079 during combustion of liquid fuel:

when under ignition and below slow working conditions: the liquid fuel system (A) is put into operation, the gas fuel system (B) is not in operation, the liquid fuel purging system (C) is not in operation, the gas fuel purging system (D) is put into operation, and the auxiliary atomizing air system (E) is put into operation,

at this time, the liquid fuel system (A) enters the liquid fuel annular pipe (1-9H) of the annular pipe system (F) of the low-emission nozzle through the liquid fuel flow path (AO), and then enters the liquid fuel path of the low-emission nozzle; the auxiliary atomizing air system (E) enters the auxiliary atomizing air annular pipe

(4-1H) through the auxiliary atomizing air flow path (EO), and then enters the atomizing air path of the low-emission nozzle for auxiliary atomization of liquid fuel; the gas fuel purging system (D) is divided into two flow paths, i.e., a first gas fuel flow path purging branch (D0-1) and a second gas fuel flow path purging branch

(DO-2), for cleaning and purging the gas fuel annular pipe in a non-operation state and the internal passages of the low-emission nozzle; when above the slow working condition: a purging air source of the atomizing air path is adjusted from the auxiliary atomizing air system (E) to be supplied from the atomizing air purging path (CO-2) of the liquid fuel path purging system (C), that is, the auxiliary atomizing air source is supplied by the compressed air in the annular cavity space formed by the combustion chamber outer shell and the flame tube of the low-emission dual-fuel combustion chamber, and the rest of the system remains unchanged;

during combustion of gas fuel: the liquid fuel system (A) is closed, the gas fuel system (B) is put into operation, and the liquid fuel purging system (C) is put into operation;

BL-5590 51 LU503079 when under the ignition and below slow working conditions: the compressed air in the annular cavity space of the low-emission dual-fuel combustion chamber enters the liquid fuel path (AO) of the liquid fuel system (A), the second gas fuel flow path purging branch (DO-2) of the gas fuel purging system (D), and the auxiliary atomizing air path (EO) of the auxiliary atomizing air system (E); the gas fuel enters the gas fuel path-1 annular pipe (2-1H) of the annular pipe system (F) of the low-emission nozzle through the gas fuel system (B), and then enters the first gas fuel inlet pipe (2-1) of the low-emission nozzle; the liquid fuel purging system (C) is in a purging working state, and the auxiliary atomizing air path inlet pipe (1-6) and the liquid fuel path inlet pipe (1-9) are both supplied by the compressed air in the annular cavity space formed by the combustion chamber outer shell and the flame tube of the low-emission dual-fuel combustion chamber to purge and cool each passage; when above the slow working condition: the gas fuel purging system (D) is closed, and the gas fuel simultaneously enters the gas fuel path-1 annular pipe (2-1H) and the gas fuel path-2 annular pipe (3-1H) of the annular pipe system (F) of the low-emission nozzle through the gas fuel system (B), and then enters the first fuel gas path and the second fuel gas path of the low-emission nozzle separately; and when the gas fuel and liquid fuel are switched, both the liquid fuel purging system (C) and the gas fuel purging system (D) are closed, and both the liquid fuel system (A) and the gas fuel system (B) are put into operation.

15. The low-emission dual-fuel combustion chamber according to claim 14, characterized in that the liquid fuel system (A) comprises a liquid fuel source (A1), a liquid fuel pipeline (AO), a pump (A2), a first filter (A3), a first regulating valve (A4),

BL-5590 52 a first shut-off valve (A5), a first flow sensor (A6), a relief valve (A7) and a first LU503079 check valve (A8); one end of the liquid fuel pipeline (AO) is connected to the liquid fuel source (A1), and the other end of the liquid fuel pipeline (AO) is sequentially connected in series with the pump (A2), the first filter (A3), the first regulating valve (A4), the first shut-off valve (A5), the first flow sensor (A6) and the first check valve (A8), and then connected to the liquid fuel annular pipe (1-9H); and the relief valve (A7) is connected in parallel with the liquid fuel pipeline (AO) between the first flow sensor (A6) and the first check valve (A8).

16. The low-emission dual-fuel combustion chamber according to claim 14 or 15, characterized in that the gas fuel system (B) comprises a gas fuel source (B1), a gas fuel path (BO), a water bath heater (B2), a second filter (B3), a second shut-off valve (BS), a relief valve (B7), a second regulating valve (B4-1), a third regulating valve (B4-2), a third shut-off valve (B5-1), a fourth shut-off valve (B5-2), a second flow sensor (B6-1), a third flow sensor (B6-2), a second check valve (B8-1) and a third check valve (B8-2), and one end of the gas fuel path (BO) is connected to the gas fuel source (B1), and the other end of the gas fuel path (BO) is sequentially connected in series with the water bath heater (B2), the second filter (B3) and the second shut-off valve (BS), and then divided into a first gas fuel branch path (BO-1) and a second gas fuel branch path (BO-2); the first gas fuel branch path (BO-1) is sequentially connected in series with the second regulating valve (B4-1), the third shut-off valve (B5-1), the second flow sensor (B6-1) and the second check valve (B8-1) and then connected to a gas fuel path-1 annular pipe (2-1H); and the second gas fuel branch path (BO-2) is sequentially connected in series with the third regulating valve (B4-2), the fourth shut-off valve (B5-2), the third flow sensor (B6-2) and the third check valve (B8-2) and then connected to a gas fuel path-2 annular pipe (3-1H).

17. The low-emission dual-fuel combustion chamber according to claim 16, characterized in that the auxiliary atomizing air system (E) comprises a compressed air source (E1), an auxiliary atomizing air path (EO), a throttle orifice plate (E2), a fifth shut-off valve (ES), an eighth flow sensor (E6) and an eighth check valve (E8), and

BL-5590 53 LU503079 one end of the auxiliary atomizing air path (EO) is connected to the compressed air source (E1), and the other end of the auxiliary atomizing air path (EO) is sequentially connected to the throttle orifice plate (E2), the fifth shut-off valve (ES), the eighth flow sensor (E6) and the eighth check valve (E8), and then connected to an auxiliary atomizing air annular pipe (4-1H).

18. The low-emission dual-fuel combustion chamber according to claim 17, characterized in that the liquid fuel purging system (C) comprises a combustion chamber bleed air path (CDO), a liquid fuel purging path (CO-1), an atomizing air purging path (CO-2), a fourth regulating valve (C4-1), a fifth regulating valve (C4-2), a fourth flow sensor (C6-1), a fifth flow sensor (C6-2), a fourth check valve (C8-1) and a fifth check valve (C8-2); and the liquid fuel purging path (CO-1) and the atomizing air purging path (CO-2) are connected in parallel and share the combustion chamber bleed air path (CDO); the liquid fuel purging path (CO-1) is sequentially connected in series with the fourth regulating valve (C4-1), the fourth flow sensor (C6-1) and the fourth check valve (C8-1) and then connected to the liquid fuel pipeline (A0); and the atomizing air purging path (CO-2) is sequentially connected in series with the fifth regulating valve (C4-2), the fifth flow sensor (C6-2) and the fifth check valve (C8-2), and then connected to the auxiliary atomizing air circuit (EO).

19. The low-emission dual-fuel combustion chamber according to claim 18, characterized in that the gas fuel purging system (D) comprises a first gas fuel flow path purging branch (D0-1), a second gas fuel flow path purging branch (DO-2), a sixth regulating valve (D4-1), a seventh regulating valve (D4-2), a sixth flow sensor (D6-1), a seventh flow sensor (D6-2), a sixth check valve (D8-1) and a seventh check valve (D8-2), and the first gas fuel flow path purging branch (DO0-1) and the second gas fuel flow path purging branch (D0-2) are connected in parallel and share the combustion chamber bleed air path (CDO); the first gas fuel flow path purging branch (DO-1) is sequentially connected in series with the sixth regulating valve (D4-1), the sixth

BL-5590 54 flow sensor (D6-1) and the sixth check valve (D8-1) and then connected to a first LU503079 gas fuel branch path (BO-1); and the second gas fuel flow path purging branch (DO-2) is sequentially connected in series with the seventh regulating valve (D4-2), the seventh flow sensor (D6-2) and the seventh check valve (D8-2), and then connected to a second gas fuel branch path (BO-2).