Cleaning method of gas turbine combustor

Abstract

The invention relates to the technical field of gas turbines, in particular to a cleaning method for a combustor of a gas turbine, which sequentially comprises the following steps of: 1, splitting a premixed fuel mother pipe and a premixed combustor, and enabling the interior of the premixed combustor to be communicated with the outside through a premixed fuel channel of the premixed combustor; secondly, an on-duty fuel valve is opened, an on-duty fuel mother pipe is opened, fuel is conveyed into an on-duty combustor, the fuel enters a combustion chamber through an on-duty fuel channel of the on-duty combustor and is mixed with high-pressure air fed into the combustion chamber by a gas compressor for combustion, and hot air is generated; and thirdly, hot air enters the premixing combustor from the combustion chamber and is blown out from a premixing fuel channel of the premixing combustor to the outside. Therefore, impurities in the premixed fuel channel of the premixed combustor can be cleaned without detaching the combustor from the gas turbine, a large amount of manpower and material resources are saved, and the influence on the power generation hours of a power plant is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbines, and in particular to a cleaning method for a gas turbine burner. Background Art

[0002] Most of the heavy-duty gas turbines used for power generation in my country use natural gas as the main fuel, which burns in the combustion chamber of the gas turbine to drive the turbine to do work. Natural gas is generally divided into oilfield gas, gasfield gas, coalbed methane, etc. according to its source. It will inevitably contain a small amount of solid particle impurities during the mining process. The impurities vary slightly according to the different mineral deposits. The solid particles are generally composed of sand, rust, solid tar contained in coalbed methane, silica (SiO2), and crude benzene-like tiny solid compounds produced during the natural gas generation process. During the pipeline transportation process, tiny natural gas impurities will gradually accumulate and will be passively heated during the natural gas pressure increase. A very small part of natural gas such as methane and ethane will crack under high temperature and will be transformed into solid polymers under certain conditions, becoming solid impurities in natural gas. In addition to solid impurities, there are also a certain amount of acidic gases such as H2S and COS in natural gas, which will react chemically with iron in the natural gas channel to generate solid particles such as iron oxide and ferrous sulfide.

[0003] Common gas turbine burners in the prior art are configured with a duty burner and a premixing burner. The duty burner is a burner that uses a duty fuel channel to transport the duty fuel from the duty fuel main pipe to the combustion chamber and mixes it with the high-pressure air from the compressor while burning, forming diffusion combustion. The premixing burner is a burner that uses a premixing fuel channel to fully mix the premixed fuel from the premixing fuel main pipe with the high-pressure air from the compressor and then injects it into the combustion chamber for combustion, forming premixed combustion. At different stages of gas turbine operation, different duty burner diffusion combustion and / or premixing burner premixing combustion combustion modes can be used to meet different operating loads. This burner configuration structure and operating method can refer to a double-layer duty fuel nozzle, burner and operating method disclosed in the Chinese invention patent with publication number CN118705647B.

[0004] In the above-mentioned burner configuration structure, the premixed fuel channel of the premixed burner has a relatively complex internal channel structure because the premixed fuel and high-pressure air are fully mixed therein before being injected into the combustion chamber for combustion. As a result, impurities in the premixed fuel may enter the premixed burner and cause the premixed fuel channel of the premixed burner to be blocked, causing combustion stability problems. In order to deal with impurities in the premixed fuel channel of the premixed burner, the usual practice is to remove the burner from the gas turbine and then perform acid washing, sandblasting and other operations on the premixed fuel channel of the premixed burner. However, the disassembly and assembly process of the burner is complicated, requiring a lot of manpower and material resources, and the cost is relatively high. For power plants, the disassembly and assembly of the burner has a great impact on the availability of the power plant and will reduce the number of power generation hours of the power plant. Summary of the invention

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a method for cleaning a gas turbine burner, which can clean impurities in the premixed fuel channel of the premixed burner without removing the burner from the gas turbine.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for cleaning a gas turbine burner, which comprises the following steps in sequence:

[0008] Step 1: Separate the premix fuel main pipe and the premix burner, so that the interior of the premix burner is connected to the outside world through the premix fuel channel of the premix burner; Step 2: Open the duty fuel valve, so that the duty fuel main pipe is opened and fuel is transported to the duty burner. The fuel enters the combustion chamber through the duty fuel channel of the duty burner and is mixed with the high-pressure air sent into the combustion chamber by the compressor to burn, generating hot air; Step 3: The hot air enters the interior of the premix burner from the combustion chamber and is blown out to the outside world from the premix fuel channel of the premix burner.

[0009] Preferably, the premix fuel main pipe and the premix burner are connected via a premix fuel hose. In the above step one, the premix fuel main pipe and the premix fuel hose are separated so that the premix fuel channel of the premix burner is connected to the outside through the premix fuel hose.

[0010] Preferably, in the above step three, the outlet pressure of the compressor increases continuously, and after the outlet pressure of the compressor reaches a preset pressure value and is maintained for a preset time, the duty fuel valve is closed to close the duty fuel main pipe.

[0011] Preferably, the preset time is 2 minutes to 3 minutes.

[0012] Preferably, the above steps 2 and 3 are repeated until all impurities in the premixing fuel channel of the premixing burner are blown out.

[0013] Compared with the prior art, the present invention has significant progress in that the premix fuel passage of the premix burner can be cleaned without removing the burner:

[0014] The cleaning method of the gas turbine burner of the present invention separates the premixed fuel main pipe and the premixed burner, so that the premixed burner is connected to the outside world through the premixed fuel channel, and then the fuel is sprayed into the combustion chamber of the gas turbine through the on-duty burner and ignition is started. The hot air generated by the combustion of the fuel in the combustion chamber enters the premixed burner. Under the adsorption force generated by the hot air flow and the blowing and scraping effect of the hot air, the impurities attached to the premixed fuel channel of the premixed burner fall off and flow with the hot air, and the impurities will eventually be blown out to the outside world. In this way, the impurities in the premixed fuel channel of the premixed burner can be cleaned without removing the burner from the gas turbine, which saves a lot of manpower and material resources and avoids affecting the power generation hours of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of a fuel pipeline and a fuel valve of a gas turbine in a method for cleaning a gas turbine burner according to an embodiment of the present invention.

[0016] Figure 2 It is a schematic diagram of the connection between the premix fuel main pipe of the gas turbine and the premix burner in the cleaning method of the gas turbine burner according to an embodiment of the present invention.

[0017] Figure 3 It is a schematic diagram of the connection between the on-duty fuel main pipe of the gas turbine and the on-duty burner in the cleaning method of the gas turbine burner according to an embodiment of the present invention.

[0018] The reference numerals are described as follows:

[0019] 1 Premix fuel main pipe

[0020] 2 Premix burner

[0021] 3 Duty fuel main pipe

[0022] 4 Burners on duty

[0023] 5 Duty fuel valve

[0024] 6 Gas turbine

[0025] 7 Premix fuel hose

[0026] 8 Premix fuel valve

[0027] 9 Duty fuel hose DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0032] like Figures 1 to 3 FIG. 1 is an embodiment of a method for cleaning a gas turbine combustor according to the present invention.

[0033] See also Figure 1The gas turbine burner to which the cleaning method of the gas turbine burner of this embodiment is applicable includes a premixing burner 2 and an on-duty burner 4, and is provided with a premixing fuel main pipe 1 and an on-duty fuel main pipe 3. The premixing fuel main pipe 1 and the on-duty fuel main pipe 3 are respectively used to receive fuel and transport the fuel to the premixing burner 2 and the on-duty burner 4 respectively. A premix fuel valve 8 is provided on the fuel pipeline connected to the premix fuel main pipe 1. By opening the premix fuel valve 8, fuel is supplied to the premix fuel main pipe 1, so that the premix fuel main pipe 1 is opened and fuel is delivered to the premix burner 2. By closing the premix fuel valve 8, the fuel supply to the premix fuel main pipe 1 is cut off, so that the premix fuel main pipe 1 is closed and the fuel delivery to the premix burner 2 is stopped; a duty fuel valve 5 is provided on the fuel pipeline connected to the duty fuel main pipe 3. By opening the duty fuel valve 5, fuel is supplied to the duty fuel main pipe 3, so that the duty fuel main pipe 3 is opened and fuel is delivered to the duty burner 4. By closing the duty fuel valve 5, the fuel supply to the duty fuel main pipe 3 is cut off, so that the duty fuel main pipe 3 is closed and the fuel delivery to the duty burner 4 is stopped.

[0034] See also Figure 2 and Figure 3 The gas turbine 6 is provided with a plurality of burners, each of which includes a premixing burner 2 and an on-duty burner 4. The premixing fuel main pipe 1 is connected to the premixing fuel passages of the plurality of premixing burners 2 through a plurality of premixing fuel hoses 7, respectively, and the premixing fuel main pipe 1 delivers the received fuel to the premixing fuel passages of the premixing burners 2 through the premixing fuel hoses 7; the on-duty fuel main pipe 3 is connected to the on-duty fuel passages of the plurality of on-duty burners 4 through a plurality of on-duty fuel hoses 9, and the on-duty fuel main pipe 3 delivers the received fuel to the on-duty fuel passages of the on-duty burners 4 through the on-duty fuel hoses 9.

[0035] When the gas turbine 6 is started and working, it can adopt a combustion mode of only the on-duty burner 4 burning, only the premixed burner 2 burning, or both the on-duty burner 4 and the premixed burner 2 burning at the same time according to the operating load. Among them, when the on-duty burner 4 is burning, the on-duty fuel valve 5 is in an open state, so that the on-duty fuel main pipe 3 is opened and receives the fuel delivered from the fuel pipeline, and the on-duty fuel main pipe 3 delivers the received fuel to the on-duty burner 4 through the on-duty fuel hose 9, and the fuel is then sprayed into the combustion chamber of the gas turbine 6 through the on-duty fuel channel of the on-duty burner 4 and burns while mixing with the high-pressure air from the compressor, forming diffusion combustion; when the premixed burner 2 is burning, the premixed fuel valve 8 is in an open state, so that the premixed fuel main pipe 1 is opened and receives the fuel delivered from the fuel pipeline, and the premixed fuel main pipe 1 delivers the received fuel to the premixed burner 2 through the premixed fuel hose 7, and the fuel is fully mixed with the high-pressure air from the compressor in the premixed fuel channel of the premixed burner 2 and then injected into the combustion chamber for combustion, forming premixed combustion. When the gas turbine 6 needs to stop working, the premix fuel valve 8 and the duty fuel valve 5 are closed, the fuel supply is cut off, and the gas turbine 6 is shut down.

[0036] The cleaning method of the gas turbine burner of this embodiment comprises the following steps in sequence:

[0037] Step 1, separate the premix fuel main pipe 1 and the premix burner 2, so that the interior of the premix burner 2 is connected to the outside through the premix fuel channel of the premix burner 2. Specifically, before performing the separation operation, ensure that the gas turbine 6 is in a shutdown state, keep the premix fuel valve 8 closed to cut off the fuel supply of the premix fuel main pipe 1, so as to prevent the fuel from leaking from the premix fuel main pipe 1 after separation. After the premix fuel main pipe 1 and the premix burner 2 are separated, one end of the premix fuel channel of the premix burner 2 is connected to the outside, and the other end is connected to the combustion chamber of the gas turbine 6, so that the gas in the combustion chamber can be blown out to the outside through the premix fuel channel of the premix burner 2.

[0038] Step 2, open the duty fuel valve 5, open the duty fuel main pipe 3 and deliver fuel to the duty burner 4, the fuel enters the combustion chamber through the duty fuel channel of the duty burner 4 and mixes and burns with the high-pressure air delivered into the combustion chamber by the compressor to generate hot air. Specifically, after opening the duty fuel valve 5, the duty fuel main pipe 3 opens and receives the fuel delivered from the fuel pipeline, the duty fuel main pipe 3 delivers the received fuel to the duty burner 4 through the duty fuel hose 9, and the fuel is then ejected into the combustion chamber of the gas turbine 6 through the duty fuel channel of the duty burner 4. At the same time, at the initial start-up of the gas turbine 6, the compressor inhales air from the external atmospheric environment and compresses the air, the compressed high-pressure air is compressed to the combustion chamber and mixed and burned with the fuel ejected from the duty burner 4, the ignition is started, and the fuel burns to generate hot air.

[0039] Step 3, hot air enters the premixed burner 2 from the combustion chamber and is blown out to the outside from the premixed fuel channel of the premixed burner 2. After the fuel combustion continues to generate hot air, the air pressure in the combustion chamber is very large, and most of the hot air will enter the turbine from the combustion chamber and drive the turbine to work. At the same time, since one end of the premixed fuel channel of the premixed burner 2 is connected to the outside world and the other end is connected to the combustion chamber, a small part of the hot air will enter the premixed fuel channel of the premixed burner 2 from the combustion chamber and be released to the outside world through the premixed fuel channel. The flow path of the hot air is opposite to the flow path of the fuel inside the premixed fuel channel of the premixed burner when the premixed burner 2 is working normally. Specifically, the hot air first enters the premixed fuel channel of the premixed burner 2 from the combustion chamber, and then continues to flow to one end of the premixed fuel channel of the premixed burner 2 connected to the outside world, and finally blows out to the outside world from the premixed fuel channel of the premixed burner 2. During this process, the hot air flowing inside the premix burner 2 will generate a certain adsorption force. Under the adsorption force and the blowing and scraping action of the hot air, the impurities attached to the premix fuel channel of the premix burner 2 fall off and flow with the hot air, and are finally blown out to the outside with the hot air.

[0040] The cleaning method of the gas turbine burner of this embodiment is to separate the premixed fuel main pipe 1 and the premixed burner 2, so that the premixed burner 2 is connected to the outside world through the premixed fuel channel, and then the fuel is sprayed into the combustion chamber of the gas turbine 6 through the on-duty burner 4 and the ignition is started. The hot air generated by the combustion of the fuel in the combustion chamber enters the premixed burner 2. Under the adsorption force generated by the hot air flow and the blowing and scraping effect of the hot air, the impurities attached to the premixed fuel channel of the premixed burner 2 fall off and flow with the hot air, and the impurities will eventually be blown out to the outside world. In this way, the impurities on the premixed fuel channel of the premixed burner 2 can be cleaned without removing the burner from the gas turbine, which saves a lot of manpower and material resources and avoids affecting the power generation hours of the power plant.

[0041] Preferably, the premix fuel main pipe 1 and the premix burner 2 are connected via a premix fuel hose 7. In the above step 1, the premix fuel main pipe 1 and the premix fuel hose 7 are separated so that the premix fuel channel of the premix burner 2 is connected to the outside through the premix fuel hose 7. Specifically, one end of the premix fuel hose 7 connected to the premix fuel main pipe 1 is separated from the premix fuel main pipe 1 to form a free end, and the other end of the premix fuel hose 7 is connected to the premix fuel channel of the premix burner 2. When the hot air in the combustion chamber is blown out from the premix fuel channel of the premix burner 2, it will enter the premix fuel hose 7 from the premix fuel channel of the premix burner 2, and finally be blown out to the outside from the free end of the premix fuel hose 7. When performing the cleaning operation, the free end of the premix fuel hose 7 can be moved to a specified position to facilitate the collection of impurities blown out by the hot air.

[0042] Preferably, in the above step 3, the outlet pressure of the compressor is continuously increased, and after the outlet pressure of the compressor reaches a preset pressure value and is maintained for a preset time, the duty fuel valve 5 is closed. Specifically, when the gas turbine 6 is working, when the outlet pressure of the compressor reaches a preset pressure value, the gas turbine 6 is kept working for a preset time at the preset pressure value, and at this time, the gas turbine 6 operates stably, so that the hot air generated in the combustion chamber is stably and continuously blown out from the premixed fuel channel of the premixed burner 2 to the outside, thereby achieving effective cleaning of impurities attached to the premixed fuel channel of the premixed burner 2. Among them, the preset pressure value of the compressor outlet is set according to the accumulation of impurities inside the premixed burner 2. The more serious the accumulation of impurities inside the premixed burner 2, the higher the preset pressure value is set, thereby increasing the airflow velocity and pressure of the hot air blown into the premixed fuel channel of the premixed burner 2, so that the cleaning effect is better; when the accumulation of impurities inside the premixed burner 2 is not serious, the preset pressure value is set accordingly low, thereby saving fuel, avoiding excessively high temperature and pressure of the hot air blown from the premixed burner 2 to the outside, and reducing the risk of cleaning operations. The preset time should not be too short to result in incomplete cleaning of impurities, and the preset time should not be too long to result in fuel waste and unnecessary operating costs. Preferably, the preset time is 2 minutes to 3 minutes.

[0043] Preferably, the above steps 2 and 3 are repeated until all the impurities in the premixed fuel channel of the premixed burner 2 are blown out. Specifically, after the first cleaning operation is completed according to the above steps 1 to 3, the gas turbine 6 is shut down, and one end of the premixed fuel hose 7 is kept as a free end and the other end is connected to the premixed fuel channel of the premixed burner 2, and then the cleaning operation is performed again according to the above steps 2 and 3. If there are still impurities blown out from the free end of the premixed fuel hose 7, the above steps 2 and 3 are repeated again after the current cleaning operation is completed, until no impurities are blown out from the free end of the premixed fuel hose 7 in the subsequent repeated cleaning operation, and the cleaning work is completed. By repeating the cleaning operation multiple times, the cleaning effect of hot air on the impurities attached to the premixed fuel channel of the premixed burner 2 can be guaranteed, and the degree of impurity cleaning can be effectively improved.

[0044] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for cleaning a gas turbine burner, characterized in that: The following steps are included in sequence: Step 1: separate the premixed fuel main pipe (1) and the premixed burner (2), so that the interior of the premixed burner (2) is connected to the outside through the premixed fuel channel of the premixed burner (2); Step 2: Open the duty fuel valve (5), so that the duty fuel main pipe (3) is opened and fuel is delivered to the duty burner (4); the fuel enters the combustion chamber through the duty fuel passage of the duty burner (4) and is mixed with the high-pressure air delivered into the combustion chamber by the compressor and burns to generate hot air; Step three: the hot air enters the interior of the premix burner (2) from the combustion chamber and is blown out to the outside from the premix fuel channel of the premix burner (2).

2. The method for cleaning a gas turbine combustor according to claim 1, characterized in that: The premix fuel main pipe (1) and the premix burner (2) are connected via a premix fuel hose (7). In step 1, the premix fuel main pipe (1) and the premix fuel hose (7) are separated so that the premix fuel channel of the premix burner (2) is connected to the outside through the premix fuel hose (7).

3. The method for cleaning a gas turbine combustor according to claim 1, characterized in that: In step three, the outlet pressure of the compressor is continuously increased. After the outlet pressure of the compressor reaches a preset pressure value and is maintained for a preset time, the duty fuel valve (5) is closed to close the duty fuel main pipe (3).

4. The method for cleaning a gas turbine combustor according to claim 3, characterized in that: The preset time is 2 minutes to 3 minutes.

5. The method for cleaning a gas turbine combustor according to claim 3, characterized in that: Repeat step 2 and step 3 until all impurities in the premixing fuel channel of the premixing burner (2) are blown out.

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