Cleaning and blowing system and method and dual-fuel gas turbine

Abstract

The invention discloses a purging system and method and a dual-fuel gas turbine, the system comprises: a first purging pipeline, one end of the first purging pipeline is used for communicating with a gas fuel header pipe, and the other end of the first purging pipeline is used for communicating with a liquid fuel header pipe; the first purging pipeline is used for guiding gas fuel in the gas fuel header pipe into the liquid fuel header pipe so as to purge the liquid fuel header pipe; and one end of the second purging pipeline is used for being connected with the gas compressor, the other end of the second purging pipeline is used for being communicated with the gas fuel header pipe, and the second purging pipeline is used for guiding compressed gas in the gas compressor into the gas fuel header pipe so as to purge the gas fuel header pipe. The first purging pipeline is communicated with the gas fuel header pipe, compared with the prior art in which instrument gas serves as a purging gas source of the liquid fuel header pipe, the storage amount of the gas fuel is much larger than that of the instrument gas source, and purging can be stably conducted on the liquid fuel pipeline for a long time.

Description

Technical Field

[0001] The present application relates to the field of gas turbines, and in particular to a purge system, method and dual-fuel gas turbine. Background Art

[0002] Dual-fuel gas turbines involve the combustion of two fuels, liquid and gas, respectively. In the fuel state, the gas circuit is dormant, and the equivalent area of ​​the gas circuit nozzle is large, which can easily cause liquid fuel to flow back into the gas circuit; in the gas state, the oil circuit is dormant. Although the equivalent area of ​​the oil circuit nozzle is small, the residual liquid fuel that remains is easily coked and blocked by carbon deposits due to the nozzle being in the high temperature area for a long time. Therefore, the purge system is essential for dual-fuel gas turbines.

[0003] Currently, gas turbines on the market mainly use the instrument air source cleaning method. However, under normal circumstances, the storage capacity of the instrument air of the gas turbine is relatively small, and long-term, stable operation cannot be achieved. If a larger volume container is replaced to hold the instrument air, additional equipment is required, and when using instrument air, an additional air compressor is also required to drive it. Summary of the invention

[0004] The present application proposes a purge system, method and dual-fuel gas turbine, aiming to solve the problem that the current purge system using instrument gas as the purge gas source cannot achieve long-term and stable operation.

[0005] In an embodiment of the present application, a purge system is proposed, which is applied to a dual-fuel gas turbine, and is characterized in that the purge system comprises:

[0006] a first purge pipeline, one end of which is used to be connected to a gas fuel main pipe of a dual-fuel gas turbine, and the other end of which is used to be connected to a liquid fuel main pipe of the dual-fuel gas turbine; the first purge pipeline is used to introduce the gas fuel in the gas fuel main pipe into the liquid fuel main pipe to purge the liquid fuel main pipe;

[0007] A second purge pipe, one end of which is used to connect to the compressor of the dual-fuel gas turbine, and the other end of which is used to connect to the gas fuel main pipe. The second purge pipe is used to introduce the compressed gas in the compressor into the gas fuel main pipe to purge the gas fuel main pipe.

[0008] In the embodiment of the present application, the first purge pipe is provided with: a first stop valve, a regulating valve, and a one-way valve in sequence from the end connected to the gas fuel main pipe to the end connected to the liquid fuel main pipe;

[0009] The first stop valve is used to close or open the gas fuel main pipe to introduce gas fuel into the first purge pipeline;

[0010] The regulating valve is used to adjust the pressure of the gas fuel introduced by the first purge pipeline to the liquid fuel main pipe;

[0011] The conducting direction of the one-way valve is from the first purge pipe to the liquid fuel main pipe.

[0012] In the embodiment of the present application, a first pressure gauge is provided between the first stop valve and the regulating valve, and the first pressure gauge is used to detect the pressure of the gas fuel introduced by the gas fuel main pipe to the first purge pipeline;

[0013] A second pressure gauge is further provided between the regulating valve and the one-way valve, and the second pressure gauge is used to detect the pressure of the gas fuel in the first purge pipeline after being regulated by the regulating valve.

[0014] In the embodiment of the present application, the purge system further includes a first branch pipeline, one end of which is connected to the first purge pipeline between the one-way valve and the second pressure gauge, and the other end of which is connected to the atmosphere;

[0015] The first branch pipeline is provided with a relief valve.

[0016] In the embodiment of the present application, the first branch pipeline is further provided with an air source interface between the relief valve and the first purge pipeline, and the air source interface is used to connect a backup air source.

[0017] In the embodiment of the present application, a second stop valve is provided at one end of the second purge pipeline close to the compressor, and a third stop valve is provided at one end of the second purge pipeline close to the gas fuel main pipe.

[0018] In the embodiment of the present application, the purge system further includes a second branch pipeline, one end of which is connected to the second purge pipeline between the second stop valve and the third stop valve, and the other end of which is connected to the atmosphere;

[0019] The second branch pipeline is provided with an exhaust orifice plate.

[0020] In the embodiment of the present application, a third pressure gauge is further provided on the second branch pipeline, and the third pressure gauge is arranged between the end of the second branch pipeline connected to the second purge pipeline and the exhaust orifice plate.

[0021] The present application also proposes a dual-fuel gas turbine, comprising any of the above-mentioned purge systems.

[0022] The present application also proposes a cleaning method, which is applied to the cleaning system described in the above embodiment, and the cleaning method comprises:

[0023] After the dual-fuel gas turbine is switched from gas fuel to liquid fuel, the gas fuel main pipe of the dual-fuel gas turbine is continuously purged based on the second purging pipeline;

[0024] After the dual-fuel gas turbine is switched from liquid fuel to gas fuel, the liquid fuel main pipe of the dual-fuel gas turbine is continuously purged based on the first purge pipeline.

[0025] In an embodiment of the present application, the continuous cleaning of the gas fuel main pipe of the dual-fuel gas turbine based on the second cleaning pipeline includes:

[0026] Opening the second stop valve and the third stop valve, and continuously purging the gas fuel main pipe of the dual-fuel gas turbine based on the second purge pipeline;

[0027] Close the first stop valve.

[0028] In an embodiment of the present application, the continuous cleaning of the liquid fuel main pipe of the dual-fuel gas turbine based on the first cleaning pipeline includes:

[0029] Open the first stop valve, and adjust the opening of the regulating valve based on the detection value of the second pressure gauge, so that the difference between the detection value of the second pressure gauge and the pressure value of the combustion chamber of the dual-fuel gas turbine is always within a preset range, so as to continuously purge the liquid fuel main pipe of the dual-fuel gas turbine based on the first purge pipeline;

[0030] Close the second stop valve and the third stop valve.

[0031] In the embodiment of the present application, a first purge pipeline is provided, and one end of the first purge pipeline is connected to the gas fuel main pipe, and the other end is connected to the liquid fuel main pipe, and the gas fuel source is used as the purge gas source for the liquid fuel main pipe. Compared with the prior art that uses instrument gas as the purge gas source for the liquid fuel main pipe, the reserve of gas fuel in the dual-fuel gas turbine is much larger than the reserve of instrument gas source. Therefore, the liquid fuel pipeline can be purged for a long time and stably; in addition, the gas fuel source of the dual-fuel gas turbine itself has a relatively high pressure, so no other auxiliary equipment is required. Driven by the pressure of the gas fuel source itself, the gas fuel can be transported from the first purge pipeline into the liquid fuel main pipe and purged, so no other complex auxiliary equipment is required; in addition, a second purge pipeline is provided, and the gas fuel main pipe can also be purged using a compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0033] Figure 1 Schematic diagram of the structure of the cleaning and blowing system in one embodiment of the present application.

[0034] Figure numerals: 100-first purge pipeline, 110-first stop valve, 120-first pressure gauge, 130-regulating valve, 140-second pressure gauge, 150-check valve, 160-first branch pipeline, 170-gas source interface, 180-release valve, 200-second purge pipeline, 210-second stop valve, 220-third stop valve, 230-second branch pipeline, 240-third pressure gauge, 250-emptying orifice plate, 300-liquid fuel main pipe, 400-gas fuel main pipe, 500-compressor.

[0035] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0039] When a dual-fuel gas turbine is operated based on a single fuel, for example, in the gas state, only gas fuel is burned without liquid fuel, and in the oil state, only liquid fuel is burned without gas fuel. Both the liquid fuel nozzle and the gas fuel nozzle are located in the head area of ​​the combustion chamber flame tube. After long-term operation or multiple switching of the fuel working mode, the residual fuel in the nozzle accumulates in the nozzle head and is heated to produce carbon deposits. The accumulated carbon deposits may also block the nozzle. In addition, after the fuel nozzle is coked and carbonized, it may also cause increased emissions of nitrogen oxides (NOx), carbon monoxide (CO) or unburned hydrocarbons (UHC), uneven distribution of the combustion temperature field, difficulty in starting, and combustion chamber noise or unstable combustion. In addition, the residual fuel is very likely to be ignited and burned. For example, when burning liquid fuel, the crosstalk between the liquid fuel nozzle and the gas fuel nozzle will cause the unburned liquid fuel to enter the non-working gas fuel pipeline. At the same time, the high-temperature gas fuel will flow upstream from the gas fuel nozzle and even reach the fuel branch pipe and main pipe. Therefore, it is essential to purge the non-operating fuel main pipe in a dual-fuel gas turbine.

[0040] like Figure 1 As shown, the present application proposes a purge system, which is applied to a dual-fuel gas turbine. In the embodiment of the present application, the purge system includes: a first purge pipeline 100, one end of the first purge pipeline 100 is used to connect to a gas fuel main pipe 400 of the dual-fuel gas turbine, and the other end of the first purge pipeline 100 is used to connect to a liquid fuel main pipe 300 of the dual-fuel gas turbine; the first purge pipeline 100 is used to introduce the gas fuel in the gas fuel main pipe 400 into the liquid fuel main pipe 300 to purge the liquid fuel main pipe 300;

[0041] A second purge pipe 200, one end of the second purge pipe 200 is used to connect to the compressor 500 of the dual-fuel gas turbine, and the other end of the second purge pipe 200 is used to connect to the gas fuel main pipe 400 of the dual-fuel gas turbine. The second purge pipe 200 is used to introduce the compressed gas in the compressor 500 into the gas fuel main pipe 400 to purge the gas fuel main pipe 400.

[0042] Among them, one end of the gas fuel main pipe 400 is connected to the gas fuel source, and the other end is provided with a gas fuel nozzle. The gas fuel provided by the gas fuel source passes through the gas fuel main pipe 400, and is finally ejected from the gas fuel nozzle and burns in the combustion chamber of the dual-fuel gas turbine; one end of the liquid fuel main pipe 300 is connected to the liquid fuel source, and the other end is provided with a liquid fuel nozzle. The fuel provided by the liquid fuel source passes through the liquid fuel main pipe 300, and is finally ejected from the liquid fuel nozzle and burns in the combustion chamber of the dual-fuel gas turbine.

[0043] like Figure 1 As shown, when the purge system is installed on a dual-fuel gas turbine, one end of the first purge pipe 100 is connected to the liquid fuel main pipe 300, and the other end is connected to the gas fuel main pipe 400. Then, the gas fuel provided by the gas fuel source can enter the liquid fuel main pipe 300 through the first purge pipe 100, and be ejected from the liquid nozzle of the liquid fuel main pipe 300, thereby achieving the purpose of purge the liquid fuel main pipe 300, i.e., the liquid fuel nozzle. That is, the embodiment of the present application can use the gas fuel in the gas fuel source as the purge gas source for the liquid fuel main pipe 300.

[0044] Continue to refer to Figure 1 When the purge system is installed on a dual-fuel gas turbine, one end of the second purge pipe 200 is connected to the compressor 500, and the other end is connected to the gas fuel main pipe 400. When the compressor 500 is running, it compresses the air and introduces it into the gas fuel main pipe 400, and finally sprays it out from the gas fuel nozzle of the gas fuel main pipe 400, thereby achieving the purpose of purge the gas fuel main pipe 400 and the gas fuel nozzle.

[0045] In the embodiment of the present application, a first purge pipe 100 is provided, and one end of the first purge pipe 100 is connected to the gas fuel main pipe 400, and the other end is connected to the liquid fuel main pipe 300, and the gas fuel source is used as the purge gas source of the liquid fuel main pipe 300. Compared with the prior art that uses instrument gas as the purge gas source of the liquid fuel main pipe 300, the reserve of gas fuel in the dual-fuel gas turbine is much larger than the reserve of the instrument gas source. Therefore, the liquid fuel pipeline can be purged for a long time and stably. In addition, the gas fuel source of the dual-fuel gas turbine itself has a relatively high pressure, so there is no need for other auxiliary equipment. Driven by the pressure of the gas fuel source itself, the gas fuel can be transported from the first purge pipe 100 into the liquid fuel main pipe 300 and purged. Therefore, there is no need for other complex auxiliary equipment, and the overall structure is relatively simple.

[0046] Next, refer to Figure 1 The working principle of the cleaning and blowing system in the embodiment of the present application is explained in detail.

[0047] In the embodiment of the present application, the first purge pipe 100 is provided with: a first stop valve 110, a regulating valve 130, and a one-way valve 150 in sequence from the end connected to the gas fuel main pipe 400 to the end connected to the liquid fuel main pipe 300;

[0048] The first stop valve 110 is used to close or open the gas fuel main pipe 400 to introduce gas fuel into the first purge pipeline 100;

[0049] The regulating valve 130 is used to adjust the pressure of the gas fuel introduced from the first purge pipeline 100 to the liquid fuel main pipe 300;

[0050] The one-way valve 150 is connected in a direction from the first purge pipe 100 to the liquid fuel main pipe 300 .

[0051] Among them, the first stop valve 110 is arranged at one end of the first purge pipe 100 close to the gas fuel main pipe 400. When the first stop valve 110 is opened, the gas fuel main pipe 400 is connected with the first purge pipe 100, and the gas fuel can enter the first purge pipe 100 through the first stop valve 110. When the first stop valve 110 is closed, the gas fuel main pipe 400 is disconnected from the first purge pipe 100, and the gas fuel cannot enter the first purge pipe 100.

[0052] When the liquid fuel main pipe 300 is purged, the fuel source of the dual-fuel gas turbine is gas fuel, that is, the gas fuel nozzle in the gas fuel main pipe 400 continuously sprays gas fuel into the combustion chamber. When the gas fuel nozzle sprays high-speed and high-pressure gas fuel, negative pressure is easily formed at the liquid fuel nozzle near the gas fuel nozzle. Moreover, the liquid fuel nozzle and the gas fuel nozzle are both connected to the combustion chamber. When the fuel burns in the combustion chamber, the pressure of the combustion chamber will also change. When the pressure of the combustion chamber is relatively high, even if the liquid fuel main pipe 300 is purged, the purged gas may not be able to be ejected from the liquid fuel nozzle, or even reach the liquid fuel nozzle. Therefore, it is necessary to adjust the air pressure of the purging gas in the first purging pipeline 100 in real time to ensure that it can be continuously ejected from the liquid fuel nozzle.

[0053] like Figure 1 As shown, in the direction from one end of the first purge pipe 100 connected to the gas fuel main pipe 400 to the one end of the first purge pipe 100 connected to the liquid fuel main pipe 300, the regulating valve 130 is arranged after the first stop valve 110. When the liquid fuel main pipe 300 is purged, the gas fuel first passes through the first stop valve 110 after entering the first purge pipe 100 from the gas fuel main pipe 400. Then, the regulating valve 130 is arranged after the first stop valve 110 to adjust the gas pressure of the gas fuel passing through the first stop valve 110, so that the gas fuel in the first purge pipe 100 has a suitable gas pressure to ensure that it can be smoothly ejected from the liquid fuel nozzle of the liquid fuel main pipe 300, thereby continuously purging the liquid fuel main pipe 300 and the liquid fuel nozzle.

[0054] Continue to refer to Figure 1 In the embodiment of the present application, in order to facilitate the real-time adjustment of the gas pressure in the first purge pipe 100, a first pressure gauge 120 and a second pressure gauge 140 are respectively arranged before and after the regulating valve 130 in the direction from the end of the first purge pipe 100 connected to the gas fuel main pipe 400 to the end of the first purge pipe 100 connected to the liquid fuel main pipe 300. The first pressure gauge 120 can detect the pressure of the gas fuel after passing through the first stop valve 110, that is, the pressure value before adjustment. After the gas fuel passes through the regulating valve 130 to adjust the pressure, it passes through the second pressure gauge 140, and the second pressure gauge 140 can detect the pressure value after adjustment. During adjustment, according to the pressure value and target value of the first pressure gauge 120, the direction and size of the adjustment of the regulating valve 130 can be determined, such as whether the pressure needs to be increased or reduced; and according to the detection value of the second pressure gauge 140, it can be determined whether the pressure value after adjustment by the regulating valve 130 meets the requirements. If not, the regulating valve 130 can be further adjusted until the pressure value of the second pressure gauge 140 is the same as the target value, or the difference with the target value is within a preset range.

[0055] In addition, in the embodiment of the present application, when adjusting the pressure value of the first purge pipe 100, the adjustment can be made based on the real-time pressure of the combustion chamber of the dual-fuel gas turbine. For example, the pressure value of the combustion chamber is monitored in real time, and the difference between the pressure value of the second pressure gauge 140 and the pressure value of the combustion chamber is maintained between 20-50Kpa, so as to ensure that the purge gas in the first purge pipe 100 can always be ejected from the liquid fuel nozzle of the liquid fuel main pipe 300.

[0056] Continue to refer to Figure 1 In the embodiment of the present application, a one-way valve 150 is provided at one end of the first purge pipe 100 close to the liquid fuel main pipe 300. The conducting direction of the one-way valve 150 is from the first purge pipe 100 to the liquid fuel main pipe 300, that is, the purge gas used for purge the liquid fuel main pipe 300 can enter the liquid fuel main pipe 300 from the first purge pipe 100 through the one-way valve 150, while the gas fuel at the liquid fuel nozzle of the liquid fuel main pipe 300 cannot pass through the one-way valve 150 after entering the first purge pipe 100 from the liquid fuel main pipe 300, thereby preventing the gas fuel at the liquid fuel nozzle from flowing back into the first purge pipe 100.

[0057] Continue to refer to Figure 1 In an embodiment of the present application, the cleaning system also includes a first branch pipe 160, one end of which is connected to the first cleaning pipe 100 between the one-way valve 150 and the second pressure gauge 140, and the other end is connected to the atmosphere; a relief valve 180 is provided on the first branch pipe 160.

[0058] like Figure 1 As shown, when the dual-fuel gas turbine is in the fuel state or shut down, there is no need to purge the liquid fuel main pipe 300, and the first purge pipeline 100 is not working. However, there may still be residual gas fuel in the first purge pipeline 100 from the purge. At this time, the gas fuel remaining in the first purge pipeline 100 can be released into the atmosphere through the release valve 180 on the first branch pipeline 160, thereby preventing the gas fuel from staying in the first purge pipeline 100 for a long time and avoiding safety hazards.

[0059] Continue to refer to Figure 1In the embodiment of the present application, the first branch pipeline 160 is further provided with an air source interface 170 between the relief valve 180 and the first cleaning and blowing pipeline 100, and the air source interface 170 is used to connect a backup air source. The air source interface 170 is provided on the first branch pipeline 160. After the backup air source is connected, the cleaning and blowing gas provided by the backup air source can enter the first branch pipeline 160 through the air source interface 170, and then enter the first cleaning and blowing pipeline 100, and finally flow into the liquid fuel main pipe 300 after passing through the first cleaning and blowing pipeline 100. Therefore, when the gas fuel main pipe 400 cannot provide cleaning and blowing gas, the air source interface 170 can be used to connect the backup cleaning and blowing gas source, and the liquid fuel main pipe 300 can also be cleaned and blown.

[0060] like Figure 1 As shown, in the embodiment of the present application, a second stop valve 210 is provided at one end of the second purge pipeline 200 close to the compressor 500, and a third stop valve 220 is provided at one end of the second purge pipeline 200 close to the gas fuel main pipe 400. When the second stop valve 210 is opened, the compressed air in the compressor 500 can enter the second purge pipeline 200 through the second stop valve 210, and when the second stop valve 210 is closed, the compressed air in the compressor 500 cannot enter the second purge pipeline 200. When the third stop valve 220 is opened, the purge gas in the second purge pipeline 200 can enter the gas fuel main pipe 400 through the third stop valve 220, and when the third stop valve 220 is closed, the purge gas in the second purge pipeline 200 cannot enter the gas fuel main pipe 400, and similarly, the gas fuel in the gas fuel main pipe 400 cannot enter the second purge pipeline 200 through the third stop valve 220. In addition, the gas introduced into the second purge pipe 200 by the compressor 500 is high-temperature and high-pressure gas. In order to ensure that the second stop valve 210 and the third stop valve 220 can work stably for a long time, the second stop valve 210 and the third stop valve 220 can use high-temperature quick-break valves.

[0061] Continue to refer to Figure 1 In an embodiment of the present application, the cleaning system also includes a second branch pipe 230, one end of the second branch pipe 230 is connected to the second cleaning pipe 200 between the second stop valve 210 and the third stop valve 220, and the other end is connected to the atmosphere; an exhaust orifice plate 250 is provided on the second branch pipe 230.

[0062] Among them, when the gas turbine is shut down, or the fuel source of the gas turbine is gas fuel, there is no need to purge the gas fuel main pipe 400 through the second purge pipe 200, and the second stop valve 210 and the third stop valve 220 are both in a closed state. However, there may still be residual purge gas in the space between the second stop valve 210 and the third stop valve 220. A second branch pipe 230 is arranged between the second stop valve 210 and the third stop valve 220, and an emptying orifice plate 250 is arranged on the second branch pipe 230. The emptying orifice plate 250 is normally open, so the purge gas in the pipe space between the second stop valve 210 and the third stop valve 220 can be discharged into the atmosphere through the second branch pipe 230 via the emptying orifice plate 250, thereby In addition, in the gas state, if the third stop valve 220 fails, the gas fuel in the gas fuel main pipe 400 will enter the second cleaning pipe 200 through the third stop valve 220, and when the gas fuel enters the second cleaning pipe 200 through the third stop valve 220, since the emptying orifice 250 is normally open, it can be directly discharged from the emptying orifice 250 of the second branch pipe 230 to the atmosphere, avoiding the existence of safety hazards, and the setting of the normally open emptying orifice 250 can ensure that the second branch pipe 230 has a stable and constant connection state with the atmosphere, avoiding the safety hazard caused by the failure of the valve equipment in the dangerous state when other valve equipment is selected. In contrast, in the fuel oil state, the gas fuel main pipe 400 is closed, and the gas fuel will not enter the first cleaning pipe 100, so the first branch pipe 160 does not need to be always connected with the atmosphere, so the first branch pipe 160 can be selected with a conventional valve equipment with a release function.

[0063] Continue to refer to Figure 1In the embodiment of the present application, a third pressure gauge 240 is further provided on the second branch pipeline 230, and the third pressure gauge 240 is provided between the end where the second branch pipeline 230 is connected to the second purge pipeline 200 and the drain orifice plate 250. When the second stop valve 210 and the third stop valve 220 are both closed, the gas in the second branch pipeline 230 is basically in a stable state, and the pressure is basically consistent with the atmospheric pressure. When either the second stop valve 210 or the third stop valve 220 fails and leaks, the compressed air in the compressor 500 or the gas fuel in the gas fuel main pipe 400 will enter the second branch pipeline 230, and the gas pressure in the second branch pipeline 230 will increase. Therefore, a second pressure gauge 140 is provided on the second branch pipeline 230 to detect the air pressure in the second branch pipeline 230 in real time. When the detection value of the second pressure gauge 140 is higher than a preset value such as atmospheric pressure, it can be determined that at least one of the second stop valve 210 and the third stop valve 220 has a gas leakage fault. By providing the second pressure gauge 140 on the second branch pipeline 230, it can be used to monitor whether the second stop valve 210 and the third stop valve 220 have a gas leakage fault, so that the fault can be discovered in time to avoid potential safety hazards.

[0064] The present application sets up a second cleaning pipeline 200, and uses the compressed air of the compressor 500 as the air source, so as to perform long-term and stable cleaning of the gas fuel main pipe 400; by setting up a first cleaning pipeline 100 and connecting it to the gas fuel main pipe 400, and using the gas fuel as the cleaning air source for the liquid fuel main pipe 300, long-term and stable cleaning can also be achieved.

[0065] The present application also proposes a dual-fuel gas turbine, including the purge system described in any of the above embodiments, and thus has all the beneficial effects of the purge system described in the above embodiments, which will not be described in detail here.

[0066] The purge system and the dual-fuel gas turbine in the exemplary embodiment of the present application are described in detail above. Next, the purge method in the exemplary embodiment is described.

[0067] In the embodiment of the present application, the purge method includes: after the dual-fuel gas turbine switches from gas fuel to liquid fuel, continuously purge the gas fuel main pipe 400 of the dual-fuel gas turbine based on the second purge pipeline 200;

[0068] After the dual-fuel gas turbine switches from liquid fuel to gas fuel, the liquid fuel main pipe 300 of the dual-fuel gas turbine is continuously purged based on the first purge pipeline 100 .

[0069] Among them, the working process of the dual-fuel gas turbine generally includes the following stages: starting, slow running, fuel state, gas state and shutdown.

[0070] Before starting, the dual-fuel gas turbine is in a shutdown state. At this time, the first purge pipe 100 and the second purge pipe are not in operation. Figure 1 As shown, the first stop valve 110 is closed, the relief valve 180 is opened, and the second stop valve 210 and the third stop valve 220 are closed.

[0071] In the stage from ignition start-up to slow running of the dual-fuel gas turbine, the first purge pipe 100 and the second purge pipe are still not working. Figure 1 As shown, the first stop valve 110 is closed, the relief valve 180 is opened, and the second stop valve 210 and the third stop valve 220 are closed.

[0072] Generally, when the dual-fuel gas turbine enters the slow mode, it is in the fuel state, that is, the liquid fuel main pipe 300 delivers liquid fuel to the combustion chamber, while the gas fuel main pipe 400 does not deliver gas fuel to the combustion chamber. Then, after the dual-fuel gas turbine enters the slow mode, the liquid fuel nozzle continues to spray liquid fuel into the combustion chamber. In order to prevent the liquid fuel sprayed by the liquid fuel nozzle from entering the gas fuel nozzle, it is necessary to continuously purge the gas fuel nozzle, that is, when the dual-fuel gas turbine enters the slow mode, open the second stop valve 210 and the third stop valve 220, so that the compressed air driven by the compressor 500 enters the gas fuel main pipe 400 from the second purge pipe 200, and continuously purge the gas fuel nozzle. In addition, in the fuel state, the first purge pipe 100 is always in a closed state, that is, the first stop valve 110 is still in a closed state.

[0073] After the dual-fuel gas turbine enters the slow-running state, the dual-fuel gas turbine can continue to be in the fuel state, that is, the liquid fuel is always transported to the combustion chamber by the liquid fuel main pipe 300. At this time, the second purge pipe 200 is kept to purge the gas fuel main pipe 400, and the first purge pipe 100 is kept closed.

[0074] Assume that the control system of the dual-fuel gas turbine issues a liquid fuel switching gas fuel instruction, that is, the dual-fuel gas turbine needs to switch the fuel from liquid fuel to gas fuel, that is, the gas fuel main pipe 400 provides gas fuel to the combustion chamber, and the liquid fuel main pipe 300 stops providing liquid fuel to the combustion chamber. When the switching is completed, the second stop valve 210 and the third stop valve 220 are closed, and the first stop valve 110 is opened at the same time, and the relief valve 180 is closed. Among them, the switching is completed, which means that the liquid fuel nozzle of the dual-fuel gas turbine has stopped spraying liquid fuel, and closing the second stop valve 210 and the third stop valve 220 means stopping the second purge pipeline 200 from purging the gas fuel main pipe 400, and opening the first stop valve 110 means opening the first purge pipeline 100 to purge the liquid fuel main pipe 300, so as to blow the liquid fuel remaining in the liquid fuel nozzle in the fuel state into the combustion chamber, so as to prevent the liquid fuel remaining on the liquid fuel nozzle from coking and carbonizing under high temperature environment. In addition, it should be noted that the cleaning method in the present application continues to clean and blow after the liquid fuel remaining in the liquid fuel nozzle is blown away, that is, the cleaning and blowing does not stop after the liquid fuel remaining in the liquid fuel nozzle is blown away, but as long as the dual-fuel gas turbine is still in the gas state, the liquid fuel main pipe 300 is still continuously cleaned and blown to prevent the gas fuel injected from the gas fuel nozzle from entering the liquid fuel main pipe 300.

[0075] In addition, when the dual-fuel gas turbine enters the gas state, when the liquid fuel main pipe 300 is purged based on the first purge pipeline 100, the opening of the regulating valve 130 is adjusted based on the first pressure gauge 120 and the second pressure gauge 140 and the target value, so that the difference between the detection value of the second pressure gauge 140 and the pressure value of the combustion chamber is always within the preset range, which is 20-50Kpa in the embodiment of the present application. Through this setting, it can be ensured that the purge gas in the first purge pipeline 100 can always be ejected from the liquid fuel nozzle.

[0076] After entering the gas state, the dual-fuel gas turbine can continue in the gas state or switch to the oil state. When the control system of the dual-fuel gas turbine issues a gas fuel to liquid fuel switch instruction, the dual-fuel gas turbine needs to switch the fuel from gas fuel to liquid fuel, that is, the gas fuel main pipe 400 stops supplying gas fuel to the combustion chamber, and the liquid fuel main pipe 300 starts supplying liquid fuel to the combustion chamber. When the switch is completed, that is, the gas fuel nozzle of the dual-fuel gas turbine has stopped spraying gas fuel to the combustion chamber, the first stop valve 110 is closed, the opening of the regulating valve 130 is adjusted to 0, and the diffuser valve 180 is opened at the same time. Among them, closing the first stop valve 110 means stopping the input of purge gas into the first purge pipeline 100, and the opening of the regulating valve 130 is adjusted to 0, that is, the regulating valve 130 is also in a closed state, and the diffuser valve 180 is opened to discharge the residual purge gas in the first purge pipeline 100 into the atmosphere. In addition, when the switch to the fuel state is completed, the second stop valve 210 and the third stop valve 220 are also opened, and the gas fuel main pipe 400 is continuously purged to prevent the liquid fuel injected from the liquid fuel nozzle from entering the gas fuel nozzle.

[0077] When the dual-fuel gas turbine is reduced from the fuel state to the slow speed, the second stop valve 210 and the third stop valve 220 are closed, that is, the second purge pipeline 200 is stopped from purging the gas fuel main pipe 400, and the residual purge gas in the second purge pipeline 200 can be discharged into the atmosphere based on the second branch pipeline 230.

[0078] In addition, when the dual-fuel gas turbine is reduced from the gas state to the slow state, the first stop valve 110 is closed, the opening value of the regulating valve 130 is adjusted to 0, and the diffuser valve 180 is opened at the same time.

[0079] The cleaning method in the present application can prevent the gas fuel injected from the gas fuel nozzle from entering the liquid fuel nozzle in the fuel gas state, and can prevent the liquid fuel injected from the liquid fuel nozzle from entering the gas fuel nozzle in the fuel oil state.

[0080] The above description is only an optional embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the inventive concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

[0081] Through the above description, this application proposes the following technical solutions, but is not limited to them:

[0082] 1. A purge system, applied to a dual-fuel gas turbine, comprising:

[0083] a first purge pipeline, one end of which is used to be connected to a gas fuel main pipe of a dual-fuel gas turbine, and the other end of which is used to be connected to a liquid fuel main pipe of the dual-fuel gas turbine; the first purge pipeline is used to introduce the gas fuel in the gas fuel main pipe into the liquid fuel main pipe to purge the liquid fuel main pipe;

[0084] A second purge pipe, one end of which is used to connect to the compressor of the dual-fuel gas turbine, and the other end of which is used to connect to the gas fuel main pipe. The second purge pipe is used to introduce the compressed gas in the compressor into the gas fuel main pipe to purge the gas fuel main pipe.

[0085] 2. As described in the purge system of technical solution 1, the first purge pipeline is provided with: a first stop valve, a regulating valve, and a one-way valve in sequence from the end connected to the gas fuel main pipe to the end connected to the liquid fuel main pipe;

[0086] The first stop valve is used to close or open the gas fuel main pipe to introduce gas fuel into the first purge pipeline;

[0087] The regulating valve is used to adjust the pressure of the gas fuel introduced by the first purge pipeline to the liquid fuel main pipe;

[0088] The conducting direction of the one-way valve is from the first purge pipe to the liquid fuel main pipe.

[0089] 3. In the purge system of technical solution 1 or 2, a first pressure gauge is provided between the first stop valve and the regulating valve, and the first pressure gauge is used to detect the pressure of the gas fuel introduced from the gas fuel main pipe to the first purge pipeline;

[0090] A second pressure gauge is further provided between the regulating valve and the one-way valve, and the second pressure gauge is used to detect the pressure of the gas fuel in the first purge pipeline after being regulated by the regulating valve.

[0091] 4. The purge system according to any one of technical solutions 1 to 3, further comprising a first branch pipeline, one end of which is connected to the first purge pipeline between the one-way valve and the second pressure gauge, and the other end of which is connected to the atmosphere;

[0092] The first branch pipeline is provided with a relief valve.

[0093] 5. In the cleaning and blowing system as described in any one of technical solutions 1 to 4, the first branch pipeline is also provided with an air source interface between the relief valve and the first cleaning and blowing pipeline, and the air source interface is used to connect a backup air source.

[0094] 6. In the purge system as described in any one of technical solutions 1-3, a second stop valve is provided at one end of the second purge pipeline close to the compressor, and a third stop valve is provided at one end of the second purge pipeline close to the gas fuel main pipe.

[0095] 7. The purge system according to any one of technical solutions 1 to 6, further comprising a second branch pipe, one end of which is connected to the second purge pipe between the second stop valve and the third stop valve, and the other end of which is connected to the atmosphere;

[0096] The second branch pipeline is provided with an exhaust orifice plate.

[0097] 8. In the cleaning and blowing system as described in any one of technical solutions 1 to 7, a third pressure gauge is also provided on the second branch pipe, and the third pressure gauge is arranged between the end of the second branch pipe connected to the second cleaning and blowing pipe and the exhaust orifice plate.

[0098] 9. A dual-fuel gas turbine, comprising a purge system as described in any one of technical solutions 1-8.

[0099] 10. A cleaning method, applied to the cleaning system according to technical solution 6, the cleaning method comprising:

[0100] After the dual-fuel gas turbine is switched from gas fuel to liquid fuel, the gas fuel main pipe of the dual-fuel gas turbine is continuously purged based on the second purging pipeline;

[0101] After the dual-fuel gas turbine is switched from liquid fuel to gas fuel, the liquid fuel main pipe of the dual-fuel gas turbine is continuously purged based on the first purge pipeline.

[0102] 11. According to the purge method of technical solution 10, the continuous purge of the gas fuel main pipe of the dual-fuel gas turbine based on the second purge pipeline comprises:

[0103] Opening the second stop valve and the third stop valve, and continuously purging the gas fuel main pipe of the dual-fuel gas turbine based on the second purge pipeline;

[0104] Close the first stop valve.

[0105] 12. The purge method according to technical solution 10 or 11, wherein the liquid fuel main pipe of the dual-fuel gas turbine is continuously purged based on the first purge pipeline, comprising:

[0106] Open the first stop valve, and adjust the opening of the regulating valve based on the detection value of the second pressure gauge, so that the difference between the detection value of the second pressure gauge and the pressure value of the combustion chamber of the dual-fuel gas turbine is always within a preset range, so as to continuously purge the liquid fuel main pipe of the dual-fuel gas turbine based on the first purge pipeline;

[0107] Close the second stop valve and the third stop valve.

Claims

1. A purge system, used in a dual-fuel gas turbine, characterized in that: The cleaning and blowing system comprises: a first purge pipeline, one end of which is used to be connected to a gas fuel main pipe of a dual-fuel gas turbine, and the other end of which is used to be connected to a liquid fuel main pipe of the dual-fuel gas turbine; the first purge pipeline is used to introduce the gas fuel in the gas fuel main pipe into the liquid fuel main pipe to purge the liquid fuel main pipe; A second purge pipe, one end of which is used to connect to the compressor of the dual-fuel gas turbine, and the other end of which is used to connect to the gas fuel main pipe. The second purge pipe is used to introduce the compressed gas in the compressor into the gas fuel main pipe to purge the gas fuel main pipe.

2. The cleaning and blowing system according to claim 1, characterized in that: The first purge pipe is provided with: a first stop valve, a regulating valve, and a one-way valve in sequence from one end connected to the gas fuel main pipe to the other end connected to the liquid fuel main pipe; The first stop valve is used to close or open the gas fuel main pipe to introduce gas fuel into the first purge pipeline; The regulating valve is used to adjust the pressure of the gas fuel introduced by the first purge pipeline to the liquid fuel main pipe; The conducting direction of the one-way valve is from the first purge pipe to the liquid fuel main pipe.

3. The cleaning and blowing system according to claim 2, characterized in that: A first pressure gauge is provided between the first stop valve and the regulating valve, and the first pressure gauge is used to detect the pressure of the gas fuel introduced from the gas fuel main pipe to the first purge pipeline; A second pressure gauge is further provided between the regulating valve and the one-way valve, and the second pressure gauge is used to detect the pressure of the gas fuel in the first purge pipeline after being regulated by the regulating valve.

4. The cleaning and blowing system according to claim 3, characterized in that: The purge system further comprises a first branch pipeline, one end of which is connected to the first purge pipeline between the one-way valve and the second pressure gauge, and the other end of which is connected to the atmosphere; The first branch pipeline is provided with a relief valve.

5. The cleaning and blowing system according to claim 4, characterized in that: The first branch pipeline is also provided with an air source interface between the relief valve and the first purge pipeline, and the air source interface is used to connect a backup air source.

6. The cleaning and blowing system according to claim 3, characterized in that: A second stop valve is provided at one end of the second purge pipeline close to the compressor, and a third stop valve is provided at one end of the second purge pipeline close to the gas fuel main pipe.

7. A dual-fuel gas turbine, characterized in that: The invention comprises a cleaning and blowing system as claimed in any one of claims 1 to 6.

8. A method for cleaning and blowing, applied to the cleaning and blowing system as claimed in claim 6, characterized in that: The blowing method comprises: After the dual-fuel gas turbine is switched from gas fuel to liquid fuel, the gas fuel main pipe of the dual-fuel gas turbine is continuously purged based on the second purging pipeline; After the dual-fuel gas turbine is switched from liquid fuel to gas fuel, the liquid fuel main pipe of the dual-fuel gas turbine is continuously purged based on the first purge pipeline.

9. The blowing method according to claim 8, characterized in that: The method of continuously cleaning the gas fuel main pipe of the dual-fuel gas turbine based on the second cleaning pipeline includes: Opening the second stop valve and the third stop valve, and continuously purging the gas fuel main pipe of the dual-fuel gas turbine based on the second purge pipeline; Close the first stop valve.

10. The blowing method according to claim 9, characterized in that: The method of continuously cleaning the liquid fuel main pipe of the dual-fuel gas turbine based on the first cleaning pipeline includes: Open the first stop valve, and adjust the opening of the regulating valve based on the detection value of the second pressure gauge, so that the difference between the detection value of the second pressure gauge and the pressure value of the combustion chamber of the dual-fuel gas turbine is always within a preset range, so as to continuously purge the liquid fuel main pipe of the dual-fuel gas turbine based on the first purge pipeline; Close the second stop valve and the third stop valve.

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