Gas turbine dual-fuel system and gas turbine with same

Abstract

The invention discloses a gas turbine dual-fuel system and a gas turbine with the same. The gas turbine dual-fuel system comprises a liquid fuel system, a gas fuel system, an air auxiliary system and a gas-liquid integrated nozzle. The liquid fuel system comprises a main liquid fuel pipeline, a liquid fuel blow-off pipeline, a first filtering assembly, a pumping assembly, a liquid fuel adjusting valve, an electromagnetic cut-off valve and an electromagnetic blow-off valve. The first filtering assembly, the pumping assembly, the liquid fuel adjusting valve and the electromagnetic cut-off valve are connected into the main liquid fuel pipeline. The air inlet end of the air auxiliary system is connected with an instrument air path in the box and the exhaust end of the compressor, and the air outlet end is connected with the gas-liquid integrated nozzle. The gas fuel system comprises a main gas fuel pipeline, a second filtering assembly, a gas fuel adjusting valve and a pneumatic switch valve set. The second filtering assembly, the gas fuel adjusting valve and the pneumatic switch valve set are connected into the main gas fuel pipeline. According to the system, on-line switching of the gas fuel and the liquid fuel can be carried out under the condition that the system is not stopped, and therefore the application range is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbines, and in particular, to a dual-fuel system for a gas turbine. In addition, the present invention also relates to a gas turbine including the above dual-fuel system for a gas turbine. Background Art

[0002] As a core power device in the energy and power industry, a gas turbine can be used in various applications such as power generation, driving, and on-vehicle emergency power supplies on the sea and on land. For different application scenarios, the types and sources of fuels are different. In some scenarios, only gaseous fuel is provided, in some scenarios, only liquid fuel can be used, and in some scenarios, both gaseous and liquid fuels exist. Therefore, to meet the above different application requirements, a dual-fuel system that can burn gaseous or liquid fuel needs to be designed.

[0003] Limited by the fuel source and the structure of the gas turbine itself, the application of dual-fuel systems on domestic gas turbines is not widespread at present. There is a dual-fuel system designed for burning two different gaseous fuels, but the nozzles used in this type of dual-fuel system are special gas nozzles and are not suitable for burning liquid fuel. There is also a dual-fuel system designed for burning gaseous and liquid fuels. Some of this type of dual-fuel systems are equipped with two sets of independent liquid nozzles and gas nozzles, and the corresponding nozzles need to be replaced according to the type of fuel during shutdown. This is not only complicated in operation but also cannot achieve online switching of gaseous (or liquid) fuel. Some are equipped with gas-liquid integrated nozzles that can achieve online switching of gaseous (or liquid) fuel. However, due to different design concepts, usage environments and scenarios, and the gas turbines they are equipped with for different projects, the configured dual-fuel systems will further vary in terms of process principle, function, layout, selection, control, etc.

[0004] The disadvantages of existing dual-fuel systems are as follows:

[0005] 1) Some existing dual-fuel systems are not suitable for burning liquid fuel, and some cannot achieve online switching of gaseous (or liquid) fuel;

[0006] 2) The process flow of existing dual-fuel systems is relatively complicated. Not only is atomizing air required for liquid fuel, but also purge air for liquid fuel and purge air for gaseous fuel are needed at the same time. On the one hand, the types of gas sources for atomizing and purging are diverse and the pipelines are complex; on the other hand, the pressures, temperatures, and hazards of each gas source are different, and an anti-backflow device needs to be added to each path. Since the pressure of the gaseous fuel branch is high, a throttling component also needs to be set to regulate the pressure and flow rate;

[0007] 3) The existing dual-fuel system has high process requirements and high energy consumption. Special external purge gas is used for purging the liquid fuel and gas fuel. The pressure requirement of the purge gas is basically the same as the gas fuel supply pressure, which is higher than the pressure of general industrial instrument air. An additional air pressurization system needs to be configured;

[0008] 4) The pipeline of the existing dual-fuel system is complex. A separate liquid fuel ignition pipeline, gas fuel ignition pipeline, and nozzle ring pipe system need to be configured. The nozzle ring pipe system includes a gas fuel annular main pipe, a liquid fuel annular main pipe, and an atomizing air annular main pipe;

[0009] 5) The existing dual-fuel system cannot simultaneously achieve online accurate measurement of the consumption of liquid fuel and gas fuel, and cannot calculate and obtain the actual operating conditions of the gas turbine;

[0010] 6) The liquid fuel process flow in the existing dual-fuel system is complex. The return oil of the liquid fuel regulating valve body and the overflow return oil of the main oil pump are both connected back to the diesel tank, and the diesel tank is often arranged in an independent area far from the unit. This not only results in too long pipeline laying, which is not conducive to the integration of the dual-fuel system, but also causes inaccurate measurement of the liquid fuel consumption measured by the flowmeter, which will be higher than the actual consumption of the gas turbine. Summary of the Invention

[0011] The present invention provides a gas turbine dual-fuel system and a gas turbine having the same, to solve the technical problems existing in the existing dual-fuel system, such as inability to perform online switching of dual fuels, complex process flow, multiple types of purge gas sources for atomization and purging, complex pipelines, high process requirements, high energy consumption, resulting in too long pipeline laying, not conducive to the integration of the dual-fuel system, and also causing inaccurate measurement of the liquid fuel consumption measured by the flowmeter, which will be higher than the actual consumption of the gas turbine.

[0012] The technical solution adopted by the present invention is as follows:

[0013] A gas turbine dual-fuel system, comprising: a liquid fuel system, a gas fuel system, an air assist system and a gas-liquid integrated nozzle; the gas-liquid integrated nozzle is integrally provided with a liquid fuel flow channel, an auxiliary air flow channel and a gas fuel flow channel, and the auxiliary air flow channel communicates with the liquid fuel flow channel; the liquid fuel system includes a main liquid fuel pipeline for transporting liquid fuel, a liquid fuel drain pipeline for purging and draining, a first filter assembly for filtering the liquid fuel, a pumping assembly for pumping the liquid fuel forward, a liquid fuel regulating valve for regulating the flow rate of the liquid fuel, an electromagnetic cut-off valve and an electromagnetic drain valve for controlling the on-off of the pipeline. The two ends of the main liquid fuel pipeline are respectively connected to the fuel supply tank and the liquid fuel flow channel of the gas-liquid integrated nozzle. The two ends of the liquid fuel drain pipeline are respectively connected to the oil outlet end of the main liquid fuel pipeline and the waste oil collection device. The first filter assembly, the pumping assembly, the liquid fuel regulating valve and the electromagnetic cut-off valve are respectively connected to the main liquid fuel pipeline, and the electromagnetic drain valve is connected to the liquid fuel drain pipeline; the air inlet end of the air assist system is respectively connected to the instrument air pipeline in the box and the exhaust end of the compressor. The air outlet end of the air assist system is connected to the auxiliary air flow channel of the gas-liquid integrated nozzle to supply air to the auxiliary air flow channel through the instrument air supplied by the instrument air pipeline in the box when the gas turbine starts, and to supply high-pressure air to the auxiliary air flow channel through the exhaust end of the compressor after the gas turbine turbine starts running, after the gas turbine shuts down, and after the liquid fuel supply is converted to gas fuel supply; the gas fuel system includes a main gas fuel pipeline for transporting gas fuel, a second filter assembly for filtering the gas fuel, a gas fuel regulating valve for regulating the flow rate of the gas fuel, and a pneumatic switch valve group for controlling the on-off of the pipeline. The two ends of the main gas fuel pipeline are respectively connected to the gas supply system and the gas fuel flow channel of the gas-liquid integrated nozzle. The second filter assembly, the gas fuel regulating valve and the pneumatic switch valve group are respectively connected to the main gas fuel pipeline.

[0014] Further, the first filter assembly includes a first filter, a second filter and a third filter sequentially arranged in the front and back along the liquid fuel transportation direction; the pumping assembly includes a transfer pump and an on-board booster pump sequentially arranged in the front and back along the liquid fuel transportation direction, and the transfer pump is located between the first filter and the second filter, and the on-board booster pump is located between the second filter and the third filter; the liquid fuel regulating valve is located downstream of the third filter, and the electromagnetic cut-off valve is located downstream of the liquid fuel regulating valve; the connection point of the oil inlet end of the liquid fuel drain pipeline and the main liquid fuel pipeline is located downstream of the electromagnetic cut-off valve.

[0015] Further, the liquid fuel system further includes a first oil return circuit and a second oil return circuit, and a first overflow valve connected to the first oil return circuit; the oil inlet end and the oil outlet end of the first oil return circuit are respectively connected to the oil outlet pipeline of the on-board booster pump and the oil inlet pipeline of the on-board booster pump; the oil inlet end and the oil outlet end of the second oil return circuit are respectively connected to the oil outlet end of the liquid fuel regulating valve and the oil inlet pipeline of the on-board booster pump.

[0016] Further, the liquid fuel system further includes a third fuel return line, a second overflow valve connected in the third fuel return line, a first pressure transmitter for measuring the fuel line pressure, and a turbine flowmeter for measuring the liquid fuel flow rate; the inlet end and the outlet end of the third fuel return line are respectively connected to the main liquid fuel line downstream of the transfer pump and the fuel supply tank; the first pressure transmitter is connected in the main liquid fuel line and is located between the transfer pump and the second filter; the turbine flowmeter is connected in the main liquid fuel line and is located between the connection point of the third fuel return line and the main liquid fuel line and the on-board booster pump.

[0017] Further, the liquid fuel system further includes a first check valve, a second check valve, and a third check valve sequentially arranged in the main liquid fuel line; the first check valve is located downstream of the transfer pump, the second check valve is located downstream of the on-board booster pump, and the third check valve is located downstream of the electromagnetic cut-off valve.

[0018] Further, the air assist system includes a compressor air supply line and an instrument air line for delivering air, a pneumatic shut-off valve and a first pneumatic cut-off valve for controlling the on / off of the pipeline; the inlet end and the outlet end of the compressor air supply line are respectively connected to the exhaust end of the compressor and the auxiliary air flow passage of the air-liquid integrated nozzle, and the pneumatic shut-off valve is connected in the compressor air supply line; the inlet end and the outlet end of the instrument air line are respectively connected to the in-tank instrument air line and the auxiliary air flow passage of the air-liquid integrated nozzle, and the first pneumatic cut-off valve is connected in the instrument air line.

[0019] Further, the air assist system further includes an air pressure reducing valve for adjusting the air pressure and a fourth check valve for controlling the air flow direction; the air pressure reducing valve and the fourth check valve are sequentially connected in the instrument air line, and the air pressure reducing valve is located upstream of the first pneumatic cut-off valve, and the fourth check valve is located downstream of the first pneumatic cut-off valve.

[0020] Further, the second filter assembly includes a fourth filter and a fifth filter sequentially arranged in the gas fuel delivery direction; the pneumatic switch valve group includes a second pneumatic cut-off valve, a first pneumatic quick cut-off valve, and a second pneumatic quick cut-off valve sequentially arranged in the gas fuel delivery direction, and the second pneumatic cut-off valve is located between the fourth filter and the fifth filter, and the first pneumatic quick cut-off valve and the second pneumatic quick cut-off valve are located between the fifth filter and the gas fuel regulating valve; the gas fuel system further includes a first manual valve and a second manual valve connected in the main gas fuel line and located on both sides of the fourth filter.

[0021] Furthermore, the gas fuel system further includes a mass flow meter for measuring gas flow rate, a first vent pipeline and a second vent pipeline for venting gas, a first pneumatic vent valve provided in the first vent pipeline, and a second pneumatic vent valve provided in the second vent pipeline; the mass flow meter is located between the second pneumatic cut-off valve and the first pneumatic quick cut-off valve; the connection point of the intake end of the first vent pipeline to the main gas fuel pipeline is located between the second pneumatic cut-off valve and the mass flow meter, and the outlet end of the first vent pipeline is connected to the atmosphere; the connection point of the intake end of the second vent pipeline to the main gas fuel pipeline is located between the first pneumatic quick cut-off valve and the second pneumatic cut-off valve, and the outlet end of the second vent pipeline is connected to the atmosphere.

[0022] According to another aspect of the present invention, there is also provided a gas turbine having a gas turbine dual fuel system as described in any one of the above.

[0023] The present invention has the following beneficial effects:

[0024] The gas turbine dual fuel system of the present invention can operate stably using only gas fuel or liquid fuel, and can also perform online switching between gas fuel and liquid fuel without shutting down the machine, thus having a wide application range; the process flow of the system of the present invention is simple and the energy consumption is low. An air-assisted system that combines two air sources, namely supplying instrument air through the instrument air pipeline inside the box or supplying compressed air from the exhaust end of the compressor, is used for atomizing and purging the liquid fuel. Moreover, the auxiliary air is not only safe and reliable itself, and except for using a small amount of external instrument air during the starting stage of the gas turbine, the rest uses the compressed air after the compressor. Under high operating conditions of the gas turbine, no additional auxiliary high-pressure boosting equipment and pressure regulating and throttling devices are required to atomize and purge the liquid fuel in a timely manner, making the system pipeline simple and the system equipment configuration simplified, thereby reducing the energy consumption of the gas turbine and improving the overall operation efficiency; the system pipeline configuration of the present invention is simple and the control logic is simple. There is no liquid fuel ignition pipeline, gas fuel ignition pipeline, gas fuel purging system, and nozzle ring pipe system for gas fuel, liquid fuel, and atomizing air. The gas fuel system, liquid fuel system, and air-assisted system all have only one main path directly connected to the gas-liquid integrated nozzle 9, which also simplifies the fuel process flow, does not cause the pipeline laying to be too long, and facilitates the integration of the dual fuel system. It also makes the liquid fuel consumption measured by the flow meter accurate, so that the actual operating conditions of the gas turbine can be accurately known; and the present invention has been manufactured, assembled, and tested, can meet the requirements of the dual fuel system for gas turbine testing, and the operation and switching also meet the requirements, and has been put into use;

[0025] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The present invention will be further described in detail below with reference to the drawings. Description of the Drawings

[0026] The accompanying drawings, which form a part of this application, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0027] Figure 1 is a schematic diagram of a gas turbine dual-fuel system according to a preferred embodiment of the present invention.

[0028] Legend:

[0029] 1. Third manual ball valve; 2. First filter; 3. Transfer pump; 4. First pressure transmitter; 5. First temperature sensor; 6. First check valve; 7. First differential pressure gauge; 8. Second filter; 9. Second overflow valve; 10. Fourth manual ball valve; 11. Turbine flowmeter;

[0030] 12. Fifth manual ball valve; 13. Sixth manual ball valve; 14. Second pressure transmitter; 15. Metal hose; 16. Onboard booster pump; 17. First overflow valve; 19. Second check valve; 20. Second differential pressure gauge; 21. Third filter;

[0031] 22. Third pressure transmitter; 23. Liquid fuel regulating valve; 24. Electromagnetic cut-off valve; 25. Third check valve; 26. Fourth pressure transmitter; 27. Electromagnetic blowdown valve; 29. Gas-liquid integrated nozzle;

[0032] 31. Pneumatic shut-off valve; 32. Air pressure reducing valve; 33. First pneumatic cut-off valve; 34. Fourth check valve; 35. First manual ball valve; 36. Third differential pressure gauge; 37. Fourth filter; 38. Second manual ball valve; 39. Second temperature sensor; 40. Second pneumatic cut-off valve; 41. First pneumatic vent valve; 42. Mass flowmeter; 43. Fifth filter; 44. Fifth pressure transmitter; 45. First pneumatic quick shut-off valve; 46. Second pneumatic quick shut-off valve; 47. Sixth pressure transmitter; 48. Gas fuel regulating valve; 49. Seventh pressure transmitter; 51. Second pneumatic vent valve;

[0033] 52. Fuel supply tank; 53. Waste oil collection device; 54. Instrument air pipeline inside the tank; 55. Compressor exhaust end; 56. Gas supply system. Detailed implementation manners

[0034] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the following.

[0035] Refer to Figure 1, a preferred embodiment of the present invention provides a gas turbine dual - fuel system, comprising: a liquid fuel system, a gas fuel system, an air - assisted system and a gas - liquid integrated nozzle 29. The gas - liquid integrated nozzle 29 is integrally provided with a liquid fuel flow channel, an auxiliary air flow channel and a gas fuel flow channel, and the auxiliary air flow channel communicates with the liquid fuel flow channel. The liquid fuel system includes a main liquid fuel pipeline for transporting liquid fuel, a liquid fuel drain pipeline for purging and draining, a first filtering component for filtering the liquid fuel, a pumping component for pumping the liquid fuel forward, a liquid fuel regulating valve 23 for regulating the flow rate of the liquid fuel, an electromagnetic cut - off valve 24 and an electromagnetic drain valve 27 for controlling the on - off of the pipeline. The two ends of the main liquid fuel pipeline are respectively connected to the fuel supply tank 52 and the liquid fuel flow channel of the gas - liquid integrated nozzle 29. The two ends of the liquid fuel drain pipeline are respectively connected to the oil outlet end of the main liquid fuel pipeline and the waste oil collection device 53. The first filtering component, the pumping component, the liquid fuel regulating valve 23 and the electromagnetic cut - off valve 24 are respectively connected to the main liquid fuel pipeline, and the electromagnetic drain valve 27 is connected to the liquid fuel drain pipeline. The air - assisted system has its air inlet end respectively connected to the instrument air pipeline 54 in the cabinet and the compressor exhaust end 55, and its air outlet end is connected to the auxiliary air flow channel of the gas - liquid integrated nozzle 29, so as to supply air to the auxiliary air flow channel through the instrument air supplied by the instrument air pipeline 54 when the gas turbine starts, and to supply high - pressure air to the auxiliary air flow channel through the compressor exhaust end 55 after the gas turbine turbine starts to operate, after the gas turbine shuts down, and after the liquid fuel supply is converted to the gas fuel supply. The gas fuel system includes a main gas fuel pipeline for transporting gas fuel, a second filtering component for filtering the gas fuel, a gas fuel regulating valve 48 for regulating the flow rate of the gas fuel, and a pneumatic switch valve group for controlling the on - off of the pipeline. The two ends of the main gas fuel pipeline are respectively connected to the gas supply system 56 and the gas fuel flow channel of the gas - liquid integrated nozzle 29. The second filtering component, the gas fuel regulating valve 48 and the pneumatic switch valve group are respectively connected to the main gas fuel pipeline.

[0036] When the dual - fuel system of the present invention operates with liquid fuel: the liquid fuel system is put into operation. The liquid fuel in the fuel supply tank 52 passes through multiple filtrations of the first filtering component and multiple - stage pumping of the pumping component under the action of the main liquid fuel pipeline, then enters the liquid fuel regulating valve 23 for flow rate regulation, and finally enters the liquid fuel flow channel of the gas - liquid integrated nozzle 29. At the same time, under the action of the air - assisted system, it is purged and atomized with compressed air and then enters the combustion chamber to participate in combustion. During this process, the electromagnetic drain valve 27 remains closed, the gas fuel system does not work, and the air - assisted system is put into operation.

[0037] The auxiliary atomizing air system of the dual - fuel system of the present invention includes three different operating states:

[0038] The first working state: When the gas turbine uses liquid fuel during the starting phase, the air-assisted system supplies air through the in-box instrument air passage 54 to atomize the liquid fuel;

[0039] The second working state: After the turbine of the gas turbine starts to operate, the air-assisted system supplies air through the compressor exhaust end 55 to atomize the liquid fuel;

[0040] The third working state: When the gas turbine shuts down or the system converts liquid fuel to gaseous fuel, the air-assisted system still supplies air through the compressor exhaust end 55. Meanwhile, the electromagnetic blowdown valve 27 is opened. The high-pressure air first enters the liquid fuel flow passage of the gas-liquid integrated nozzle 29 and flows reversely along the main liquid fuel pipeline to reversely blow and wash the main liquid fuel pipeline behind the electromagnetic cut-off valve 24, removing the residual fuel to avoid carbon deposition blockage.

[0041] When the dual-fuel system of the present invention operates using gaseous fuel: The gas supply system 56 is put into operation. The gaseous fuel is filtered and purified multiple times by the second filter assembly under the action of the main gas fuel pipeline and then enters the gas fuel regulating valve 48 for flow regulation, and finally is supplied to the gas fuel flow passage of the gas-liquid integrated nozzle 29. During this process, neither the liquid fuel system nor the air-assisted system is put into operation.

[0042] The process of the dual-fuel system of the present invention switching from gaseous fuel to liquid fuel under high operating conditions is as follows:

[0043] Before the start of the switch, the gaseous fuel system remains in the working state, that is, the gaseous fuel is supplied from the main gas fuel pipeline to the gas-liquid integrated nozzle 29 for combustion; the liquid fuel system and the air-assisted system do not work;

[0044] At the start of the switch, the liquid fuel system starts to work. The pumping assembly starts, the electromagnetic cut-off valve 24 is opened, and the liquid fuel regulating valve 23 is adjusted to the minimum valve opening. The liquid fuel finally enters the liquid fuel flow passage of the gas-liquid integrated nozzle 29 and simultaneously enters the combustion chamber to participate in combustion under the purging and atomizing assistance of the compressed air supplied by the air-assisted system. Meanwhile, to ensure that the power fluctuation of the gas turbine unit is within 5%, the opening of the gas fuel regulating valve 48 is reduced; as the fuel switching process progresses, the opening of the liquid fuel regulating valve 23 increases and the opening of the gas fuel regulating valve 48 decreases; when reaching the specified moment, the gas fuel regulating valve 48 is completely closed, and at the same time, the pneumatic switch valve group is also adjusted to the closed state;

[0045] After the switch ends, the liquid fuel system remains in the working state, the gaseous fuel system is in the closed state, and the pneumatic switch valve group remains closed.

[0046] The process of the dual-fuel system of the present invention switching from liquid fuel to gaseous fuel under high operating conditions is as follows:

[0047] Before the start of the switch, the liquid fuel system remains in operation, i.e., liquid fuel is supplied through the main liquid fuel pipeline to the liquid fuel flow channel of the gas-liquid integrated nozzle for injection, atomization, and combustion. The gas fuel system is in the closed state, and the air assistance system is in operation. Compressed air enters the auxiliary air flow channel of the gas-liquid integrated nozzle 29 and fully atomizes the liquid fuel through the holes communicating with the liquid fuel flow channel.

[0048] At the start of the switch, all the pneumatic switch valves in the main gas fuel pipeline are opened, and the gas fuel regulating valve 48 is opened to the minimum opening. After the gas fuel is supplied into the gas fuel flow channel of the gas-liquid integrated nozzle 29, it participates in combustion. At the same time, the opening of the liquid fuel regulating valve 23 is reduced to keep the power of the gas turbine unit stable within 5%. As the switching process progresses, when the opening of the gas fuel regulating valve 48 is adjusted and increased to the specified opening, the opening remains unchanged. At the same time, the opening of the liquid fuel regulating valve 23 continues to decrease until it is closed, and the gas fuel system is fully put into a stable working state to complete the dual-fuel switch. The air assistance system continues to remain in operation.

[0049] After the switch is completed, the liquid fuel system stops working, i.e., the pumping assembly, the liquid fuel regulating valve 23, and the electromagnetic cut-off valve 24 all remain in the closed state. The gas fuel system is in the open and stable operating state, and the air assistance system continues to remain in operation. The electromagnetic blowdown valve 27 is opened, and compressed air enters the liquid fuel flow channel of the gas-liquid integrated nozzle 29 and flows reversely along the main liquid fuel pipeline to reversely flush the main liquid fuel pipeline behind the electromagnetic cut-off valve 24 to remove the residual fuel and avoid carbon deposition blockage. The residual liquid after flushing is discharged outside the unit through the liquid fuel blowdown pipeline. After ensuring the safety of the unit, the electromagnetic blowdown valve 27 is adjusted to the closed state.

[0050] The dual-fuel system of the present invention can operate stably using either gaseous fuel or liquid fuel alone. Meanwhile, it can also perform on-line switching between gaseous fuel and liquid fuel without shutting down the machine, thus having a wide range of applications. The system process flow of the present invention is simple and has low energy consumption. It adopts an air-assisted system that combines two air sources, namely, supplying instrument air through the in-box instrument air duct 54 or supplying compressed air from the exhaust end 55 of the compressor, for atomizing and purging the liquid fuel. Moreover, the auxiliary air is not only safe and reliable itself, and except for using a small amount of external instrument air during the starting stage of the gas turbine, the rest uses the compressed air after the compressor. Under the high-condition operation of the gas turbine, without adding additional auxiliary high-pressure boosting equipment and pressure-regulating throttling devices, it can atomize and purge the liquid fuel in a timely manner, making the system pipeline simple and the system equipment configuration simplified, thereby reducing the energy consumption of the gas turbine and improving the overall operation efficiency. The system pipeline configuration of the present invention is simple and the control logic is simple. There is no liquid fuel ignition pipeline, gaseous fuel ignition pipeline, gaseous fuel purging system, and nozzle ring pipe system for gaseous fuel, liquid fuel, and atomizing air. The gaseous fuel system, liquid fuel system, and air-assisted system all have only one main path directly connected to the gas-liquid integrated nozzle 29, thus also making the fuel process flow simple, not causing the pipeline laying to be too long, facilitating the integration of the dual-fuel system, and making the liquid fuel consumption measured by the flowmeter accurate, so that the actual operation condition of the gas turbine can be accurately known. Moreover, the present invention has completed manufacturing, assembly, and testing, can meet the requirements of the dual-fuel system for gas turbine testing, the operation and switching also meet the requirements, and it has been put into use.

[0051] Optionally, the gas-liquid integrated nozzle 29 of the present invention integrates three annular channels, namely, a liquid fuel channel, a gaseous fuel channel, and an auxiliary air channel. The three annular channels are radially arranged, with the gaseous fuel channel on the outermost side, the auxiliary air channel in the middle, and the liquid fuel channel on the innermost side. And the auxiliary air channel is communicated with the liquid fuel channel, while the gaseous fuel channel is relatively independent and not communicated with the two. Due to the unique internal structure design of the gas-liquid integrated nozzle 29 of the present invention, there are three annular channels, namely, a liquid fuel channel, an auxiliary air channel, and a gaseous fuel channel, which are radially arranged and sequentially arranged outward. When the gaseous fuel channel and the auxiliary air channel are communicated, it can play a role in cooling the gas-liquid integrated nozzle 29. And only the liquid fuel channel and the auxiliary air channel are internally communicated, and the gaseous fuel channel is relatively closed, effectively avoiding the problem that the gaseous fuel flows back into the liquid fuel channel and the auxiliary air channel. Therefore, when the liquid fuel system is operating normally, there is no need to introduce auxiliary air to purge and cool the gaseous fuel channel, and when the gaseous fuel system is operating normally, there is also no need to introduce auxiliary air to purge and cool the liquid fuel channel.

[0052] Optionally, as Figure 1As shown, the first filtration component includes a first filter 2, a second filter 8, and a third filter 21 arranged in sequence along the liquid fuel delivery direction from front to back. The pumping component includes a delivery pump 3 and an on-board booster pump 16 arranged in sequence along the liquid fuel delivery direction from front to back, and the delivery pump 3 is located between the first filter 2 and the second filter 8, and the on-board booster pump 16 is located between the second filter 8 and the third filter 21. The liquid fuel regulating valve 23 is located downstream of the third filter 21, and the electromagnetic cut-off valve 24 is located downstream of the liquid fuel regulating valve 23. The oil inlet end of the liquid fuel drain pipeline is connected to the main liquid fuel pipeline at a point downstream of the electromagnetic cut-off valve 24. In this alternative solution, a first filter 2 (Y-type filter) with a filtration accuracy of 76 μm is provided in front of the delivery pump 3, a second filter 8 (pipeline filter) with a filtration accuracy of 20 μm is provided in front of the on-board booster pump 16, and a third filter 21 (pipeline filter) with a filtration accuracy of 10 μm is provided in front of the liquid fuel regulating valve 23, which is used to filter impurities in the liquid fuel and the body residues dropped when accessories such as pumps and valves fail, so as to protect the normal and safe operation of the delivery pump 3, the on-board booster pump 16, and the liquid fuel regulating valve 23 as much as possible.

[0053] Optionally, as Figure 1 shown, the liquid fuel system further includes a first oil return line and a second oil return line, and a first overflow valve 17 connected to the first oil return line. The oil inlet end and the oil outlet end of the first oil return line are respectively connected to the oil outlet pipeline and the oil inlet pipeline of the on-board booster pump 16. The oil inlet end and the oil outlet end of the second oil return line are respectively connected to the oil outlet end of the liquid fuel regulating valve 23 and the oil inlet pipeline of the on-board booster pump 16. In this alternative solution, the oil return of the liquid fuel regulating valve 23 and the oil return after the first overflow valve 17 of the on-board booster pump 16 are both connected to the oil inlet pipeline of the on-board booster pump 16, so that the oil return pipeline is short and it is convenient for internal integration of the structure.

[0054] In this alternative solution, as Figure 1As shown in the figure, the liquid fuel system further includes a third oil return line, a second overflow valve 9 connected to the third oil return line, a first pressure transmitter 4 for measuring the oil line pressure, and a turbine flowmeter 11 for measuring the liquid fuel flow rate. The inlet end and the outlet end of the third oil return line are respectively connected to the main liquid fuel line downstream of the transfer pump 3 and the fuel supply tank 52. The first pressure transmitter 4 is connected to the main liquid fuel line and is located between the transfer pump 3 and the second filter 8. The turbine flowmeter 11 is connected to the main liquid fuel line and is located between the connection point of the third oil return line and the main liquid fuel line and the on-board booster pump 16. In this alternative solution, the turbine flowmeter 11 is arranged between the on-board booster pump 16 and the second overflow valve 9, which can effectively avoid the influence of the oil return of both the first oil return line and the second oil return line on the turbine flowmeter 11, so that the turbine flowmeter 11 can accurately measure the actual liquid fuel consumption of the gas turbine; at the same time, a dedicated second overflow valve 9 and a first pressure transmitter 4 are provided in front of the turbine flowmeter 11 to adjust and monitor the inlet pressure of the on-board booster pump 16, and an alarm is triggered when the pressure is lower than the set value.

[0055] In this alternative solution, as Figure 1 shown in the figure, the liquid fuel system further includes a first check valve 6, a second check valve 19, and a third check valve 25 sequentially arranged in the main liquid fuel line. The first check valve 6 is located downstream of the transfer pump 3, the second check valve 19 is located downstream of the on-board booster pump 16, and the third check valve 25 is located downstream of the electromagnetic cut-off valve 24. In this alternative solution, the first check valve 6 is provided behind the transfer pump 3, and the second check valve 19 is provided behind the on-board booster pump 16 to prevent overpressure in the pipeline from affecting the normal operation of the pump. At the same time, a third check valve 25 is provided in front of the air-liquid integrated nozzle 29 in the main liquid fuel line to prevent the compressed air after the compressor with a temperature of up to 327 °C from flowing back into the main liquid fuel line and damaging key equipment such as the liquid fuel regulating valve 23, the transfer pump 3, and the on-board booster pump 16.

[0056] In this alternative solution, as Figure 1 shown in the figure, the liquid fuel system further includes a third manual ball valve 1, a fourth manual ball valve 10, a fifth manual ball valve 12, and a sixth manual ball valve 13 sequentially arranged in the main liquid fuel line. The third manual ball valve 1 is located upstream of the first filter 2, the fourth manual ball valve 10 is located upstream of the turbine flowmeter 11, the fifth manual ball valve 12 is located downstream of the turbine flowmeter 11, and the sixth manual ball valve 13 is connected to the upstream of the fourth manual ball valve 10 and the downstream of the fifth manual ball valve 12 through a pipeline. In this alternative solution, as Figure 1As shown, the liquid fuel system also includes a first temperature sensor 5, a first differential pressure gauge 7, a second pressure transmitter 14, a second differential pressure gauge 20, a third pressure transmitter 22 and a fourth pressure transmitter 26 which are sequentially arranged in the main liquid fuel pipeline, wherein the first temperature sensor 5 is located between the first pressure transmitter 4 and the first check valve 6, the first differential pressure gauge 7 is connected to both sides of the second filter 8, the second pressure transmitter 14 is located upstream of the onboard boost pump 16, the second differential pressure gauge 20 is connected to both sides of the third filter 21, the third pressure transmitter 22 is located between the third filter 21 and the liquid fuel regulating valve 23, and the fourth pressure transmitter 26 is located downstream of the electromagnetic shut-off valve 24. In this optional solution, as Figure 1 As shown, metal hoses 15 are provided at multiple locations in the main liquid fuel pipeline of the liquid fuel system. The system of the present invention also has online monitoring functions for liquid fuel flow, pressure, temperature, etc., and the instrument positions are reasonable, which is particularly suitable for occasions where gas turbine performance tests are required. At the same time, the system of the present invention has perfect functions, simple pipelines, modular design, small space occupation, high integration, convenient transportation and maintenance, and is particularly suitable for vehicle-mounted and container-type sea and land power generation projects with limited space.

[0057] When using liquid fuel: the liquid fuel system is put into operation, the liquid fuel in the fuel tank 52 is firstly coarsely filtered by the first filter 2, then pressurized by the delivery pump 3, filtered and impurized by the second filter 8, and the flow rate is measured by the turbine flowmeter 11, and then successively pressurized by the onboard boost pump 16 of the reducer, finely filtered by the third filter 21, and flow regulated by the liquid fuel regulating valve 23, and finally enters the liquid fuel flow channel of the gas-liquid integrated nozzle 29, and enters the combustion chamber to participate in combustion under the purge-assisted atomization of the compressed air supplied by the air-assisted system. During this process, the electromagnetic drain valve 27 remains closed, the gas fuel system does not work, and the air-assisted system is put into operation, supplying compressed air to the auxiliary air flow channel of the gas-liquid integrated nozzle 29 to atomize the liquid fuel, and cool the gas-liquid integrated nozzle 29 at the same time.

[0058] Alternatively, if Figure 1As shown in the figure, the air-assisted system includes a compressor air supply pipeline and an instrument air pipeline for conveying air, a pneumatic shut-off valve 31 and a first pneumatic cut-off valve 33 for controlling the on / off of the pipeline. The air inlet end and the air outlet end of the compressor air supply pipeline are respectively connected to the exhaust end 55 of the compressor and the auxiliary air flow channel of the gas-liquid integrated nozzle 29, and the pneumatic shut-off valve 31 is connected in the compressor air supply pipeline. The air inlet end and the air outlet end of the instrument air pipeline are respectively connected to the in-tank instrument air path 54 and the auxiliary air flow channel of the gas-liquid integrated nozzle 29, and the first pneumatic cut-off valve 33 is connected in the instrument air pipeline. In this alternative solution, the air-assisted system is divided into two paths. One path uses external instrument air as the atomizing air for liquid fuel during the starting stage of the gas turbine, and the other path uses the compressed air after the compressor as the atomizing air for liquid fuel during the operation of the gas turbine, the air for cooling the nozzle, and the purging air when the gas turbine shuts down or the liquid fuel is switched to gas fuel. In this alternative solution, a normally open double-acting pneumatic shut-off valve 31 is provided on the compressed air branch after the compressor of the air-assisted system. On the one hand, it is used to automatically and quickly connect or disconnect the compressor bleed air. On the other hand, when the liquid fuel system is working, even in the event of a sudden failure, the pneumatic shut-off valve 31 can maintain its previous open state to ensure that the compressed air after the compressor purges the residual liquid fuel and cools the nozzle, ensuring the safe shutdown of the gas turbine in case of a fault.

[0059] In this alternative solution, as Figure 1 shown, the air-assisted system further includes an air pressure reducing valve 32 for adjusting the air pressure, and a fourth check valve 34 for controlling the air flow direction. The air pressure reducing valve 32 and the fourth check valve 34 are sequentially connected in the instrument air pipeline, and the air pressure reducing valve 32 is located upstream of the first pneumatic cut-off valve 33, and the fourth check valve 34 is located downstream of the first pneumatic cut-off valve 33. In this alternative solution, as Figure 1 shown, an air pressure reducing valve 32 is provided on the external instrument air branch of the air-assisted system to adjust the instrument air pressure to match the low flow rate of the liquid fuel during the starting stage. A normally closed single-acting first pneumatic cut-off valve 33 is also provided on the external instrument air branch of the air-assisted system to automatically and quickly connect or disconnect the external instrument air source. A fourth check valve 34 is also provided on the external instrument air branch of the air-assisted system to prevent the compressed air after the compressor with a temperature up to 327 °C from flowing back into this branch and damaging its pipeline accessories.

[0060] The air-assisted system of the present invention includes three different working states:

[0061] The first working state: When the gas turbine uses liquid fuel during the starting stage, the first pneumatic cut-off valve 33 is opened. The instrument air from the outside with a pressure of 0.5 MPa - 0.8 MPa enters the gas-liquid integrated nozzle 29 through the air pressure reducing valve 32 and then through the fourth check valve 34 to atomize the liquid fuel.

[0062] The second working state: After the gas turbine turbine starts to operate, when the pressure of the compressed air after the compressor exceeds the set value, the double-acting pneumatic shut-off valve 31 on this branch is opened, and the first pneumatic cut-off valve 33 on the external instrument air branch is closed to cut off the external instrument air source. The auxiliary air for atomizing the liquid fuel is switched to the compressed air after the compressor;

[0063] The third working state: When the gas turbine shuts down or converts the liquid fuel to gas fuel, the double-acting pneumatic shut-off valve 31 on the compressed air branch after the compressor remains open, the first pneumatic cut-off valve 33 on the external instrument air branch remains closed, and the electromagnetic blowdown valve 27 is opened. The compressed air after the compressor enters the liquid fuel flow path of the gas-liquid integrated nozzle 29 and flows reversely along the main liquid fuel pipeline to conduct reverse flushing on the main liquid fuel pipeline after the third check valve 25 to remove the residual fuel and avoid carbon deposition blockage.

[0064] Optionally, as Figure 1 shown, the second filter assembly includes a fourth filter 37 and a fifth filter 43 arranged in sequence before and after in the gas fuel conveying direction. The pneumatic switch valve group includes a second pneumatic cut-off valve 40, a first pneumatic quick cut-off valve 45, and a second pneumatic quick cut-off valve 46 arranged in sequence before and after in the gas fuel conveying direction. The second pneumatic cut-off valve 40 is located between the fourth filter 37 and the fifth filter 43, and the first pneumatic quick cut-off valve 45 and the second pneumatic quick cut-off valve 46 are located between the fifth filter 43 and the gas fuel regulating valve 48. The gas fuel system also includes a first manual valve and a second manual valve connected to the main gas fuel pipeline and located on both sides of the fourth filter 37.

[0065] In this optional solution, as Figure 1 shown, the gas fuel system also includes a mass flow meter 42 for measuring the gas flow rate, a first vent pipeline and a second vent pipeline for venting the gas, a first pneumatic vent valve 41 arranged in the first vent pipeline, and a second pneumatic vent valve 51 arranged in the second vent pipeline. The mass flow meter 42 is located between the second pneumatic cut-off valve 40 and the first pneumatic quick cut-off valve 45. The connection point of the intake end of the first vent pipeline to the main gas fuel pipeline is located between the second pneumatic cut-off valve 40 and the mass flow meter 42, and the outlet end of the first vent pipeline is connected to the atmosphere. The connection point of the intake end of the second vent pipeline to the main gas fuel pipeline is located between the first pneumatic quick cut-off valve 45 and the second pneumatic quick cut-off valve 46, and the outlet end of the second vent pipeline is connected to the atmosphere.

[0066] In this optional solution, a mass flow meter 42 is arranged after the first pneumatic vent valve 41 to accurately measure the actual consumption of the gas fuel of the gas turbine. In this optional solution, as Figure 1As shown, a second temperature sensor 39, a second pneumatic cut-off valve 40, and a first pneumatic vent valve 41 are also provided near the unit outside the fuel tank of the gas fuel system. On the one hand, in the initial stage of burning gas fuel, when the second temperature sensor 39 monitors that the temperature of the gas fuel is lower than the set value, the first pneumatic vent valve 41 is opened to discharge the gas fuel to a safe area until the temperature reaches the set value, thus protecting the normal and safe operation of the gas turbine. On the other hand, it can ensure that in case of a fire inside the fuel tank, the second pneumatic cut-off valve 40 can timely cut off the gas fuel supply of the system outside the tank. In this alternative solution, a second manual ball valve 38 is provided in front of the second pneumatic cut-off valve 40 outside the fuel tank of the gas fuel system. The installation position and height of the second manual ball valve 38 should be convenient for personnel to quickly reach and operate, which can ensure that when all the active valves in the system fail, the gas fuel supply of the system can be manually cut off in time. At the same time, together with the first manual ball valve 35, it serves as an isolation valve for offline maintenance of the fourth filter 37. In this alternative solution, the gas fuel system also includes a third differential pressure gauge 36, a fifth pressure transmitter 44, a sixth pressure transmitter 47, and a seventh pressure transmitter connected to the main gas fuel pipeline. Among them, the third differential pressure gauge 36 is connected to the front and rear ends of the fourth filter 37, the fifth pressure transmitter 44 is located downstream of the fifth filter 43, the sixth pressure transmitter 47 is located upstream of the gas fuel regulating valve 48, and the seventh pressure transmitter is located downstream of the gas fuel regulating valve 48.

[0067] When the present invention works with gaseous fuel: The gas fuel system is put into operation, the second pneumatic cut-off valve 40, the first pneumatic quick cut-off valve 45, and the second pneumatic quick cut-off valve 46 are all opened, and the gas fuel system is in the fuel supply working state. The gas fuel in the gas supply system 56 is sequentially filtered and purified by the fourth filter 37 (fine filter), metered by the mass flow meter 42, simply filtered and purified again by the fifth filter 43 (Y-type filter), and the flow rate is adjusted by the gas fuel regulating valve 48, and finally supplied to the gas-liquid integrated nozzle 29 for combustion. During this process, the first pneumatic vent valve 41 and the second pneumatic vent valve 51 remain closed, and the liquid fuel system and the air auxiliary system are not put into operation.

[0068] When switching from gas fuel to liquid fuel under a high operating condition:

[0069] Before the switching starts, the gas fuel system remains in the working state, that is, the gas fuel is supplied from the main liquid fuel pipeline to the gas-liquid integrated nozzle 29 for combustion; the liquid fuel system and the air auxiliary system do not work;

[0070] At the start of the fuel switchover, the liquid fuel system starts operating. The transfer pump 3 and the on-board booster pump 16 are started, the electromagnetic cut-off valve 24 is opened, and the liquid fuel regulating valve 23 is adjusted to its minimum opening. The liquid fuel finally enters the liquid fuel passage of the gas-liquid integrated nozzle 29 and enters the combustion chamber for combustion under the purging and auxiliary atomization effect of the compressed air after the compressor. At the same time, to ensure that the power fluctuation of the gas turbine unit is within 5%, the gas fuel regulating valve 48 reduces its opening. As the fuel switchover process progresses, the opening of the liquid fuel regulating valve 23 increases and the opening of the gas fuel regulating valve 48 decreases. When the specified time is reached, the gas fuel regulating valve 48 is completely closed, and at the same time, the second pneumatic cut-off valve 40, the first pneumatic quick cut-off valve 45, and the second pneumatic quick cut-off valve 46 are also adjusted to the closed state.

[0071] After the switchover is completed, the liquid fuel system remains in the operating state, the gas fuel system is in the closed state, the second pneumatic cut-off valve 40, the first pneumatic quick cut-off valve 45, and the second pneumatic quick cut-off valve 46 all remain closed. The first pneumatic vent valve 41 and the second pneumatic vent valve 51 of the gas fuel system are opened to safely vent the residual gas fuel in the main gas fuel pipeline. After the venting, the first pneumatic vent valve 41 and the second pneumatic vent valve 51 are adjusted to the closed state.

[0072] When switching from liquid fuel to gas fuel during a high load condition:

[0073] Before the switchover starts, the liquid fuel system remains in the operating state, that is, the liquid fuel is supplied through the main liquid fuel pipeline to the liquid fuel passage of the gas-liquid integrated nozzle 29 for injection, atomization, and combustion. The gas fuel system is in the closed state, and the air assistance system is in the operating state. The compressed air after the compressor enters the auxiliary air passage of the gas-liquid integrated nozzle 29 and enters the liquid fuel swirl chamber through the circumferential swirl holes communicating with the liquid fuel passage to fully atomize the liquid fuel.

[0074] At the start of the switchover, the second pneumatic cut-off valve 40, the first pneumatic quick cut-off valve 45, and the second pneumatic quick cut-off valve 46 of the gas fuel line are opened, the gas fuel regulating valve 48 is opened to its minimum opening, and the gas fuel is supplied to the gas fuel passage of the gas-liquid integrated nozzle 29 for combustion. At the same time, the liquid fuel regulating valve 23 reduces its opening to keep the power of the gas turbine unit stable within 5%. As the switchover process progresses, when the gas fuel regulating valve 48 is adjusted to the specified opening, the opening remains unchanged. At the same time, the liquid fuel regulating valve 23 continues to reduce its opening until it is closed, and the gas fuel system is fully put into a stable operating state to complete the dual-fuel switchover. The compressed air passage after the compressor of the air assistance system continues to remain in the operating state.

[0075] After the switching is completed, the liquid fuel system stops working, that is, the delivery pump 3, the on-board booster pump 16, the liquid fuel regulating valve 23, and the electromagnetic cut-off valve 24 all remain closed. The gas fuel system is in an open and stable operating state, and the compressed air path after the compressor of the air-assisted system continues to operate. Open the electromagnetic blowdown valve 27, and the compressed air after the compressor enters the liquid fuel flow path of the gas-liquid integrated nozzle 29 and flows reversely along the main liquid fuel pipeline to reversely blow and wash the main liquid fuel pipeline after the third check valve 25 to remove the residual fuel and avoid carbon deposition blockage. The residual liquid after the blow and wash is discharged outside the unit through the liquid blowdown pipeline. After ensuring the safety of the unit, the electromagnetic blowdown valve 27 is adjusted to be closed.

[0076] During the mutual switching process between the above-mentioned gas fuel and liquid fuel, the increase and decrease rates of the fuel are matched according to the calorific value, that is, to ensure that the product of the increase rate of the liquid fuel and its calorific value is equal to the product of the decrease rate of the gas fuel and its calorific value, or the product of the decrease rate of the liquid fuel and its calorific value is equal to the product of the increase rate of the gas fuel and its calorific value; when switching the fuel, the increase and decrease rates of the fuel flow of both should be strictly controlled to achieve the shortest switching time and the smoothest power fluctuation of the unit. The switching time refers to the time used to completely switch from the current working fuel to another fuel for operation when the switching instruction is given and the timing starts. The power fluctuation of the unit refers to the ratio of the difference between the maximum and minimum powers of the unit during the switching process to the power of the unit during stable operation. To ensure stable operation of the load, it is required that the power fluctuation range of the unit is not greater than 5%.

[0077] A preferred embodiment of the present invention further provides a gas turbine, which has a gas turbine dual-fuel system as described in any one of the above. Therefore, the gas turbine of the present invention can operate stably using only gaseous fuel or liquid fuel, and can also perform online switching between gaseous fuel and liquid fuel without shutting down, so that the application range is wide; the gas turbine process flow of the present invention is simple and the energy consumption is low. An air-assisted system that combines two air sources, namely, supplying instrument air through the in-box instrument air path 54 or supplying compressed air from the exhaust end 55 of the compressor, is used for atomizing and purging the liquid fuel. Moreover, the auxiliary air is not only safe and reliable itself, and except for using a small amount of external instrument air during the starting stage of the gas turbine, the rest uses the compressed air after the compressor. Under high operating conditions of the gas turbine, no additional auxiliary high-pressure boosting equipment and pressure-regulating throttling devices are required to atomize and purge the liquid fuel in a timely manner, making the system pipeline simple and the system equipment configuration simplified, thereby reducing the energy consumption of the gas turbine and improving the overall operation efficiency; the gas turbine pipeline configuration of the present invention is simple and the control logic is simple. There is no liquid fuel ignition pipeline, gaseous fuel ignition pipeline, gaseous fuel purging system, and nozzle ring pipe system for gaseous fuel, liquid fuel, and atomizing air. The gaseous fuel system, liquid fuel system, and air-assisted system all have only one main path directly connected to the gas-liquid integrated nozzle 29, which also simplifies the fuel process flow, does not cause the pipeline laying to be too long, and is convenient for the integration of the dual-fuel system. It also makes the liquid fuel consumption measured by the flowmeter accurate, so that the actual operating conditions of the gas turbine can be accurately known. Moreover, the present invention has been manufactured, assembled, and tested, and can meet the requirements of the dual-fuel system for gas turbine testing. The operation and switching also meet the requirements and have been put into use.

[0078] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A gas turbine dual fuel system, characterized in that: include: Liquid fuel system, gas fuel system, air-assisted system and gas-liquid integrated nozzle (29); A liquid fuel flow channel, an auxiliary air flow channel and a gas fuel flow channel are integrated in the gas-liquid integrated nozzle (29), and the auxiliary air flow channel is connected to the liquid fuel flow channel; The liquid fuel system comprises a main liquid fuel pipeline for conveying liquid fuel, a liquid fuel drain pipeline for purging and draining, a first filter assembly for filtering the liquid fuel, a pumping assembly for pumping the liquid fuel forward, a liquid fuel regulating valve (23) for regulating the flow rate of the liquid fuel, an electromagnetic shut-off valve (24) and an electromagnetic drain valve (27) for controlling the on-off of the pipeline, the two ends of the main liquid fuel pipeline are respectively connected to the oil supply tank (52) and the liquid fuel flow channel of the gas-liquid integrated nozzle (29), the two ends of the liquid fuel drain pipeline are respectively connected to the oil outlet end of the main liquid fuel pipeline and the waste oil collection device (53), the first filter assembly, the pumping assembly, the liquid fuel regulating valve (23) and the electromagnetic shut-off valve (24) are respectively connected to the main liquid fuel pipeline, and the electromagnetic drain valve (27) is connected to the liquid fuel drain pipeline; The air inlet end of the air-assisted system is respectively connected to the instrument air path (54) in the box and the exhaust end (55) of the compressor, and the air outlet end of the air-assisted system is connected to the auxiliary air flow channel of the gas-liquid integrated nozzle (29), so as to supply the auxiliary air flow channel with the instrument air supplied through the instrument air path (54) in the box when the gas turbine is started, and to supply the auxiliary air flow channel with the high-pressure air supplied through the exhaust end (55) of the compressor after the gas turbine turbine starts to run, the gas turbine is shut down, and the liquid fuel supply is converted to the gas fuel supply; The gas fuel system comprises a main gas fuel pipeline for conveying gas fuel, a second filter assembly for filtering the gas fuel, a gas fuel regulating valve (48) for regulating the flow of the gas fuel, and a pneumatic switch valve group for controlling the on-off of the pipeline. The two ends of the main gas fuel pipeline are respectively connected to the gas supply system (56) and the gas fuel flow channel of the gas-liquid integrated nozzle (29), and the second filter assembly, the gas fuel regulating valve (48) and the pneumatic switch valve group are respectively connected to the main gas fuel pipeline.

2. The gas turbine dual fuel system according to claim 1, characterized in that: The first filter assembly comprises a first filter (2), a second filter (8) and a third filter (21) which are arranged in sequence in the direction of liquid fuel delivery; The pumping assembly comprises a delivery pump (3) and an onboard booster pump (16) which are arranged in sequence in the front and rear direction of the liquid fuel delivery direction, wherein the delivery pump (3) is located between the first filter (2) and the second filter (8), and the onboard booster pump (16) is located between the second filter (8) and the third filter (21); The liquid fuel regulating valve (23) is located downstream of the third filter (21), and the electromagnetic shut-off valve (24) is located downstream of the liquid fuel regulating valve (23); The connection point between the oil inlet end of the liquid fuel drain pipeline and the main liquid fuel pipeline is located downstream of the electromagnetic shut-off valve (24).

3. The gas turbine dual fuel system according to claim 2, characterized in that: The liquid fuel system also includes a first oil return circuit and a second oil return circuit, and a first overflow valve (17) connected to the first oil return circuit; The oil inlet end and the oil outlet end of the first oil return circuit are respectively connected to the oil outlet pipeline of the onboard booster pump (16) and the oil inlet pipeline of the onboard booster pump (16); The oil inlet end and the oil outlet end of the second oil return circuit are respectively connected to the oil outlet end of the liquid fuel regulating valve (23) and the oil inlet pipeline of the onboard boost pump (16).

4. The gas turbine dual fuel system according to claim 2, characterized in that: The liquid fuel system also includes a third oil return line, a second overflow valve (9) connected to the third oil return line, a first pressure transmitter (4) for measuring the oil line pressure, and a turbine flowmeter (11) for measuring the liquid fuel flow rate; The oil inlet end and the oil outlet end of the third oil return circuit are respectively connected to the main liquid fuel pipeline and the oil supply tank (52) downstream of the delivery pump (3); The first pressure transmitter (4) is connected to the main liquid fuel pipeline and is located between the delivery pump (3) and the second filter (8); The turbine flowmeter (11) is connected to the main liquid fuel pipeline and is located between the connection point between the third oil return line and the main liquid fuel pipeline and the onboard boost pump (16).

5. The gas turbine dual fuel system according to claim 2, characterized in that: The liquid fuel system also includes a first check valve (6), a second check valve (19) and a third check valve (25) which are sequentially arranged in the main liquid fuel pipeline; The first check valve (6) is located downstream of the delivery pump (3), the second check valve (19) is located downstream of the onboard booster pump (16), and the third check valve (25) is located downstream of the electromagnetic shut-off valve (24).

6. The gas turbine dual fuel system according to claim 1, characterized in that: The air auxiliary system comprises a compressor air supply pipeline and an instrument air pipeline for conveying air, a pneumatic shut-off valve (31) for controlling the on-off of the pipeline, and a first pneumatic shut-off valve (33); The air inlet and air outlet of the compressor air supply pipeline are respectively connected to the compressor exhaust end (55) and the auxiliary air flow channel of the gas-liquid integrated nozzle (29), and the pneumatic shut-off valve (31) is connected to the compressor air supply pipeline; The air inlet and air outlet of the instrument air pipeline are respectively connected to the instrument air pipeline (54) in the box and the auxiliary air flow channel of the gas-liquid integrated nozzle (29), and the first pneumatic shut-off valve (33) is connected to the instrument air pipeline.

7. The gas turbine dual fuel system according to claim 6, characterized in that: The air assist system also includes an air pressure reducing valve (32) for adjusting air pressure, and a fourth check valve (34) for controlling the direction of air flow; The air pressure reducing valve (32) and the fourth check valve (34) are connected to the instrument air pipeline in sequence, and the air pressure reducing valve (32) is located upstream of the first pneumatic shut-off valve (33), and the fourth check valve (34) is located downstream of the first pneumatic shut-off valve (33).

8. The gas turbine dual fuel system according to claim 1, characterized in that: The second filter assembly comprises a fourth filter (37) and a fifth filter (43) which are arranged in sequence in the front and back direction along the gas fuel delivery direction; The pneumatic switch valve group comprises a second pneumatic shut-off valve (40), a first pneumatic quick-off valve (45) and a second pneumatic quick-off valve (46) which are arranged in sequence along the gas fuel delivery direction, and the second pneumatic shut-off valve (40) is located between the fourth filter (37) and the fifth filter (43), and the first pneumatic quick-off valve (45) and the second pneumatic quick-off valve (46) are located between the fifth filter (43) and the gas fuel regulating valve (48); The gas fuel system also includes a first manual valve and a second manual valve which are connected to the main gas fuel pipeline and are located on both sides of the fourth filter (37).

9. The gas turbine dual fuel system according to claim 8, characterized in that: The gas fuel system further comprises a mass flow meter (42) for measuring gas flow, a first venting pipeline and a second venting pipeline for venting gas, a first pneumatic venting valve (41) arranged in the first venting pipeline, and a second pneumatic venting valve (51) arranged in the second venting pipeline; The mass flow meter (42) is located between the second pneumatic shut-off valve (40) and the first pneumatic quick-off valve (45); The connection point between the air inlet end of the first vent line and the main gas fuel line is located between the second pneumatic shut-off valve (40) and the mass flow meter (42), and the air outlet end of the first vent line is connected to the atmosphere; The connection point between the air inlet end of the second venting pipeline and the main gas fuel pipeline is located between the first pneumatic quick-break valve (45) and the second pneumatic quick-break valve (46), and the air outlet end of the second venting pipeline is connected to the atmosphere.

10. A gas turbine, characterized in that: A gas turbine dual fuel system as claimed in any one of claims 1 to 9.

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