Fuel oil control system applied to small and medium-sized gas turbines

Abstract

The invention discloses a fuel oil control system applied to small and medium-sized gas turbines. Existing electronic control may have a crash situation, the reliability is slightly low, and once the crash situation occurs, extremely serious consequences can be caused, and the safety of unit equipment and personnel is affected. The system comprises an oil tank, a fuel oil booster pump and a fuel oil main pipe, an outlet of the fuel oil booster pump is communicated with the fuel oil main pipe through a fuel oil discharge pipe, the fuel oil discharge pipe is communicated with a fault discharge pipe, and the fault discharge pipe is provided with a fault discharge valve; a discharge pipe is installed below the fuel oil main pipe, and a mechanical discharge valve is installed on the discharge pipe. And the pressure control end of the mechanical discharge valve is communicated with the fuel oil discharge pipe through a pressure control pipe. The method is used for fuel oil control of small and medium-sized gas turbines.

Description

Technical Field

[0001] The invention relates to a fuel control system applied to small and medium-sized gas turbines. Background Art

[0002] For gas turbines, the fuel system not only provides the corresponding fuel flow according to the operating conditions of the gas turbine, but also determines the speed of emergency shutdown of the gas turbine. The rationality of the fuel system design will ensure whether the gas turbine can quickly and reliably cut off the fuel supply to ensure the safety of the unit and personnel.

[0003] By analyzing the types, causes and impacts of gas turbine failures, it can be found that surge, overheating and overspeed are the most serious failures. When the above failures occur, emergency shutdown is required. The faster the fuel supply is cut off, the smaller the loss will be. The traditional fuel system of small and medium-sized gas turbines is mechanically controlled, and its functions are mainly realized through mechanical devices. The advantages are low cost, relatively low maintenance cost, simple structure, high stability, and not prone to failure. However, the mechanical control accuracy is low, and it is difficult to replace the control components, and it cannot be accurately adjusted. Electronic control is a modern mainstream control method that achieves precise control through electronic components. It has high control accuracy and more flexible control methods. At the same time, the three-redundancy design also guarantees its safety to a certain extent. However, from a gas turbine accident, it can be found that in a small probability event, the electronic control may crash, and the reliability is slightly low. Once it happens, it will cause extremely serious consequences and affect the safety of the unit equipment and personnel. Therefore, it is of great significance to study the fuel control system of gas turbines and design a highly reliable fuel control system. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems and provide a fuel control system for small and medium-sized gas turbines.

[0005] The above purpose is achieved through the following technical solutions: A fuel control system for small and medium-sized gas turbines, comprising: a fuel tank, a fuel booster pump and a fuel main pipe, wherein the outlet of the fuel booster pump is connected to the fuel main pipe through a fuel drain pipe, the fuel drain pipe is connected to a fault drain pipe, and a fault drain valve is installed on the fault drain pipe; A discharge pipe is installed below the fuel main pipe, and a mechanical discharge valve is installed on the discharge pipe; The pressure control end of the mechanical discharge valve is communicated with the fuel discharge pipe through a pressure control pipe.

[0006] The fuel control system is applied to small and medium-sized gas turbines, and a fuel regulating valve and a fuel shut-off valve are installed on the fuel discharge pipe.

[0007] The fuel control system applied to small and medium-sized gas turbines, the fuel regulating valve and the fuel shut-off valve are electric control valves.

[0008] In the fuel control system applied to small and medium-sized gas turbines, the fault discharge valve is a solenoid valve. Beneficial Effects

[0009] 1. In the event of a fault, the fuel regulating valve and the fuel shut-off valve of the present invention quickly cut off the fuel passing through, and at the same time, the fault discharge valve opens to release the fuel in the pipeline between the shut-off valve and the fuel main pipe. At this time, the pressure at point a decreases, and under the action of the spring force, the mechanical discharge valve opens to release the fuel in the fuel main pipe. The three act simultaneously to ensure that the fuel is quickly cut off and cannot enter the combustion chamber of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Attached Figure 1 It is a schematic diagram of the present invention; Attached Figure 2 This is the diagram of the mechanical discharge valve in the closed state; Attached Figure 3 This is the diagram of the mechanical discharge valve in the open state; In the figure: 1. Fuel boost pump; 2. Frequency conversion controller; 3. Fuel regulating valve; 4. Fuel shut-off valve; 5. Fault drain valve; 6. Mechanical drain valve; 7. Fuel main pipe; 8. Emergency stop button; 9. Fuel tank; 10. UPS backup power supply; 11. Low-pressure compressor; 12. High-pressure compressor; 13. Combustion chamber; 14. High-pressure turbine; 15. Low-pressure turbine; 16. Fuel drain pipe; 17. Fault drain pipe; 18. Drain pipe; 19. Pressure control pipe. DETAILED DESCRIPTION

[0011] Reference Figure 1 , a fuel control system applied to small and medium-sized gas turbines, which comprises: a fuel tank 9, a fuel booster pump 1 and a fuel main pipe 7, wherein the outlet of the fuel booster pump is connected to the fuel main pipe through a fuel drain pipe 16, and a fault drain pipe 17 is connected to the fuel drain pipe, and a fuel regulating valve 3 and a fuel shut-off valve 4 are installed on the fuel drain pipe, wherein the fuel regulating valve and the fuel shut-off valve are electric control valves, and the fault drain valve is a solenoid valve, which are all controlled by the fuel control system, wherein the fuel regulating valve receives a 4-20mA valve position command signal and a dry contact fast closing signal of the fuel control system, and feeds back a 4-20mA valve position feedback signal; the fuel shut-off valve receives a dry contact signal of the fuel control system's opening and closing commands; the fault drain valve opens when it is powered on and closes when it loses power, and is connected to a UPS backup power supply, so that when the power in the plant fails, the fault drain valve can be opened. A fault drain valve 5 is installed on the fault drain pipe; In the figure, the solid line represents the fuel pipeline, the dotted line represents the control cable, and the double solid line represents the power line. The fuel booster pump is controlled by a frequency converter, which can adjust the speed and change the outlet fuel pressure. According to the different operating conditions of the gas turbine, the fuel booster pump is controlled to reach the corresponding outlet fuel pressure. The pressurized fuel enters the fuel main pipe after passing through the regulating valve and the shut-off valve and is distributed to the combustion chamber of the gas turbine. Among them, the fault discharge valve is installed after the shut-off valve and before the fuel main pipe, and the mechanical discharge valve is installed below the fuel main pipe.

[0012] A discharge pipe 18 is installed below the fuel main pipe, a mechanical discharge valve 6 is installed on the discharge pipe, and the pressure control end of the mechanical discharge valve is connected to the fuel discharge pipe 16 through a pressure control pipe 19; The mechanical drain valve is mechanically controlled: (1) When the oil pressure at point a increases and the pressure F1 is greater than the spring force F2, the mechanical drain valve closes and the fuel cannot be discharged. Figure 2 As shown; (2) When the oil pressure at point a decreases and the pressure F1 is less than the spring force F2, the mechanical drain valve opens and the fuel is discharged. Figure 3 As shown; When a major failure occurs in the gas turbine and an emergency shutdown is required, the fuel control system will issue the following instructions: (1) Close the fuel regulating valve 3 (quick closing command); (2) Close the fuel cut-off valve 4; (3) Open the fault discharge valve 5. The above commands are triggered simultaneously. This control method and control principle are both existing technologies and will not be described in detail here. The fuel regulating valve quick closing instruction and the fuel cut-off valve of the present invention quickly cut off the passing fuel, and at the same time, the fault discharge valve opens to release the fuel in the pipeline between the cut-off valve and the fuel main pipe. At this time, the pressure at point a decreases, and under the action of the spring force, the mechanical discharge valve opens to release the fuel in the fuel main pipe. The three act simultaneously to ensure that the fuel is quickly cut off and cannot enter the combustion chamber of the engine.

[0013] In order to prevent the fuel control system from malfunctioning or getting stuck, the present invention designs an emergency stop button 8 on the operating table. The button controls the fault discharge valve in parallel with the fuel control system, bypassing the fuel control system, turning on the power, and controlling the fault discharge valve to open.

[0014] In this case, even if the fuel control system is stuck and cannot be operated, and the fuel regulating valve and fuel shut-off valve cannot be moved, the operator can directly press the emergency stop button on the operating console to open the fault drain valve. At this time, the oil pressure at point a is reduced and the mechanical drain valve is opened, which can also achieve the function of quickly cutting off the fuel supply, thereby increasing the reliability and safety of the fuel system.

[0015] The system couples electronic control and mechanical control to quickly cut off the fuel supply. At the same time, an emergency stop button is designed in parallel with the control system to increase redundancy and avoid being unable to shut down when the electronic control fails, thereby increasing the safety and reliability of the gas turbine operation.

Claims

1. A fuel control system for small and medium-sized gas turbines, comprising: A fuel tank, a fuel booster pump and a fuel main pipe, wherein the outlet of the fuel booster pump is connected to the fuel main pipe through a fuel drain pipe, the fuel drain pipe is connected to a fault drain pipe, and a fault drain valve is installed on the fault drain pipe; A discharge pipe is installed below the fuel main pipe, and a mechanical discharge valve is installed on the discharge pipe; The pressure control end of the mechanical discharge valve is communicated with the fuel discharge pipe through a pressure control pipe.

2. A fuel control system for small and medium-sized gas turbines according to claim 1, characterized in that: A fuel regulating valve and a fuel cut-off valve are installed on the fuel discharge pipe.

3. The fuel control system for small and medium-sized gas turbines according to claim 2 is characterized in that: The fuel regulating valve and the fuel cut-off valve are electrically controlled valves.

4. The fuel control system for small and medium-sized gas turbines according to claim 3 is characterized in that: The fault discharge valve is a solenoid valve.

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