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

Abstract

The utility model 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 device 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 device is used for fuel oil control of small and medium-sized gas turbines.

Description

Technical Field

[0001] The utility model relates to a fuel control system applied to medium and small gas turbines. Background Art

[0002] For a gas turbine, on the one hand, the fuel system provides a corresponding fuel flow according to the operating conditions of the gas turbine, and on the other hand, it also determines the emergency shutdown speed 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 and guarantee the safety of the unit and personnel.

[0003] By analyzing the gas turbine fault types, causes and influence degrees, it can be found that surge, over-temperature and overspeed are the most serious faults among them. When the above faults occur, emergency shutdown is required. The faster the fuel supply is cut off, the smaller the loss will be. The traditional fuel system of medium and small 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 easy to fail. However, the mechanical control accuracy is low, and it is difficult to replace the control components, and precise adjustment cannot be carried out. Electronic control realizes precise control through electronic components and is the modern mainstream control method. It has high control accuracy and more flexible control methods. At the same time, the triple redundancy design also ensures its safety to a certain extent. However, from a certain gas turbine accident, it can be found that in small probability events, the electronic control may freeze, and the reliability is slightly low. Once it occurs, 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 Utility Model

[0004] The purpose of the utility model is to solve the above-mentioned existing problems and provide a fuel control system applied to medium and small gas turbines.

[0005] The above purpose is achieved through the following technical solutions:

[0006] A fuel control system applied to medium and small gas turbines, which comprises: a fuel tank, a fuel boost pump and a fuel main pipe. The outlet of the fuel boost pump is communicated with the fuel main pipe through a fuel discharge pipe. A fault discharge pipe is communicated with the fuel discharge pipe, and a fault discharge valve is installed on the fault discharge pipe;

[0007] A discharge pipe is installed below the fuel main pipe, and a mechanical discharge valve is installed on the discharge pipe;

[0008] The pressure control end of the mechanical discharge valve is communicated with the fuel discharge pipe through a pressure control pipe.

[0009] The described fuel control system applied to medium and small gas turbines, a fuel regulating valve and a fuel stop valve are installed on the fuel discharge pipe.

[0010] The described fuel control system applied to medium and small gas turbines, the fuel regulating valve and the fuel stop valve are electric control valves.

[0011] The described fuel control system applied to medium and small gas turbines, the fault discharge valve is a solenoid valve. Beneficial effects

[0012] 1. When a fault occurs in the present utility model, the fuel regulating valve and the fuel stop valve quickly cut off the fuel passage. At the same time, the fault discharge valve opens to drain the fuel in the pipeline between the stop 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 drain 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 gas turbine. Description of the drawings

[0013] Attached Figure 1 is the schematic diagram of the present utility model;

[0014] Attached Figure 2 is the closed state diagram of the mechanical discharge valve;

[0015] Attached Figure 3 is the open state diagram of the mechanical discharge valve;

[0016] In the figure: 1, fuel booster pump; 2, frequency conversion controller; 3, fuel regulating valve; 4, fuel stop valve; 5, fault discharge valve; 6, mechanical discharge 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 discharge pipe; 17, fault discharge pipe; 18, discharge pipe; 19, pressure control pipe. Specific implementation manners

[0017] Refer to Figure 1, A fuel control system applied to medium and small gas turbines, which consists of: a fuel tank 9, a fuel booster pump 1, and a fuel main pipe 7. The outlet of the fuel booster pump is connected to the fuel main pipe through a fuel discharge pipe 16. A fault discharge pipe 17 is connected to the fuel discharge pipe. A fuel regulating valve 3 and a fuel stop valve 4 are installed on the fuel discharge pipe. The fuel regulating valve and the fuel stop valve are electric control valves, and the fault discharge valve is a solenoid valve, all of which are controlled by the fuel control system. Among them, the fuel regulating valve receives a 4-20 mA valve position command signal and a dry contact quick-close signal from the fuel control system, and feeds back a 4-20 mA valve position feedback signal; the fuel stop valve receives a dry contact signal of the open and close commands of the fuel control system; the fault discharge valve is open when powered on and closed when powered off, and is connected to a UPS backup power supply. When the power supply in the plant is lost, it can ensure that the fault discharge valve can be opened. A fault discharge valve 5 is installed on the fault discharge pipe;

[0018] 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 supply line. The fuel booster pump is controlled by a frequency converter controller, and its speed can be adjusted to change the outlet fuel pressure. According to 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 stop valve, and is distributed to the gas turbine combustion chamber. Among them, the fault discharge valve is installed behind the stop valve and in front of the fuel main pipe, and the mechanical discharge valve is installed below the fuel main pipe.

[0019] A discharge pipe 18 is installed below the fuel main pipe, and a mechanical discharge valve 6 is installed on the discharge pipe. The pressure control end of the mechanical discharge valve is connected to the fuel discharge pipe 16 through a pressure control pipe 19;

[0020] The mechanical discharge valve is mechanically controlled:

[0021] (1) When the oil pressure at point a rises and the pressure F1 is greater than the spring force F2, the mechanical discharge valve closes and the fuel cannot be discharged, as Figure 2 shown;

[0022] (2) When the oil pressure at point a drops and the pressure F1 is less than the spring force F2, the mechanical discharge valve opens and the fuel is discharged, as Figure 3 shown;

[0023] When a major fault occurs in the gas turbine and an emergency shutdown is required, the fuel control system will issue the following commands:

[0024] (1) Close the fuel regulating valve 3 (quick-close command); (2) Close the fuel stop valve 4; (3) Open the fault discharge valve 5. The above commands are triggered simultaneously. This control method and control principle are both prior arts and will not be elaborated here;

[0025] The fast - closing command of the fuel regulating valve of the present utility model and the fuel cut - off valve quickly cut off the fuel. At the same time, the failure discharge valve opens to drain the fuel in the pipeline between the cut - off valve and the fuel main pipe. At this time, the pressure at point a decreases. Under the action of the spring force, the mechanical discharge valve opens to drain the fuel in the fuel main pipe. The three work simultaneously to ensure the rapid cut - off of fuel, preventing it from entering the combustion chamber of the gas turbine.

[0026] To prevent failures or jams in the fuel control system, an emergency stop button 8 is designed on the console of the present invention. This button is in parallel with the fuel control system to control the failure discharge valve, bypassing the fuel control system to connect the power supply and control the opening of the failure discharge valve.

[0027] In this case, even if the fuel control system jams and cannot be operated, and the fuel regulating valve and the fuel cut - off valve cannot act, the operator can directly press the emergency stop button on the console to open the failure discharge valve. At this time, the oil pressure at point a decreases and the mechanical discharge valve opens, which can also achieve the function of quickly cutting off the fuel supply, increasing the reliability and safety of the fuel system.

[0028] This system couples electronic control and mechanical control, can quickly cut off the fuel supply, and at the same time designs an emergency stop button in parallel with the control system to increase redundancy, avoiding the inability to stop when the electronic control fails, and increasing the safety and reliability of the gas turbine operation.

Claims

1. A fuel control system applied to medium and small gas turbines, which comprises: Fuel tank, fuel boost pump and fuel manifold, characterized in that: the outlet of the fuel boost pump is communicated with the fuel manifold through a fuel discharge pipe, a fault discharge pipe is communicated with the fuel discharge pipe, and a fault discharge valve is installed on the fault discharge pipe; A discharge pipe is installed below the fuel manifold, 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. The fuel control system for a medium and small gas turbine according to claim 1, wherein: A fuel regulating valve and a fuel stop valve are installed on the fuel discharge pipe.

3. The fuel control system for a medium and small-sized gas turbine according to claim 2, wherein: The fuel regulating valve and the fuel stop valve are electric control valves.

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

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