A high-energy, high-efficiency ignition circuit and method for heavy-duty gas turbines

Abstract

This invention discloses a high-energy, high-efficiency ignition circuit and method for heavy-duty gas turbines. It includes a rectifier voltage multiplier circuit, a charging energy storage circuit, and a discharge voltage boosting circuit. The rectifier voltage multiplier circuit rectifies low-voltage AC power to obtain a unidirectional pulsating voltage. The charging energy storage circuit stores the energy of the unidirectional pulsating voltage. The discharge voltage boosting circuit triggers a discharge signal based on energy storage requirements, and through the boosting circuit, outputs a high-energy, high-voltage pulse to break down the ignition nozzle and generate an electric spark. This invention achieves highly reliable and safe ignition for heavy-duty gas turbines, with a simple, reliable circuit and a long service life.

Description

Technical Field

[0001] This invention relates to the field of heavy-duty gas turbine ignition system technology, specifically to a high-energy, high-efficiency ignition circuit and method for heavy-duty gas turbines. Background Technology

[0002] A 100-megawatt heavy-duty gas turbine has a power output nearly 100 times that of a kilowatt-class general aviation engine, and its combustion chamber diameter reaches over 5 meters. Therefore, it requires greater electric spark energy during startup to effectively ignite the natural gas-air mixture in the combustion chamber. To overcome the problem that the ignition voltage of the electric nozzle increases with the length of time in traditional ignition systems, resulting in the voltage released by the ignition device being unable to reliably break down the electric nozzle to generate an electric spark, the output voltage of the ignition device needs to be boosted to improve the reliability of the ignition system.

[0003] Compared to the ignition energy storage and output voltage requirements of aero-engines (energy storage no more than 5J, output voltage below 10kV), heavy-duty gas turbines require a design energy storage of 20J and an output voltage of 15kV. Furthermore, traditional ignition circuits using resistor-divided frequency modulation typically have a conversion efficiency of 65%–70%. This method is insufficient to meet the requirements of heavy-duty gas turbines for ignition energy storage of 20J, an output voltage of 15kV, and a circuit conversion efficiency of at least 85%. Summary of the Invention

[0004] The purpose of this invention is to provide a high-energy, high-efficiency ignition circuit and method for heavy-duty gas turbines. This invention enables highly reliable and safe ignition of heavy-duty gas turbines, with a simple, reliable circuit and a long service life.

[0005] The technical solution of this invention is: a high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, comprising a rectifier voltage multiplier circuit, a charging energy storage circuit, and a discharge voltage boosting circuit; the rectifier voltage multiplier circuit is used to rectify low-voltage AC power to obtain a unidirectional pulsating voltage; the charging energy storage circuit is used to store the energy of the unidirectional pulsating voltage; the discharge voltage boosting circuit is used to trigger a discharge signal according to the energy storage requirements, and to achieve a high-energy, high-voltage pulse output through the voltage boosting circuit, breaking down the ignition nozzle and forming an electric spark.

[0006] In the aforementioned high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, the rectifier voltage multiplier circuit adopts a full-bridge structure connection, converting low-voltage AC power into unidirectional pulsating voltage, and charging and storing energy in the energy storage capacitor C4 through current-limiting resistors R1 and R2.

[0007] In the aforementioned high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, the rectifier voltage multiplier circuit consists of a transformer T1, high-voltage diodes D1 to D4, and a voltage multiplier capacitor C3. The positive terminal of high-voltage diode D1 and the negative terminal of D3 are connected to one output terminal of transformer T1, the positive terminal of D2 and the negative terminal of D4 are connected to one end of C3, the other end of C3 is connected to the other output terminal of transformer T1, the negative terminals of D1 and D2 are connected as the input of the charging energy storage circuit, and the positive terminals of D3 and D4 are grounded.

[0008] In the aforementioned high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, the voltage multiplier capacitor C3 is a reactive component. This ensures no energy loss during frequency modulation, guaranteeing a circuit conversion efficiency of no less than 85%.

[0009] In the aforementioned high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, the charging and energy storage circuit consists of current-limiting resistors R1 and R2, energy storage capacitor C4, and protection resistors R7 to R9. One end of the parallel connection of R1 and R2 is connected to the energy storage capacitor C4, and the other end of C4 is connected to GND. The protection resistors R7 to R9 are connected in parallel with C4, and the other end of the parallel connection of the current-limiting resistors R1 and R2 is connected to the output terminal of the rectifier transformer circuit T1.

[0010] In the aforementioned high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, the energy storage capacitor C4 has a capacitance of 5uF and a withstand voltage of 3.5kV.

[0011] In the aforementioned high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, the discharge boost circuit includes a discharge tube DS1, output resistors R3 to R6, a trigger capacitor C5, and a boost transformer T2. One end of the discharge tube DS1 is connected to the input terminal of the transformer T2, the other end of the discharge tube DS1 is connected to one end of the trigger capacitor C5, the other end of C5 is connected to one output terminal of the transformer T2, and the other output terminal of T2 is connected to the high-voltage electrode.

[0012] The aforementioned working method for the high-energy, high-efficiency ignition circuit of heavy-duty gas turbines involves low-voltage AC power entering a rectifier and voltage multiplier circuit after passing through a filter circuit. The rectifier and voltage multiplier circuit rectifies the low-voltage AC power to obtain a unidirectional pulsating voltage. The obtained unidirectional pulsating voltage is then stored in a charging energy storage circuit. The discharge boost circuit triggers a discharge signal according to the energy storage requirements, and the boost circuit outputs a high-energy, high-voltage pulse to break down the ignition nozzle and generate an electric spark.

[0013] In the aforementioned working method for the high-energy, high-efficiency ignition circuit of heavy-duty gas turbines, when the energy of the charging energy storage capacitor C4 reaches a set threshold, a discharge signal is triggered, and a high-energy, high-voltage pulse is output through the discharge boost circuit, breaking down the ignition nozzle and forming an electric spark.

[0014] In the aforementioned working method for the high-energy, high-efficiency ignition circuit of heavy-duty gas turbines, the output spark frequency of the circuit is adjusted by regulating the capacitance value of the voltage multiplier capacitor C3 during operation.

[0015] The advantages of this invention are: this invention provides a highly efficient and reliable ignition circuit for heavy-duty gas turbine ignition devices, ensuring reliable burn-in of the ignition nozzle in a gas environment, and the circuit is simple and reliable.

[0016] The ignition circuit of this invention converts low-voltage AC power into high-voltage pulsed power through a filter circuit, a rectifier circuit, a charging and energy storage circuit, a discharging circuit, and a boost circuit. The ignition device using the above technical solution can achieve ignition energy storage of 20J, output voltage of 15kV, and conversion efficiency of 85%, providing a highly efficient and reliable ignition circuit for heavy-duty gas turbine ignition systems, ensuring that the ignition nozzle can effectively break down and form a good electric spark.

[0017] The ignition circuit of this invention underwent a 2436-hour long-term test at the Wenchang Power Plant in Hainan. During the test, no ignition failures caused by insufficient ignition voltage or insufficient spark energy occurred.

[0018] This invention fundamentally solves the problems caused by the high pressure and high temperature of the electric nozzle assembly, which is in a working environment in the combustion chamber for a long time, such as burn-off of the nozzle end face, damage of the semiconductor block, and increase of ignition voltage. The service life of the electric nozzle is increased from 2,000 working hours to more than 20,000 working hours.

[0019] This invention has been successfully applied to a 300MW-class gas turbine ignition system, breaking through the high-energy-storage and high-voltage ignition technology of ignition devices.

[0020] According to the procurement contract, 20 sets of ignition systems will be delivered in May 2023. With the increase in the number of gas turbines delivered, it is expected that the product delivery volume will exceed 100 sets in the next 5 to 10 years, generating operating revenue of about 24 million yuan, with significant economic benefits. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a high-energy, high-efficiency ignition circuit for heavy-duty gas turbines according to the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0023] Example 1. A high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, see [link to example]. Figure 1As shown, it includes a rectifier voltage multiplier circuit, a charging energy storage circuit, and a discharging voltage boost circuit; the rectifier voltage multiplier circuit is used to rectify low-voltage AC power to obtain a unidirectional pulsating voltage; the charging energy storage circuit is used to realize the energy storage of the unidirectional pulsating voltage; the discharging voltage boost circuit is used to trigger a discharge signal according to the energy storage requirements, and realize the output of a high-energy high-voltage pulse through the boost circuit to break down the electrode and form an electric spark.

[0024] The aforementioned rectifier voltage multiplier circuit adopts a full-bridge structure connection, converting low-voltage AC power into unidirectional pulsating voltage, and charging and storing energy in energy storage capacitor C4 through current-limiting resistors R1 and R2.

[0025] The aforementioned rectifier voltage multiplier circuit consists of transformer T1, high-voltage diodes D1 to D4, and voltage multiplier capacitor C3. The positive terminal of high-voltage diode D1 and the negative terminal of D3 are connected to one output terminal of transformer T1, the positive terminal of D2 and the negative terminal of D4 are connected to one end of C3, the other end of C3 is connected to the other output terminal of transformer T1, the negative terminals of D1 and D2 are connected as the input of the charging energy storage circuit, and the positive terminals of D3 and D4 are grounded.

[0026] The aforementioned voltage multiplier capacitor C3 is a reactive component. This ensures no energy loss during frequency modulation, guaranteeing a circuit conversion efficiency of no less than 85%.

[0027] The aforementioned charging and energy storage circuit consists of current-limiting resistors R1 and R2, an energy storage capacitor C4, and protective resistors R7 to R9. One end of the parallel connection of R1 and R2 is connected to the energy storage capacitor C4, and the other end of C4 is connected to GND. The protective resistors R7 to R9 are connected in parallel with C4. The other end of the parallel connection of the current-limiting resistors R1 and R2 is connected to the output terminal of the rectifier transformer circuit T1. The parallel connection of the current-limiting resistors R1 and R2 enables adjustment of the charging current and voltage division. The parallel connection of the protective resistors R7 to R9 with the energy storage capacitor C4 enables voltage division under high voltage and prevents circuit damage caused by overvoltage open circuit of the energy storage capacitor.

[0028] The aforementioned energy storage capacitor C4 has a capacitance of 5uF and a withstand voltage of 3.5kV. It can achieve an ignition energy storage capacity of 20J.

[0029] The aforementioned discharge boost circuit includes a discharge tube DS1, output resistors R3-R6, a trigger capacitor C5, and a boost transformer T2. One end of the discharge tube DS1 is connected to the input terminal of transformer T2, and the other end of the discharge tube DS1 is connected to one end of the trigger capacitor C5. The other end of C5 is connected to one output terminal of transformer T2, and the other output terminal of T2 is connected to the high-voltage probe. The output resistors R3-R6 are connected to one end of the discharge tube DS1 to stabilize the load resistance and prevent circuit damage caused by an open circuit. The boost circuit composed of trigger capacitor C5, boost transformer T2, and discharge tube DS1 can boost the discharge voltage to 15kV via LC resonant secondary voltage.

[0030] The aforementioned working method for the high-energy, high-efficiency ignition circuit of heavy-duty gas turbines involves low-voltage AC power entering a rectifier and voltage multiplier circuit after passing through a filter circuit. The rectifier and voltage multiplier circuit rectifies the low-voltage AC power to obtain a unidirectional pulsating voltage. The obtained unidirectional pulsating voltage is then stored in a charging energy storage circuit. The discharge boost circuit triggers a discharge signal according to the energy storage requirements, and the boost circuit outputs a high-energy, high-voltage pulse to break down the ignition nozzle and generate an electric spark.

[0031] When the energy of the charging storage capacitor C4 reaches the set threshold, a discharge signal is triggered, and a high-energy high-voltage pulse is output through the discharge boost circuit, which breaks down the electrode and forms an electric spark.

[0032] During operation, the output spark frequency of the circuit is adjusted by adjusting the capacitance value of the voltage multiplier capacitor C3.

Claims

1. A high-energy, high-efficiency ignition circuit for heavy-duty gas turbines, characterized in that, It includes a rectifier voltage multiplier circuit, a charging energy storage circuit, and a discharging voltage boost circuit; the rectifier voltage multiplier circuit is used to rectify low-voltage AC power to obtain a unidirectional pulsating voltage; the charging energy storage circuit is used to realize the energy storage of the unidirectional pulsating voltage. The discharge boost circuit is used to trigger a discharge signal based on energy storage requirements, and then outputs a high-energy, high-voltage pulse to break down the contact nozzle and generate an electric spark. The rectifier voltage multiplier circuit consists of transformer T1, high-voltage diodes D1-D4, and voltage multiplier capacitor C3. The positive terminal of high-voltage diode D1 and the negative terminal of D3 are connected to one output terminal of transformer T1; the positive terminal of D2 and the negative terminal of D4 are connected to one end of capacitor C3; the other end of capacitor C3 is connected to the other output terminal of transformer T1; and the negative terminals of D1 and D2 are connected together. This circuit serves as the charging energy storage circuit. Input: D3 positive terminal and D4 positive terminal grounded; the charging and energy storage circuit consists of current-limiting resistors R1 and R2, energy storage capacitor C4, and protection resistors R7 to R9; one end of the parallel connection of R1 and R2 in the charging and energy storage circuit is connected to the energy storage capacitor C4, and the other end of C4 is connected to GND; the protection resistors R7 to R9 are connected in parallel with C4; the other end of the parallel connection of the current-limiting resistors R1 and R2 is connected to the output terminal of the rectifier transformer circuit T1; the voltage multiplier capacitor C3 is a reactive device, so there is no energy loss during the frequency modulation process, ensuring that the circuit conversion efficiency is not less than 85%.

2. The high-energy, high-efficiency ignition circuit for heavy-duty gas turbines as described in claim 1, characterized in that, The rectifier voltage multiplier circuit adopts a full-bridge structure connection, which converts low-voltage AC power into unidirectional pulsating voltage, and charges and stores energy in the energy storage capacitor C4 through current-limiting resistors R1 and R2.

3. The high-energy, high-efficiency ignition circuit for heavy-duty gas turbines as described in claim 1, characterized in that, The energy storage capacitor C4 has a capacitance of 5uF and a withstand voltage of 3.5kV.

4. The high-energy, high-efficiency ignition circuit for heavy-duty gas turbines as described in claim 1, characterized in that, The discharge boost circuit includes a discharge tube DS1, output resistors R3 to R6, trigger capacitor C5, and boost transformer T2. One end of the discharge tube DS1 is connected to the input terminal of transformer T2, the other end of the discharge tube DS1 is connected to one end of trigger capacitor C5, the other end of C5 is connected to one output terminal of transformer T2, and the other output terminal of T2 is connected to the high-voltage nozzle.

5. A method of operation for a high-energy, high-efficiency ignition circuit for a heavy-duty gas turbine as described in any one of claims 1-4, characterized in that, Low-voltage AC power enters the rectifier and voltage multiplier circuit after passing through the filter circuit. The rectifier and voltage multiplier circuit rectifies the low-voltage AC power to obtain a unidirectional pulsating voltage. The obtained unidirectional pulsating voltage is stored in the charging energy storage circuit. The discharge boost circuit triggers the discharge signal according to the energy storage requirements. The boost circuit then outputs a high-energy high-voltage pulse, which breaks down the electrode and forms an electric spark.

6. The operating method for a high-energy, high-efficiency ignition circuit in a heavy-duty gas turbine as described in claim 5, characterized in that, When the energy of the charging storage capacitor C4 reaches the set threshold, a discharge signal is triggered, and a high-energy high-voltage pulse is output through the discharge boost circuit, which breaks down the electrode and forms an electric spark.

7. The operating method for a high-energy, high-efficiency ignition circuit in a heavy-duty gas turbine as described in claim 5, characterized in that, During operation, the output spark frequency of the circuit is adjusted by adjusting the capacitance value of the voltage multiplier capacitor C3.

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