Gas fuel ignition system of turboshaft gas turbine under low-temperature working condition

Abstract

The invention discloses a low-temperature working condition turboshaft gas turbine gas fuel ignition system. The system comprises a fuel supply module, a power driving module, a control module, a monitoring module, a fuel oil switching module and an auxiliary module. According to the working principle, the advantages of atomization performance and combustion stability of gas fuel at low temperature are utilized, all components are controlled through a controller in a time sequence mode, the gas fuel supply duration is automatically adjusted in combination with a temperature-viscosity compensation model, and the cut-in frequency of a fuel pump is dynamically adjusted according to the exhaust temperature rising rate; a soft grid-connected mode is adopted to switch a lithium battery and a starting integrated generator, and the ignition state is comprehensively judged through multiple parameters. The system solves the problem of low ignition success rate caused by high fuel viscosity at low temperature, improves ignition reliability, control precision, environmental adaptability and energy utilization efficiency, and is suitable for complex working conditions such as low temperature, extremely cold and plateau.

Description

Technical Field

[0001] The present invention relates to the technical field of turboshaft gas turbines, and in particular to a gas fuel ignition system and a control method for a turboshaft gas turbine suitable for low-temperature working conditions. Background Art

[0002] During the operation of turboshaft gas turbines, low temperatures have always been a significant factor affecting their normal startup and reliable operation. Under low-temperature conditions, the physical properties of conventional fuels undergo significant changes, including a significant increase in fuel viscosity. This change triggers a series of problems, seriously affecting the ignition performance of turboshaft gas turbines.

[0003] Specifically, increased fuel viscosity directly leads to a significant deterioration in fuel atomization. Poor fuel atomization results in uneven mixing of fuel and air, making it difficult to form a well-combustible mixture, which greatly complicates the ignition process. Furthermore, changes in fuel viscosity can cause significant flow fluctuations, making the fuel supply unstable and further impacting ignition reliability.

[0004] These problems ultimately lead to a significant reduction in the ignition success rate of turboshaft gas turbines in low-temperature environments, seriously restricting the application of turboshaft gas turbines in cold areas and situations where they need to work in low-temperature environments.

[0005] To address these issues, existing technologies have proposed several solutions, but these often have limitations. For example, some approaches heat the fuel to reduce viscosity, but this method requires additional heating equipment, increasing system complexity and cost. Furthermore, the heating effect is significantly affected by ambient temperature and is not ideal in extremely cold operating conditions. Other solutions improve atomization by adjusting the fuel injection pressure, but this is also limited by fuel viscosity and struggles to achieve the desired effect at low temperatures.

[0006] Therefore, how to effectively solve the problem of low ignition success rate of turboshaft gas turbines due to increased fuel viscosity in low temperature environments has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the Invention

[0007] The present invention aims to overcome the significant drawbacks of prior art turboshaft gas turbines in low-temperature environments, such as significantly increased fuel viscosity, which leads to severe deterioration in fuel atomization, significant flow rate fluctuations, and a significant reduction in ignition success rate. By configuring a gas fuel tank within the fuel system of a hybrid turboshaft gas turbine, a gas fuel ignition system and control method specifically designed for low-temperature operation are constructed, thereby significantly improving the turboshaft gas turbine's ignition reliability and success rate under low-temperature conditions.

[0008] 1. Device composition

[0009] The ignition system of the present invention is mainly composed of the following functional modules:

[0010] (1) Fuel supply module: This module mainly includes a gas fuel tank and its matching gas supply solenoid valve. Its core function is to accurately and stably supply gas fuel to the combustion chamber in strict accordance with the control instructions during the critical stage of low-temperature ignition, providing the necessary fuel guarantee for the low-temperature ignition process.

[0011] (2) Power drive module: This module consists of a lithium battery and an integrated generator. The lithium battery provides the necessary initial power for the startup of the entire system, while the integrated generator can flexibly switch between the motor drive mode and the power generation mode according to actual working requirements, thereby efficiently starting the turboshaft gas turbine.

[0012] (3) Control module: Its core component is the controller, which can accurately receive the ignition command issued by the host computer and comprehensively coordinate the working sequence of each module through logical operations, specifically covering a series of key operations such as driving the lithium battery to discharge, accurately controlling the opening and closing of the gas supply solenoid valve, and timely triggering the ignition discharge.

[0013] The main controller also integrates a temperature-viscosity compensation algorithm:

[0014] Formula: T comp =K1·ln(μ / μ0)+K2·(T env +273.15)

[0015] (where T comp is the temperature compensation, μ is the current fuel viscosity, μ0 is the standard viscosity, T env is the ambient temperature, K1 and K2 are compensation coefficients), and the gas fuel supply duration can be automatically adjusted according to the real-time ambient temperature (with an adjustment accuracy of ±0.1s).

[0016] (4) Monitoring module: It is mainly used to collect the speed signal and exhaust temperature data of the turboshaft gas turbine in real time. By obtaining these key parameters, it provides a solid basis for accurately judging whether the ignition is successful or not.

[0017] (5) Fuel switching module: Contains the fuel pump. When the key condition of successful ignition is met, the module quickly starts the fuel pump and promptly cuts in the fuel supply, achieving a smooth and reliable conversion of fuel types.

[0018] (6) Auxiliary modules

[0019] Lithium battery preheating system (starting in extremely cold conditions); high-pressure air purge device (performs combustion chamber purge when ignition fails).

[0020] 2. Working Principle

[0021] The working principle of the present invention is based on the important characteristic that gas fuel has better atomization performance and combustion stability than traditional fuel in low temperature environment. The controller implements precise timing control of each functional component, thereby efficiently realizing the ignition process.

[0022] When the host computer issues an ignition command, the controller first drives the lithium battery to discharge, driving the integrated motor to operate in electric motor mode, and then forcefully drives the turboshaft gas turbine to reach the initial speed, creating the necessary air flow conditions for subsequent ignition.

[0023] Subsequently, the controller promptly opens the gas supply solenoid valve to steadily supply gas fuel to the combustion chamber, and at the same time quickly triggers the igniter to discharge and ignite.

[0024] During the ignition process, the lithium battery intelligently switches to charging mode, and the integrated motor synchronously switches to power generation mode to maintain the energy balance of the system and ensure that the energy requirements of the entire ignition process are reasonably met.

[0025] The monitoring module continuously monitors the speed and exhaust temperature of the turboshaft gas turbine in real time. When these two key parameters reach the preset speed thresholds N2 and T 4_1 When the temperature reaches ℃, the ignition is determined to be successful, and the fuel pump is started, and the gas fuel supply is shut off after a delay of T2 seconds, thus successfully completing the switching process from gas fuel ignition to fuel combustion.

[0026] Based on the above working principle, especially based on the fluidity advantage of gas fuel at low temperature, the following intelligent control algorithm is combined to achieve precise ignition:

[0027] (1) In the control process, the temperature-viscosity compensation model is introduced, that is, the formula: T comp =K1·ln(μ / μ0)+K2·(T env +273.15)

[0028] (where T comp is the temperature compensation, μ is the current fuel viscosity, μ0 is the standard viscosity, T env is the ambient temperature, K1 and K2 are compensation coefficients), and the gas fuel supply time can be automatically adjusted according to the real-time ambient temperature (the adjustment accuracy is ±0.1s). This model uses a pre-calibrated mapping relationship (such as table lookup or function calculation) to convert T comp It is converted into a correction value for the gas fuel supply duration. The model automatically and accurately adjusts the gas fuel supply duration according to the real-time ambient temperature, with an adjustment accuracy of up to ±0.1 second, further improving the system's adaptability and control accuracy in different temperature environments.

[0029] (2) After successful ignition, the controller introduces energy closed-loop control logic, that is, dynamically adjusts the fuel pump cut-in frequency according to the exhaust temperature rise rate (dT / dt):

[0030] when When F1=F base +0.2F base

[0031] When 2℃ / s≤dT / dt≤5℃ / s, F1=F base

[0032] When dT / dt<2℃ / s, F1=F base -0.15F base

[0033] F base It is the reference frequency to solve the combustion instability problem caused by traditional fixed value cut-in.

[0034] (3) When switching between the lithium battery and the integrated generator, the soft grid-connected mode is used. When the phase difference between the output voltage and the grid voltage is detected, the switching is performed when the phase difference is less than 15°, and the voltage fluctuation is controlled to be ≤±5%;

[0035] (4) Use multi-parameter ignition judgment, combined with speed>N2, exhaust temperature>T 4_1 The ignition status is comprehensively determined by the following factors: ℃, combustion chamber pressure fluctuation>P0 and igniter energy decay rate<5%.

[0036] 3. Operation Mode

[0037] The ignition system of the present invention operates according to the following process:

[0038] (1) Startup preparation phase: Before the system is ignited, the lithium battery needs to maintain a certain amount of power reserve. This is a prerequisite for ensuring that the integrated generator can be driven smoothly into the motor drive mode, and to prepare energy for subsequent ignition operations.

[0039] (2) Gas turbine drive stage: When the host computer issues the ignition command, the controller responds immediately, drives the lithium battery to generate electricity, drives the integrated motor to start efficient operation, and then drives the turboshaft gas turbine to run continuously for 5 seconds. Through these 5 seconds of operation, it lays the foundation for the subsequent ignition process and creates good initial conditions.

[0040] (3) Gas fuel supply and ignition stage: While the turboshaft gas turbine is running, the controller quickly outputs the gas supply solenoid valve opening command, and the gas tank begins to stably supply gas fuel to the combustion chamber. The supply time is automatically and accurately adjusted according to the real-time ambient temperature based on the temperature-viscosity compensation model. At the same time, the controller synchronously issues the igniter discharge ignition command to ignite the gas fuel, ensuring that the ignition operation and fuel supply are carried out synchronously, thereby improving the reliability of ignition.

[0041] (4) Mode switching stage: After the ignition operation is completed, the lithium battery automatically switches to charging mode based on the system's energy management requirements, and the integrated electric motor accordingly enters the power generation mode to meet the energy requirements of the system's subsequent operation. During this process, the mode switching between the lithium battery and the integrated electric generator adopts "soft grid connection" technology. By accurately detecting the phase difference between the generator output voltage and the grid voltage, the switching is executed when the phase difference is less than 15°, so that the voltage fluctuation during the switching process is strictly controlled within ±5%, effectively avoiding electromagnetic interference to the control system and ensuring the stable operation of the system.

[0042] (5) Ignition success judgment stage: The host computer monitors the speed and exhaust temperature of the turboshaft gas turbine in real time. When the speed exceeds N2 and the temperature is higher than T 4_1 When the temperature is 0.5°C, the combustion chamber pressure fluctuation is greater than P0 and the ignition energy decay rate is less than 5%, which comprehensively determines that the gas ignition is successful, providing an accurate basis for subsequent fuel switching. In addition, after the ignition is successfully judged, the controller will dynamically adjust the fuel pump cut-in frequency according to the exhaust temperature rise rate dT / dt:

[0043] when When F1=F base +0.2F base

[0044] When 2℃ / s≤dT / dt≤5℃ / s, F1=F base

[0045] When dT / dt<2℃ / s, F1=F base -0.15F base

[0046] F base This dynamic adjustment mechanism effectively solves the combustion instability problem caused by traditional fixed-value cut-in and further improves the stability and reliability of the system.

[0047] (6) Fuel cut-in stage: After confirming that the ignition is successful, the host computer promptly issues the fuel cut-in command, and the fuel pump starts at a fixed frequency of F1; T2 seconds after the fuel pump starts, the gas fuel tank gas supply solenoid valve is closed, and the fuel is officially cut in, completing the entire ignition process and achieving a smooth transition of fuel.

[0048] In addition, to further improve the system's adaptability under complex working conditions, the operating mode also has the following adaptive expansion capabilities:

[0049] (1) Multi-condition startup strategy:

[0050] Extremely cold conditions (T env <-30°C): For extremely cold environments, the system will activate the lithium battery preheating system in advance, heating it to 25±2°C, extending the gas fuel supply time, and increasing the igniter discharge energy to 120J. These measures ensure reliable ignition in extremely cold conditions.

[0051] Plateau working conditions (altitude>3000m): Taking into account the particularity of the plateau environment, the ignition success judgment threshold is corrected according to the altitude, N'2=N2·(1-0.00012·H),T' 4_1 =T 4_1 +0.03H (H is the altitude, unit is m), so that the system can accurately determine the success of ignition in plateau areas and ensure the normal startup of the equipment.

[0052] (2) Fault tolerance mechanism: If the first ignition fails (the speed does not reach N2 and the temperature <T 4_1 ℃), the system will automatically execute the "purge-reignition" process, first start the high-pressure air to purge the combustion chamber for 10 seconds to remove the unburned matter and impurities in the combustion chamber, and then according to the temperature deviation ΔT=T env -(-20℃) Adjustment of re-ignition parameters: When ΔT>10℃, the gas fuel supply is increased by 15%; when ΔT≤10℃, the number of igniter discharges is increased to 3. Through this fault-tolerant mechanism, the ignition fault tolerance capability under complex working conditions is effectively improved, ensuring that the system can ignite as successfully as possible in various situations.

[0053] Beneficial effects

[0054] Significantly improve low-temperature ignition reliability: By adopting the technical solution of gas fuel ignition, the two core problems of poor atomization and unstable flow caused by high fuel viscosity in low-temperature environments are effectively solved. This fundamentally improves the ignition success rate of the turboshaft gas turbine under low-temperature conditions, allowing the equipment to start reliably in cold environments.

[0055] Achieve precise control of the ignition process: By adjusting the time parameters of each stage (such as gas fuel supply time, T2 second delay switching time), key parameter thresholds (such as N2 speed, T 4_1℃ temperature), the introduction of a temperature-viscosity compensation model, and a series of control measures such as dynamic adjustment of the fuel pump cut-in frequency according to the exhaust temperature rise rate have achieved a seamless connection between the gas fuel ignition and the fuel cut-in process, ensuring that the entire ignition process is stable and controllable, and greatly improving the control accuracy and reliability of the system.

[0056] Greatly improve the environmental adaptability of the system: Through innovative designs such as multi-condition startup strategies and fault tolerance mechanisms, the present invention enables the turboshaft gas turbine to start reliably in complex environments such as different temperature environments (including extreme cold conditions) and different altitudes (plateau conditions), effectively expanding the application scenarios of the equipment, significantly improving the system's adaptability to complex environments, and meeting the usage requirements under different working conditions.

[0057] Optimizing system energy efficiency: The mode switching design of the lithium battery and the Qiqi integrated generator, along with the application of "soft grid connection" technology, achieves rational energy distribution and efficient utilization during the ignition process. While ensuring successful ignition, it minimizes energy waste and improves the system's overall energy efficiency. In addition, the addition of energy closed-loop control logic further optimizes the system's energy management, making the system more efficient and reasonable in terms of energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the present invention.

[0059] Figure 2 It is a schematic diagram of the operation process of the present invention. DETAILED DESCRIPTION

[0060] The following describes in detail the specific implementation of the low-temperature working condition turboshaft gas turbine gas fuel ignition system of the present invention with reference to the embodiments.

[0061] Example:

[0062] (1) Composition of ignition system in low temperature environment

[0063] (1) Fuel supply module: It is equipped with a 50L gas fuel tank that stores propane gas and is equipped with a high-precision gas supply solenoid valve with a response time of no more than 50ms. This ensures that during the critical stage of low-temperature ignition, gas fuel can be accurately and stably supplied to the combustion chamber in strict accordance with the control instructions.

[0064] (2) Power drive module: It uses a 20Ah lithium battery that can operate normally in an environment of -40°C and provide initial power for the startup of the entire system; it is paired with a 15kW integrated generator that can flexibly switch between motor drive mode and power generation mode, thereby efficiently realizing the startup drive of the turboshaft gas turbine.

[0065] (3) Control Module: The core component is the controller, which has an operating speed of up to 400MHz. It can accurately receive ignition commands from the host computer and comprehensively coordinate the operating timing of each module through logical operations. At the same time, the controller integrates a temperature-viscosity compensation algorithm, which can automatically adjust the gas fuel supply duration according to the real-time ambient temperature, with an adjustment accuracy of ±0.1s.

[0066] (4) Monitoring module: A high-precision speed sensor and temperature sensor are selected. The speed sensor has a measurement accuracy of ±0.1% and the temperature sensor has a measurement accuracy of ±1°C. These sensors are used to collect the speed signal and exhaust temperature data of the turboshaft gas turbine in real time, providing a basis for accurately judging whether the ignition is successful or not.

[0067] (5) Fuel switching module: It uses a fuel pump with a flow rate of 30L / min. When ignition is successful, the module quickly starts the fuel pump and promptly cuts in the fuel supply to achieve a smooth conversion of fuel types.

[0068] (6) Auxiliary module: The lithium battery preheating system uses a PTC heating element, which can heat the lithium battery to 25±2℃ under extremely cold working conditions; the high-pressure air purge device has a purge pressure of 0.8MPa, and performs combustion chamber purge when ignition fails.

[0069] (2) Operation mode

[0070] 1. Ignition operation under standard low temperature conditions (-20℃, 1000m above sea level)

[0071] (1) Startup preparation stage: The power of the lithium battery is maintained above 80% to ensure that it can drive the integrated generator to smoothly enter the motor drive mode.

[0072] (2) Gas turbine drive stage: When the host computer issues the ignition command, the controller drives the lithium battery to generate electricity, drives the ignition integrated motor to operate, and drives the turboshaft gas turbine to run continuously for 5 seconds, so that the turboshaft gas turbine reaches the initial speed of 1000rpm.

[0073] (3) Gas fuel supply and ignition stage: The controller outputs the gas supply solenoid valve opening command, and the gas tank supplies gas fuel into the combustion chamber. The supply time is calculated to be 10 seconds based on the temperature-viscosity compensation model. At the same time, the controller issues the igniter discharge ignition command. The discharge energy of the igniter is 100J, igniting the gas fuel.

[0074] (4) Mode switching phase: After the ignition operation is completed, the lithium battery automatically switches to charging mode, and the integrated electric motor enters power generation mode. During the switching process, "soft grid connection" technology is used to detect the phase difference between the generator output voltage and the grid voltage. When the phase difference is less than 15°, the switching is executed to control the voltage fluctuation within ±5%.

[0075] (5) Ignition success judgment stage: The host computer monitors the speed and exhaust temperature of the turboshaft gas turbine in real time. When the speed exceeds 3000rpm and the temperature is higher than 500℃, combined with the combustion chamber pressure fluctuation >5kPa and the igniter energy attenuation rate <5%, it is comprehensively judged that the gas ignition is successful. Then, the controller dynamically adjusts the fuel pump cut-in frequency according to the exhaust temperature rise rate dT / dt. Assuming that the exhaust temperature rise rate is 3℃ / s at this time, which is in the range of 2℃ / s≤dT / dt≤5℃ / s, the fuel pump cut-in frequency F1=F base (F base is 50Hz).

[0076] (6) Fuel cut-in stage: After confirming that the ignition is successful, the host computer issues an oil fuel cut-in command, and the fuel pump starts at a frequency of 50 Hz; 5 seconds after the fuel pump starts, the gas fuel tank gas supply solenoid valve is closed, and the fuel is officially cut in, completing the ignition process.

[0077] 2. Ignition operation under extremely cold conditions (-40℃, 500m above sea level)

[0078] (1) Startup preparation phase: Start the lithium battery preheating system in advance to heat the lithium battery to 25±2℃, and at the same time check the pressure of the gas fuel tank to ensure that it meets the supply requirements.

[0079] (2) Gas turbine drive stage: Same as the standard low-temperature operating conditions, the turboshaft gas turbine is driven to run continuously for 5 seconds and reach the initial speed of 1000 rpm.

[0080] (3) Gas fuel supply and ignition stage: According to the temperature-viscosity compensation model, the gas fuel supply time is extended to 15 seconds, and the igniter discharge energy is increased to 120J to ensure that the gas fuel can be ignited.

[0081] (4) Mode switching stage: Same as the standard low-temperature operating conditions, the “soft grid connection” technology is used for mode switching to ensure that the voltage fluctuation is within the allowable range.

[0082] (5) Ignition success judgment stage: Due to the special circumstances under extremely cold working conditions, the judgment threshold for ignition success may be appropriately adjusted according to the actual situation, but the ignition status is still determined by combining multiple parameters.

[0083] (6) Fuel cut-in stage: After confirming successful ignition, the fuel pump cut-in frequency F1 is dynamically adjusted according to the exhaust temperature rising rate to ensure stable combustion.

[0084] 3. Ignition operation under plateau conditions (4000m above sea level, temperature -10°C)

[0085] (1) Start preparation stage: The lithium battery is kept fully charged, and the ignition success threshold is adjusted according to the altitude. Calculation shows N'2 = N2·(1-0.00012·H) = 3000·(1-0.00012·4000) = 3000·(1-0.48) = 3000·0.52 = 1560rpm, T' 4_1 =T 4_1 +0.03H=500+0.03·4000=500+120=620℃.

[0086] (2) Gas turbine driving stage: The turboshaft gas turbine is driven to run for 5 seconds and reaches an initial speed of 1000 rpm.

[0087] (3) Gas fuel supply and ignition stage: The gas fuel supply time is calculated to be 12 seconds based on the temperature-viscosity compensation model, and the igniter discharge energy is 100J.

[0088] (4) Mode switching stage: the same as the standard low-temperature working condition.

[0089] (5) Ignition success judgment stage: When the speed exceeds 1560 rpm and the temperature is higher than 620°C, combined with other parameters, the ignition is judged to be successful.

[0090] (5) Fuel cut-in stage: The fuel pump cut-in frequency is dynamically adjusted according to the exhaust temperature rising rate to complete the fuel switching.

[0091] 2. Comparative Example

[0092] (1) Traditional fuel ignition system (no gas fuel ignition system)

[0093] 1. Device composition

[0094] (1) Fuel supply module: Equipped with a fuel tank and a fuel pump. The flow rate of the fuel pump is 30L / min. In a low temperature environment, the viscosity of the fuel increases significantly, resulting in a serious deterioration of the fuel atomization effect.

[0095] (2) Power drive module: It uses a traditional starter motor and generator. The power of the starter motor is 10kW and the power of the generator is 15kW. In a low temperature environment, the starting ability of the starter motor decreases, and more energy is required to start the turboshaft gas turbine.

[0096] (3) Control module: A simple controller that cannot make real-time adjustments based on ambient temperature and can only be controlled according to a fixed timing.

[0097] (4) Monitoring module: Ordinary speed sensors and temperature sensors have low measurement accuracy and cannot accurately determine whether the ignition is successful or not.

[0098] (5) Fuel switching module: the same as the fuel switching module in the embodiment.

[0099] (6) Auxiliary module: no lithium battery preheating system and high-pressure air purge device.

[0100] 2. Operation mode

[0101] In a -20°C environment, after the host computer issues the ignition command, the motor starts the turboshaft gas turbine, and the fuel pump supplies fuel to the combustion chamber. Due to the high viscosity of the fuel and poor atomization, the ignition success rate is low. Even if ignition is successful, during the fuel injection process, the control module cannot dynamically adjust to the rate of increase in exhaust temperature, which can easily lead to unstable combustion.

[0102] (2) Ignition system with only gas fuel tank but no intelligent control algorithm

[0103] 1. Device composition

[0104] (1) Fuel supply module: equipped with the same gas fuel tank and gas supply solenoid valve as in the embodiment, but the control module does not integrate the temperature-viscosity compensation algorithm and energy closed-loop control logic.

[0105] (2) Power drive module: same as in the embodiment.

[0106] (3) Control module: A simple controller that can only supply gas fuel at a fixed time and cannot make real-time adjustments based on ambient temperature.

[0107] (4) Monitoring module: same as in the embodiment.

[0108] (5) Fuel switching module: same as in the embodiment.

[0109] (6) Auxiliary module: same as in the embodiment.

[0110] 2. Operation mode

[0111] In an environment of -20℃, after the host computer issues the ignition command, the controller drives the lithium battery to discharge, drives the ignition integrated motor to operate, and drives the turboshaft gas turbine to reach the initial speed. Then, the controller opens the gas fuel tank supply solenoid valve to supply gas fuel to the combustion chamber. The supply time is fixed at 10 seconds, and at the same time triggers the igniter to discharge and ignite. Due to the lack of a temperature-viscosity compensation algorithm, the gas fuel supply time cannot be adjusted according to the real-time ambient temperature. In a low temperature environment, insufficient or excessive gas fuel supply may occur, affecting the ignition success rate. After the ignition is successfully judged, the fuel pump cut-in frequency is fixed at F base , it is impossible to make dynamic adjustments according to the rate of increase of exhaust temperature, which can easily lead to unstable combustion.

[0112] Effect comparison between the embodiment and the comparative example

[0113]

[0114] By comparison, it can be seen that the ignition system of the present invention has significantly better ignition success rate and combustion stability than traditional fuel ignition systems and ignition systems that only add gas fuel tanks but have no intelligent control algorithms under complex working conditions such as low temperature, extreme cold and plateau. At the same time, the energy utilization efficiency is also significantly improved.

Claims

1. A low temperature working condition turboshaft gas turbine gas fuel ignition system, characterized in that: Suitable for low temperature conditions, including: The fuel supply module, which includes a gas fuel tank and its corresponding gas supply solenoid valve, is used to accurately and stably supply gas fuel to the combustion chamber according to control instructions during the low-temperature ignition stage; The power drive module consists of a lithium battery and an integrated generator. The lithium battery provides initial power for system startup, and the integrated generator can switch between motor drive mode and power generation mode to drive the turboshaft gas turbine to start; The control module, whose core component is the controller, is used to receive ignition commands from the host computer and coordinate the working sequence of each module, including driving the lithium battery discharge, controlling the opening and closing of the gas supply solenoid valve, and triggering the ignition discharge. The controller also integrates a temperature-viscosity compensation algorithm; The monitoring module is used to collect the speed signal and exhaust temperature data of the turboshaft gas turbine in real time to determine whether the ignition is successful or not; The fuel switching module includes a fuel pump, which is used to start the fuel pump and cut in the fuel supply after the ignition is successful; The auxiliary module includes a lithium battery preheating system and a high-pressure air purge device. The lithium battery preheating system is used to heat the lithium battery when starting in extremely cold conditions, and the high-pressure air purge device is used to purge the combustion chamber when ignition fails.

2. The low temperature working condition turboshaft gas turbine gas fuel ignition system according to claim 1, characterized in that: Based on the advantages of gas fuel atomization performance and combustion stability at low temperatures, the controller controls the timing of each functional component. The operation modes include: Startup preparation stage: The lithium battery maintains power reserve to drive the Qiqi integrated generator to enter the motor drive mode; Gas turbine drive stage: The controller drives the lithium battery to generate electricity, drives the inspiration integrated motor to operate, and drives the turboshaft gas turbine to run continuously for 5 seconds to reach the initial speed; Gas fuel supply and ignition stage: The controller opens the gas supply solenoid valve, adjusts the gas fuel supply duration according to the temperature-viscosity compensation model, and triggers the igniter to discharge and ignite; Mode switching stage: After ignition, the lithium battery switches to charging mode, and the integrated motor switches to power generation mode. Soft grid-connected technology is used for switching. When the phase difference between the output voltage and the grid voltage is less than 15°, the switching is executed, and the voltage fluctuation is controlled to be ≤±5%; Ignition success judgment stage: when the speed exceeds N2 and the temperature is higher than T 4_1 When ℃, the combustion chamber pressure fluctuation is greater than P0 and the ignition energy attenuation rate is less than 5%, which is a comprehensive judgment of the gas ignition success; Fuel cut-in stage: After successful ignition, the fuel pump is started, and the gas fuel supply is shut off after a delay of T2 seconds to complete the fuel switch.

3. The low-temperature turboshaft gas turbine gas fuel ignition system according to claim 1 further comprises an intelligent control algorithm to achieve precise ignition, characterized in that: The temperature-viscosity compensation algorithm utilizes the formula: T comp =K1·ln(μ / μ0)+K2·(T env +273.15)(of which T comp is the temperature compensation, μ is the current fuel viscosity, μ0 is the standard viscosity, T env is the ambient temperature, K1 and K2 are compensation coefficients), the gas fuel supply time can be automatically adjusted according to the real-time ambient temperature (the adjustment accuracy is ±0.1s); After successful ignition, the controller introduces energy closed-loop control logic, which dynamically adjusts the fuel pump cut-in frequency according to the exhaust temperature rise rate (dT / dt): when When F1=F base +0.2F base When 2℃ / s≤dT / dt≤5℃ / s, F1=F base When dT / dt<2℃ / s, F1=F base -0.15F base F base It is the reference frequency to solve the combustion instability problem caused by traditional fixed value cut-in.

4. The low temperature working condition turboshaft gas turbine gas fuel ignition system according to claim 2, characterized in that: The operation mode also includes multi-condition startup strategy: Extremely cold conditions (T env <-30℃): The system will start the lithium battery preheating system in advance, heating it to 25±2℃, while extending the gas fuel supply time and increasing the igniter discharge energy to 120J; Plateau working conditions (altitude>3000m): Taking into account the particularity of the plateau environment, the ignition success judgment threshold is corrected according to the altitude, N'2=N2·(1-0.00012·H),T' 4_1 =T 4_1 +0.03H (H is the altitude, unit is m).

5. The low temperature working condition turboshaft gas turbine gas fuel ignition system according to claim 2, characterized in that: The operation mode also includes fault tolerance mechanisms: If the first ignition fails (the speed does not reach N2 and the temperature <T 4_1 ℃), the system will automatically execute the "purge-reignition" process, first starting high-pressure air to purge the combustion chamber for 10 seconds to remove unburned matter and impurities in the combustion chamber, and then according to the temperature deviation ΔT=T env -(-20℃) Adjust the re-ignition parameters: when ΔT>10℃, the gas fuel supply is increased by 15%; when ΔT≤10℃, the number of igniter discharges is increased to 3 times.

6. The low temperature working condition turboshaft gas turbine gas fuel ignition system according to claim 1, characterized in that: The lithium battery capacity of the power drive module is 20Ah, which can work in an environment of -40°C, and the power of the integrated generator is 15kW.

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