A thyristor controlled discharge high energy ignition system

Abstract

The present invention discloses a thyristor controlled discharge high energy ignition system, which relates to the technical field of boiler start-up ignition, and includes a switch power supply charging circuit, a protection circuit, a charge and discharge timing control circuit, a thyristor discharge circuit and a working state indication circuit. The present invention uses thyristors instead of gas discharge tubes to control the pulse discharge of a high energy igniter, and the ignition system has a low failure rate, a stable ignition frequency, and a thorough discharge. The ignition system has low requirements for ignition guns, and high energy ignition guns of various materials can work normally.

Description

Technical Field

[0001] The invention relates to the technical field of boiler starting and ignition, in particular to a thyristor-controlled discharge high-energy ignition system. Background Art

[0002] Thermal power generation is a method of generating electricity by converting the heat energy generated by the combustion of combustibles into electrical energy through a power generation device. Existing large and medium-sized industrial boilers and most thermal power plants use coal as fuel. When using coal as an energy source for combustion, it is generally ignited by burning fuel oil or natural gas, high-voltage arc plasma torches, etc.

[0003] At present, when starting and igniting industrial boilers at home and abroad, the preferred method is to use the ignition system to ignite the fuel of the burner, and then the burner heats the furnace. The traditional ignition system uses a high-power power frequency transformer to boost the 220V, then charges the energy storage capacitor through a high-voltage silicon stack rectifier, discharges with a gas discharge tube, and ignites the fuel oil or gas through a high-energy ignition gun. The traditional high-energy ignition system has the following disadvantages:

[0004] 1. The use of power frequency transformers has large volume and weight, which has an adverse effect on the installation method and cannot achieve integrated design;

[0005] 2. The gas discharge high-energy ignition system has consumption problems. The performance of the discharge tube will change with the increase of discharge times, affecting the ignition performance;

[0006] 3. In the traditional high-energy ignition system, the separation of charging and discharging is not achieved, and only resistors with large volume and consumption can be used to limit the current, which reduces the working efficiency;

[0007] 4. The traditional high-energy ignition system has residual voltage during discharge, a large part of the energy of the energy storage capacitor cannot be released, the ignition energy is small, the spark shape is not ideal, and the ignition success rate is low;

[0008] 5. The traditional high-energy ignition system has imperfect self-protection. It is easy to burn out the high-energy ignition system when working for too long, especially the power transformer;

[0009] 7. The charging time of the traditional high-energy ignition system is not fixed, and the discharge frequency fluctuates, resulting in low efficiency.

[0010] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0011] In view of the problems in the related art, the present invention proposes a thyristor-controlled discharge high-energy ignition system, which solves the technical problems of high failure rate of gas discharge tubes, unstable discharge frequency, and incomplete discharge energy.

[0012] The technical solution of the present invention is achieved in this way:

[0013] A thyristor controlled discharge high energy ignition system, comprising a switch power supply charging circuit, a protection circuit, a charge and discharge timing control circuit, a thyristor discharge circuit and a working state indication circuit, wherein;

[0014] The switching power supply charging circuit is used for the PWM circuit to drive the half-bridge switching circuit, send the voltage to the transformer for boosting, and charge the energy storage capacitor after rectification;

[0015] The protection circuit is used to collect the charging voltage and charging current of the energy storage capacitor and measure the temperature of the transformer to achieve voltage, current and temperature protection of the circuit;

[0016] The charge and discharge timing control circuit is used to generate two mutually exclusive charge and discharge signals from the high and low levels of the clock signal, wherein the charge signal controls the switch power supply to charge the capacitor, and the discharge signal controls the discharge circuit to generate oscillation to control the unidirectional thyristor to discharge the capacitor through the drive circuit and the isolation transformer;

[0017] The thyristor discharge circuit is used for the oscillation circuit to generate a driving signal, which is output to the isolation transformer through the driving circuit to trigger the unidirectional thyristor discharge;

[0018] The working status indication circuit is used for measuring the discharge current signal by the current transformer and outputting it to the relay by driving the time base circuit to indicate the working status of the ignition system;

[0019] The thyristor discharge circuit uses an auto-boosting transformer L1 to instantaneously increase the discharge voltage;

[0020] Furthermore, the charge and discharge timing control circuit is composed of a time base circuit to form a periodically adjustable circuit, including a timer chip U2, the timer chip U2 pin is connected to capacitor C16, capacitor C17 and relay J1, the relay J1 pin is connected to resistor R17 and resistor R18, the resistor R17 and the resistor R18 are connected to diode D14, and the relay J1 pin is connected to transistor U3C, the transistor U3C pin is connected to resistor R25, resistor R29 and resistor R32, the resistor R25 is connected to diode D15, the resistor R29 is connected to R24 and resistor R33, and the resistor R32 is connected to capacitor C19.

[0021] Furthermore, the thyristor discharge circuit includes an oscillation circuit, a drive circuit and a unidirectional thyristor, including a transistor U3D, the transistor U3D pin is connected to a resistor R23, a resistor R31 and a capacitor C20, the capacitor C20 is connected to a transistor Q7, a resistor R37 and a resistor R35, the resistor R23 is connected to a resistor R22, a resistor R26 and a resistor R34, the resistor R31 is connected to a resistor R28 and a transistor Q6, the transistor Q6 is connected to a capacitor C18 and a diode D16, the capacitor C18 is connected to a capacitor C21 and a resistor R36, the resistor R36 is connected to a transformer T3, the transformer T3 is connected to a bridge rectifier diode VD1, a transistor VT1 and a transistor VT2, the bridge rectifier diode VD1 is connected to a capacitor C4, the transistor VT2 is connected to an auto-coupling boost transformer L1, and the auto-coupling boost transformer L1 is connected to a capacitor C5 and a resistor R5.

[0022] Furthermore, the switching power supply charging circuit includes a PWM circuit, a drive circuit, a switch tube, a boost transformer, a high-voltage rectifier circuit and a capacitor.

[0023] Furthermore, the protection circuit includes a voltage detection circuit, a current detection circuit, a temperature detection circuit and a protection locking circuit.

[0024] Furthermore, the working status indication circuit includes a current transformer, a delay circuit and a relay output circuit.

[0025] Beneficial effects of the present invention:

[0026] The present invention uses a thyristor instead of a gas discharge tube to control the pulse discharge of a high-energy igniter. The ignition system has a low failure rate, a stable ignition frequency, and a thorough discharge. The ignition system has low requirements on the ignition gun, and high-energy ignition guns made of various materials can work normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 is a principle block diagram of a thyristor-controlled discharge high-energy ignition system according to an embodiment of the present invention;

[0029] Figure 2 It is a circuit diagram of a charge and discharge timing control circuit of a thyristor-controlled discharge high-energy ignition system according to an embodiment of the present invention;

[0030] Figure 3It is a circuit diagram of a switching power supply charging circuit of a thyristor-controlled discharge high-energy ignition system according to an embodiment of the present invention;

[0031] Figure 4 is a circuit diagram of a protection circuit of a thyristor controlled discharge high energy ignition system according to an embodiment of the present invention;

[0032] Figure 5 is a circuit diagram of a thyristor discharge circuit of a thyristor controlled discharge high energy ignition system according to an embodiment of the present invention;

[0033] Figure 6 The present invention is a working indication output circuit diagram of a thyristor controlled discharge high energy ignition system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0035] According to an embodiment of the present invention, a thyristor-controlled discharge high-energy ignition system is provided.

[0036] like Figure 1-Figure 6 As shown, the thyristor controlled discharge high energy ignition system according to the embodiment of the present invention comprises a switching power supply charging circuit, a protection circuit, a charge and discharge timing control circuit, a thyristor discharge circuit and a working state indication circuit, wherein;

[0037] The switching power supply charging circuit is used for the PWM circuit to drive the half-bridge switching circuit, send the voltage to the transformer for boosting, and charge the energy storage capacitor after rectification, and the charging adopts the constant current mode;

[0038] The protection circuit is used to collect the charging voltage and charging current of the energy storage capacitor and measure the temperature of the transformer to achieve voltage, current and temperature protection of the circuit;

[0039] The charge and discharge timing control circuit is used to generate two mutually exclusive charge and discharge signals from the high and low levels of the clock signal, wherein the charge signal controls the switch power supply to charge the capacitor, and the discharge signal controls the discharge circuit to generate oscillation to control the unidirectional thyristor to discharge the capacitor through the drive circuit and the isolation transformer;

[0040] The thyristor discharge circuit is used for the oscillation circuit to generate a driving signal, which is output to the isolation transformer through the driving circuit to trigger the unidirectional thyristor discharge;

[0041] The thyristor discharge circuit uses an auto-boosting transformer L1 to instantaneously increase the discharge voltage;

[0042] The working state indicating circuit is used for measuring the discharge current signal by the current transformer, and outputting it to the relay by driving the time base circuit to indicate the working state of the ignition system.

[0043] With the help of the above technical solution, by using thyristors instead of gas discharge tubes to control the pulse discharge of high-energy igniters, the ignition system has a low failure rate, a stable ignition frequency, and a thorough discharge. The ignition system has low requirements for ignition guns, and high-energy ignition guns of various materials can work normally.

[0044] Among them, the charge and discharge timing control circuit is composed of a time base circuit to form a periodic adjustable circuit, including a timer chip U2, the timer chip U2 pin is connected to capacitor C16, capacitor C17 and relay J1, the relay J1 pin is connected to resistor R17 and resistor R18, the resistor R17 and the resistor R18 are connected to diode D14, and the relay J1 pin is connected to transistor U3C, the transistor U3C pin is connected to resistor R25, resistor R29 and resistor R32, the resistor R25 is connected to diode D15, the resistor R29 is connected to R24 and resistor R33, and the resistor R32 is connected to capacitor C19.

[0045] Among them, the thyristor discharge circuit includes an oscillation circuit, a drive circuit and a unidirectional thyristor, including a transistor U3D, the transistor U3D pin is connected to a resistor R23, a resistor R31 and a capacitor C20, the capacitor C20 is connected to a transistor Q7, a resistor R37 and a resistor R35, the resistor R23 is connected to a resistor R22, a resistor R26 and a resistor R34, the resistor R31 is connected to a resistor R28 and a transistor Q6, the transistor Q6 is connected to a capacitor C18 and a diode D16, the capacitor C18 is connected to a capacitor C21 and a resistor R36, the resistor R36 is connected to a transformer T3, the transformer T3 is connected to a bridge rectifier diode VD1, a transistor VT1 and a transistor VT2, the bridge rectifier diode VD1 is connected to a capacitor C4, the transistor VT2 is connected to an auto-coupling boost transformer L1, and the auto-coupling boost transformer L1 is connected to a capacitor C5 and a resistor R5.

[0046] The switching power supply charging circuit includes a PWM circuit, a drive circuit, a switch tube, a boost transformer, a high-voltage rectifier circuit and a capacitor.

[0047] Wherein, the protection circuit includes a voltage detection circuit, a current detection circuit, a temperature detection circuit and a protection locking circuit.

[0048] Wherein, the working status indication circuit includes a current transformer, a delay circuit and a relay output circuit.

[0049] Specifically, the charge and discharge timing control circuit uses a time base circuit to generate a clock signal, and can also generate a clock signal by detecting the voltage of the energy storage capacitor. The two signals are selected by a jumper, and the working state of the circuit is determined by the high and low levels of the clock signal. When the level is high, the switching power supply is controlled to charge the capacitor. When the level is low, the discharge circuit is controlled to generate oscillations and the unidirectional thyristor is controlled to discharge the capacitor through the drive circuit.

[0050] The charge and discharge timing control circuit is composed of a time base circuit to form a period adjustable circuit, and a timer chip U2, a 555 time base circuit and an external capacitor C16, a capacitor C17, a resistor R17, a diode D14, and a resistor R18 to form an asymmetric self-excited oscillation circuit to generate a square wave output signal. The high level drives the PWM switching power supply to charge the energy storage capacitor, and the low level controls the unidirectional thyristor to conduct and discharge. The working system of the thyristor discharge high-energy igniter is as follows: the entire charge and discharge cycle is 100ms, the charging cycle is 80ms, and the discharge cycle is 20ms, and the cycle works in a cycle.

[0051] The voltage detection circuit composed of transistor U3C and peripheral circuit resistors R24, R33, R29, R32, diode D15, R25 and capacitor C19 detects the voltage on the energy storage capacitor and outputs a square wave signal to control charging and discharging; the working system of the thyristor discharge high-energy igniter is as follows: charging when the energy storage capacitor voltage is lower than 800V, and discharging when it is higher than 800V, and the two working modes are selected by the relay J1 jumper.

[0052] In addition, the switching power supply charging circuit uses a TL494 integrated circuit to generate a PWM signal and outputs a 40KHz signal to control the switch of the half-bridge MOS tube.

[0053] In summary, with the aid of the above technical solution of the present invention, by using thyristors instead of gas discharge tubes to control the pulse discharge of high-energy igniters, the problems of high failure rate of gas discharge tubes, unstable discharge frequency, and incomplete discharge energy are solved; the ignition system of the present invention has a low failure rate, a stable ignition frequency, and a thorough discharge. The discharge spark is in the shape of a flame-shaped plasma spark, and the ignition system has low requirements on the ignition gun. High-energy ignition guns of various materials can work normally.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thyristor controlled discharge high energy ignition system, It is characterized in that It includes a switching power supply charging circuit, a protection circuit, a charging and discharging timing control circuit, a thyristor discharge circuit and a working status indication circuit, wherein; The switching power supply charging circuit is used for the PWM circuit to drive the half-bridge switching circuit, send the voltage to the transformer for boosting, and charge the energy storage capacitor after rectification; The protection circuit is used to collect the charging voltage and charging current of the energy storage capacitor and measure the temperature of the transformer to achieve voltage, current and temperature protection of the circuit; The charge and discharge timing control circuit is used to generate two mutually exclusive charge and discharge signals from the high and low levels of the clock signal, wherein the charge signal controls the switch power supply to charge the capacitor, and the discharge signal controls the discharge circuit to generate oscillation to control the unidirectional thyristor to discharge the capacitor through the drive circuit and the isolation transformer; The thyristor discharge circuit is used for the oscillation circuit to generate a driving signal, which is output to the isolation transformer through the driving circuit to trigger the unidirectional thyristor discharge; The thyristor discharge circuit uses an auto-boosting transformer L1 to instantaneously increase the discharge voltage; The working status indication circuit is used for measuring the discharge current signal by the current transformer and outputting it to the relay by driving the time base circuit to indicate the working status of the ignition system; The charge and discharge timing control circuit is composed of a time base circuit to form a period-adjustable circuit, including a timer chip U2, the timer chip U2 pin is connected to a capacitor C16, a capacitor C17 and a relay J1, the relay J1 pin is connected to a resistor R17 and a resistor R18, the resistor R17 and the resistor R18 are connected to a diode D14, and the relay J1 pin is connected to a transistor U3C, the transistor U3C pin is connected to a resistor R25, a resistor R29 and a resistor R32, the resistor R25 is connected to a diode D15, the resistor R29 is connected to R24 and a resistor R33, and the resistor R32 is connected to a capacitor C19; The thyristor discharge circuit includes an oscillation circuit, a drive circuit and a unidirectional thyristor, including a transistor U3D, the transistor U3D pin is connected to a resistor R23, a resistor R31 and a capacitor C20, the capacitor C20 is connected to a transistor Q7, a resistor R37 and a resistor R35, the resistor R23 is connected to a resistor R22, a resistor R26 and a resistor R34, the resistor R31 is connected to a resistor R28 and a transistor Q6, the transistor Q6 is connected to a capacitor C18 and a diode D16, the capacitor C18 is connected to a capacitor C21 and a resistor R36, the resistor R36 is connected to a transformer T3, the transformer T3 is connected to a bridge rectifier diode VD1, a transistor VT1 and a transistor VT2, the bridge rectifier diode VD1 is connected to a capacitor C4, and the transistor VT2 is connected to a capacitor C5 and a resistor R5.

2. A thyristor controlled discharge high energy ignition system according to claim 1, It is characterized in that The switching power supply charging circuit comprises a PWM circuit, a driving circuit, a switching tube, a boost transformer, a high-voltage rectification circuit and a capacitor.

3. A thyristor controlled discharge high energy ignition system according to claim 1, It is characterized in that The protection circuit includes a voltage detection circuit, a current detection circuit, a temperature detection circuit and a protection locking circuit.

4. A thyristor controlled discharge high energy ignition system according to claim 1, It is characterized in that The working state indicating circuit comprises a current transformer, a delay circuit and a relay output circuit.

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