Flame detection device and combustion equipment

Abstract

The utility model discloses a flame detection device and combustion equipment. The flame detection device comprises a driving output module and an ion detection module, the driving output module comprises a transformer, a charging and discharging module and a controllable electronic switch; the transformer comprises a first primary coil, a second primary coil and a secondary coil; one end of the secondary coil is grounded; the charging and discharging module is a capacitor; the controllable electronic switch comprises a control end, a first end and a second end; two ends of the first primary coil are respectively connected with the first end and the direct-current power supply; two ends of the second primary coil are respectively connected with the direct-current power supply and the control end; two ends of the charging and discharging module are respectively connected with the control end and the second end; the second end is grounded; the other end of the secondary coil outputs sine alternating current; the ion detection module comprises an ion end and a detection output module which are respectively connected with the other end of the secondary coil; the detection output module outputs a detection signal. According to the utility model, the accuracy of flame detection and the safety of combustion equipment are improved.

Description

Technical Field

[0001] This utility model belongs to the field of flame ion detection technology, specifically, it relates to a flame detection device and combustion equipment. Background Technology

[0002] Because combustible materials are generally flammable, explosive, and prone to leakage, the safety requirements for combustion equipment are becoming increasingly stringent. The EN298 standard requires that gas application control systems must be equipped with flame ionization detection devices to monitor the flame status of gas equipment in real time; and that the gas valve be shut off promptly in case of abnormal flame detection signals to prevent gas leakage.

[0003] Existing flame ionization detection circuits only detect the presence of current between the flame probe and the casing, and then determine whether the flame is normal based on the absence of current when there is no flame and the presence of current when there is a flame. However, as combustion equipment is used over time, dust or moisture accumulation on the controller PCB can easily generate microampere-level currents similar to flame ionization signals. This can cause the combustion equipment to be mistakenly identified as having a flame and normal flame even when there is no flame, posing a safety hazard.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0005] This invention addresses the problem in existing technologies where dust and / or moisture contamination can easily lead to misjudgments of flame conditions as flame-prone and pose a safety hazard. This invention proposes a flame detection device and combustion equipment that can accurately identify flame ion current even in the presence of contamination, thereby improving the accuracy and reliability of flame detection and enhancing the safety of combustion equipment use.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0007] A flame detection device includes a drive output module and an ion detection module;

[0008] The drive output module includes a transformer, a charging / discharging module, and a controllable electronic switch; the transformer includes a first primary coil, a second primary coil, and a secondary coil; one end of the secondary coil is grounded; the charging / discharging module is a capacitor used for rapid charging and discharging; the controllable electronic switch includes a control terminal, a first terminal, and a second terminal; the two ends of the first primary coil are respectively connected to the first terminal and a DC power supply; the two ends of the second primary coil are respectively connected to the DC power supply and the control terminal; the two ends of the charging / discharging module are respectively connected to the control terminal and the second terminal; the second terminal is grounded; the other end of the secondary coil outputs a sinusoidal alternating current with a positive voltage peak value greater than the negative voltage peak value.

[0009] The ion detection module includes an ion terminal and a detection output module; the ion terminal is positioned at the flame location and is used to detect the flame; the other end of the secondary coil is connected to the ion terminal and the detection output module respectively, providing a detection driving voltage to the ion terminal and a detection voltage to the detection output module; the detection output module includes an output terminal for outputting a detection signal.

[0010] In some specific embodiments, the controllable electronic switch is an NPN transistor; the control terminal is the base; the first terminal is the collector; and the second terminal is the emitter.

[0011] In some specific embodiments, the controllable electronic switch is an N-channel MOS transistor; the control terminal is the gate; the first terminal is the drain; and the second terminal is the source.

[0012] In some specific embodiments, a resistor module is also included, which is connected in series with the second primary coil and its two ends are respectively connected to the DC power supply and the control terminal.

[0013] In some specific embodiments, the resistor module includes a first resistor and a second resistor, which are located on both sides of the second primary coil and connected in series with the second primary coil.

[0014] In some specific embodiments, the ion detection module further includes a drive input module and a voltage divider module;

[0015] The drive input module is a resistor-capacitor combination, with its two ends connected to the other end of the secondary coil and one end of the voltage divider module, respectively, for forming a voltage divider with the voltage divider module and filtering the sinusoidal AC current; the other end of the voltage divider module is connected to the ion terminal.

[0016] In some specific embodiments, the voltage divider module is a resistor, with its two ends connected to the drive input module and the ion terminal, respectively.

[0017] In some specific embodiments, the number of turns of the first primary coil is less than the number of turns of the second primary coil, and the other end of the secondary coil outputs a sinusoidal alternating current with a positive voltage peak value greater than the absolute value of the negative voltage peak value;

[0018] The detection output module also includes a first diode, a second diode, a first capacitor, a third resistor, and a fourth resistor;

[0019] The positive terminal of the first diode is connected to the drive input module, and the negative terminal is connected to the DC power supply;

[0020] The positive terminal of the second diode is grounded, and the negative terminal is connected to the drive input module;

[0021] One end of the first capacitor is connected to the positive terminal of the first diode and the negative terminal of the second diode, and the other end is grounded;

[0022] The two ends of the third resistor and the fourth resistor connected in series are respectively connected to the DC power supply and one end of the first capacitor; the common terminal of the third resistor and the fourth resistor is connected to the output terminal.

[0023] In some specific embodiments, the detection output module further includes a fifth resistor;

[0024] The common terminal of the third resistor and the fourth resistor is connected to the output terminal through the fifth resistor.

[0025] A combustion device, comprising the flame detection device described above.

[0026] Compared with the prior art, the advantages and positive effects of this utility model are:

[0027] The flame detection device and combustion equipment of this invention can provide sinusoidal alternating current through the drive output module to generate a detection voltage that is different from that when there is no flame or no flame pollution when the flame is normal. Then, the output terminal outputs different detection signals corresponding to different detection voltages, accurately detecting the normal flame condition and the absence of flame condition. This avoids the situation where the detection drive voltage is only positive and there is no flame pollution, which can easily lead to misjudgment as a normal flame, thus improving the accuracy of flame detection and improving the safety of the combustion equipment.

[0028] Other features and advantages of this utility model will become clearer after reading the detailed embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a circuit structure diagram of a flame detection device proposed by the present invention according to an embodiment;

[0031] Figure 2 This is a schematic diagram of the circuit structure of the drive output module according to an embodiment;

[0032] Figure 3 This is a schematic diagram of the circuit structure of the drive output module according to another embodiment;

[0033] Figure 4 This is a schematic diagram of the module structure of the ion detection module according to an embodiment;

[0034] Figure 5 This is a schematic diagram of the circuit structure of the ion detection module according to an embodiment.

[0035] In the picture,

[0036] T1, Transformer; T11, First primary coil; T12, Second primary coil; T13, Secondary coil; Vcc, DC power supply; N1, Controllable electronic switch; 1, Control terminal; 2, First terminal; 3, Second terminal; N2, Resistor module; N3, Charge / discharge module; N4, Drive input module; N5, Detection output module; N6, Voltage divider module; IB, Ion terminal; OUT1, Output terminal; R1, First resistor; R2, Second resistor; D1, First diode; D2, Second diode; D3, Third diode; C1, First capacitor; C2, Second capacitor; R3, Third resistor; R4, Fourth resistor; R5, Fifth resistor; R6, Sixth resistor; R7, Seventh resistor; R8, Eighth resistor; R9, Ninth resistor; R10, Tenth resistor. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0038] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0039] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. In the description of the embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0040] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0041] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0042] Reference Figure 1 The flame detection device of this utility model includes a drive output module and an ion detection module. The drive output module is connected to the ion detection module and provides the ion detection module with a detection drive voltage and a detection voltage.

[0043] The drive output module includes a transformer T1, which includes a first primary coil T11, a second primary coil T12, and a secondary coil T13; one end of the secondary coil T13 is grounded.

[0044] The drive output module also includes a charge / discharge module N3, which is a capacitor used for rapid charging and discharging to provide varying control voltage.

[0045] The drive output module also includes a controllable electronic switch N1, which includes a control terminal 1, a first terminal 2, and a second terminal 3; the first terminal 2 and the second terminal 3 are the two ends of the switch, respectively; the two ends of the first primary coil T11 are connected to the first terminal 2 and the DC power supply Vcc, respectively; the two ends of the second primary coil T12 are connected to the DC power supply Vcc and the control terminal 1, respectively; the two ends of the charge / discharge module N3 are connected to the control terminal 1 and the second terminal 3, respectively; the second terminal 3 is grounded.

[0046] The DC power supply Vcc charges the charging and discharging module N3, causing the voltage connected to the control terminal 1 of the charging and discharging module N3 to gradually increase. At this time, the charging current of the second primary coil T12 causes the secondary coil T13 to couple and generate a negative voltage output. When the charging voltage reaches the control voltage value of the controllable electronic switch N1, the first terminal 2 and the second terminal 3 are connected. At this time, the first primary coil T11 forms a current-carrying circuit, and there is current, causing the secondary coil T13 to couple and generate a positive voltage output. At the same time, the charging and discharging module N3 discharges, and when its voltage is below the control voltage value of the controllable electronic switch N1, the first terminal 2 and the second terminal 3 are disconnected, and the charging and discharging module N3 is charged. The controllable electronic switch N1, the charging and discharging module N3, and the first primary coil T11 and the second primary coil T12 of the transformer T1 form an oscillation circuit.

[0047] The ion detection module includes an ion terminal IB, one end of which is connected to the other end of the secondary coil T13 to receive the detection drive voltage. The other end is set at the flame position, and the casing is grounded, so that a strong electric field is formed between the ion terminal IB and the casing. When the flame is normal, the ion terminal IB and the casing are connected to form a unidirectional path through the flame ionization principle.

[0048] The ion detection module also includes a detection output module N5, which is connected to the other end of the secondary coil T13 and receives the detection voltage. The value of the detection voltage is affected by the conduction status of the ion terminal IB. The detection output module N5 includes an output terminal OUT1. The detection output module N5 generates different detection signals according to different detection voltages and outputs them through the output terminal OUT1.

[0049] When the flame is normal, a one-way conduction path is formed between the ion terminal IB and the housing, which can be equivalent to a series circuit of the third diode D3 and the seventh resistor R7; the positive terminal of the third diode D3 is connected to the ion rod; during the positive half-cycle of the sinusoidal alternating current, a path is formed from the ion terminal IB to the housing; during the negative half-cycle, the ion terminal IB is disconnected from the housing, forming a different detection voltage than during the positive half-cycle, and then the output terminal OUT1 outputs the corresponding detection signal.

[0050] When there is no flame, that is, when the other end of the ion terminal IB is in a high-resistance state, the detection voltage is a sinusoidal alternating current, and the output terminal OUT1 outputs the corresponding detection signal.

[0051] When there is no flame contamination, that is, the ion rod and the casing are connected by a resistor or short circuit, which can be equivalent to the eighth resistor R8 and the ninth resistor R9; the resistance of the ninth resistor R9 is 0; similarly, the detection voltage is a sinusoidal alternating current or no voltage, and the output terminal OUT1 outputs the corresponding detection signal.

[0052] The flame detection device and combustion equipment of this invention can provide a sinusoidal alternating current with a positive voltage peak greater than the negative voltage peak through the drive output module. This generates a detection voltage that is different when the flame is normal compared to when there is no flame or no flame contamination. Then, the output terminal OUT1 outputs different detection signals corresponding to different detection voltages, accurately detecting the normal flame condition and the absence of flame. This avoids the situation where the detection drive voltage is only positive and there is no flame contamination, which can easily lead to misjudgment as a normal flame, thus improving the accuracy of flame detection and improving the safety of the combustion equipment.

[0053] This utility model also discloses a combustion device, which includes the above-mentioned flame detection device, and similarly has the technical effect of improving the safety of using the combustion device.

[0054] The specific circuit structure and principle of the flame detection device and combustion equipment of this utility model will be described in detail below through specific embodiments.

[0055] In some specific embodiments, refer to Figure 1 , Figure 2 The controllable electronic switch N1 is an NPN transistor; control terminal 1 is the base; first terminal 2 is the collector; and second terminal 3 is the emitter.

[0056] That is, the common terminal of the second primary coil T12 and the charging / discharging module N3 is connected to the base; the collector is connected to one end of the first primary coil T11, and the other end of the first primary coil T11 is connected to the DC power supply Vcc; the emitter is grounded.

[0057] In some specific embodiments, refer to Figure 1 , Figure 3 The controllable electronic switch N1 is an N-channel MOS transistor; control terminal 1 is the gate; first terminal 2 is the drain; and second terminal 3 is the source.

[0058] That is, the gate is connected to one end of the second primary coil T12, and the other end of the second primary coil T12 is connected to the DC power supply Vcc; one end of the charging and discharging module N3 is connected to the gate, and the other end is grounded; the drain is connected to one end of the first primary coil T11, and the other end of the first primary coil T11 is connected to the DC power supply Vcc; the source is grounded.

[0059] In some specific embodiments, refer to Figure 1 , Figure 2 , Figure 3 The drive output module also includes a resistor module N2, which is connected in series with the second primary coil T12 and its two ends are connected to the DC power supply Vcc and the control terminal 1, respectively, to limit the current of the control terminal 1.

[0060] In some specific embodiments, refer to Figure 1 , Figure 2 , Figure 3 The resistor module N2 includes a first resistor R1 and a second resistor R2, which are located on both sides of the second primary coil T12 and connected in series with the second primary coil T12.

[0061] That is, the two ends of the first resistor R1 are connected to the DC power supply Vcc and one end of the second primary coil T12, respectively; the two ends of the second resistor R2 are connected to the other end of the second primary coil T12 and the control terminal 1, respectively.

[0062] In some specific embodiments, refer to Figure 1 , Figure 4 The ion detection module also includes a drive input module N4, which is a resistor-capacitor combination, including a sixth resistor R6 and a second capacitor C2, which are connected in series. One end of the drive input module N4 is connected to the other end of the secondary coil T13.

[0063] The ion detection module also includes a voltage divider module N6, whose two ends are connected to the other end of the drive input module N4 and one end of the ion terminal IB, respectively. When the flame is in the positive half-cycle of a normal sinusoidal alternating current and there is no flame contamination, the voltage divider module N6 and the drive input module N4 form a voltage divider to obtain the required detection voltage.

[0064] In addition, the resistor-capacitor combination of the drive input module N4 filters the sinusoidal AC power to ensure the quality of the sinusoidal AC power and improve the accuracy and reliability of the detection.

[0065] In some specific embodiments, refer to Figure 1 , Figure 4 , Figure 5 The voltage divider module N6 is a resistor, and its two ends are connected to one end of the second capacitor C2 and the other end of the ion terminal IB, respectively; the other end of the second capacitor C2 is connected to one end of the sixth resistor R6; the other end of the sixth resistor R6 is connected to the other end of the secondary coil T13.

[0066] In some specific embodiments, refer to Figure 1 , Figure 4 , Figure 5 The number of turns of the first primary coil T11 is less than the number of turns of the second primary coil T12, and the other end of the secondary coil T13 outputs a sinusoidal alternating current with a positive voltage peak greater than the negative voltage peak.

[0067] The detection output module N5 also includes a first diode D1, a second diode D2, a first capacitor C1, a third resistor R3, and a fourth resistor R4.

[0068] The positive terminal of the first diode D1 is connected to the drive input module N4, and the negative terminal is connected to the DC power supply Vcc; the positive terminal of the second diode D2 is grounded, and the negative terminal is connected to the drive input module N4; that is, the positive terminal of the first diode D1 is connected to the negative terminal of the second diode D2 and is also connected to the drive input module N4; the negative terminal of the first diode D1 is connected to the DC power supply Vcc; and the positive terminal of the second diode D2 is grounded.

[0069] The two ends of the first capacitor C1 are connected to the positive terminal of the first diode D1 and ground, respectively; that is, the first capacitor C1 is connected in parallel with the second diode D2.

[0070] The third resistor R3 and the fourth resistor R4 are connected in series, and their two ends are connected to the DC power supply Vcc and the positive terminal of the first diode D1, respectively; that is, the two ends of the series connection of the third resistor R3 and the fourth resistor R4 are connected to the DC power supply Vcc and the negative terminal of the second diode D2, respectively; the common terminal of the third resistor R3 and the fourth resistor R4 is the output terminal OUT1.

[0071] The flame detection device in this embodiment clamps the voltage of one end of the first capacitor C1 relative to the other end between the DC power supply Vcc, the sum of the conduction voltage of the first diode D1, and the negative value of the conduction voltage of the second diode D2 through the first diode D1 and the second diode D2, so that the detection signal determined by the detection voltage is within the DC power supply Vcc.

[0072] When the flame is normal, the ion terminal IB is unidirectionally connected to the casing; during the positive half-cycle of the sinusoidal alternating current, the ion terminal IB is connected to the casing, and the detection voltage is close to 0; during the negative half-cycle of the sinusoidal alternating current, the ion terminal IB is disconnected from the casing, and the detection voltage is the negative half-cycle voltage; then the first capacitor C1 stores negative charge; the detection signal at the output terminal OUT1 is the component of the sum of the DC power supply voltage Vcc and the negative charge.

[0073] When there is no flame, the ion terminal IB is suspended, and the detection voltage is a sinusoidal alternating current. Since the peak value of the positive voltage of the sinusoidal alternating current is greater than the peak value of the negative voltage, the first capacitor C1 stores positive electricity. The detection signal at the output terminal OUT1 is the component of the sum of the DC power supply Vcc voltage and the positive electricity.

[0074] When there is no flame contamination, the ion terminal IB is connected to the housing through a resistor or short circuit. Due to the large voltage division of the drive input module N4, the voltage division of the path between the ion terminal IB and the housing is almost zero; the potential of the first capacitor C1 is close to 0; the detection signal of the output terminal OUT1 is the component of the DC power supply Vcc voltage.

[0075] The detection signals for normal flame, no flame, and no flame pollution are clearly distinguished, improving the accuracy and reliability of flame detection and enhancing the safety of gas use.

[0076] In some specific embodiments, refer to Figure 5The detection output module N5 also includes a fifth resistor R5.

[0077] The common terminal of the third resistor R3 and the fourth resistor R4 is connected to the output terminal OUT1 through the fifth resistor R5; the fifth resistor R5 is used to limit the current of the output detection signal.

[0078] In some specific embodiments, refer to Figure 5 The detection output module N5 also includes a tenth resistor R10, whose two ends are connected to the common terminal of the drive input module N4, the first diode D1, and the second diode D2, respectively.

[0079] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by this utility model.

Claims

1. A flame detection device, characterized in that, include: The drive output module includes a transformer, a charging / discharging module, and a controllable electronic switch. The transformer includes a first primary coil, a second primary coil, and a secondary coil; one end of the secondary coil is grounded. The charging / discharging module is a capacitor used for rapid charging and discharging. The controllable electronic switch includes a control terminal, a first terminal, and a second terminal. The two ends of the first primary coil are respectively connected to the first terminal and a DC power supply. The two ends of the second primary coil are respectively connected to the DC power supply and the control terminal. The two ends of the charging / discharging module are respectively connected to the control terminal and the second terminal; the second terminal is grounded. The other end of the secondary coil outputs a sinusoidal alternating current. An ion detection module includes an ion terminal and a detection output module. The ion terminal is positioned at the flame location and is used to detect the flame. The other end of a secondary coil is connected to both the ion terminal and the detection output module, providing a detection driving voltage to the ion terminal and a detection voltage to the detection output module. The detection output module includes an output terminal for outputting a detection signal.

2. The flame detection device according to claim 1, characterized in that, The controllable electronic switch is an NPN transistor; the control terminal is the base; the first terminal is the collector; and the second terminal is the emitter.

3. The flame detection device according to claim 1, characterized in that, The controllable electronic switch is an N-channel MOS transistor; the control terminal is the gate; the first terminal is the drain; and the second terminal is the source.

4. The flame detection device according to claim 2 or 3, characterized in that, It also includes a resistor module, which is connected in series with the second primary coil and its two ends are respectively connected to the DC power supply and the control terminal.

5. The flame detection device according to claim 4, characterized in that, The resistor module includes a first resistor and a second resistor, which are located on both sides of the second primary coil and connected in series with the second primary coil.

6. The flame detection device according to any one of claims 1 to 3, characterized in that, The ion detection module also includes a drive input module and a voltage divider module; The drive input module is a resistor-capacitor combination, with its two ends connected to the other end of the secondary coil and one end of the voltage divider module, respectively, for forming a voltage divider with the voltage divider module and filtering the sinusoidal AC current; the other end of the voltage divider module is connected to the ion terminal.

7. The flame detection device according to claim 6, characterized in that, The voltage divider module is a resistor, and its two ends are connected to the drive input module and the ion terminal, respectively.

8. The flame detection device according to claim 7, characterized in that, The number of turns of the first primary coil is less than the number of turns of the second primary coil, and the other end of the secondary coil outputs a sinusoidal alternating current with a positive voltage peak value greater than the absolute value of the negative voltage peak value; The detection output module also includes a first diode, a second diode, a first capacitor, a third resistor, and a fourth resistor; The positive terminal of the first diode is connected to the drive input module, and the negative terminal is connected to the DC power supply; The positive terminal of the second diode is grounded, and the negative terminal is connected to the drive input module; One end of the first capacitor is connected to the positive terminal of the first diode and the negative terminal of the second diode, and the other end is grounded; The two ends of the third resistor and the fourth resistor connected in series are respectively connected to the DC power supply and one end of the first capacitor; the common terminal of the third resistor and the fourth resistor is connected to the output terminal.

9. The flame detection device according to claim 8, characterized in that, The detection output module also includes a fifth resistor; The common terminal of the third resistor and the fourth resistor is connected to the output terminal through the fifth resistor.

10. A combustion device, characterized in that, Includes the flame detection device according to any one of claims 1 to 9.

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