A combustion safety controller

Abstract

This invention discloses a combustion safety controller, belonging to the field of combustion safety control technology. The controller includes a power terminal, a flame detector interface, a first relay, a second relay, and a control unit. The control unit includes a detection circuit, which is shared by the safety start detection circuit and the flame detection circuit. After the power supply is connected to the power terminal, the control unit performs safety start detection through the detection circuit. When a flame signal is detected, the first relay is opened to prevent ignition; when no flame signal is detected, the first relay is closed to allow ignition. During ignition operation, the on / off state of the second relay is controlled according to the real-time flame signal. This invention, by sharing the same circuit structure for safety start detection and flame detection, can effectively identify abnormal flame conditions before ignition and promptly interrupt ignition, improving the safety and reliability of combustion equipment operation.

Description

Technical Field

[0001] This invention belongs to the field of combustion safety control technology, and particularly relates to a combustion safety controller. Background Technology

[0002] In large commercial and industrial combustion devices, the flame safety controller is a core component ensuring the safe operation of the combustion equipment. During startup and operation, the burner requires real-time monitoring of the flame status and must promptly cut off the fuel supply in case of abnormal flames or ignition failure to prevent fuel accumulation that could lead to deflagration or explosion. In existing technologies, combustion safety controllers typically include a flame detector interface, a signal amplification circuit, and an output control relay to determine the presence or absence of a flame and provide corresponding interlocking protection.

[0003] However, existing combustion safety controllers generally have the following shortcomings: First, most controllers only have simple flame signal amplification and judgment functions, lacking a pre-ignition safety self-check mechanism. This means that during startup, they cannot detect false flame signals or false alarms caused by ambient light interference from the flame detector. If abnormal signals are present, ignition may still be allowed, potentially leading to serious safety accidents. Second, the controller's safety startup detection circuit and the flame detection circuit during normal operation typically use separate circuit structures, resulting in a larger overall controller size, more complex circuitry, and increased cost. Furthermore, existing products also have numerous safety hazards regarding wiring specifications and insulation protection between the flame detector and the controller.

[0004] With the continuous improvement of industrial safety standards, higher requirements are being placed on the safety, reliability, and integration of combustion safety controllers. To address the shortcomings of existing technologies, it is necessary to provide a combustion safety controller that integrates the safety start detection circuit and the flame detection circuit into a single circuit structure. This controller can automatically detect abnormal states of the flame signal before ignition and interrupt ignition upon detection of an anomaly, only resuming operation after the anomaly is eliminated. This effectively avoids malfunctions caused by false alarms from the flame detector or environmental interference, improving the safety and reliability of combustion control, while simultaneously simplifying the circuit structure, reducing size, and lowering manufacturing costs. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a combustion safety controller, comprising: Power terminals are used to connect to the operating power supply; A flame detector interface, including a first terminal and a second terminal, is used to connect a flame detector to receive flame signals; The first relay is used to control the on / off state of the ignition circuit; The second relay is used to output a flame status signal; The control unit is connected to the power terminal, the flame detector interface, the first relay and the second relay respectively. The control unit includes a detection circuit, and the safety start detection circuit and the flame detection circuit share the detection circuit. The control unit is configured to: After the power supply is connected to the power terminal, a safety start test is performed through the detection circuit. During the safety start test, the flame signal is acquired through the flame detector interface. When the flame signal is received during the safety start detection, the first relay is controlled to disconnect to prevent ignition. If the flame signal is not received during the safety start detection, the first relay is controlled to close to allow ignition; During ignition operation, the detection circuit controls the on / off state of the second relay based on the flame signal acquired in real time by the flame detector interface.

[0006] Optionally, the detection circuit includes: A rectifier module is used to rectify the flame signal; A current limiting module is used to limit the current of the rectified flame signal; An isolation module is used to electrically isolate the flame signal after current limiting and convert it into a detection signal; A switch module is used to output a signal input to the control unit based on the detection signal.

[0007] Optionally, the detection circuit includes: The first connecting terminal and the second connecting terminal are respectively used to connect the two ends of the flame detector; A rectifier diode is connected in series between the first connection terminal and the current-limiting resistor network; The current-limiting resistor network includes a first current-limiting resistor, a second current-limiting resistor, and a third current-limiting resistor connected in parallel, and a fourth current-limiting resistor connected in series, used to limit the current of the flame signal and input it to the input side of the optocoupler. The other end of the input side of the optocoupler is connected to the second connection terminal. The first filter capacitor is connected in parallel between the input terminal of the fourth current-limiting resistor and the second connection terminal; The optocoupler has one output end grounded, and the other end connected to the power supply through a pull-up resistor and grounded through a pull-down resistor, forming a detection signal node; A switching transistor, the base of which is connected to the detection signal node, the emitter of which is grounded, and the collector of which is connected to the output terminal through an output resistor; The second filter capacitor is connected between the output terminal and ground; The output terminal is connected to the signal input terminal of the control unit.

[0008] Optionally, the control unit performs the safety start detection by: detecting the presence of the flame signal or simulated flame signal through the detection circuit within a preset time after the power supply terminal is connected.

[0009] Optionally, when the flame signal is acquired during the safety start detection, the control unit keeps the first relay disconnected and continues to monitor the flame detector interface through the detection circuit until the flame signal disappears and then re-executes the safety start detection.

[0010] Optionally, if the flame signal is not received during the safety start detection, the control unit controls the first relay to close and allows the external ignition switch to trigger ignition.

[0011] Optionally, the control unit controls the on / off state of the second relay according to the flame signal as follows: When the detection circuit does not detect the flame signal, it controls the second relay to disconnect; When the detection circuit detects the flame signal, it controls the second relay to close.

[0012] Optionally, the control unit is further configured to, during ignition operation, control the second relay to disconnect to cut off the fuel valve when the detection circuit detects that the flame signal changes from present to absent.

[0013] Optionally, the first terminal corresponds to the first connection terminal in the detection circuit, and the second terminal corresponds to the second connection terminal in the detection circuit; the first terminal is used to connect to the signal terminal of the ultraviolet flame detector, and the second terminal is used to connect to the common terminal of the ultraviolet flame detector.

[0014] Compared with the prior art, the present invention has the following advantages and technical effects: This invention integrates the safety start detection circuit and the flame detection circuit into a single detection circuit. It can automatically identify whether the flame detector has false flame signals or ambient light interference before ignition. When an abnormal flame signal is detected, the ignition process is interrupted in a timely manner, effectively avoiding the risk of fuel leakage or deflagration caused by false alarms from the detector, and significantly improving the safety of the combustion equipment during the start-up phase. Simultaneously, the safety start detection and flame detection share the same circuit structure. Compared to the traditional solution using two independent circuits, this simplifies the controller's circuit layout, reduces product size, lowers hardware costs and failure rates, and improves product integration and reliability. Furthermore, during ignition operation, the control unit can quickly respond to and precisely control the output state of the second relay based on the real-time flame signal, promptly cutting off the fuel valve when the flame signal abnormally disappears, further ensuring the safety and stability of the combustion equipment throughout its entire operating cycle. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the controller structure according to an embodiment of the present invention; Figure 2 This is a circuit structure diagram of an embodiment of the present invention. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0018] Example 1 like Figure 1 As shown, this embodiment provides a combustion safety controller, including: Power terminals are used to connect to the operating power supply; A flame detector interface, including a first terminal and a second terminal, is used to connect a flame detector to receive flame signals; The first relay is used to control the on / off state of the ignition circuit; The second relay is used to output the flame status signal; The control unit is connected to the power supply terminal, the flame detector interface, the first relay and the second relay respectively. The control unit includes a detection circuit, and the safety start detection circuit and the flame detection circuit share the detection circuit. The control unit is configured as follows: After the power supply is connected to the power terminal, a safety start test is performed through the detection circuit. During the safety start test, the flame signal is acquired through the flame detector interface. When a flame signal is detected during the safety start-up test, the first relay is disconnected to prevent ignition. If no flame signal is received during the safety start-up test, the first relay is closed to allow ignition; During ignition operation, the detection circuit controls the on / off state of the second relay based on the flame signal obtained in real time from the flame detector interface.

[0019] Furthermore, the detection circuit includes: The rectifier module is used to rectify the flame signal; The current limiting module is used to limit the current of the rectified flame signal; The isolation module is used to electrically isolate the flame signal after current limiting and convert it into a detection signal; The switch module is used to output the detection signal to the signal input terminal of the control unit.

[0020] Furthermore, such as Figure 2 As shown, the detection circuit includes: The detection circuit includes a first connection terminal CN3-1 and a second connection terminal CN2-1, which are used to connect the two ends of the flame detector, respectively.

[0021] A rectifier diode D9 is connected in series between the first connection terminal CN3-1 and the current-limiting resistor network. The current-limiting resistor network includes a first current-limiting resistor R49, a second current-limiting resistor R48, and a third current-limiting resistor R47 connected in parallel, and a fourth current-limiting resistor R46 connected in series. The current-limiting resistor network is used to limit the current of the flame signal before inputting it to the input side of the optocoupler U5. The other end of the input side of the optocoupler U5 is connected to the second connection terminal CN2-1.

[0022] The first filter capacitor C32 is connected in parallel between the input terminal of the fourth current-limiting resistor R46 and the second connection terminal CN2-1.

[0023] One end of the output side of optocoupler U5 is grounded, and the other end is connected to power supply VC2 through pull-up resistor R40 and grounded through pull-down resistor R43, forming a detection signal node.

[0024] The base of the switching transistor Q5 is connected to the detection signal node, the emitter is grounded, and the collector is connected to the output terminal CN3-4 through the output resistor R44.

[0025] The second filter capacitor C28 is connected between the output terminal CN3-4 and ground. The output terminal CN3-4 is connected to the signal input terminal of the control unit.

[0026] Furthermore, the control unit performs a safety start detection including: within a preset time after the power supply terminal is connected, detecting the presence of a flame signal or simulated flame signal through a detection circuit.

[0027] Furthermore, when a flame signal is detected during the safety start test, the control unit keeps the first relay 1K open and continuously monitors the flame detector interface through the detection circuit until the flame signal disappears, at which point the safety start test is re-executed.

[0028] Furthermore, when no flame signal is received during the safety start detection, the control unit controls the first relay 1K to close and allows the external ignition switch to trigger ignition.

[0029] Furthermore, the control unit controls the on / off state of the second relay 2K based on the flame signal as follows: When the detection circuit does not detect a flame signal, it controls the second relay 2K to disconnect; When the detection circuit detects a flame signal, it controls the second relay 2K to close.

[0030] Furthermore, the control unit is also used to control the second relay to disconnect and cut off the fuel valve when the detection circuit detects that the flame signal changes from present to absent during ignition operation.

[0031] Furthermore, the first terminal corresponds to the first connection terminal in the detection circuit, and the second terminal corresponds to the second connection terminal in the detection circuit; the first terminal is used to connect to the signal terminal of the ultraviolet flame detector, and the second terminal is used to connect to the common terminal of the ultraviolet flame detector.

[0032] To determine if the flame detector is installed correctly, the flame voltage needs to be measured. This is done by connecting the (+) and (-) terminals to terminals 9 and 10 on the front side, respectively. A flame voltage greater than 2Vdc is recommended. Simultaneously, the flame detection voltage should not exceed 5.5V.

[0033] Table 1 is the operating sequence table for a manual ignition system with continuous pilot flame.

[0034] Table 1 In the table, ① if a flame is detected before the safety check is completed, operation will stop and continue until the flame signal disappears.

[0035] ②The flame output signal is detected and the ignition switch is released.

[0036] ③ If the flame signal disappears during operation, the system will stop operating (the gas valve will shut down due to power failure).

[0037] ④ Pilot Fire Setup Time (PFEP): Should meet standard requirements.

[0038] Table 2 is the normal operating sequence table for the flame detection system.

[0039] Table 2 In the table, ① if a flame is detected before the safety check is completed, operation will stop and continue until the flame signal disappears.

[0040] ②The flame output signal is detected, and the flame relay switch is switched.

[0041] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A combustion safety controller, characterized in that, include: Power terminals are used to connect to the operating power supply; A flame detector interface, including a first terminal and a second terminal, is used to connect a flame detector to receive flame signals; The first relay is used to control the on / off state of the ignition circuit; The second relay is used to output the flame status signal; The control unit is connected to the power terminal, the flame detector interface, the first relay and the second relay respectively. The control unit includes a detection circuit, and the safety start detection circuit and the flame detection circuit share the detection circuit. The control unit is configured to: After the power supply is connected to the power terminal, a safety start test is performed through the detection circuit. During the safety start test, the flame signal is acquired through the flame detector interface. When the flame signal is received during the safety start detection, the first relay is controlled to disconnect to prevent ignition. If the flame signal is not received during the safety start detection, the first relay is controlled to close to allow ignition; During ignition operation, the detection circuit controls the on / off state of the second relay based on the flame signal acquired in real time by the flame detector interface.

2. The combustion safety controller according to claim 1, characterized in that, The detection circuit includes: A rectifier module is used to rectify the flame signal; A current limiting module is used to limit the current of the rectified flame signal; An isolation module is used to electrically isolate the flame signal after current limiting and convert it into a detection signal; A switch module is used to output a signal input to the control unit based on the detection signal.

3. The combustion safety controller according to claim 1, characterized in that, The detection circuit includes: The first connecting terminal and the second connecting terminal are respectively used to connect the two ends of the flame detector; A rectifier diode is connected in series between the first connection terminal and the current-limiting resistor network; The current-limiting resistor network includes a first current-limiting resistor, a second current-limiting resistor, and a third current-limiting resistor connected in parallel, and a fourth current-limiting resistor connected in series, used to limit the current of the flame signal and input it to the input side of the optocoupler. The other end of the input side of the optocoupler is connected to the second connection terminal. The first filter capacitor is connected in parallel between the input terminal of the fourth current-limiting resistor and the second connection terminal; The optocoupler has one output end grounded, and the other end connected to the power supply through a pull-up resistor and grounded through a pull-down resistor, forming a detection signal node; A switching transistor, the base of which is connected to the detection signal node, the emitter of which is grounded, and the collector of which is connected to the output terminal through an output resistor; The second filter capacitor is connected between the output terminal and ground; The output terminal is connected to the signal input terminal of the control unit.

4. The combustion safety controller according to claim 1, characterized in that, The control unit performs the safety start detection by: within a preset time after the power supply terminal is connected, detecting the presence of the flame signal or simulated flame signal through the detection circuit.

5. The combustion safety controller according to claim 1, characterized in that, When the flame signal is detected during the safety start-up test, the control unit keeps the first relay open and continues to monitor the flame detector interface through the detection circuit until the flame signal disappears and then re-executes the safety start-up test.

6. The combustion safety controller according to claim 1, characterized in that, If the flame signal is not received during the safety start detection, the control unit controls the first relay to close and allows the external ignition switch to trigger ignition.

7. The combustion safety controller according to claim 1, characterized in that, The control unit controls the on / off state of the second relay according to the flame signal as follows: When the detection circuit does not detect the flame signal, it controls the second relay to disconnect; When the detection circuit detects the flame signal, it controls the second relay to close.

8. The combustion safety controller according to claim 1, characterized in that, The control unit is also configured to, during ignition operation, control the second relay to disconnect to cut off the fuel valve when the detection circuit detects that the flame signal changes from present to absent.

9. The combustion safety controller according to claim 3, characterized in that, The first terminal corresponds to the first connection terminal in the detection circuit, and the second terminal corresponds to the second connection terminal in the detection circuit; The first terminal is used to connect to the signal terminal of the ultraviolet flame detector, and the second terminal is used to connect to the common terminal of the ultraviolet flame detector.

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