Multifunctional combustion controller

Abstract

The invention relates to a plurality of multifunctional combustion controllers, each multifunctional combustion controller comprises an MCU, a communication port, a logic port, an input port and an output port, the communication port, the logic port, the input port and the output port are all connected with the MCU, the input port is used for receiving state information of UV ultraviolet light flame detection and ionization flame detection, and the logic port is used for receiving state information of UV ultraviolet light flame detection and ionization flame detection. The output port is used for driving the ignition transformer, the small fire valve, the main fire gas valve, the main fire air valve and the smoke exhaust valve to be opened / closed, and each multifunctional combustion controller is connected with the central control unit. The multifunctional combustion controller has the advantages that the multifunctional combustion controller integrates two paths of independent flame detection modes, has two functions of UV flame detection and ionization type flame detection, is suitable for three working modes of UV flame detection, integrated electrode flame detection and independent electrode flame detection, and can be connected to two flame detection interfaces of the MFCC for burners with two sets of flame detection, so that the flame detection efficiency is improved. And a flame detection signal amplifier does not need to be additionally configured.

Description

Technical Field

[0001] The invention relates to the field of industrial heat treatment, and in particular to a multifunctional combustion controller. Background Art

[0002] A large number of burners (or burners) are used in industrial production. They are a general term for devices that organize the mixed combustion of air and gas in a certain way. With the continuous advancement of combustion technology, the combination of a set of burners and auxiliary control valves with a combustion control device as a combustion unit has become increasingly widely used. However, the current combustion controllers generally have the disadvantages of single function and few control loops. In order to realize the multi-state combustion mode of various burners, many peripheral auxiliary electronic control devices need to be added, resulting in the combined combustion control device with cumbersome lines, high cost and large size. The main fire valve requires the central control unit to control it remotely through a long cable. In addition, when an industrial furnace is heated by multiple sets of combustion units, the combustion control device and the central control unit need to form a complete thermal control system, and a monitoring mechanism for command sending and status feedback is established between the central control unit and each combustion unit. At present, the combustion unit generally uses a multi-core signal cable to connect to the central control unit, and the types of commands and states correspond to the number of core wires. If there are many types of commands and states, many combustion units, and the distance between the central control unit and the industrial furnace site is far, the number of cables will increase exponentially, and the engineering and maintenance volume will be large, time-consuming and labor-intensive. Summary of the invention

[0003] The object of the present invention is to provide a multi-function combustion controller (Multi-Function Combustion Controller, MFCC), which realizes multi-functions and saves the number of connecting cables between the burner controller and the central control unit, facilitates wiring, and shortens maintenance time.

[0004] To achieve the above object, the present invention is implemented through the following technical solutions:

[0005] A multifunctional combustion controller, the number of which is multiple, each of which comprises an MCU, a communication port, a logic port, an input port and an output port, the communication port, the logic port, the input port and the output port are all connected to the MCU, the input port is used to receive status information of UV ultraviolet light fire detection and ionization fire detection, the output port is used to drive the ignition transformer, the small fire valve, the main fire gas valve, the main fire air valve and the smoke exhaust valve on / off, and each multifunctional combustion controller is connected to a central control unit.

[0006] The input port includes a UV interface and an ionization interface. The UV ultraviolet light fire detection is detected by an ultraviolet photosensitive tube, which is located at the fire peephole at the tail end of the burner and is used to convert the UV ultraviolet light emitted by the flame into a microcurrent signal. The microcurrent signal is connected to the UV interface; the ionization fire detection is detected by an ionization type fire detection electrode, and the detection end of the ionization type fire detection electrode is located inside the combustion chamber of the burner. The collected ionization microcurrent signal is transmitted to the ionization interface by the electrode sending end.

[0007] The ignition electrode and the fire detection electrode are two independent electrodes. The I end of the high-voltage side of the ignition transformer is connected to the ignition electrode, and the G end of the high-voltage side of the ignition transformer is grounded; the ionization interface 1 is connected to the fire detection electrode, and the ionization microcurrent signal is connected to the signal amplification circuit through a jumper, and the ionization interface 2 is grounded; the ignition electrode and the fire detection electrode are respectively arranged on both sides of the burner; the output end of the signal amplification circuit is connected to the MCU, and the signal amplification circuit includes an integrated amplifier chip.

[0008] The ignition electrode and the fire detection electrode are the same electrode. The I end of the high-voltage side of the ignition transformer is connected to the electrode, the G end of the high-voltage side of the ignition transformer is connected to the moving contact 1 of the relay through the ionization interface 1, the normally open static contact 1 of the relay is grounded through the ionization interface 2, the L end of the low-voltage side of the ignition transformer is connected to the ignition interface 1, the ignition interface 1 is connected to the AC power supply L through the moving contact 2 of the relay, the N end of the low-voltage side of the ignition transformer is connected to the ignition interface 2, the ignition interface 2 is connected to the AC power supply N through the normally open static contact 2 of the relay; the coil of the relay is connected to the digital output end of the MCU; the electrode is installed on one side of the burner.

[0009] The output port includes a valve control port, and the valve control port is respectively connected with a large air valve, a large gas valve, a smoke exhaust valve, and a small gas valve.

[0010] The communication port is an RS485 communication port, which is used to connect to the communication module of the PLC of the central control unit.

[0011] The logic port is an input / output port, and the input / output port is respectively connected to the digital output port of the PLC of the central control unit and the digital input port of the PLC, or the input / output port is respectively connected to the digital input / output module of the touch screen.

[0012] Each multifunctional combustion controller and the central control unit use a logical port to transmit the burner's command / status feedback information through 8421 coding, the content is as follows:

[0013] 1) The central control unit transmits the burner command information to the multifunctional combustion controller, which performs the corresponding action. The 8421 coded command information is:

[0014] The digital code is 0010, which means air cooling;

[0015] The digital code is 0011, which means a big fire;

[0016] The digital code is 0100, which means reset;

[0017] The digital code is 1001, which means forced ignition;

[0018] The digital code is 1010, which means forced smoke exhaust;

[0019] The digital code is 1011, which means forced fire;

[0020] 2) The multifunctional combustion controller transmits the status feedback information of the ignition burner to the central control unit. The 8421 coded status feedback information is:

[0021] The digital code is x000, which means stop working;

[0022] The digital code is x001, which means there is fire;

[0023] The digital code is x010, which means air cooling / smoke exhaust;

[0024] The digital code is x011, which means a big fire;

[0025] The digital code is x1xx, indicating an alarm;

[0026] The digital code is 1a01, which means forced low fire, where a represents a periodic jump between 0 and 1;

[0027] The digital code is 1a11, which means forced fire;

[0028] The digital code is 10a0, which means smoke exhaust;

[0029] The digital code is 1xxx, indicating remote operation;

[0030] The digital code is 0xxx, indicating local operation.

[0031] Each multifunctional combustion controller and the central control unit use a communication port to exchange instructions / status feedback information through messages. The content is as follows:

[0032] 1) The central control unit sends a command message to the multi-function combustion controller. The message format is hexadecimal:

[0033] Message 1: 16#0000-stop working; 16#0001-ignition; 16#0002-air cooling; 16#0003-high fire; 16#0004-reset; 16#0009-forced ignition; 16#000A-smoke exhaust; 16#000B-forced high fire;

[0034] Message 2: 16#01xx-01 is to modify the slave address of the multi-function combustion controller, xx is the new address number;

[0035] 2) Feedback status message from the multifunctional combustion controller to the central control unit:

[0036] a. Message 1: 16-bit status word, the content is as follows:

[0037] Bit number b0 indicates that the ionization fire detector detects the flame;

[0038] Position number b1 indicates that the UV fire detector detects a flame;

[0039] Bit number b2 indicates alarm indication;

[0040] Position number b3 indicates air cooling indication;

[0041] Position number b4 indicates smoke exhaust indication;

[0042] Position number b5, indicating valve position signal 1;

[0043] Position number b6, indicating valve position signal 2;

[0044] Bit number b7 means remote;

[0045] Bit number b8 indicates ignition signal output;

[0046] Position number b9 indicates that the small fire valve is open;

[0047] Position number b10 indicates that the main fire gas valve is open;

[0048] Position number b11 indicates that the main fire air valve is open;

[0049] Position number b12 indicates that the smoke exhaust valve is open;

[0050] b. Message 2: 16-bit status word, the content is as follows:

[0051] Bit number b0 means panel switch 0 is disconnected (local operation);

[0052] Bit number b1 indicates that panel switch 0 is turned on (remote operation);

[0053] Position number b2 indicates switch 1 (ignition on the spot when connected);

[0054] Position number b3 indicates that switch 2 is set to 1 (ignition is on-site when connected);

[0055] Position number b4 means switch 2 is set to 2 (local air cooling when turned on);

[0056] Bit number b5 indicates the reset button (reset in place when pressed);

[0057] c. Message 3: 16-bit status word: cumulative number of ignition failures;

[0058] d. Message 4: The continuous burning time of this ignition, which will be reset to zero when the ignition is turned off;

[0059] e. Message 5: duration of time when flame is not detected, returns to zero when flame is detected;

[0060] f. Message 6: Current slave address of MFCC;

[0061] g. Messages 7 to 10: reserved for extension.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] 1. For medium and large industrial furnaces, there are many burners. The communication module of the central control unit is connected to the multi-function combustion controller (MFCC) through a master-slave communication cable using a communication port. There is no need to add additional digital input and output modules to the central control unit to connect multiple burners one by one, which saves the number of connecting cables, facilitates wiring, reduces construction workload, and saves operation and maintenance costs;

[0064] 2. For industrial furnaces with few burners, a multifunctional combustion controller (MFCC) is used through a logic port to connect with the digital input and output module of the central control unit PLC (i.e., the input and output ports of the MFCC are connected one-to-one with the digital output and input modules of the central control unit PLC), or is connected with a touch screen with a digital port (i.e., the input and output ports of the MFCC are connected one-to-one with the digital output and input modules of the touch screen), which saves the number of connecting cables, facilitates wiring, reduces construction workload, and saves operation and maintenance costs;

[0065] 3. Each multifunctional combustion controller is connected to the central control unit by a logic port or a communication port. Either the logic port or the communication port can be selected, which is suitable for industrial furnace control systems of different sizes;

[0066] 4. The multifunctional combustion controller (MFCC) integrates two independent fire detection modes, and has both UV fire detection and ionization fire detection functions. It is applicable to the three working modes of UV fire detection, integrated electrode fire detection, and independent electrode fire detection. Moreover, the burners with two sets of fire detection can be connected to the two fire detection interfaces of MFCC respectively, without the need for additional configuration of fire detection signal amplifier. It is fully functional and easy to implement.

[0067] 5. The multi-function combustion controller (MFCC) integrates up to four independent valve control output functions, which can be flexibly applied to combustion units with different valve configurations. Compared with the traditional long-distance connection between the main fire valve, smoke exhaust valve and central control unit, the corresponding MFCC is connected with the nearest small fire valve, main gas valve, main air valve and smoke exhaust valve, shortening the cable distance, saving cables and reducing construction workload;

[0068] 6. The multifunctional combustion controller (MFCC) has a variety of options such as local operation, logic coding control feedback, and full-function communication monitoring. The indicator lights on the combustion controller panel can display various working conditions. Switches and buttons can be operated locally, which is convenient for operators to monitor / operate on-site or remotely through the central control, reducing production and operation costs and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 It is a schematic diagram of the principle of a multifunctional combustion controller.

[0070] Figure 2 It is a schematic diagram of the connection between the multifunctional combustion controller and the central control unit using logical coding.

[0071] Figure 3 This is a schematic diagram of the network topology for the communication connection between the multifunctional combustion controller and the central control unit.

[0072] Figure 4 It is a schematic diagram of a 2-state burner structure and supporting valves configured with an integrated electrode.

[0073] Figure 5 It is a schematic diagram of the structure of a three-state burner configured with a separation electrode and a matching valve.

[0074] Figure 6 It is a schematic diagram of the 3-state burner structure and supporting valves equipped with UV fire detection.

[0075] Figure 7 It is a schematic diagram of the heat storage burner structure and supporting valves.

[0076] Figure 8 It is a schematic diagram of the self-preheating burner structure and supporting valves.

[0077] Fig. 9 It is a connection diagram of separate electrodes.

[0078] Fig.10 It is a schematic diagram of ignition and fire detection of the integrated electrode.

[0079] Fig.11 It is the main process of the multi-functional combustion controller.

[0080] Fig.12 It is a schematic diagram of the ignition process.

[0081] Fig.13 This is a fire flow diagram.

[0082] Fig.14 It is a schematic diagram of the air cooling process.

[0083] Fig.15 It is a schematic diagram of the smoke exhaust process.

[0084] In the figure: 101- straight flame burner 102- heat storage burner 103- self-preheating burner 2- ignition burner 301- integrated electrode 302- ignition electrode 303- fire detection electrode 4- UV probe 501- gas valve 502- small gas valve 503- main gas valve

[0085] 601-air valve 602-main air valve 7-smoke exhaust valve 8-smoke exhaust port 9-preheater 10-ignition transformer 11-relay 12-jumper 13-heat storage body. DETAILED DESCRIPTION

[0086] The present invention is described in detail below in conjunction with the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0087] A multifunctional combustion controller, the number of which is multiple, each of which comprises an MCU, a communication port, a logic port, an input port and an output port, the communication port, the logic port, the input port and the output port are all connected to the MCU, the input port is used to receive status information of UV ultraviolet light fire detection and ionization fire detection, the output port is used to drive the ignition transformer, the small fire valve, the main fire gas valve, the main fire air valve and the smoke exhaust valve to open / close, and each multifunctional combustion controller is connected to a central control unit; the output port comprises a valve control port, and the valve control port is respectively connected to a large air valve, a large gas valve, a smoke exhaust valve and a small gas valve; the communication port adopts an RS485 interface chip, and is used for master-slave communication with the central control unit based on the Modbus-RTU protocol; the logic port is an input and output port, and the input and output ports are respectively connected to the digital output port of the PLC of the central control unit and the digital input port of the PLC, or the input and output ports are respectively connected to the digital input and output modules of the touch screen of the central control unit. The digital port is connected to two valve position feedback signals, which are respectively connected to the closing position sensor of the main fire air valve and the closing position sensor of the smoke exhaust valve in the application of the regenerative combustion unit to ensure that at least one of the two valves is closed during operation.

[0088] The input port includes a UV interface and an ionization interface. The UV ultraviolet light fire detection is detected by an ultraviolet photosensitive tube, which is located at the fire peephole at the tail end of the burner and is used to convert the UV ultraviolet light emitted by the flame into a microcurrent signal. The microcurrent signal is connected to the UV interface; the ionization fire detection is detected by an ionization type fire detection electrode, and the detection end of the ionization type fire detection electrode is located inside the combustion chamber of the burner. The collected ionization microcurrent signal is transmitted to the ionization interface by the electrode sending end.

[0089] There are two connection methods for ionization fire detection, independent fire detection and integrated fire detection. In the independent fire detection method, the ignition electrode and the fire detection electrode are two independent electrodes, while in the integrated fire detection method, the ignition and fire detection use the same electrode. If the ignition electrode and the fire detection electrode are two independent electrodes, the I end of the high-voltage side of the ignition transformer is connected to the ignition electrode, and the G end of the high-voltage side of the ignition transformer is grounded; the ionization interface 1 is connected to the fire detection electrode, and the ionization microcurrent signal is connected to the signal amplification circuit through a jumper, and the ionization interface 2 is grounded; the ignition electrode and the fire detection electrode are respectively arranged on both sides of the burner; the output end of the signal amplification circuit is connected to the MCU, and the signal amplification circuit includes an integrated amplifier chip; if the ignition electrode and the fire detection electrode are the same electrode, the I end of the high-voltage side of the ignition transformer is connected to the electrode, the G end of the high-voltage side of the ignition transformer is connected to the moving contact 1 of the relay through the ionization interface 1, and the normally open static contact 1 of the relay is grounded through the ionization interface 2, the L end of the low-voltage side of the ignition transformer is connected to the ignition interface 1, and the ignition interface 1 is connected to the AC power supply L through the moving contact 2 of the relay, and the N end of the low-voltage side of the ignition transformer is connected to the ignition interface 2, and the ignition interface 2 is connected to the AC power supply N through the normally open static contact 2 of the relay; the coil of the relay is connected to the digital output end of the MCU; the electrode is installed on one side of the burner.

[0090] Working process:

[0091] During ignition, the coil of the relay is energized, and the moving contact 1 of the relay contacts the normally open static contact 1 of the relay. At this time, the G end of the ignition transformer is grounded. The moving contact 2 of the relay contacts the normally open static contact 2 of the relay, so that the low-voltage side of the ignition transformer is connected to the AC 220V power supply, and the high-voltage side I end of the ignition transformer discharges and ignites the burner through the integrated electrode; after the ignition is completed, the coil of the relay loses power, the moving contact 2 of the relay is separated from the normally open static contact 2 of the relay, the ignition transformer loses power, and the electrode stops igniting; the moving contact 1 of the relay resets and contacts the normally closed static contact 1 of the relay, and the G end of the ignition transformer is connected to the amplification circuit; at this time, the ionization micro-current signal captured by the electrode passes through the I end of the ignition transformer, the high-voltage coil, the G end, the ionization interface 1 of the controller, the jumper, the moving contact 1 of the relay, and the normally closed static contact 1, and then is transmitted to the signal amplification circuit.

[0092] The burner command / status feedback information is transmitted between each multifunctional combustion controller and the central control unit through 8421 coding in the logical coding mode, and the contents are as follows:

[0093] 1) The central control unit transmits the burner command information to the multifunctional combustion controller, which performs the corresponding action. The 8421 coded command information is:

[0094] The digital code is 0010, which means air cooling;

[0095] The digital code is 0011, which means a big fire;

[0096] The digital code is 0100, which means reset;

[0097] The digital code is 1001, which means forced ignition;

[0098] The digital code is 1010, which means forced smoke exhaust;

[0099] The digital code is 1011, which means forced fire;

[0100] 2) The multifunctional combustion controller transmits the burner status feedback information to the central control unit. The 8421 coded status feedback information is:

[0101] The digital code is x000, which means stop working;

[0102] The digital code is x001, which means there is fire;

[0103] The digital code is x010, which means air cooling / smoke exhaust;

[0104] The digital code is x011, which means a big fire;

[0105] The digital code is x1xx, indicating an alarm;

[0106] The digital code is 1a01, which means forced low fire, where a represents a periodic jump between 0 and 1;

[0107] The digital code is 1a11, which means forced fire;

[0108] The digital code is 10a0, which means smoke exhaust;

[0109] The digital code is 1xxx, indicating remote operation;

[0110] The digital code is 0xxx, indicating local operation.

[0111] The messages transmitted between the multifunctional combustion controller MFCC and the central control unit in communication mode are as follows:

[0112] 1) The central control unit sends a command message to the multi-function combustion controller MFCC. The message format is hexadecimal:

[0113] Message 1: 16#0000-stop working; 16#0001-ignition; 16#0002-air cooling; 16#0003-high fire; 16#0004-reset; 16#0009-forced ignition; 16#000A-smoke exhaust; 16#000B-forced high fire;

[0114] Message 2: 16#01xx-01 is to modify the slave address of MFCC, xx is the new address number;

[0115] Messages 3 to 10: reserved for function extension;

[0116] 2) The multifunctional combustion controller MFCC feeds back status messages to the central control unit:

[0117] Message 1: 16-bit status word

[0118] Position No. Status Description b0 Ionization flame detection detects flames b1 UV fire detector detects flame b2 Alarm indication b3 Air cooling indication b4 Smoke exhaust indicator b5 Valve position signal 1 b6 Valve position signal 2 b7 remote b8 Ignition signal output b9 Small fire valve open b10 Main fire gas valve open b11 Main fire air valve open b12 Smoke exhaust valve open b13～15 Reserve

[0119] Message 2: 16-bit status word

[0120] Position No. Status Description b0 Panel switch 0 is disconnected (local operation) b1 Panel switch 0 is turned on (remote operation) b2 Switch 1 (ignition when connected) b3 Switch 2 is set to 1 (ignition on the spot when connected) b4 Switch 2 is set to 2 (local air cooling when turned on) b5 Reset button (reset in place when pressed) b6～15 Reserve

[0121] Message 3: 16-bit status word: cumulative number of ignition failures;

[0122] Message 4: The continuous burning time of this ignition, which will be reset to zero when the ignition is turned off;

[0123] Message 5: duration of time when flame is not detected, returns to zero when flame is detected;

[0124] Message 6: Current slave address of MFCC;

[0125] Messages 7 to 10: reserved for extension.

[0126] The following examples are implemented on the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[0127] [Example 1]

[0128] A multifunctional combustion controller integrates the ignition, fire detection and valve control functions of the combustion unit into one controller. In addition to the basic ignition function, it also has the functions of 2-way fire detection and 4-way valve control. No auxiliary control equipment is required to realize the localized control of multi-state combustion of different types of burners. The indicator light on the combustion controller panel can display various working states, and the switches and buttons can realize local operation. When the remote function is selected, one of the two methods can be used to establish a connection with the central control unit: the first method is to use the logical port through the 8421 encoding method to encode the command and status separately, which can save the number of cable cores and materials; the second method is to use the bus communication method, through the communication cable to form a communication network with multiple combustion controllers and the central control unit, and use the message to transmit more control commands and status information, which can save the number of cables and engineering work, save operation and maintenance costs, save time and effort, and have excellent economy and cost performance.

[0129] The multi-function combustion controller (MFCC) cooperates with the central control unit to realize the combustion control of the integrated electrode burner. Figure 4 .

[0130] Due to the limitation of structure size, the low-power burner can only install one electrode, that is, the integrated electrode is used to realize ignition and flame detection, and because of the low power, the energy provided by the spark generated by the electrode is sufficient to ignite the air-fuel mixture and ignite successfully. It adopts two-state pulse combustion, that is, flameout and full-power combustion and heat supply, and the heat supply is adjusted by periodically controlling the combustion time duty cycle.

[0131] The combustion unit includes a burner 101, an integrated electrode 301, a gas valve 501, an air valve 601, an ignition transformer 10, and a MFCC. Fig.10 shown.

[0132] The integrated electrode is connected to the I end of the high voltage side of the ignition transformer 10; the G end of the high voltage side of the ignition transformer is connected to the ionization interface 1 of the multifunctional combustion controller, and then connected to the moving contact a3 of the relay 11 through the jumper 12; the normally closed static contact a1 of the relay is connected to the input end of the amplifier circuit, and the normally open static contact a2 is grounded through the ionization interface 2; the moving contact b3 of the relay is connected to the L end of the low voltage side of the ignition transformer through the ignition interface 1; the normally open static contact b2 of the relay is connected to the live wire L of the AC power supply; the neutral wire N of the AC power supply is connected to the N end of the low voltage side of the ignition transformer through the ignition interface 2.

[0133] During ignition, the coil of the relay in the MFCC is energized (the coil of the relay is connected to the digital output terminal of the MCU chip), the moving contact a3 of the relay contacts the normally open static contact a2 of the relay, the G terminal on the high voltage side of the ignition transformer 10 is grounded, and the moving contact b3 of the relay contacts the normally open static contact b2 of the relay, so that the low voltage side of the ignition transformer is energized, and the high voltage side I terminal of the ignition transformer discharges through the electrode 301 to ignite the burner.

[0134] After ignition is completed, the relay coil loses power and resets, the relay moving contact b3 separates from the normally open static contact b2 of the relay, the low-voltage side of the ignition transformer loses power, and the high-voltage side of the ignition transformer stops discharging. The relay moving contact a3 separates from the normal static contact a2 and returns to contact with the normally closed static contact a1 of the relay. The electrode 301 captures the ionization micro-current signal generated by the flame and sequentially passes through the I end of the high-voltage side of the ignition transformer, the high-voltage coil, the G end, the ionization interface 1 of the MFCC, the line, the relay moving contact a3, the relay normally closed static contact a1, and is transmitted to the amplification circuit and finally sent to the MCU to achieve flame monitoring.

[0135] During ignition, MFCC controls the gas valve 501 and air valve 601 to open, respectively introducing gas and combustion-supporting air into the burner for mixing and ignition by the electrode spark. When ignition is completed and MFCC detects a fire signal, the gas valve and air valve are kept open to allow the burner to continue burning and supplying heat.

[0136] [Example 2]

[0137] A multifunctional combustion controller (MFCC) is added on the basis of Example 1 to cooperate with the central control unit to realize the combustion control of the high-power burner. Figure 5 , Figure 6 .

[0138] Due to the large size of the high-power burner, there is sufficient space to install two electrodes or one electrode + one UV probe. Due to the large amount of air and gas in the main fire, the energy of the electrode spark is not enough to reliably achieve ignition; in addition, the power variation of the two-state fire is large, which does not meet the demand for precise regulation of the heat supply; based on the above two factors, a three-state fire pulse combustion method is adopted, namely stop, small fire pulse, and main fire pulse.

[0139] The combustion unit includes a burner 101, an ignition electrode 302, a fire detection electrode 303 (or a UV probe 4), a small gas valve 502, a main gas valve 503, a main air valve 602, an ignition transformer 10, and a MFCC. The connection of the electrodes is as follows Fig. 9 shown.

[0140] The ignition electrode 302 is connected to the I terminal of the high voltage side of the ignition transformer, and the G terminal of the high voltage side of the ignition transformer is directly grounded; the fire detection electrode 303 is directly connected to the signal amplification circuit through the ionization interface 1 and then through the line 12. If UV fire detection is adopted, the signal amplification circuit is directly connected through the UV interface. The UV probe is equipped with an ultraviolet photosensitive tube, which can receive the ultraviolet light of the flame and convert it into a micro-current signal. The L and N terminals of the low voltage side of the ignition transformer are respectively connected to the ignition interfaces 1 and 2, which is the same as Example 1.

[0141] During ignition, the low-voltage side of the ignition transformer 10 is energized, and the high-voltage side of the ignition transformer discharges and ignites through the ignition electrode 302. At the same time, the small fire gas valve 502 is opened. In engineering practice, the small fire combustion air pipeline is not equipped with a control valve, and a small air volume is directly introduced. The air and gas are mixed in the burner and ignited by the spark. The fire detection electrode or UV probe simultaneously monitors the flame. When the MFCC detects the flame signal, the small fire gas valve 502 is kept open to keep the small fire burning. The small fire can provide sufficient energy to ignite the main fire.

[0142] When main fire combustion is required, MFCC opens the main gas valve 503 and the main air valve 602 through the main gas valve interface and the main air valve interface, and a large amount of gas and combustion-supporting air enter the burner for full-power combustion and heating.

[0143] [Example 3]

[0144] A multifunctional combustion controller (MFCC) is added on the basis of embodiments 1 and 2 to cooperate with the central control unit to realize the combustion control of the regenerative burner. Figure 7 .

[0145] The regenerative burner periodically switches between combustion and heat storage and smoke exhaust to achieve energy-saving combustion. The ignition burner is configured to ignite the main fire during the combustion cycle of the regenerative burner. The ignition burner has small power and size, and is suitable for using integrated electrodes to achieve ignition and monitor the flame state of the ignition burner. The main burner is suitable for using UV probes to monitor the flame.

[0146] The regenerative combustion unit includes a regenerative burner 102, an ignition burner 2, an integrated electrode 301, a UV probe 4, an ignition transformer 10, a small gas valve 502, a main gas valve 503, a main air valve 602, a smoke exhaust valve 7, and a MFCC.

[0147] The connection of ignition burner 2 is the same as that of Example 1. First, MFCC ignites ignition burner 2. After successful ignition, small gas generator 502 is continuously turned on to keep ignition burner 2 in a normal burning state. MFCC monitors the flame state of ignition burner 2 in real time. Once the flame is extinguished, an alarm is issued, the main fire gas is cut off and the ignition is restarted. A fault is reported after three consecutive ignition failures.

[0148] During the combustion cycle, MFCC closes the smoke exhaust valve 7, opens the main gas valve 503 to connect the main fire gas, opens the main air valve 602, and the main fire combustion air flows through the heat storage body 13 and absorbs heat before entering the burner, where it mixes with the gas and is ignited by the normal flame of the ignition burner 2 to start combustion and heat supply. MFCC monitors the main fire status through the UV probe 4, and alarms if no flame is detected; monitors the valve position status of the smoke exhaust valve 7, and alarms and cuts off the main fire if the valve position closing state is not detected.

[0149] During the smoke exhaust cycle, MFCC closes the main gas valve 503 and the main air valve 602, and opens the smoke exhaust valve 7. The high-temperature smoke in the furnace flows through the heat storage body 13, and the heat is stored in the heat storage body. Then, the low-temperature smoke is discharged through the smoke exhaust valve 7. MFCC monitors the valve position status of the main air valve 602. If the valve position closing state is not detected, an alarm is issued and the smoke exhaust valve 7 is closed.

[0150] [Example 4]

[0151] A multifunctional combustion controller (MFCC) is added on the basis of embodiments 1 to 3 to cooperate with the central control unit to realize the combustion control of the self-preheating burner, such as Figure 8 .

[0152] The self-preheating burner is equipped with a preheater, which transfers the waste heat of the flue gas to the combustion-supporting air during combustion to achieve energy-saving combustion.

[0153] The self-preheating combustion unit includes a main burner 103, an electrode 302, a UV probe 4, an ignition transformer 10, a small gas valve 502, a main gas valve 503, a main air valve 602, a smoke exhaust valve 7, a smoke exhaust port 8, a preheater 9, and a MFCC.

[0154] The main burner part of the self-preheating burner is similar to that of a conventional burner, and can adopt any of three ignition and fire detection methods: integrated electrode, separated electrode, or electrode + UV.

[0155] Different from the regenerative burner, the smoke exhaust valve of the self-preheating burner is synchronized with the combustion, that is, when the main fire is burning, the MFCC opens the main gas valve 503, the main air valve 602 and the smoke exhaust valve 7 at the same time, and the hot flue gas flows through the outer cavity of the preheater 9, and the combustion-supporting air flows through the inner cavity of the preheater 9. The two exchange heat through heat conduction of the cavity wall, and the combustion-supporting air brings back part of the heat in the hot flue gas to achieve energy-saving combustion.

[0156] [Example 5]

[0157] In this embodiment, a multi-function combustion controller (MFCC) realizes a multi-state combustion control process based on embodiments 1 to 4. Figures 11 to 15 )

[0158] The fire detection interface of MFCC can be connected to any of the three fire detection methods: UV, single electrode, and double electrode, and two independent fire detections can be performed simultaneously. The 4-way independent valve output port can control part or all of the small gas valve, main gas valve, main air valve, and exhaust valve.

[0159] MFCC operation is divided into two modes: local operation and remote monitoring:

[0160] 1) Local operation: The operating conditions of the combustion unit are controlled by the switches and buttons on the controller panel, and the indicator light group displays the status of the combustion unit.

[0161] 2) There are two ways for remote monitoring to communicate with the central control unit:

[0162] The first is to connect the 4-input 4-output digital port with the corresponding digital port of the central control unit in the form of logical coding (coding adopts 8421 code);

[0163] The second is the Modbus-RTU one-master-multiple-slave communication method, which transmits information to each other through messages.

[0164] Choose one of the two methods: MFCC receives instructions and feedbacks status.

[0165] The operation process of MFCC is shown in Figure 9-13 , realize the multi-state working conditions of the combustion unit:

[0166] S0, stop

[0167] MFCC closes the ignition interface and each valve interface as output, and the combustion unit stops working;

[0168] S1, ignition ( Fig.12 )

[0169] Ignite the burner three times in succession. If any ignition is successful, keep the low-fire valve open to maintain low-fire combustion. If ignition fails three times in a row, an alarm will sound and ignition will be stopped to avoid burning of the ignition transformer until the alarm is reset.

[0170] S2, Fire Fig.13 )

[0171] Open the main gas valve and main air valve to start high-fire combustion. If the combustion device is a self-preheating burner, open the smoke exhaust valve to make the preheater work to preheat the combustion air and realize waste heat recovery;

[0172] S3, air cooling ( Fig.14 )

[0173] Close the large and small gas valves and exhaust valve, only open the air valve, and blow cold air into the furnace from the burner to cool it down;

[0174] S4, smoke exhaust ( Fig.15 )

[0175] If the combustion device is a regenerative burner, close the main gas valve and main air valve when exhausting smoke during the exhaust cycle;

[0176] S5, forced low fire

[0177] When the industrial furnace is in the high-temperature production stage, the gas entering the furnace has the conditions for spontaneous combustion (when the central control unit detects that the furnace temperature exceeds the set threshold, it is judged that the spontaneous combustion conditions have been reached). If the ignition or fire detection fails, in order to ensure the continuity of the industrial furnace production, the central control unit PLC issues a mandatory command to open the small gas valve;

[0178] If the fire detector (electrode or UV) detects a flame signal, it will feedback that there is a fire state, otherwise the alarm light will flash, and the feedback will be a no-fire alarm, and it will be in a forced state;

[0179] S6, forced fire

[0180] When the industrial furnace is in the high-temperature production stage, the furnace temperature meets the conditions for the gas to self-ignite, and high-power heating is required, the main gas valve and main air valve are opened to achieve forced high-fire combustion;

[0181] S7, Reset

[0182] When various alarm states occur in the combustion unit, after confirmation, through the reset button on the panel or remote reset command, MFCC clears the alarm signal and closes the output of all interfaces, and the combustion unit returns to the stopped state.

[0183] [Example 6]

[0184] In this embodiment, a multifunctional combustion controller (MFCC) is the same as that of embodiments 1 to 5, and on this basis, the digital port logic coding instructions and coding state feedback process are described in detail.

[0185] Each controller uses a 5-core control cable and a 5-core feedback cable to communicate with the central control unit. The use of coding can reduce the number of wire cores and save cables; the multifunctional combustion controller uses 4 command bits to receive 8 control commands, and 4 status bits can feedback 10 working states, see Table 1 and Table 2. In comparison, if the coding method is not used, 8 commands require 9-core (8 commands + 1 common) cables, and 10 states require 11-core (10 states + 1 common) cables, see Table 1 and Table 2.

[0186] Table 1 Command codes sent by the central control unit to the multi-function combustion controller (MFCC)

[0187]

[0188]

[0189] Table 2 Status codes fed back by the multifunctional combustion controller (MFCC) to the central control unit

[0190] Serial number b3 b2 b1 b0 state 1 x 0 0 0 stop 2 x 0 0 1 There is fire 3 x 0 1 0 Air Cooling 4 x 0 1 1 fire 5 x 1 x x Call the police 6 1 0, 1 cycle jump 0 1 Forced low fire 7 1 0, 1 cycle jump 1 1 Forced Fire 8 1 0 0, 1 cycle jump 0 Smoke exhaust 9 1 x x x Remote Operation 10 0 x x x Local Operation

[0191] [Example 7]

[0192] In this embodiment, a multifunctional combustion controller (MFCC) is the same as that of embodiments 1 to 6, and on this basis, a process based on communication, using messages to transmit instructions and status feedback is described in detail.

[0193] The central control unit is connected to several multi-function combustion controllers (MFCC) through communication cables to form a bus communication network with one master and multiple slaves. Compared with the logic coding method, each multi-function combustion controller requires two multi-core cables to communicate with the central control unit in a star-shaped radial manner. The bus communication method can save materials and engineering work to the greatest extent. Furthermore, the communication method can transmit multiple messages with a large amount of information. The central control unit can send more comprehensive instructions to the MFCC and have a more comprehensive understanding of the status information of the MFCC, which helps to achieve more refined control of the industrial furnace as a whole and improve the operation quality of the equipment.

[0194] The messages transmitted between the multifunctional combustion controller MFCC and the central control unit are as follows:

[0195] 1) The central control unit sends a command message to the MFCC. The message format is hexadecimal:

[0196] Message 1: 16#0000-stop working; 16#0001-ignition; 16#0002-air cooling; 16#0003-high fire; 16#0004-reset; 16#0009-forced ignition; 16#000A-smoke exhaust; 16#000B-forced high fire;

[0197] Message 2: 16#01xx-01 is to modify the slave address of MFCC, xx is the new address number;

[0198] Messages 3 to 10: reserved for function extension;

[0199] 2) MFCC sends status message to the central control unit:

[0200] Message 1: 16-bit status word, see Table 3.

[0201] Table 3 is the 16-bit status word of message 1.

[0202] Position No. Status Description b0 Ionization flame detection detects flames b1 UV fire detector detects flame b2 Alarm indication b3 Air cooling indication b4 Smoke exhaust indicator b5 Valve position signal 1 b6 Valve position signal 2 b7 remote b8 Ignition signal output b9 Small fire valve open b10 Main fire gas valve open b11 Main fire air valve open b12 Smoke exhaust valve open b13～15 Reserve

[0203] Message 2: 16-bit status word, see Table 4.

[0204] Table 4 is the 16-bit status word of message 2.

[0205] Position No. Status Description b0 Panel switch 0 is disconnected (local operation) b1 Panel switch 0 is turned on (remote operation) b2 Switch 1 (ignition on the spot when connected) b3 Switch 2 is set to 1 (ignition on the spot when connected) b4 Switch 2 is set to 2 (local air cooling when turned on) b5 Reset button (reset in place when pressed) b6～15 Reserve

[0206] Message 3: 16-bit status word: cumulative number of ignition failures;

[0207] Message 4: The continuous burning time of this ignition, which returns to zero when the flame is turned off; Message 5: The duration of no flame detection, which returns to zero when the flame is detected; Message 6: The current slave station address of MFCC.

[0208] Messages 7 to 10: reserved for extension.

Claims

1. A multifunctional combustion controller, characterized in that: There are multiple multifunctional combustion controllers, each of which includes an MCU, a communication port, a logic port, an input port, and an output port. The communication port, the logic port, the input port, and the output port are all connected to the MCU. The input port is used to receive status information of UV ultraviolet light fire detection and ionization fire detection. The output port is used to drive the ignition transformer, small fire valve, main fire gas valve, main fire air valve, and smoke exhaust valve on / off. Each multifunctional combustion controller is connected to the central control unit.

2. A multifunctional combustion controller according to claim 1, characterized in that: The input port includes a UV interface and an ionization interface. The UV ultraviolet light fire detection is detected by an ultraviolet photosensitive tube, which is located at the fire peephole at the tail end of the burner and is used to convert the UV ultraviolet light emitted by the flame into a microcurrent signal, and the microcurrent signal is connected to the UV interface; the ionization fire detection is detected by an ionization type fire detection electrode, and the detection end of the ionization type fire detection electrode is located inside the combustion chamber of the burner. The collected ionization microcurrent signal is transmitted to the ionization interface by the electrode sending end.

3. A multifunctional combustion controller according to claim 2, characterized in that: The ignition electrode and the fire detection electrode are two independent electrodes. The I end of the high-voltage side of the ignition transformer is connected to the ignition electrode, and the G end of the high-voltage side of the ignition transformer is grounded; the ionization interface 1 is connected to the fire detection electrode, and the ionization microcurrent signal is connected to the signal amplification circuit through a jumper, and the ionization interface 2 is grounded; the ignition electrode and the fire detection electrode are respectively arranged on both sides of the burner; the output end of the signal amplification circuit is connected to the MCU, and the signal amplification circuit includes an integrated amplifier chip.

4. A multifunctional combustion controller according to claim 2, characterized in that: The ignition electrode and the fire detection electrode are the same electrode. The I end of the high-voltage side of the ignition transformer is connected to the electrode, the G end of the high-voltage side of the ignition transformer is connected to the moving contact 1 of the relay through the ionization interface 1, the normally open static contact 1 of the relay is grounded through the ionization interface 2, the L end of the low-voltage side of the ignition transformer is connected to the ignition interface 1, the ignition interface 1 is connected to the AC power supply L through the moving contact 2 of the relay, the N end of the low-voltage side of the ignition transformer is connected to the ignition interface 2, the ignition interface 2 is connected to the AC power supply N through the normally open static contact 2 of the relay; the coil of the relay is connected to the digital output end of the MCU; the electrode is installed on one side of the burner.

5. A multifunctional combustion controller according to claim 1, characterized in that: The output port comprises a valve control port, and the valve control port is respectively connected with a large air valve, a large gas valve, a smoke exhaust valve, and a small gas valve.

6. A multifunctional combustion controller according to claim 1, characterized in that: The communication port is an RS485 communication port, which is used to connect to the communication module of the PLC of the central control unit.

7. A multifunctional combustion controller according to claim 1, characterized in that: The logic ports are input and output ports, which are respectively connected to the digital output port of the PLC of the central control unit and the digital input port of the PLC, or the input and output ports are respectively connected to the digital input and output modules of the touch screen.

8. A multifunctional combustion controller according to claim 1, characterized in that: Each multifunctional combustion controller and the central control unit use a logical port to transmit the burner's command / status feedback information through 8421 coding, the content is as follows: 1) The central control unit transmits the burner command information to the multifunctional combustion controller, which performs the corresponding action. The 8421 coded command information is: The digital code is 0010, which means air cooling; The digital code is 0011, which means a big fire; The digital code is 0100, which means reset; The digital code is 1001, which means forced ignition; The digital code is 1010, which means forced smoke exhaust; The digital code is 1011, which means forced fire; 2) The multifunctional combustion controller transmits the status feedback information of the ignition burner to the central control unit. The 8421 coded status feedback information is: The digital code is x000, which means stop working; The digital code is x001, which means there is fire; The digital code is x010, which means air cooling / smoke exhaust; The digital code is x011, which means a big fire; The digital code is x1xx, indicating an alarm; The digital code is 1a01, which means forced low fire, where a represents a periodic jump between 0 and 1; The digital code is 1a11, which means forced fire; The digital code is 10a0, which means smoke exhaust; The digital code is 1xxx, indicating remote operation; The digital code is 0xxx, indicating local operation.

9. A multifunctional combustion controller according to claim 1, characterized in that: Each multifunctional combustion controller and the central control unit use a communication port to exchange instructions / status feedback information through messages. The content is as follows: 1) The central control unit sends a command message to the multi-function combustion controller. The message format is hexadecimal: Message 1: 16#0000-stop working; 16#0001-ignition; 16#0002-air cooling; 16#0003-high fire; 16#0004-reset; 16#0009-forced ignition; 16#000A-smoke exhaust; 16#000B-forced high fire; Message 2: 16#01xx-01 is to modify the slave address of the multi-function combustion controller, xx is the new address number; 2) Feedback status message from the multifunctional combustion controller to the central control unit: a. Message 1: 16-bit status word, the content is as follows: Bit number b0 indicates that the ionization fire detector detects the flame; Position number b1 indicates that the UV fire detector detects a flame; Bit number b2 indicates alarm indication; Position number b3 indicates air cooling indication; Position number b4 indicates smoke exhaust indication; Position number b5, indicating valve position signal 1; Position number b6, indicating valve position signal 2; Bit number b7 means remote; Bit number b8 indicates ignition signal output; Position number b9 indicates that the small fire valve is open; Position number b10 indicates that the main fire gas valve is open; Position number b11 indicates that the main fire air valve is open; Position number b12 indicates that the smoke exhaust valve is open; b. Message 2: 16-bit status word, the content is as follows: Bit number b0 means panel switch 0 is disconnected (local operation); Bit number b1 indicates that panel switch 0 is turned on (remote operation); Position number b2 indicates switch 1 (ignition on the spot when connected); Position number b3 indicates that switch 2 is set to 1 (ignition is on-site when connected); Position number b4 means switch 2 is set to 2 (local air cooling when turned on); Bit number b5 indicates the reset button (reset in place when pressed); c. Message 3: 16-bit status word: cumulative number of ignition failures; d. Message 4: The continuous burning time of this ignition, which will be reset to zero when the ignition is turned off; e. Message 5: duration of time when flame is not detected, returns to zero when flame is detected; f. Message 6: Current slave address of MFCC; g. Messages 7 to 10: reserved for extension.

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