Biogas burner control device

Abstract

The utility model provides a marsh gas burner control device which comprises a burning device, a power supply and a DCS (distributed control system), the burning device comprises a burner and an anaerobic jar, the burner is connected with the anaerobic jar through a gas pipeline, the gas pipeline is provided with a switch, a control valve and a pressure gauge, and the control valve is connected with the pressure gauge. An ion flame detector is arranged at a combustion nozzle of the combustor, and a flame stabilizer is fixedly mounted at the top of the combustion nozzle; an anaerobic jar pressure transmitter is arranged at the outlet end of the anaerobic jar, and an anaerobic jar pressure control valve is arranged at the top end of the anaerobic jar. The device is simple in structure, high in monitoring precision, safe and more stable.

Description

Technical Field

[0001] The utility model belongs to a biogas combustion control device, in particular to a biogas burner control device. Background Art

[0002] After sludge treatment at waste incineration plants, a large amount of biogas is produced. Because biogas contains methane, it is an ideal gas fuel and burns when mixed with an appropriate amount of air. Compared with other gases, it has better anti-explosion properties and is a good clean fuel, so it can be used as fuel for waste incineration burners. However, existing waste incineration burners have the following problems:

[0003] At present, furnace burners generally use ultraviolet sensors for flame detection. However, during the combustion process, the flame signal may be misjudged due to interference from other stray signals inside the furnace or unreasonable design of the ultraviolet sensor installation structure, resulting in unstable operation of the burner.

[0004] Failure to replenish fermentation materials in a biogas digester can lead to unstable gas pressure and combustion flames. This not only causes the burner to ignite frequently, but also hinders biogas transmission to the combustion equipment when the gas supply pressure is low during combustion. This can also lead to negative pressure in the digester, causing biogas backfire and explosions. These issues are urgent and need to be addressed. Utility Model Content

[0005] The purpose of the utility model is to provide a biogas burner control device with a simple structure and improved monitoring accuracy and safety.

[0006] In order to achieve the above object, the utility model provides:

[0007] A biogas burner control device comprises a combustion device, a power supply and a DCS control system. The combustion device comprises a burner, a fan and an anaerobic tank. The burner and the anaerobic tank are connected via a gas pipeline, on which a switch, a control valve and a pressure gauge are provided. An ion flame detector is provided at the combustion nozzle of the burner, and a flame stabilizer is fixedly installed on the top of the combustion nozzle. An anaerobic tank pressure transmitter is provided at the outlet end of the anaerobic tank, and an anaerobic tank pressure control valve is provided at the top of the anaerobic tank.

[0008] Furthermore, a water seal device is provided between the anaerobic tank and the burner, and the water seal device includes a water tank and a water seal layer, a drying layer and an isolation layer arranged in the water tank. The water seal layer is provided at the lower end of the water tank, the upper end of the water seal layer is the drying layer, and the upper end of the drying layer is the isolation layer. The water tank is provided with an overflow port at the water seal layer.

[0009] Furthermore, the overflow outlet is provided with a U-shaped overflow pipe.

[0010] Furthermore, a muffler is provided at the air inlet of the fan.

[0011] Furthermore, the switches include a low air pressure switch SW1, a high air pressure switch SW2, a low air pressure switch SW3, a leak detection switch SW4, a low fire ignition switch and a high fire switch, and the control valve includes a first low fire ignition valve SV1, a second low fire ignition valve SV2, a first main air valve XV1 and a second main air valve XV2.

[0012] Furthermore, the low-fire ignition switch and the high-fire switch are both control switches of the DCS control system.

[0013] Furthermore, the burner is provided with two ion flame detectors.

[0014] Furthermore, a flexible connection device is used between the fan and the burner.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The utility model has a simple structure and adopts an ion flame detector to directly contact the flame of the combustion nozzle to form 8-20μA current, which is converted into a fire signal feedback of a switching signal by the ion flame detector, thereby improving the monitoring accuracy.

[0017] A flame stabilizer is fixedly installed on the top of the combustion nozzle, an anaerobic tank is provided with an anaerobic tank pressure transmitter and an anaerobic tank pressure control valve, and a water seal device is also provided between the anaerobic tank and the burner, which effectively avoids backfire, improves the safety performance of biogas use, and realizes arbitrary adjustment of the heat load of the biogas burner and stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of the utility model;

[0019] Figure 2 This is a circuit diagram of the utility model;

[0020] Figure 3 This is a schematic structural diagram of the water seal device of the utility model; DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention will be described in more detail below with reference to the schematic diagrams. The advantages and features of the present invention will become clearer based on the following description. It should be noted that the drawings are all in very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in illustrating the purpose of the embodiments of the present invention. It should be understood that the drawings in the specification do not necessarily show the specific structure of the present invention in proportion, and the illustrative features used to illustrate certain principles of the present invention in the drawings in the specification may also be drawn in a slightly simplified manner. The specific design features of the present invention disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment in which they are to be applied and used. In addition, in the embodiments described below, the same figure mark is sometimes used in common between different drawings to represent the same part or a part with the same function, and its repeated description is omitted. In this specification, similar numbers and letters are used to represent similar items. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings. Specific embodiments

[0022] See also Figures 1 to 3 As shown, a biogas burner control device includes a combustion device, a power supply and a DCS control system. The combustion device includes a burner, a fan and an anaerobic tank. The burner and the anaerobic tank are connected by a gas pipeline. An ion flame detector SW5 is provided at the combustion nozzle of the burner. A flame stabilizer is fixedly installed on the top of the combustion nozzle. The burner is provided with a flame detector and a fire viewing hole. In this specific embodiment: the burner is provided with two ion flame detectors, and the two ion flame detectors are respectively provided at the upper and lower positions of the fire viewing hole. A muffler is provided at the air inlet of the fan. In this specific embodiment, the fan adopts a blower. A soft connection device is used between the fan and the burner. The soft connection device adopts the existing combustion chamber soft connection device. The air inlet of the burner is provided with a damper. An anaerobic tank pressure transmitter PT is provided at the outlet end of the anaerobic tank, and an anaerobic tank pressure control valve PSV is provided at the top of the anaerobic tank. The anaerobic tank pressure control valve PSV and the anaerobic tank pressure transmitter PT are electrically connected to a pressure controller PIC to control the anaerobic tank pressure control valve PSV. The air pressure in the anaerobic tank is controlled by the anaerobic tank pressure control valve PSV, thereby reducing the tempering problem caused by uneven air pressure in the anaerobic tank.

[0023] The anaerobic flask is connected to the burner via two gas pipelines: one main pipeline and one branch pipeline. The main pipeline is equipped with an expansion joint, while the branch pipeline is equipped with a metal hose. A filter is installed at the anaerobic flask's gas outlet. The gas pipeline is equipped with switches, control valves, and a pressure gauge. The switches include a low-pressure switch SW1, a high-pressure switch SW2, a low-pressure switch SW3, a leak detection switch SW4, a low-fire ignition switch, and a high-fire switch. The control valves are electrically controlled and include a first low-fire ignition valve SV1, a second low-fire ignition valve SV2, a first main air valve XV1, and a second main air valve XV2. The first main gas valve XV1, the second main gas valve XV2, the high pressure switch SW2, the low pressure switch SW3 and the leak detection switch SW4 are arranged on the main pipe of the gas transmission pipeline. The first main gas valve XV1, the second main gas valve XV2, the low pressure switch SW3 and the leak detection switch SW4 are combined into a control valve group for realizing the pressure regulation of the gas. A gas regulating valve is also provided on the main pipe. The first small fire ignition valve SV1 and the second small fire ignition valve SV2 are arranged on the branch pipe of the gas transmission pipeline. The first small fire ignition valve SV1 and the second small fire ignition valve SV2 are connected to the ignition transformer. The control interface of the DCS control system is provided with an ignition start and stop button. The small fire ignition switch and the high fire switch are both control switches of the DCS control system.

[0024] See also Figure 2As shown, in this specific embodiment: the ignition start button is electrically connected to the live wire L of the power supply through the fuse FUSE, the ignition start / stop button is electrically connected to the neutral wire N of the power supply through the coil winding of the first contactor KM1, the low air pressure switch SW1, the high air pressure switch SW2, the low air pressure switch SW3, the leak detection switch SW4, the low fire ignition switch, the first low fire ignition valve SV1, the second low fire ignition valve SV2, the ignition coil TA, the ion flame detector SW5, the high fire switch, the first main air valve XV1, the second main air valve XV2 are electrically connected to the first The normally open switch of the contactor KM1 and the fuse FUSE are electrically connected to the live wire L of the power supply. The low air pressure switch SW1 is electrically connected to the neutral wire N of the power supply through the coil winding of the second relay KA2. The high air pressure switch SW2 and the low air pressure switch SW3 are electrically connected to the neutral wire N of the power supply through the coil winding of the third relay KA3. The leakage detection switch SW4 is electrically connected to the neutral wire N of the power supply through the coil winding of the fourth relay KA4. The low fire ignition switch is electrically connected to the neutral wire N of the power supply through the coil winding of the fifth relay KA5. A small ignition valve SV1, a second small ignition valve SV2, and an ignition coil TA are connected in parallel to the normally open switch of the fifth relay KA5. The TA ignition coil adopts a high-voltage ignition coil and is electrically connected to the normally open switch of the first contactor KM1 through the normally open switch of the fifth relay KA5. The normally closed switch of the sixth relay is connected between the ignition coil TA and the normally open switch of the fifth relay KA5. The ion flame detector SW5 is electrically connected to the neutral line N of the power supply through the coil winding of the sixth relay KA6. The high fire switch is electrically connected to the neutral line N of the power supply through the coil winding of the seventh relay KA7. The group is electrically connected to the neutral line N of the power supply. The first and second main gas valves XV1 and XV2 are electrically connected to the normally open switch of the first contactor KM1 via the normally open switches of the seventh relay KA7 and the sixth relay KA6. The gas regulating valve MV1 and the air volume regulating valve MV2 are electrically connected to the normally open switch of the first contactor KM1. The flame detector power supply FD is electrically connected to the normally open switch of the first relay KM1. The blower is electrically connected to the normally open switch of the first relay KM1 via the coil winding of the second contactor KM2 to control the start and stop of the blower. The anaerobic tank pressure control valve PSV is electrically connected to the normally open switch of the first relay KM1.

[0025] A water seal device is also provided between the anaerobic tank and the burner. The water seal device includes a water tank 3 and a water seal layer 3-1, a drying layer 3-2 and an isolation layer 3-3 arranged in the water tank 3. Two partitions are provided in the water tank 3, and a plurality of vents are opened on the partitions, dividing the water tank 3 into three layers. The bottom end is the water seal layer 3-1, the middle is the drying layer 3-2, and the top end is the isolation layer 3-3. The water tank 3 is provided with an air inlet hole, an exhaust hole 3-5 and a water inlet hole 3-4. The water inlet hole 3-4 is provided in the water seal layer 3-1. The anaerobic tank extends to the water seal layer through a pipe 5 through the air inlet hole in sequence through the isolation layer and the drying layer. The drying layer 3-2 uses sand or existing desiccant, which is mainly used to remove moisture in the biogas, thereby avoiding excessive moisture in the biogas affecting combustion or associated control electrical components. The isolation layer 3-3 can be made of flame-retardant materials such as sand, stone, or metal. It is primarily used to prevent backfire by blocking flames through the isolation layer, thereby interrupting the backfire. The water tank has an overflow port at the water seal layer, which may be equipped with a U-shaped overflow pipe 6. The drying layer 3-2 can reduce the moisture content in the biogas. The isolation layer 3-3 can absorb the heat generated by the biogas combustion during backfire, reducing it to below the ignition point, or blocking the flames, thereby interrupting the backfire.

[0026] Possibly, an alarm is also included, which sounds an alarm after activating the low air pressure switch, the high air pressure switch, and the low air pressure switch.

[0027] The working principle of this utility model:

[0028] Step 1: Click the ignition start button on the DCS system screen, the first contactor KM1 is energized, and the 220V control power supply and fan are started.

[0029] Step 2: Check the high, low and low air pressure switches of gas. If normal, the second relay KA2 and the third relay KA3 will be energized and feedback will be given to the DCS system.

[0030] Step 3: Install a leak detection switch SW4 in the pipe between the first and second main air valves XV1 and XV2. Based on the DCS system logic, if the leak detection switch SW4 detects a leak in either the first or second main air valve XV1 or XV2, the DCS system will display an alarm and cancel ignition. If there is no leak, proceed to the next step. (Logical condition for valve group leakage: If both the first and second main air valves XV1 and XV2 are leaking, the control valve group is considered qualified.)

[0031] 1. Judgment of the second main air valve: Close the second main air valve, open the first main air valve and close it after a delay of 3 seconds. At this time, the pressure at the leak detection switch SW4 should be the intake pressure. If the pressure does not rise to the preset value during 5 seconds, the rear valve is leaking, otherwise it is not leaking.

[0032] 2. Judgment of the first main air valve: Close the first main air valve, open the second main air valve and close it after a delay of 5S. At this time, the pressure at the leak detection switch SW4 should be zero. If the pressure rises to the preset value, the first main air valve is leaking. If it does not rise, it is not leaking.

[0033] Step 4: Fully open the air volume control valve MV2 and fully close the other valves to purge the combustible gas that may exist in the pipeline. The DCS delay is 30 seconds.

[0034] Step 5: The gas regulating valve MV1 and the air volume regulating valve MV2 maintain a minimum air-to-gas ratio opening.

[0035] Step 6: The low-fire ignition switch automatically closes, opens the first low-fire ignition valve SV1 and the second low-fire ignition valve SV2, turns on the high-voltage ignition coil and starts ignition.

[0036] Step 7: The ion flame detector detects the flame. If a flame signal is detected, the ignition coil is stopped and the next step is performed. If there is no flame signal within 6 seconds, the reverse procedure of step 6 is performed, the fourth step is performed, and the ignition is stopped.

[0037] Step 8: When the conditions for high-fire combustion are met, the DCS system automatically turns on the high-fire switch and opens the first and second main gas valves on the pipeline.

[0038] Step 9: According to the actual situation of process use, the furnace temperature can be automatically adjusted by PID through the functional module of the DCS system to adjust the gas and air volume regulating valves to control the flame size and furnace temperature.

[0039] Step 10: An anaerobic tank pressure transmitter is installed at the outlet of the anaerobic tank, and an anaerobic tank pressure control valve is installed at the top of the anaerobic tank. The pressure in the anaerobic tank is controlled by the anaerobic tank pressure control valve to reduce the tempering problem caused by uneven pressure in the anaerobic tank.

[0040] At the same time, in order to avoid safety accidents, the following conditions are set in the DCS control system to stop working:

[0041] 1. Stop when hot air temperature is high

[0042] 2. Stop when exhaust temperature is high

[0043] 3. Stop when flue gas flow is low

[0044] 4. Furnace outlet flue gas temperature is high and the furnace stops

[0045] 5. Gas pressure low stop

[0046] 6. Blower failure

[0047] 7. Furnace flameout and stop

[0048] 8. Burner failure and shutdown

[0049] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any person skilled in the art who, without departing from the scope of the present invention, makes any equivalent substitution, modification, or other variation to the technical solution and technical content disclosed herein shall be deemed to fall within the scope of the present invention and remain within the scope of protection of the present invention.

Claims

1. A biogas burner control device, comprising a combustion device, a power supply, and a DCS control system. The combustion device comprises a burner, a blower, and an anaerobic tank. The burner and the anaerobic tank are connected by a gas pipeline, and the gas pipeline is provided with a switch, a control valve, and a pressure gauge. The device is characterized by: An ion flame detector is provided at the combustion nozzle of the burner, and a flame stabilizer is fixedly installed on the top of the combustion nozzle; an anaerobic tank pressure transmitter is provided at the outlet end of the anaerobic tank, and an anaerobic tank pressure control valve is provided at the top of the anaerobic tank.

2. The biogas burner control device according to claim 1, characterized in that: A water seal device is also provided between the anaerobic tank and the burner. The water seal device includes a water tank and a water seal layer, a drying layer and an isolation layer arranged in the water tank. The water seal layer is provided at the lower end of the water tank, the upper end of the water seal layer is the drying layer, and the upper end of the drying layer is the isolation layer. The water tank is provided with an overflow port at the water seal layer.

3. The biogas burner control device according to claim 2, characterized in that: The overflow port is provided with a U-shaped overflow pipe.

4. The biogas burner control device according to claim 1, characterized in that: The air inlet of the fan is provided with a muffler.

5. The biogas burner control device according to claim 1, characterized in that: The switches include a low air pressure switch SW1, a high air pressure switch SW2, a low air pressure switch SW3, a leak detection switch SW4, a low fire ignition switch and a high fire switch; the control valves include a first low fire ignition valve SV1, a second low fire ignition valve SV2, a first main air valve XV1 and a second main air valve XV2.

6. The biogas burner control device according to claim 5, characterized in that: The low-fire ignition switch and the high-fire switch are both control switches of the DCS control system.

7. The biogas burner control device according to claim 1, characterized in that: The burner is provided with two ion flame detectors.

8. The biogas burner control device according to claim 1, characterized in that: A soft connection device is used between the blower and the burner.

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