Combustion system for large tonnage steam boilers capable of firing without load reduction

Abstract

The utility model discloses a kind of combustion systems of large-tonnage steam boiler that can not reduce load ignition, comprising: furnace, more than one burner is arranged in one side of furnace, air conveying branch pipe with conveying control valve is connected on each burner, each air conveying branch pipe is connected with air conveying main pipe, the air conveying main pipe is communicated with air input device, each burner is also provided with ignition combustion-supporting air input branch pipe, the output end of each ignition combustion-supporting air input branch pipe is connected to the air conveying branch pipe between corresponding burner and conveying control valve, ignition combustion-supporting air control valve is arranged on each ignition combustion-supporting air input branch pipe, the input end of each ignition combustion-supporting air input branch pipe is connected to ignition combustion-supporting air conveying main pipe, and the ignition combustion-supporting air conveying main pipe is communicated with compressed air source.The utility model has the advantages that one or several burners can be re-ignited without reducing load.

Description

Technical Field

[0001] This utility model relates to the field of steam boiler technology. Background Technology

[0002] Large-tonnage steam boilers typically refer to medium to large-sized boilers with a capacity exceeding 20 tons, primarily used in industrial applications with high steam demand. Larger-tonnage steam boilers are usually equipped with multiple burners, with the air for combustion of these burners being forced in by a single blower. This means that if one burner malfunctions or needs to be restarted for other reasons, the load on all operating burners must be reduced to lower the airflow and pressure to ensure the needs of the burner requiring restarting are met. Obviously, this affects the steam output of the boiler. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a combustion system for a large-tonnage steam boiler that can be ignited without reducing the load. The system has a simple structure and can re-ignite some of the burners without reducing the load, thus greatly improving combustion stability.

[0004] To solve the above problems, the technical solution adopted by this utility model is: a combustion system for a large-tonnage steam boiler capable of ignition without load reduction, comprising: a furnace, one or more burners arranged on one side of the furnace, each burner connected to an air supply branch pipe with a supply control valve, each air supply branch pipe connected to an air supply main pipe, the air supply main pipe being connected to an air input device, each burner also being provided with an ignition and combustion air input branch pipe, the output end of each ignition and combustion air input branch pipe being connected to the air supply branch pipe between the corresponding burner and the supply control valve, each ignition and combustion air input branch pipe being provided with an ignition and combustion air control valve, the input end of each ignition and combustion air input branch pipe being connected to the ignition and combustion air supply main pipe, the ignition and combustion air supply main pipe being connected to a compressed air source.

[0005] Furthermore, in the aforementioned combustion system of a large-tonnage steam boiler capable of ignition without reducing load, the compressed air source includes an air compressor unit.

[0006] Furthermore, in the aforementioned combustion system of a large-tonnage steam boiler capable of ignition without reducing load, each ignition and combustion air input branch pipe is equipped with an ignition and combustion air flow regulating valve.

[0007] Furthermore, in the aforementioned combustion system of a large-tonnage steam boiler capable of ignition without reducing load, the output end of each ignition and combustion air input branch pipe is connected to the air delivery branch pipe via a tee.

[0008] Furthermore, in the aforementioned combustion system of a large-tonnage steam boiler that can ignite without reducing load, each air delivery branch pipe is also equipped with a check valve.

[0009] Furthermore, in the aforementioned combustion system of a large-tonnage steam boiler that can ignite without reducing load, each air delivery branch pipe is equipped with a pressure sensor. The check valve, delivery control valve, and pressure sensor on each air delivery branch pipe are arranged sequentially in the direction of air flow. The output end of each ignition and combustion air input branch pipe is connected to the air delivery branch pipe between the pressure sensor and the delivery control valve.

[0010] Furthermore, the combustion system of the aforementioned large-tonnage steam boiler capable of ignition without load reduction employs a power supply structure comprising: a 380V three-phase external power supply, with two live wires connected to the two high-voltage side terminals of an isolation transformer; the isolation transformer outputs 220V from its low-voltage side; and each of the two low-voltage side terminals of the isolation transformer is connected to an internal power supply line for powering the equipment. The isolation transformer is an AC220V isolation transformer.

[0011] Furthermore, in the combustion system of the aforementioned large-tonnage steam boiler that can ignite without reducing load, an indicator light is installed between the two internal power lines.

[0012] The advantages of this utility model are: the combustion system of the large-tonnage steam boiler described in this application, which can ignite without reducing the load, has a simple and ingenious structure. It can ignite one of the burners without reducing the load, greatly improving the combustion stability of all burners and the heat output stability of the boiler. The novel power supply structure, using an isolation transformer to output a stable voltage, avoids the impact of voltage fluctuations on the equipment, further ensuring stable burner operation. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the air supply principle in the combustion system of the burner in the large-tonnage steam boiler that can ignite without reducing load, as described in this utility model.

[0014] Figure 2 This is a schematic diagram of the power supply structure of the combustion system of the large-tonnage steam boiler that can ignite without reducing the load, as described in this utility model. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and preferred embodiments.

[0016] like Figure 1As shown, the combustion system of a large-tonnage steam boiler capable of ignition without load reduction includes: a furnace, with one or more burners 1 installed on one side of the furnace; this embodiment uses four burners 1 as an example. Each burner 1 is connected to an air supply branch pipe 2 with a supply control valve 21, and each air supply branch pipe 2 is connected to an air supply main pipe 3, which is connected to an air input device; in this embodiment, the air input device is a blower 4. Each air supply branch pipe 2 is also equipped with a check valve 22. To facilitate real-time pressure monitoring, each air supply branch pipe 2 is also equipped with a pressure sensor 23. The steam boiler mainly includes a combustion system and a steam-water system. The combustion system mainly includes the furnace, flue, and burners; the steam-water system mainly includes a steam drum and heat exchangers, including economizers, evaporators, and superheaters. The structure of the steam boiler is conventional technology for those skilled in the art and will not be elaborated in detail in this embodiment.

[0017] In this embodiment, each burner 1 is connected to an ignition and combustion air input branch pipe 5 with an ignition and combustion air input control valve 51. The output end of each ignition and combustion air input branch pipe 5 is connected to the air delivery branch pipe 2 between the corresponding burner 1 and the delivery control valve 21. In this embodiment, the output end of each ignition and combustion air input branch pipe 5 is connected to the air delivery branch pipe 2 via a tee 8. The check valve 22, delivery control valve 21, and pressure sensor 23 on each air delivery branch pipe 2 are arranged sequentially in the direction of airflow. The output end of each ignition and combustion air input branch pipe 5 is connected to the air delivery branch pipe 2 between the pressure sensor 23 and the delivery control valve 21.

[0018] Each ignition and combustion air inlet branch pipe 5 is equipped with an ignition and combustion air control valve 51, which is a solenoid valve for easy control. Each ignition and combustion air inlet branch pipe 5 is also equipped with an ignition and combustion air flow regulating valve 52, which facilitates the adjustment of the ignition and combustion air flow. In this embodiment, the ignition and combustion air control valve 51 is a needle valve, which features simple structure, high sealing performance, high temperature resistance, high pressure resistance, and good corrosion resistance.

[0019] The input end of each ignition and combustion air input branch pipe 5 is connected to the ignition and combustion air supply main pipe 6, which is connected to a compressed air source. In this embodiment, the compressed air source includes an air compressor unit 7.

[0020] Furthermore, to ensure voltage stability for the large-tonnage steam boiler, the power supply structure used in this embodiment includes: a 380V three-phase external power supply 10, with its two live wires connected to the two high-voltage side terminals of an isolation transformer 20. The isolation transformer outputs 220V on its low-voltage side, and the two low-voltage side terminals of the isolation transformer 20 are connected to internal power lines 30 used to power the equipment. An indicator light 301 is installed between the two internal power lines 30 to facilitate checking for power supply abnormalities. The isolation transformer is an AC 220V isolation transformer.

[0021] When the boiler is operating normally, the ignition and combustion air control valve 51 on each ignition and combustion air input branch pipe 5 is in the closed state, and the delivery control valve 21 on each air delivery branch pipe 2 is in the open state. All burners 1 are in operation, and air is delivered by the blower 4 through the air delivery main pipe 3, and then through each air delivery branch pipe 2 to each burner 1 as the combustion gas required for combustion.

[0022] When one of the burners 1 malfunctions and needs to be re-ignited, the supply control valve 21 on the air supply branch pipe 2 corresponding to burner 1 is closed, and the ignition and combustion air control valve 51 on the ignition and combustion air input branch pipe 5 corresponding to burner 1 is opened. Compressed air generated by the air compressor unit 7 enters the burner 1 through the ignition and combustion air supply main pipe 6 and the air supply branch pipe 2 to supply the ignition requirements. The flow rate of the combustion air can be adjusted by regulating the opening of the ignition and combustion air flow regulating valve 52 to ensure effective ignition. Since the air for the burner that needs to be re-ignited is supplied separately, the other burners that are in operation do not need to reduce their load, and the boiler can basically maintain its original load operation, which greatly improves the boiler's operating efficiency.

[0023] Furthermore, during the long-term operation of the boiler, the applicant discovered that the traditional boiler power supply structure, which uses one live wire and one neutral wire from a 380V three-phase external power supply connected to the boiler, has the following drawbacks: large voltage fluctuations easily cause damage to pressure, temperature, and other transmitters in the boiler equipment, which seriously affects the normal operation of the boiler.

[0024] See Figure 2 As shown, compared with the traditional structure, the power supply structure of the boiler in this application uses two live wires of a 380V three-phase external power supply 10 to be transformed into 220V voltage through an isolation transformer 20, which serves as the internal power supply of the boiler. This can effectively reduce voltage fluctuations, thereby greatly extending the service life of the boiler equipment.

[0025] As can be seen from the above, the combustion system of the large-tonnage steam boiler described in this application, which can ignite without reducing the load, has a simple and ingenious structure. It can re-ignite one or more burners without reducing the load, greatly improving the combustion stability of all burners and the heat output stability of the boiler. The novel power supply structure, through the isolation transformer 20, outputs a stable voltage, thereby avoiding the impact of voltage fluctuations on the equipment and further ensuring the stable operation of the burners.

Claims

1. Combustion systems for large-tonnage steam boilers capable of ignition without load reduction, including: The furnace has one or more burners on one side. Each burner is connected to an air supply branch pipe with a supply control valve. Each air supply branch pipe is connected to an air supply main pipe, which is connected to an air input device. The furnace is characterized by: each burner also having an ignition and combustion air input branch pipe; the output end of each ignition and combustion air input branch pipe is connected to the air supply branch pipe between the corresponding burner and the supply control valve; each ignition and combustion air input branch pipe has an ignition and combustion air control valve; and the input end of each ignition and combustion air input branch pipe is connected to the ignition and combustion air supply main pipe, which is connected to a compressed air source.

2. The combustion system of the large-tonnage steam boiler capable of ignition without load reduction according to claim 1, characterized in that: Compressed air sources include air compressor units.

3. The combustion system of a large-tonnage steam boiler capable of ignition without load reduction as described in claim 1, characterized in that: Each ignition and combustion air inlet branch pipe is equipped with an ignition and combustion air flow regulating valve.

4. The combustion system of a large-tonnage steam boiler capable of ignition without load reduction according to claim 1, characterized in that: The output end of each ignition and combustion air input branch pipe is connected to the air delivery branch pipe via a tee.

5. The combustion system of a large-tonnage steam boiler capable of ignition without load reduction according to claim 1, characterized in that: Each air delivery branch pipe is also equipped with a check valve.

6. The combustion system of a large-tonnage steam boiler capable of ignition without load reduction according to claim 5, characterized in that: Each air delivery branch pipe is also equipped with a pressure sensor. The check valve, delivery control valve, and pressure sensor on each air delivery branch pipe are arranged sequentially in the direction of air flow. The output end of each ignition and combustion air input branch pipe is connected to the air delivery branch pipe between the pressure sensor and the delivery control valve.

7. The combustion system of a large-tonnage steam boiler capable of ignition without load reduction according to claim 1, characterized in that: The power supply structure adopted includes: a 380V three-phase external power supply, with two live wires of the 380V three-phase external power supply connected to the two high-voltage side terminals of the isolation transformer respectively, and the low-voltage side of the isolation transformer outputting 220V voltage. The two low-voltage side terminals of the isolation transformer are each connected to an internal power supply line for powering the equipment. The isolation transformer is an AC220V isolation transformer.

8. The combustion system of a large-tonnage steam boiler capable of ignition without load reduction according to claim 7, characterized in that: An indicator light is installed between the two internal power lines.

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