Combustor capable of reducing exhaust gas temperature

Abstract

The utility model discloses a combustor capable of reducing exhaust gas temperature. The combustor capable of reducing exhaust gas temperature comprises at least two combustor sets. The burner groups are arranged at intervals along the height direction of the hearth; each combustor group comprises four combustors, and the four combustors in each combustor group are arranged at four corners of the hearth; pulverized coal airflow jetted by the burner group located on the lowermost layer of the hearth can form an imaginary tangent circle in the center of the hearth; nozzles of all the combustors in the other layers of combustor sets are arranged downwards in an inclined mode, pulverized coal airflow jetted by the combustors can also form an imaginary tangent circle in the center of the hearth, and the direction of the imaginary tangent circle is opposite to the direction of the imaginary tangent circle located on the lowermost layer of the hearth. The installation angle of the burner on the coal-fired boiler is improved, the flowing path of smoke can be changed, one path of airflow in a hearth is prevented from rotating and rising, the residence time of the smoke in the boiler is prolonged, and therefore the smoke exhaust temperature of the coal-fired boiler is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal-fired boilers, and in particular relates to a burner for reducing exhaust gas temperature. Background Art

[0002] The economical operation of coal-fired boilers is of great significance for energy conservation, environmental protection, and achieving sustainable and coordinated development. Heat loss from boiler exhaust gas is the largest of all boiler losses, generally accounting for 60% to 70% of boiler heat losses. The primary factor influencing exhaust gas losses is exhaust gas temperature. Generally, for every 10°C increase in exhaust gas temperature, exhaust gas losses increase by 0.5% to 0.8%, and the unit's coal consumption for power generation increases by 1.0g / kWh. Furthermore, high exhaust gas temperatures pose a threat to the safe operation of post-furnace dust collectors, desulfurization devices, and chimneys. Clearly, lowering exhaust gas temperature can reduce exhaust gas heat loss, thereby improving boiler efficiency. This has important practical implications for energy conservation, consumption reduction, and improving boiler safety and reliability.

[0003] Research has shown that exhaust gas temperature is closely related to the boiler's combustion process and combustion conditions. During the combustion process of a coal-fired boiler, factors such as the sufficiency of the combustion reaction, the level of the combustion temperature, and the size of the excess air coefficient will directly affect the temperature of the flue gas. A normal combustion process should ensure that the coal is fully burned, the fuel and air are evenly mixed, and the combustion temperature and excess air coefficient are well controlled to achieve an appropriate exhaust gas temperature. Secondly, the exhaust gas temperature is also closely related to the heat transfer effect of the boiler. The heat transfer effect of the boiler is mainly determined by factors such as the combustion space and heat transfer area in the furnace, and the speed and path of the flue gas flow. A reasonable design of the combustion space in the furnace, sufficient heat transfer area, and smooth flue gas circulation are conducive to improving the heat transfer effect and reducing the exhaust gas temperature. At the same time, appropriately increasing the heat transfer area of ​​the boiler and extending the residence time of the flue gas in the boiler will also help improve the heat transfer effect and reduce the exhaust gas temperature. The utility model mainly reduces the exhaust gas temperature of the boiler to reduce energy consumption by improving the installation of the burner. Utility Model Content

[0004] The utility model aims to solve the technical problem of high exhaust gas temperature of coal-fired boilers in the prior art and provides a burner capable of reducing the exhaust gas temperature.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present utility model is as follows:

[0006] A burner for reducing the exhaust temperature comprises at least two groups of burner groups; the burner groups are arranged at intervals along the height direction of the furnace; each group of the burner groups comprises four burners, and the four burners in each group of the burner groups are placed at the four corners of the furnace; the burner group located at the bottom layer of the furnace can spray a coal powder airflow that can form an imaginary tangential circle in the center of the furnace; the nozzle of each burner in each of the remaining burner groups is arranged tilted downward, and the coal powder airflow it sprays can also form an imaginary tangential circle in the center of the furnace, and the direction is opposite to that of the imaginary tangential circle located at the bottom layer of the furnace.

[0007] Furthermore, the burner group includes three groups, which are respectively installed in the upper layer, middle layer and lower layer of the furnace.

[0008] Furthermore, in the burner groups in the middle layer and the upper layer, each burner is arranged to be inclined downward by 5 to 15 degrees.

[0009] Furthermore, the burner is a direct-flow burner.

[0010] Furthermore, the direct current burner includes a shell, a primary air duct and a secondary air duct; the secondary air duct is arranged in the center of the shell, the primary air duct is arranged around the circumference of the secondary air duct and the nozzle end of the primary air duct gradually decreases and is arranged toward the secondary air duct.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) The utility model improves the installation angle and position of the burner on the coal-fired boiler, and sets the upper and middle burners at a downward angle of 5°-15°, and makes the airflow direction of the imaginary tangential circle formed by the upper and middle burners opposite to the airflow direction of the imaginary tangential circle located at the bottom of the furnace. This can change the flow path of the flue gas, hinder the airflow inside the furnace from rotating and rising all the way, prolong the residence time of the flue gas in the boiler, and thus reduce the exhaust temperature of the coal-fired boiler.

[0013] (2) In the present invention, the primary air duct of each burner is arranged around the secondary air duct, and the nozzle end of the primary air duct gradually decreases and is arranged toward the secondary air duct. The secondary air ejected can be supplemented and mixed with the fuel through the secondary air duct, so that the fuel and air can be fully mixed and fully burned, which is beneficial to controlling the exhaust temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A three-dimensional cross-sectional view of a burner for reducing exhaust temperature according to the utility model;

[0015] Figure 2 A cross-sectional view of a burner for reducing exhaust temperature according to the utility model;

[0016] In the figure, 1-burner, 2-furnace, 3-shell, 4-secondary air duct, 5-primary air duct. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1

[0019] like Figure 1-Figure 2 As shown, this embodiment provides a burner for reducing the exhaust gas temperature, comprising at least two groups of burner groups; the burner groups are arranged at intervals along the height direction of the furnace 2; each group of the burner groups comprises four burners 1, and the four burners 1 in each group of the burner groups are respectively placed at the four corners of the furnace 2; the burner group located at the bottom layer of the furnace 2, the coal powder airflow it ejects can form an imaginary tangential circle in the center of the furnace 2; the nozzles of each burner 1 in each of the remaining layers of the burner groups are arranged tilted downward, and the coal powder airflow it ejects can also form an imaginary tangential circle in the center of the furnace 2, and the airflow direction is opposite to the airflow direction of the imaginary tangential circle located at the bottom layer of the furnace 2. In this embodiment, the imaginary tangential circle airflow formed by the burners 1 in the upper and middle layers is opposite to the airflow direction of the imaginary tangential circle located at the bottom layer of the furnace 2, thereby changing the flow path of the flue gas, hindering the airflow inside the furnace 2 from rotating all the way up, and prolonging the residence time of the flue gas in the boiler, thereby reducing the exhaust gas temperature of the coal-fired boiler.

[0020] Preferably, in this embodiment, the burner group includes 3 groups, which are respectively installed in the upper layer, middle layer and lower layer of the furnace 2. Among them, the burners 1 in the middle layer and the upper layer are tilted downward by 5 to 15 degrees. During actual installation, the appropriate tilt angle can be selected by comprehensively considering factors such as coal burning characteristics to adjust the flow direction of the flue gas. In this embodiment, since the burners 1 in the upper and middle layers are tilted downward, and the flow direction of the imaginary tangential circle airflow in the upper and middle layers is opposite to the flow direction of the imaginary tangential circle located at the bottom layer of the furnace 2. Therefore, the upper and middle layers can form a counter-flow and mixing with the airflow in the lower layer, and at the same time can further slow down the rising rate of the airflow, which is beneficial to reduce the exhaust temperature.

[0021] Preferably, in this embodiment, the burner 1 is a direct-flow burner. More preferably, the direct-flow burner 1 includes a housing 3, a primary air duct 5, and a secondary air duct 4; the secondary air duct 4 is disposed at the center of the housing 3, and the primary air duct 5 is disposed around the circumference of the secondary air duct 4, with the nozzle end of the primary air duct 5 gradually decreasing and disposed toward the secondary air duct 4. The design of the secondary air duct 4 and the primary air duct 5 allows the secondary air ejected from the secondary air duct 4 to be fully mixed with the primary air and fuel, allowing the fuel and air to be fully mixed and burned, thereby facilitating control of exhaust gas temperature.

[0022] The utility model mainly improves the arrangement structure of the multi-layer four-corner burner 1 in the prior art, can change the traditional air flow path, adjust the flow direction of the air flow, and thus can reduce the salt discharge temperature.

[0023] Although the present invention has been disclosed above by way of embodiments, they are not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A burner for reducing exhaust gas temperature, characterized in that: It comprises at least two groups of burner groups; the burner groups are arranged at intervals along the height direction of the furnace; each group of the burner groups comprises four burners, and the four burners in each group of the burner groups are placed at the four corners of the furnace; the burner group located at the bottom layer of the furnace can form an imaginary tangential circle in the center of the furnace by the coal powder airflow it sprays; the nozzles of each burner in the burner groups on each of the remaining layers are arranged tilted downward, and the coal powder airflow it sprays can also form an imaginary tangential circle in the center of the furnace, and the direction is opposite to that of the imaginary tangential circle located at the bottom layer of the furnace.

2. A burner for reducing exhaust temperature according to claim 1, characterized in that: The burner group includes three groups, which are respectively installed on the upper layer, middle layer and lower layer of the furnace.

3. A burner for reducing exhaust gas temperature according to claim 2, characterized in that: In the burner groups of the middle layer and the upper layer, each burner is arranged to be inclined downward by 5 to 15 degrees.

4. A burner for reducing exhaust gas temperature according to claim 1, characterized in that: The burner is a direct-flow burner.

5. A burner for reducing exhaust gas temperature as claimed in claim 4, characterized in that: The direct-flow burner includes a shell, a primary air duct and a secondary air duct; the secondary air duct is arranged at the center of the shell, the primary air duct is arranged around the circumference of the secondary air duct, and the nozzle end of the primary air duct gradually decreases and is arranged toward the secondary air duct.

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