Low-nitrogen oil burning boiler system

Abstract

A low-nitrogen oil burning boiler system comprises an air blower, an air duct, an ultra-mixing burner, an oil burning boiler, a flue and an over-fire air pipeline, the air blower is connected with the rear end of the air duct, the front end of the air duct is connected with the ultra-mixing burner, the ultra-mixing burner is fixed to the lower portion of a hearth of the oil burning boiler, and the over-fire air pipeline is connected with the flue. The oil burning boiler is provided with a nozzle used for conveying over fire air into the hearth, the nozzle is located above the ultra-mixing burner, the distance between the fixed position of the ultra-mixing burner on the oil burning boiler and the center line of the nozzle is 0.15-1 time of the smoke flow speed, the flue is arranged on the downstream portion of the oil burning boiler, and the ultra-mixing burner is arranged on the flue. One end of the over-fire air pipeline is connected with the air duct, the other end of the over-fire air pipeline is closed, and over-fire air branch pipes connected with the nozzles in a one-to-one correspondence mode are arranged on the over-fire air pipeline. On the basis of applying the ultra-mixing burner, the over fire air technology is adopted, and sufficient burning and low emission of the oil burning boiler are achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of boilers, and in particular relates to a low-nitrogen fuel oil boiler system. Background Art

[0002] Oil-fired boilers emit high levels of nitrogen oxides (NOx). This is primarily due to the high concentration of nitrogen compounds in the fuel. During fuel combustion, these nitrogen compounds combine with oxygen in the air to produce fuel-type NOx. Furthermore, the high combustion temperature of fuel also produces significant amounts of thermal NOx. Currently, without post-denitrification, NOx emissions from heavy oil-fired boilers are typically around 500mg / Nm³.

[0003] Heavy oil has a large molecular weight and high viscosity, and is easily affected by factors such as atomization, resulting in incomplete combustion and the emission of black smoke. Therefore, for oil-fired boilers, the completeness of fuel combustion must also be fully considered when reducing nitrogen. Utility Model Content

[0004] Based on this, in order to solve the above technical problems, a low-nitrogen fuel oil boiler system is provided.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A low-nitrogen fuel boiler system, characterized in that it includes a blower, an air duct, a supermix burner, a fuel boiler, a flue and a burnt-out air duct, the blower is connected to the rear end of the air duct, the front end of the air duct is connected to the supermix burner, the supermix burner is fixed to the lower part of the furnace of the fuel boiler, the fuel boiler is provided with a nozzle for conveying burnt-out air into the furnace, the nozzle is located above the supermix burner, the fixed position of the supermix burner on the fuel boiler is 0.15-1 times the flue gas flow rate from the center line of the nozzle, the flue is placed downstream of the fuel boiler, one end of the burnt-out air duct is connected to the air duct, and the other end is closed, and is provided with a burnt-out air branch pipe connected one-to-one with the nozzle.

[0007] The utility model uses the overburning air technology on the basis of applying the super-mixing burner, thereby realizing the full combustion and low emission of the oil boiler, and can reduce nitrogen oxides by 30% under the condition of full combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a structural diagram of the utility model;

[0009] Figure 2 This is a schematic structural diagram of the super mixing burner of the present utility model;

[0010] Figure 3(a) and (b) are respectively a schematic diagram of nozzle distribution and an AA cross-sectional view of the supermix burner of the present invention when it is installed on the front and rear walls;

[0011] Figure 4 (a) and (b) are respectively a schematic diagram of nozzle distribution and an AA cross-sectional view of the supermix burner of the present invention when the supermix burner is installed in a four-corner tangential circle;

[0012] Figure 5 This is a schematic diagram of the distance between the fixed position of the super mixing burner on the oil boiler and the center line of the nozzle of the utility model. DETAILED DESCRIPTION

[0013] The following will illustrate the implementation of the present utility model in conjunction with the drawings in the specification. It should be noted that the implementation methods involved in this specification are not exhaustive and do not represent the only implementation methods of the present utility model. The following corresponding embodiments are only for the purpose of clearly illustrating the utility model content of the utility model patent and are not intended to limit its implementation methods. For ordinary technicians in this field, different forms of changes and modifications can be made on the basis of the description of this embodiment. All obvious changes or modifications that belong to the technical concept and utility model content of the present utility model are also within the scope of protection of the present utility model.

[0014] like Figure 1 As shown, an embodiment of the present application provides a low-nitrogen fuel oil boiler system, including a blower 110 , an air duct 120 , a supermix burner 130 , a fuel oil boiler 140 , a flue 150 and a burnt air duct 160 .

[0015] The blower 110 is connected to the rear end of the air duct 120 , and the front end of the air duct 120 is connected to the supermix burner 130 . The blower 110 introduces combustion-supporting air and sends it into the supermix burner 130 through the air duct 120 .

[0016] The supermix burner 130 is used for complete combustion and is fixed to the lower portion of the furnace of the oil boiler 140 .

[0017] like Figure 2 As shown, the supermix burner 130 includes an oil gun 131, a primary air channel 132, a swirl air channel 133 and a direct air channel 134 which are concentrically arranged from the inside to the outside.

[0018] The supermix burner 130 may be mounted vertically or horizontally within the boiler.

[0019] The top of the oil gun 131 passes through the outlet of the primary air channel 132 and is provided with an oil mist nozzle 131 a , and the outlet of the swirl air channel 133 is provided with a cyclone 133 a .

[0020] Supermix burner 130 is designed to have a high air velocity. Specifically, the ventilation volume of primary air duct 132 is no less than 15% of the total ventilation volume of supermix burner 130. This high velocity allows for thorough mixing with the oil mist ejected from oil mist nozzle 131a of oil gun 131. The air from swirl air duct 133, after passing through swirler 133a, possesses sufficient power and swirl intensity to thoroughly mix with the atomized oil mist. This thorough mixing results in more uniform and complete combustion, avoiding issues such as black smoke.

[0021] The ratio of the swirl wind and the direct wind can be adjusted by the manual valves (not shown in the figure) in the swirl wind channel 133 and the direct wind channel 134 to adjust the flame size and maintain the flame rigidity.

[0022] like Figure 3 and Figure 4 As shown, the fuel oil boiler 140 has a nozzle 141 for delivering burnt air into the furnace. The nozzle 141 is located above the supermix burner 130 (downstream of the flue gas of the supermix burner 130) and extends into the furnace. The inclination angle of the nozzle 141 can be adjusted according to the installation position.

[0023] The nozzles 141 are arranged in at least one layer, and each layer has a plurality of nozzles.

[0024] Overcombustion air involves injecting a portion of the combustion-supporting air into the rear of the furnace, creating an oxygen-deficient atmosphere at the burner head, thereby reducing NOx. Overcombustion air technology was originally used in coal-fired boilers, and later manufacturers adapted it for nitrogen reduction in gas-fired boilers. While overcombustion air technology is significantly effective in reducing fuel-induced NOx, due to the inherent difficulty of complete combustion of fuel oil, it is currently rarely used in oil-fired boilers for nitrogen reduction.

[0025] The system of this embodiment can be used for π-type furnaces, D-type furnaces, etc. Taking the π-type furnace as an example, the nozzle 141 is set above the super mixing burner 130, that is, downstream of the flue gas, and lower than the flame deflection angle of the oil boiler 140.

[0026] like Figure 3 As shown, taking one layer of nozzles as an example, if the supermix burner 130 is installed on the front and rear walls, that is, its fixed position W on the oil boiler 140 is the front and rear furnace walls, then the multiple nozzles of this layer are arranged on the four furnace walls of the oil boiler 140.

[0027] like Figure 4 As shown, taking one layer of nozzles as an example, if the supermix burner 130 is installed in a four-corner tangential circle, that is, its fixed position W on the oil boiler 140 is the four corners formed by the four furnace walls, then the multiple nozzles of this layer are arranged at the above four corners.

[0028] The distance H between the fixed position of the supermix burner 130 on the oil boiler 140 and the center line of the nozzle 141 is 0.15-1 times the flue gas flow rate, so that there is enough reduction space to reduce the NOx that has been generated. Figure 5 .

[0029] like Figure 1 As shown, the flue 150 is placed downstream of the oil-fired boiler 140 .

[0030] like Figure 1 As shown, one end (upstream) of the burnout air duct 160 is connected to the air duct 120, and the other end (downstream) is closed. There are multiple burnout air branch pipes 161 on the downstream section. The number of burnout air branch pipes 161 is equal to the total number of nozzles 141, and they are connected one-to-one. A part of the combustion-supporting air in the air duct 120 enters the furnace through the burnout air duct 160 and the nozzles 141.

[0031] The overburnt air duct 160 is provided with an overburnt air regulating valve 162 for adjusting the air volume of the overburnt air.

[0032] During operation, the air entering the furnace from the supermix burner 130 accounts for 75-95% of the total air required for combustion, and the air volume entering the furnace from the nozzle 141 is 5-25%. In the primary combustion zone, the excess air coefficient α is less than 1, that is, oxygen-deficient combustion occurs here, thus forming a reducing atmosphere, reducing NOx generated in the primary combustion zone to N2.

[0033] As can be seen from the above, the low-nitrogen fuel boiler system provided in the embodiment of the present application, based on the application of supermix burners, adopts overburnt air technology to achieve full combustion and low emissions of the fuel boiler, and can reduce nitrogen oxides by 30% under full combustion.

[0034] Obviously, those skilled in the art should realize that the above embodiments are only used to illustrate the present invention and are not used to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A low-nitrogen fuel oil boiler system, characterized in that: The utility model comprises a blower, an air duct, a supermix burner, an oil-fired boiler, a flue and a burnt-out air duct, wherein the blower is connected to the rear end of the air duct, the front end of the air duct is connected to the supermix burner, the supermix burner is fixed to the lower part of the furnace of the oil-fired boiler, the oil-fired boiler is provided with a nozzle for conveying burnt-out air into the furnace, the nozzle is located above the supermix burner, the fixed position of the supermix burner on the oil-fired boiler and the distance from the center line of the nozzle is 0.15-1 times the flue gas flow rate, the flue is placed downstream of the oil-fired boiler, one end of the burnt-out air duct is connected to the air duct, and the other end is closed, and is provided with a burnt-out air branch pipe connected one-to-one with the nozzle.

2. A low-nitrogen fuel oil boiler system according to claim 1, characterized in that: The supermix burner includes an oil gun, a primary air channel, a swirl air channel and a direct air channel which are concentrically arranged from the inside to the outside. The top of the oil gun passes through the outlet of the primary air channel and is provided with an oil mist nozzle. The outlet of the swirl air channel is provided with a swirler.

3. A low-nitrogen fuel oil boiler system according to claim 2, characterized in that: The ventilation volume of the primary air channel is not less than 15% of the total ventilation volume of the super mixing burner.

4. A low-nitrogen fuel oil boiler system according to claim 1, characterized in that: The oil-fired boiler is a π-shaped furnace, and the nozzle is lower than the flame folding angle of the oil-fired boiler.

5. A low-nitrogen fuel oil boiler system according to claim 4, characterized in that: The nozzles are arranged in at least one layer, and each layer has a plurality of nozzles. The number of the overburnt air branch pipes is equal to the total number of the nozzles.

6. A low-nitrogen fuel oil boiler system according to claim 5, characterized in that: The fixed positions of the super-mixing burner on the oil boiler are the front and rear furnace walls, and the multiple nozzles of each layer are arranged on the four furnace walls of the oil boiler.

7. A low-nitrogen fuel oil boiler system according to claim 5, characterized in that: The fixed positions of the supermix burner on the oil boiler are the four corners formed by the four furnace walls, and the multiple nozzles of each layer are arranged at the four corners.

8. The low-nitrogen fuel oil boiler system according to claim 1, characterized in that: The burnt-out air duct is provided with a burnt-out air regulating valve.

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