Smoke exhaust temperature adjusting structure of low-load boiler

Abstract

The utility model relates to the field of boilers, in particular to a low-load boiler exhaust gas temperature adjusting structure. The utility model discloses a low-load boiler exhaust gas temperature adjusting structure which comprises a flue. The number of the coal economizers is at least two, and the peripheral face of each coal economizer is connected with the inner wall face of the flue in an abutting mode; the air pre-heater is arranged in the flue and located on the side, close to the lower end of the flue, of the economizer. And the adjusting device is formed into a tubular part, one end of the adjusting device communicates with the containing cavity between the upper-layer coal economizer and the lower-layer coal economizer, and the other end of the adjusting device communicates with a smoke outlet of the air pre-heater. By arranging the adjusting device, a small amount of flue gas in the high-temperature area is conveyed to the position above the air pre-heater through the adjusting device, so that the flue gas amount of the lower-layer economizer is reduced. In order to meet the requirement for on-load loads, the coal feeding amount needs to be slightly increased, the boiler smoke amount is increased, the air coefficient is increased, and the smoke exhaust temperature is slightly increased.

Description

Technical Field

[0001] The utility model relates to the field of boilers, in particular to a low-load boiler exhaust gas temperature regulating structure. Background Art

[0002] In order to save energy and reduce consumption, existing enterprises need to upgrade and transform boilers from sub-high temperature and sub-high pressure to high temperature and high pressure or higher level parameters, thus improving the power generation efficiency of boilers. At the same time, the maximum heat loss exhaust temperature of the boiler is also controlled, because every 15℃ exhaust temperature will affect the thermal efficiency of the boiler by 1%. According to this characteristic, controlling the boiler exhaust temperature to a lower temperature (above the dust collector dew point) at high load can ensure the maximum thermal efficiency of the boiler.

[0003] Due to the influence of the peak load shaving area, the load difference between daytime and nighttime is large. In order to increase the load span, the boiler is designed to increase the main steam temperature by adding a superheater and control the furnace temperature by adding an ash cooler. After this design and arrangement, the peak load shaving capacity of the boiler is enhanced. In order to further save energy and reduce consumption, more economizers are also used in the design. In this design, the exhaust gas temperature of the boiler will be lower than 100°C at low load in winter. When the exhaust gas temperature is low, it will form adhesion on the bag of the tail dust collector, causing the negative pressure of the tail dust collector to rise, affecting the operation cycle of the boiler. Utility Model Content

[0004] In order to solve the above technical problems, the present application provides a low-load boiler exhaust temperature adjustment structure.

[0005] The present application provides a low-load boiler exhaust gas temperature adjustment structure adopts the following technical solution:

[0006] A low-load boiler exhaust gas temperature regulating structure, comprising:

[0007] A flue, the flue being formed as a tubular member with both ends open so that hot flue gas is input from the upper end of the flue and transferred toward the lower end of the flue;

[0008] Economizers, at least two economizers are provided, the outer peripheral surface of each economizer is abutted and connected with the inner wall surface of the flue, the economizer near the upper end of the flue is an upper economizer, and the economizer near the lower end of the flue is a lower economizer, and the upper economizer and the lower economizer are arranged at intervals and form a receiving cavity;

[0009] An air preheater, the air preheater is arranged in the flue and located on a side of the economizer close to the lower end of the flue;

[0010] The regulating device is formed as a tubular member, one end of the regulating device is connected to the accommodating cavity between the upper economizer and the lower economizer, and the other end of the regulating device is connected to the flue gas outlet of the air preheater.

[0011] Through the above technical solution, the present application sets a regulating device to transport a small amount of flue gas in the high temperature zone to the top of the air preheater through the regulating device, so that the flue gas volume of the lower economizer is reduced. In order to meet the needs of load, it is necessary to increase the amount of coal input slightly, the boiler flue gas volume increases, the air coefficient increases, and the exhaust gas temperature increases slightly.

[0012] Preferably, the adjusting device further comprises:

[0013] A regulating valve is arranged on the regulating device to adjust the connection and closing of the two ends of the regulating device.

[0014] Through the above technical solution, the present application arranges a larger regulating device at the outlet of the upper economizer and the outlet of the air preheater, and arranges a regulating valve between the regulating devices. Since the heat absorption of the air preheater is constant, when the temperature entering the air preheater inlet exceeds the heat required by the design, the excess heat will increase the existing exhaust temperature, causing the exhaust temperature to rise. Since a regulating valve is arranged in the middle of the regulating device, the exhaust temperature can be accurately controlled after adjustment. While ensuring the safe operation of the dust collector, the low-load adjustment range is increased to meet the need to adjust the exhaust temperature in winter.

[0015] Preferably, three economizers are provided, and the three economizers are respectively an upper economizer, a middle economizer and a lower economizer from the upper end of the flue toward the lower end of the flue.

[0016] Preferably, the upper economizer and the middle economizer are arranged at intervals and form a accommodating cavity.

[0017] Preferably, the air preheater comprises:

[0018] A cold air inlet, the cold air inlet is arranged on one side of the outer peripheral surface of the flue and is connected with the interior of the flue;

[0019] An air pre-duct, one end of which is connected to the cold air inlet and is provided with a plurality of folded ducts, at least a portion of which is connected to the interior of the flue;

[0020] A hot air outlet is provided at the other side of the outer peripheral surface of the flue and is communicated with the other end of the air pre-duct.

[0021] Preferably, the air preheater comprises a first air preheater duct and a second air preheater duct which are spaced apart from each other, the first air preheater duct is provided with a first hot air outlet and a first cold air inlet, and the second air preheater duct is provided with a second hot air outlet and a second cold air inlet.

[0022] Preferably, the first cold air inlet is arranged on a side of the second cold air inlet close to the lower end of the flue, and the second hot air outlet is arranged on a side of the first hot air outlet close to the upper end of the flue.

[0023] In summary, the present application includes at least one of the following beneficial technical effects:

[0024] 1. This application sets a regulating device to transport a small amount of flue gas in the high temperature zone to the top of the air preheater through the regulating device, so that the flue gas volume of the lower economizer is reduced. In order to meet the needs of load, it is necessary to increase the amount of coal input slightly, the boiler flue gas volume increases, the air coefficient increases, and the exhaust gas temperature rises slightly.

[0025] 2. This application arranges a relatively large regulating device at the outlet of the upper economizer and the outlet of the air preheater, and arranges a regulating valve between the regulating devices. Since the heat absorption of the air preheater is constant, when the temperature entering the air preheater inlet exceeds the heat required by the design, the excess heat will increase the existing exhaust temperature, causing the exhaust temperature to rise. Since a regulating valve is arranged in the middle of the regulating device, the exhaust temperature can be accurately controlled after adjustment. While ensuring the safe operation of the dust collector, the low-load adjustment range is increased to meet the need to adjust the exhaust temperature in winter. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a low-load boiler exhaust temperature regulation structure according to an embodiment of the present application.

[0027] Explanation of the reference numerals: 1. Flue; 2. Economizer; 21. Upper economizer; 22. Middle economizer; 23. Lower economizer; 3. Air preheater; 31. First cold air inlet; 32. Second cold air inlet; 33. First hot air outlet; 34. Second hot air outlet; 4. Adjusting device; 41. Adjusting valve. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1 This application is described in further detail.

[0029] Example 1 of the present application discloses a low-load boiler exhaust temperature regulating structure.

[0030] The low-load boiler exhaust gas temperature regulating structure includes a flue 1, which is formed into a tubular structure. Hot flue gas is input from the upper end of the flue 1 and output through the lower end of the flue 1; at the upper end of the flue 1, an economizer 2 is provided, and three economizers 2 are provided, and the outer peripheral surface of each economizer 2 is fixedly connected to the inner wall surface of the flue 1. The economizers 2 are respectively an upper economizer 21, a middle economizer 22 and a lower economizer 23 from top to bottom. Each layer of economizers 2 is arranged at intervals, and a accommodating cavity is provided between the upper economizer 21 and the middle economizer 22.

[0031] At the lower end of the economizer 2, an air preheater 3 is also provided. The air preheater 3 is formed into two coils and is spaced apart along the length direction of the flue 1. A part of the air preheater 3 is provided in the flue 1. The air preheater 3 includes two first air preheater pipes and a second air preheater pipe spaced apart from each other. The first air preheater pipe is provided with a first hot air outlet 33 and a first cold air inlet 31. The second air preheater pipe is provided with a second hot air outlet 34 and a second cold air inlet 32. The first cold air inlet 31 is provided on the side of the second cold air inlet 32 ​​close to the lower end of the flue 1, and the second hot air outlet 34 is provided on the side of the first hot air outlet 33 close to the upper end of the flue 1.

[0032] On one side of the flue 1, a regulating device 4 is provided. The regulating device 4 is a U-shaped tubular structure. One end of the regulating device 4 is connected to the accommodating cavity between the upper economizer 21 and the middle economizer 22, and the other end of the regulating device 4 is connected to the flue gas outlet of the air preheater 3. A regulating valve 41 is provided between the regulating devices 4. The regulating valve 41 is provided on the regulating device 4 to adjust the connection and closing of the two ends of the regulating device 4.

[0033] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A low-load boiler exhaust gas temperature adjustment structure, characterized in that: include: A flue (1), the flue (1) being formed as a tubular member with both ends open so that hot flue gas is input from the upper end of the flue (1) and transferred toward the lower end of the flue (1); Economizers (2), at least two economizers (2) are provided, the outer peripheral surface of each economizer (2) is abutted and connected to the inner wall surface of the flue (1), the economizer (2) close to the upper end of the flue (1) is an upper economizer (21), and the economizer (2) close to the lower end of the flue (1) is a lower economizer (23), and the upper economizer (21) and the lower economizer (23) are arranged at intervals and form a receiving cavity; An air preheater (3), the air preheater (3) being arranged in the flue (1) and located on a side of the economizer (2) close to the lower end of the flue (1); An adjusting device (4), wherein the adjusting device (4) is formed as a tubular member, one end of the adjusting device (4) is connected to the accommodating cavity between the upper economizer (21) and the lower economizer (23), and the other end of the adjusting device (4) is connected to the flue gas outlet of the air preheater (3).

2. A low-load boiler exhaust gas temperature adjustment structure according to claim 1, characterized in that: The regulating device (4) further comprises: A regulating valve (41), wherein the regulating valve (41) is arranged on the regulating device (4) to regulate the connection and closing of the two ends of the regulating device (4).

3. A low-load boiler exhaust gas temperature adjustment structure according to claim 1, characterized in that: The three economizers (2) are provided, and the three economizers (2) are respectively an upper economizer (21), a middle economizer (22) and a lower economizer (23) from the upper end of the flue (1) toward the lower end of the flue (1).

4. A low-load boiler exhaust gas temperature adjustment structure according to claim 3, characterized in that: The upper economizer (21) and the middle economizer (22) are arranged at intervals and form a receiving cavity.

5. A low-load boiler exhaust gas temperature adjustment structure according to claim 1, characterized in that: The air preheater (3) comprises: A cold air inlet, the cold air inlet being arranged on one side of the outer peripheral surface of the flue (1) and being in communication with the interior of the flue (1); An air pre-duct, one end of which is connected to the cold air inlet and is provided with a plurality of sections of folded ducts, at least a portion of which is connected to the interior of the flue (1); A hot air outlet is provided on the other side of the outer peripheral surface of the flue (1) and is connected to the other end of the air pre-duct.

6. A low-load boiler exhaust gas temperature adjustment structure according to claim 5, characterized in that: The air preheater (3) comprises two first air preheating ducts and a second air preheating duct which are spaced apart from each other, the first air preheating duct being provided with a first hot air outlet (33) and a first cold air inlet (31), and the second air preheating duct being provided with a second hot air outlet (34) and a second cold air inlet (32).

7. A low-load boiler exhaust gas temperature adjustment structure according to claim 6, characterized in that: The first cold air inlet (31) is arranged on a side of the second cold air inlet (32) close to the lower end of the flue (1), and the second hot air outlet (34) is arranged on a side of the first hot air outlet (33) close to the upper end of the flue (1).

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