High-temperature heating surface wall temperature deviation adjusting device

Abstract

The invention provides a high-temperature heating surface wall temperature deviation adjusting device, and belongs to the technical field of boiler wall temperature control. The problems that in the prior art, operation adjusting means influencing the metal wall temperature of the high-temperature heating surface are limited, and the effect is not obvious are solved. The secondary air nozzle group structure comprises a main air pipe, a first-stage upper branch air pipe, a first-stage lower branch air pipe, a plurality of upper secondary air nozzle groups and a plurality of lower secondary air nozzle groups, and the upper secondary air nozzle groups are uniformly arranged on the top end face of a horizontal flue of a hearth at intervals in the width direction of the horizontal flue of the hearth. The upper secondary air nozzle group comprises a plurality of upper secondary air nozzles which are uniformly arranged at intervals along the length direction of the horizontal flue of the hearth, and the plurality of lower secondary air nozzle groups are uniformly arranged on the bottom end surface of the horizontal flue of the hearth at intervals along the width direction of the horizontal flue of the hearth. The device is mainly used for adjusting wall temperature deviation of a high-temperature heating surface.

Description

Technical Field

[0001] The invention belongs to the technical field of boiler wall temperature control, and in particular relates to a high-temperature heating surface wall temperature deviation adjustment device. Background Art

[0002] With the gradual commissioning of high-capacity and large-parameter coal-fired units in China, the parameters of superheated and reheated steam at the boiler outlet have been further improved, especially for high-efficiency and secondary reheat units. In actual operation, such high-parameter units often fail to reach the design temperature due to local overheating of the high-temperature heating surface, or the steam temperature can only reach the standard under extreme conditions, which not only reduces the safety of boiler operation, but also reduces the overall economy of the unit. At the same time, due to the rearward arrangement of the high-temperature heating surface, the current operating adjustment means that affect the metal wall temperature of the high-temperature heating surface are limited and the effect is not obvious. Generally, targeted transformation and equalization are required in the later stage to achieve uniform wall temperature. Therefore, it is necessary to invent a device that can adjust the wall temperature deviation of the high-temperature heating surface on site, so as to effectively adjust the wall temperature of the high-temperature heating surface in actual operation, so as to achieve the designed steam temperature. Summary of the invention

[0003] In view of this, the present invention aims to propose a high-temperature heating surface wall temperature deviation adjustment device to solve the problem in the prior art that the operating adjustment means affecting the high-temperature heating surface metal wall temperature are limited and the effect is not obvious.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a high-temperature heating surface wall temperature deviation adjustment device, which includes a main air duct, a first-level upper branch air duct, a first-level lower branch air duct, a plurality of upper secondary air nozzle groups and a plurality of lower secondary air nozzle groups, the plurality of upper secondary air nozzle groups are evenly spaced along the width direction of the furnace horizontal flue on the top surface of the furnace horizontal flue, the upper secondary air nozzle group includes a plurality of upper secondary air nozzles evenly spaced along the length direction of the furnace horizontal flue, the plurality of lower secondary air nozzle groups are evenly spaced along the width direction of the furnace horizontal flue on the bottom surface of the furnace horizontal flue, the lower secondary air nozzle group includes a plurality of lower secondary air nozzles evenly spaced along the length direction of the furnace horizontal flue, the main air duct is connected to the upper secondary air nozzles through the first-level upper branch air duct, and the main air duct is connected to the lower secondary air nozzles through the first-level lower branch air duct.

[0005] Furthermore, the air outlet of the first-level upper branch air duct is connected to multiple second-level upper branch air ducts, and the second-level upper branch air ducts are arranged in a one-to-one correspondence with the upper secondary air nozzle group. The air outlet of the second-level upper branch air duct is connected to multiple third-level upper branch air ducts, and the third-level upper branch air ducts are arranged in a one-to-one correspondence with the upper secondary air nozzles of the upper secondary air nozzle group, and the air outlet of the third-level upper branch air duct is connected to the upper secondary air nozzle.

[0006] Furthermore, the three-level upper branch air duct is arranged perpendicular to the top surface of the horizontal flue of the furnace.

[0007] Furthermore, the air outlet of the first-level lower branch air duct is connected to multiple second-level lower branch air ducts, and the second-level lower branch air ducts are arranged in a one-to-one correspondence with the lower secondary air nozzle group. The air outlet of the second-level lower branch air duct is connected to multiple third-level lower branch air ducts, and the third-level lower branch air ducts are arranged in a one-to-one correspondence with the lower secondary air nozzles of the lower secondary air nozzle group, and the air outlet of the third-level lower branch air duct is connected to the lower secondary air nozzle.

[0008] Furthermore, the three-level lower branch air duct is arranged perpendicular to the bottom end surface of the horizontal flue of the furnace.

[0009] Furthermore, the secondary upper branch air duct and the secondary lower branch air duct are both provided with air volume regulating valves.

[0010] Furthermore, the air inlet of the main air duct is connected to the secondary air box.

[0011] Furthermore, the upper secondary air nozzle group and the lower secondary air nozzle group are both arranged at the front end of the high-temperature heating surface of the horizontal flue of the furnace.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a high-temperature heating surface wall temperature deviation adjustment device, which can effectively adjust the flue gas temperature distribution and metal wall temperature of the high-temperature heating surface of the horizontal flue of the boiler furnace, thereby improving the uniformity of the flue gas temperature and the metal temperature, thereby achieving the standard steam temperature parameters at the outlet of the heating surface and improving the overall energy efficiency and safety of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0014] Figure 1 It is a structural schematic diagram of a high-temperature heating surface wall temperature deviation adjustment device according to the present invention;

[0015] Figure 2 This is a temperature distribution curve diagram of the flue gas at the inlet and outlet of a high-temperature heating surface wall temperature deviation adjustment device described in the present invention along the width direction of the horizontal flue of the furnace.

[0016] 1-upper secondary air nozzle, 2-lower secondary air nozzle, 3-first-level upper branch air duct, 4-first-level lower branch air duct, 5-second-level upper branch air duct, 6-second-level lower branch air duct, 7-third-level upper branch air duct, 8-third-level lower branch air duct, 9-air volume regulating valve, 10-main air duct, 11-high-temperature heating surface, 12-furnace horizontal flue, 13-high-temperature heating surface inlet flue gas window. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0018] See also Figure 1-2 To illustrate the present embodiment, a high-temperature heated surface wall temperature deviation adjustment device comprises a main air duct 10, a first-level upper branch air duct 3, a first-level lower branch air duct 4, a plurality of upper secondary air nozzle groups and a plurality of lower secondary air nozzle groups, wherein the plurality of upper secondary air nozzle groups are evenly spaced along the width direction of the furnace horizontal flue 12 on the top surface of the furnace horizontal flue 12, the upper secondary air nozzle group comprises a plurality of upper secondary air nozzles 1 evenly spaced along the length direction of the furnace horizontal flue 12, the plurality of lower secondary air nozzle groups are evenly spaced along the width direction of the furnace horizontal flue 12 on the bottom surface of the furnace horizontal flue 12, the lower secondary air nozzle group comprises a plurality of lower secondary air nozzles 2 evenly spaced along the length direction of the furnace horizontal flue 12, the main air duct 10 is connected to the upper secondary air nozzle 1 through the first-level upper branch air duct 3, and the main air duct 10 is connected to the lower secondary air nozzle 2 through the first-level lower branch air duct 4.

[0019] In the present embodiment, the air outlet of the first-level upper branch air duct 3 is connected to a plurality of second-level upper branch air ducts 5, and the second-level upper branch air ducts 5 are arranged in a one-to-one correspondence with the upper secondary air nozzle groups. The air outlet of the second-level upper branch air duct 5 is connected to a plurality of third-level upper branch air ducts 7, and the third-level upper branch air ducts 7 are arranged in a one-to-one correspondence with the upper secondary air nozzles 1 of the upper secondary air nozzle group. The air outlet of the third-level upper branch air duct 7 is connected to the upper secondary air nozzle 1. In the present embodiment, each of the upper secondary air nozzle groups includes two upper secondary air nozzles 1.

[0020] In the present embodiment, the air outlet of the first-level lower branch air duct 4 is connected to a plurality of second-level lower branch air ducts 6, and the second-level lower branch air ducts 6 are arranged in one-to-one correspondence with the lower secondary air nozzle group, and the air outlet of the second-level lower branch air duct 6 is connected to a plurality of third-level lower branch air ducts 8, and the third-level lower branch air ducts 8 are arranged in one-to-one correspondence with the lower secondary air nozzles 2 of the lower secondary air nozzle group, and the air outlet of the third-level lower branch air duct 8 is connected to the lower secondary air nozzle 2. In the present embodiment, each of the upper secondary air nozzle groups includes two lower secondary air nozzles 2.

[0021] In this embodiment, the air inlet of the main air duct 10 is connected to the secondary air box.

[0022] In the present embodiment, an upper secondary air nozzle 1 and a lower secondary air nozzle 2 are respectively provided on the top end surface and the bottom end surface of the furnace horizontal flue 12. The secondary air in the secondary air box enters through the main air duct 10, and passes through the first-level upper branch air duct 3, the second-level upper branch air duct 5, the third-level upper branch air duct 7 and the upper secondary air nozzle 1 in sequence to enter the furnace horizontal flue 12 from the top end surface of the furnace horizontal flue 12, and passes through the first-level lower branch air duct 4, the second-level lower branch air duct 6, the third-level lower branch air duct 8 and the lower secondary air nozzle 2 in sequence to enter the furnace horizontal flue 12 from the bottom end surface of the furnace horizontal flue 12. The secondary air entering the furnace horizontal flue 12 area through the upper secondary air nozzle 1 and the lower secondary air nozzle 2 can effectively improve the flue gas temperature distribution in the corresponding area, thereby finely adjusting the flue gas temperature distribution of the high-temperature heating surface inlet flue gas window 13, and further affecting the metal wall temperature distribution of the high-temperature heating surface 11 along the width direction of the furnace horizontal flue 12.

[0023] The average smoke temperature in the furnace horizontal flue 12 described in this embodiment is 800°C to 1000°C, and the temperature of the introduced secondary air is 300°C to 400°C.

[0024] In this embodiment, the three-stage lower branch air duct 8 is arranged perpendicular to the bottom end surface of the furnace horizontal flue 12, and the three-stage upper branch air duct 7 is arranged perpendicular to the top end surface of the furnace horizontal flue 12.

[0025] In this embodiment, both the secondary upper branch air duct 5 and the secondary lower branch air duct 6 are provided with air volume regulating valves 9, which are used to adjust the air volume of the secondary air of the upper secondary air nozzle 1 and the lower secondary air nozzle 2.

[0026] In this embodiment, the upper secondary air nozzle group and the lower secondary air nozzle group are both arranged at the front end of the high-temperature heating surface 11 of the horizontal flue 12 of the furnace.

[0027] The working principle of this embodiment is as follows:

[0028] Step 1: According to the size of the furnace horizontal flue 12 and the heating surface, as well as the actual positions of the upper secondary air nozzle 1 and the lower secondary air nozzle 2, the upper secondary air nozzle 1 and the lower secondary air nozzle 2 corresponding to different screens of the high-temperature heating surface 11 are numbered;

[0029] Step 2: During the operation of the boiler, observe the initial metal wall temperature distribution of the high-temperature heating surface (11) along the width direction of the horizontal flue 12 of the furnace, find the relative high point and the relative low point, determine the high-temperature screen and low-temperature screen numbers that need to be adjusted, and correspond them to the upper secondary air nozzle 1 and the lower secondary air nozzle 2 numbers;

[0030] Step 3: Open and adjust the upper secondary air nozzle 1 and the lower secondary air nozzle 2 corresponding to the high-temperature screen through the air volume regulating valve 9 to reduce the flue gas temperature at the entrance of the high-temperature screen, thereby reducing the heat exchange of the high-temperature screen and the metal wall temperature of the high-temperature screen;

[0031] Step 4: Comprehensively adjust the upper secondary air nozzle 1 and the lower secondary air nozzle 2 to change the temperature distribution of the high-temperature heating surface inlet flue gas window 13 according to demand, and finally achieve uniform metal wall temperature of the high-temperature heating surface 11 along the width direction of the furnace, and further increase the steam temperature of the heating surface while ensuring the safety of the wall temperature.

[0032] like Figure 2 As shown, after using the high-temperature heating surface wall temperature deviation adjustment device, the high-temperature area of ​​the two shoulders of the curve at the device outlet is significantly lower than the high-temperature area of ​​the two shoulders of the curve at the device inlet, the smoke temperature at the two shoulders of the curve is significantly reduced, and the smoke temperature distribution along the width direction of the horizontal flue 12 of the furnace becomes uniform, thereby achieving the standard steam temperature parameters at the outlet of the heating surface and improving the overall energy efficiency and safety of the boiler.

[0033] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well.

Claims

1. A device for adjusting the temperature deviation of a high-temperature heating surface, characterized in that: It comprises a main air duct (10), a first-level upper branch air duct (3), a first-level lower branch air duct (4), a plurality of upper secondary air nozzle groups and a plurality of lower secondary air nozzle groups. The plurality of upper secondary air nozzle groups are evenly spaced along the width direction of the furnace horizontal flue (12) on the top surface of the furnace horizontal flue (12). The upper secondary air nozzle group comprises a plurality of upper secondary air nozzles (1) evenly spaced along the length direction of the furnace horizontal flue (12). The plurality of lower secondary air nozzle groups are evenly spaced along the width direction of the furnace horizontal flue (12) on the bottom surface of the furnace horizontal flue (12). The lower secondary air nozzle group comprises a plurality of lower secondary air nozzles (2) evenly spaced along the length direction of the furnace horizontal flue (12). The main air duct (10) is connected to the upper secondary air nozzles (1) via the first-level upper branch air duct (3), and the main air duct (10) is connected to the lower secondary air nozzles (2) via the first-level lower branch air duct (4).

2. A high temperature heating surface wall temperature deviation adjustment device according to claim 1, characterized in that: The air outlet of the first-level upper branch air duct (3) is connected to a plurality of second-level upper branch air ducts (5), the second-level upper branch air ducts (5) are arranged in one-to-one correspondence with the upper secondary air nozzle group, the air outlet of the second-level upper branch air duct (5) is connected to a plurality of third-level upper branch air ducts (7), the third-level upper branch air ducts (7) are arranged in one-to-one correspondence with the upper secondary air nozzle (1) of the upper secondary air nozzle group, and the air outlet of the third-level upper branch air duct (7) is connected to the upper secondary air nozzle (1).

3. A high temperature heating surface wall temperature deviation adjustment device according to claim 2, characterized in that: The three-level upper branch air duct (7) is arranged perpendicular to the top end surface of the furnace horizontal flue (12).

4. A high temperature heating surface wall temperature deviation adjustment device according to claim 2, characterized in that: The air outlet of the first-level lower branch air duct (4) is connected to a plurality of second-level lower branch air ducts (6), and the second-level lower branch air ducts (6) are arranged in a one-to-one correspondence with the lower secondary air nozzle group. The air outlet of the second-level lower branch air duct (6) is connected to a plurality of third-level lower branch air ducts (8), and the third-level lower branch air ducts (8) are arranged in a one-to-one correspondence with the lower secondary air nozzles (2) of the lower secondary air nozzle group. The air outlet of the third-level lower branch air duct (8) is connected to the lower secondary air nozzle (2).

5. A high temperature heating surface wall temperature deviation adjustment device according to claim 4, characterized in that: The three-level lower branch air duct (8) is arranged perpendicular to the bottom end surface of the furnace horizontal flue (12).

6. A high temperature heating surface wall temperature deviation adjustment device according to claim 4, characterized in that: The secondary upper branch air duct (5) and the secondary lower branch air duct (6) are both provided with air volume regulating valves (9).

7. The high-temperature heating surface wall temperature deviation adjustment device according to claim 1, characterized in that: The air inlet of the main air duct (10) is connected to the secondary air box.

8. The high-temperature heating surface wall temperature deviation adjustment device according to claim 1, characterized in that: The upper secondary air nozzle group and the lower secondary air nozzle group are both arranged at the front end of the high-temperature heating surface (11) of the furnace horizontal flue (12).

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