System capable of improving boiler primary air temperature efficiency and improving SCR inlet smoke temperature

Abstract

The utility model relates to the technical field of boiler primary air temperature increasing and SCR inlet smoke temperature increasing, and discloses a system with the boiler primary air temperature increasing and SCR inlet smoke temperature increasing functions. The steering chamber is connected with the hearth, a low-temperature superheater is installed in the steering chamber, and an economizer located below the low-temperature superheater is further installed in the steering chamber; the SCR inlet flue is communicated with the steering chamber, a main flue adjusting baffle is installed in the SCR inlet flue, the SCR inlet flue is connected with a bypass air flue adjusting baffle, a bypass hot air flue and a main air flue adjusting baffle, and a primary hot air main pipeline is arranged between the bypass air flue adjusting baffle and the main air flue adjusting baffle. The device has the effects of improving the primary air temperature efficiency of the boiler and improving the SCR inlet smoke temperature, and has far-reaching significance for solving the problems that the boiler output is influenced by coal quality change and boiler deep peak regulation denitration cannot be put into operation.

Description

Technical Field

[0001] The utility model relates to the technical field of improving the primary air temperature efficiency of a boiler and increasing the smoke temperature at an SCR inlet, and in particular to a system for improving the primary air temperature efficiency of a boiler and increasing the smoke temperature at an SCR inlet. Background Art

[0002] (1) Affected by certain factors, the type of coal used in thermal power plants will change, with the calorific value lower than the designed type and the total moisture content of the raw coal increasing. The impact of changes in coal types on boiler equipment is as follows:

[0003] ① Mechanical incomplete combustion losses increase and efficiency decreases;

[0004] ② The output of the pulverizing system is insufficient, resulting in the boiler being unable to operate at full load;

[0005] ③The low-nitrogen combustion effect is significantly reduced and the amount of urea used is significantly increased.

[0006] Low primary air temperature and high primary air rate will cause high direct economic losses and safety hazards.

[0007] The primary air temperature is low and the pulverizing system is inefficient, resulting in insufficient output of the coal mill, which in turn limits the boiler from reaching its maximum load.

[0008] The primary air rate is too high, combustion cannot be organized normally, combustion efficiency is low and the NOx concentration at the SCR inlet is too high.

[0009] Therefore, increasing the primary air temperature, improving the drying output of the coal mill, and optimizing the boiler primary air rate are of great significance to the safe and economical operation of thermal power plant units and improving the load capacity of the units.

[0010] With the national dual carbon goals, transforming the energy structure and increasing the proportion of new energy power generation will be one of the most important means to reduce carbon emissions. The proportion of new energy power generation represented by wind and solar power has increased rapidly, and the large-scale grid connection of new energy has brought about the problem of absorption. For this reason, the country has introduced a policy for the flexibility transformation of thermal power. Thermal power units, especially coal-fired power units, will continue to operate at low loads or deep peak regulation in the next few years. Low-load operation will cause the SCR inlet flue gas temperature to be low, affecting the commissioning of denitrification. One way to solve the low inlet flue gas temperature of denitrification at low load is to transform the bypass flue duct, by extracting the high-temperature flue gas from the low-temperature superheater or economizer inlet to the SCR inlet, so as to increase the SCR inlet temperature and meet the denitrification temperature requirements.

[0011] To this end, we proposed a system that can both improve the boiler primary air temperature and increase the SCR inlet flue gas temperature to solve the problem. Utility Model Content

[0012] The utility model aims to provide a system for improving the efficiency of boiler primary air temperature and SCR inlet smoke temperature, thereby solving the problems in the above-mentioned background technology.

[0013] To achieve the above purpose, the utility model provides the following technical solution: a system for improving the efficiency of boiler primary air temperature and increasing the SCR inlet smoke temperature, comprising:

[0014] furnace;

[0015] A turning chamber is connected to the furnace, wherein a low-temperature superheater is installed inside the turning chamber, and an economizer is also installed inside the turning chamber below the low-temperature superheater;

[0016] An SCR inlet flue is connected to the turning chamber, a main flue regulating baffle is installed in the SCR inlet flue, and the SCR inlet flue is connected to a bypass air duct regulating baffle, a bypass hot air duct, and a main air duct regulating baffle, and a primary hot air mother pipe is arranged between the bypass air duct regulating baffle and the main air duct regulating baffle;

[0017] The high-temperature flue is arranged on one side of the turning chamber. A high-temperature non-metallic expansion joint, a high-temperature shut-off baffle, a high-temperature regulating baffle, a medium-high-temperature non-metallic expansion joint b, a medium-high-temperature shut-off baffle, and a medium-high-temperature regulating baffle are installed between the high-temperature flue and the turning chamber respectively. A medium-high-temperature non-metallic expansion joint a, a medium-high-temperature flue, a medium-high-temperature non-metallic expansion joint c, a first-level medium-high-temperature wide flow channel plate exchanger, and a second-level high-temperature wide flow channel plate exchanger are installed between the high-temperature flue and the SCR inlet flue.

[0018] Preferably, the high-temperature non-metallic expansion joint and the medium-high-temperature non-metallic expansion joint a are arranged in the horizontal flue of the smoke inlet to absorb the expansion of the boiler.

[0019] Preferably, the high-temperature shutoff baffle, the high-temperature adjustment baffle, the medium-high temperature shutoff baffle and the medium-high temperature adjustment baffle are arranged in the horizontal flue or in the vertical flue.

[0020] Preferably, the first-stage medium-high temperature wide flow channel plate exchanger and the second-stage high temperature wide flow channel plate exchanger are both arranged vertically, the two are connected in parallel and in series, the flue gas flows from top to bottom, and the primary hot air enters and exits from the side, thereby achieving primary air temperature improvement.

[0021] The utility model provides a system for improving the primary air temperature of a boiler and the smoke temperature at the inlet of an SCR. The system for improving the primary air temperature of a boiler and the smoke temperature at the inlet of an SCR has the following beneficial effects:

[0022] The utility model has the dual functions of improving the efficiency of the boiler's primary air temperature and increasing the SCR inlet smoke temperature, which has far-reaching significance for solving the problems of coal quality changes affecting boiler output and the inability of the boiler to be put into operation due to deep peak-shaving and denitrification. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the utility model.

[0024] In the figure: 1-furnace, 2-turning chamber, 3-low-temperature superheater, 4-economizer, 5-SCR inlet flue, 6-primary hot air main pipe, 7-high-temperature non-metallic expansion joint, 8-high-temperature shut-off damper, 9-high-temperature regulating damper, 10-high-temperature flue, 11-medium and high-temperature non-metallic expansion joint a, 12-medium and high-temperature non-metallic expansion joint b, 13-medium and high-temperature shut-off damper, 14-medium and high-temperature regulating damper, 15-medium and high-temperature flue, 16-medium and high-temperature non-metallic expansion joint c, 17-first-level medium and high-temperature wide flow channel plate exchanger, 18-second-level high-temperature wide flow channel plate exchanger, 19-bypass air duct regulating damper, 20-bypass hot air duct, 21-main air duct regulating damper, 22-main flue regulating damper. DETAILED DESCRIPTION

[0025] In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation methods of the utility model are now described with reference to the accompanying drawings.

[0026] The utility model provides a preferred embodiment of a system for improving the efficiency of boiler primary air temperature and SCR inlet smoke temperature. Figure 1 Shown: A system for improving the efficiency of boiler primary air temperature and SCR inlet flue gas temperature, including:

[0027] Furnace 1;

[0028] A turning chamber 2 is connected to the furnace 1, a low-temperature superheater 3 is installed inside the turning chamber 2, and an economizer 4 is also installed inside the turning chamber 2 and is located below the low-temperature superheater 3;

[0029] The SCR inlet flue 5 is connected to the turning chamber 2, a main flue regulating baffle 22 is installed in the SCR inlet flue 5, and the SCR inlet flue 5 is connected to a bypass air duct regulating baffle 19, a bypass hot air duct 20, and a main air duct regulating baffle 21, and a primary hot air mother pipe 6 is arranged between the bypass air duct regulating baffle 19 and the main air duct regulating baffle 21;

[0030] The high-temperature flue 10 is arranged on one side of the turning chamber 2. A high-temperature non-metallic expansion joint 7, a high-temperature shut-off baffle 8, a high-temperature regulating baffle 9, a medium-high-temperature non-metallic expansion joint b12, a medium-high-temperature shut-off baffle 13, and a medium-high-temperature regulating baffle 14 are respectively installed between the high-temperature flue 10 and the turning chamber 2. A medium-high-temperature non-metallic expansion joint a11, a medium-high-temperature flue 15, a medium-high-temperature non-metallic expansion joint c16, a first-level medium-high-temperature wide flow channel plate exchanger 17, and a second-level high-temperature wide flow channel plate exchanger 18 are respectively installed between the high-temperature flue 10 and the SCR inlet flue 5.

[0031] Among them, high-temperature non-metallic expansion joints 7 and medium-high-temperature non-metallic expansion joints a11 are arranged in the horizontal flue of the smoke inlet to absorb the expansion of the boiler; high-temperature shut-off baffles 8, high-temperature regulating baffles 9, medium-high-temperature shut-off baffles 13 and medium-high-temperature regulating baffles 14 are arranged in the horizontal flue and can also be arranged in the vertical flue; the first-level medium-high-temperature wide flow channel plate exchanger 17 and the second-level high-temperature wide flow channel plate exchanger 18 are both arranged vertically, the two are connected in parallel and in series, the flue gas flows from top to bottom, and the primary hot air enters and exits from the side, realizing the primary air temperature improvement.

[0032] During the specific implementation process, when the boiler load is high and the primary air temperature is low, the high temperature regulating damper 9 is fully opened, and the medium and high temperature regulating damper 9 and the main air duct regulating damper 21 are used to adjust the primary air outlet temperature; when the boiler is in the deep peak regulation stage, it is necessary to increase the SCR inlet flue gas temperature, the medium and high temperature regulating damper 14 and the bypass air duct regulating damper 19 are closed, and the high temperature regulating damper 9 and the main flue gas regulating damper 22 are coordinated to meet the denitrification temperature requirements.

[0033] The above description is only an illustrative specific implementation method of the utility model, and is not intended to limit the scope of the utility model. Any equivalent changes and modifications made by any technician in this field without departing from the concept and principle of the utility model should fall within the scope of protection of the utility model. It should also be noted that the various components of the utility model are not limited to the above-mentioned overall application. The various technical features described in the specification of the utility model can be selected for use alone or in combination according to actual needs. Therefore, the utility model should naturally cover other combinations and specific applications related to the utility model points of this case.

Claims

1. A system for improving the efficiency of boiler primary air temperature and the flue gas temperature at the SCR inlet, characterized by: include: Furnace (1); A turning chamber (2) is connected to the furnace (1), a low-temperature superheater (3) is installed inside the turning chamber (2), and an economizer (4) is also installed inside the turning chamber (2) and is located below the low-temperature superheater (3); An SCR inlet flue (5) is arranged in communication with the turning chamber (2), a main flue regulating baffle (22) is installed in the SCR inlet flue (5), and the SCR inlet flue (5) is connected to a bypass air duct regulating baffle (19), a bypass hot air duct (20), and a main air duct regulating baffle (21), and a primary hot air main duct (6) is arranged between the bypass air duct regulating baffle (19) and the main air duct regulating baffle (21); A high-temperature flue (10) is arranged on one side of the turning chamber (2); a high-temperature non-metal expansion joint (7), a high-temperature shut-off baffle (8), a high-temperature regulating baffle (9), a medium-high-temperature non-metal expansion joint b (12), a medium-high-temperature shut-off baffle (13), and a medium-high-temperature regulating baffle (14) are respectively installed between the high-temperature flue (10) and the turning chamber (2); and a medium-high-temperature non-metal expansion joint a (11), a medium-high-temperature flue (15), a medium-high-temperature non-metal expansion joint c (16), a first-stage medium-high-temperature wide flow channel plate exchanger (17), and a second-stage high-temperature wide flow channel plate exchanger (18) are respectively installed between the high-temperature flue (10) and the SCR inlet flue (5).

2. According to claim 1, a system for improving the efficiency of boiler primary air temperature and the SCR inlet flue gas temperature, characterized in that: The high-temperature non-metal expansion joint (7) and the medium-high-temperature non-metal expansion joint a (11) are arranged at the horizontal flue of the smoke inlet to absorb the expansion of the boiler.

3. According to claim 1, a system for improving the efficiency of boiler primary air temperature and the flue gas temperature at the SCR inlet is characterized by: The high temperature shutoff damper (8), the high temperature regulating damper (9), the medium and high temperature shutoff damper (13) and the medium and high temperature regulating damper (14) are arranged in a horizontal flue or in a vertical flue.

4. According to claim 1, a system for improving the efficiency of boiler primary air temperature and the SCR inlet flue gas temperature is characterized by: The first-stage medium-high temperature wide-channel plate exchanger (17) and the second-stage high temperature wide-channel plate exchanger (18) are both arranged vertically, and the two are connected in parallel and in series, so that the flue gas flows from top to bottom, and the primary hot air enters and exits from the side, thereby achieving primary air temperature improvement.

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