CN211399842U

CN211399842U - Multistage air preheater

Info

Publication number: CN211399842U
Application number: CN201922427886.9U
Authority: CN
Inventors: 赵兴春; 高文彬; 梁瑞萍
Original assignee: Shaanxi Zhonghe Electric Power Engineering Co ltd
Current assignee: Shaanxi Zhonghe Electric Power Engineering Co ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-09-01
Anticipated expiration: 2029-12-27

Abstract

The utility model discloses a multistage air preheater, which comprises a high-temperature section air preheater, a flue gas purification system, an induced draft fan and a low-temperature section air preheater which are connected in sequence through pipelines; the inlet end of the high-temperature section air preheater is connected with the flue gas outlet end of the boiler, and the outlet end of the high-temperature section air preheater is connected with the air inlet of the boiler; the inlet end of the low-temperature section air preheater is also connected with a blower, one of the outlet ends of the low-temperature section air preheater is connected with a chimney, and the other outlet end of the low-temperature section air preheater is connected with the inlet end of the high-temperature section air preheater through a hot air pipeline. The utility model discloses a reasonable structural design has fully improved the utilization ratio of boiler flue gas heat energy to need not to heat up it alone before gas cleaning, reduced the energy consumption. Therefore, the utility model discloses be suitable for popularization and application.

Description

Multistage air preheater

Technical Field

The utility model relates to an energy saving and emission reduction technical field, concretely relates to be a multistage air heater.

Background

According to the policy of leaving the boiler in 2018, the biomass power station requires to execute ultra-clean emission of flue gas, the traditional flue gas purification scheme of the boiler in the power station is characterized in that a flue gas heating system is additionally arranged at the outlet of a draught fan, and the heated flue gas is denitrated in a low-temperature SCR (selective catalytic reduction) catalysis mode, so that the purpose of ultra-clean emission is achieved. However, the method has the problem of high energy consumption due to the need of heating the flue gas, and is not suitable for popularization and application.

SUMMERY OF THE UTILITY MODEL

To the not enough of above-mentioned prior art, the utility model provides a multistage air heater can reduce the energy consumption effectively when guaranteeing gas cleaning.

In order to achieve the above object, the utility model adopts the following technical scheme:

a multi-stage air preheater comprises a high-temperature section air preheater, a flue gas purification system, an induced draft fan and a low-temperature section air preheater which are sequentially connected through pipelines; the inlet end of the high-temperature section air preheater is connected with the flue gas outlet end of the boiler, and the outlet end of the high-temperature section air preheater is connected with the air inlet of the boiler; the inlet end of the low-temperature section air preheater is also connected with a blower, one of the outlet ends of the low-temperature section air preheater is connected with a chimney, and the other outlet end of the low-temperature section air preheater is connected with the inlet end of the high-temperature section air preheater through a hot air pipeline.

Furthermore, the inlet end of the high-temperature section air preheater is connected with a primary air fan through a cold air pipeline.

Or the inlet end of the low-temperature section air preheater is connected with a primary fan.

The utility model discloses under same inventive concept, to this kind of multistage air heater, still provided another kind of scheme, promptly: the multistage air preheater comprises a high-temperature section air preheater, a flue gas purification system, an induced draft fan, a low-temperature section air preheater and a blower which are sequentially connected through pipelines; the inlet end of the high-temperature section air preheater is connected with the flue gas outlet end of the boiler, and the outlet end of the high-temperature section air preheater is connected with the air inlet of the boiler; the inlet end of the low-temperature section air preheater is also connected with a primary fan, one outlet end of the low-temperature section air preheater is connected with a chimney, and the other outlet end of the low-temperature section air preheater is connected with the inlet end of the high-temperature section air preheater through a hot air pipeline; the air feeder is connected with the inlet end of the high-temperature section air preheater through a cold air pipeline.

In the scheme, the high-temperature section air preheater is a rotary preheater or a tubular preheater.

In the scheme, the low-temperature section air preheater is a rotary preheater, a tubular preheater, a finned tube heat exchanger or a plate heat exchanger.

Compared with the prior art, the utility model discloses following beneficial effect has:

the utility model discloses install between boiler exhaust port and chimney, through mutually supporting of high temperature segment air heater and low temperature segment air heater, can be with the boiler flue gas reduce to the required temperature of low temperature SCR catalysis in high temperature segment air heater, then obtain clean gas after carrying out gas cleaning, clean gas does not have sour non-corrosiveness, can carry out the heat exchange in low temperature segment air heater, further reduce the discharge temperature of flue gas when preheating outside air (can fall to below 40 ℃), and continue heating behind the air admission high temperature segment air heater after preheating (can reach more than 170 ℃), finally enter into the boiler. So circulate, can avoid prior art because flue gas cleaning needs the intensification and lead to the problem that the energy consumption is big, can avoid again getting into the air temperature in the boiler and hang down the heat energy that the combustion reaction produced in the low consumption boiler, fully improved the efficiency of boiler.

Drawings

Fig. 1 is a schematic structural diagram of embodiment 1 of the present invention.

Fig. 2 is a schematic structural diagram of embodiment 2 of the present invention.

Fig. 3 is a schematic structural diagram of embodiment 3 of the present invention.

Fig. 4 is a schematic structural diagram of embodiment 4 of the present invention.

Wherein, the names corresponding to the reference numbers are:

the method comprises the following steps of 1-a boiler, 2-a high-temperature section air preheater, 3-a flue gas purification system, 4-an induced draft fan, 5-a low-temperature section air preheater, 6-a chimney, 7-a blower and 8-a primary air fan.

Detailed Description

The utility model discloses a multistage air heater can be applied to the system of no wet process deacidification, and when mainly solving flue gas low temperature denitration, prior art has the problem that the energy consumption is big because need heat up. The present invention will be further described with reference to the following description and examples, which include but are not limited to the following examples.

Example 1

As shown in fig. 1, the present embodiment structurally includes a high-temperature section air preheater 2, a flue gas purification system 3, an induced draft fan 4 and a low-temperature section air preheater 5 which are sequentially connected through a pipeline. The inlet end of the high-temperature section air preheater 2 is connected with the flue gas outlet end of the boiler 1, and the outlet end of the high-temperature section air preheater 2 is connected with the air inlet of the boiler 1. The inlet end of the low-temperature section air preheater 5 is also connected with a blower 7, one of the outlet ends of the low-temperature section air preheater 5 is connected with a chimney 6, and the other outlet end is connected with the inlet end of the high-temperature section air preheater 2 through a hot air pipeline.

When the utility model is used, the flue gas generated by the boiler enters the high-temperature section air preheater 2 for heat exchange, the temperature of the flue gas is reduced to the temperature required by SCR catalysis, and then the flue gas enters the flue gas purification system 3 for purification, the purified flue gas enters the low-temperature section air preheater 5 for heat exchange with the external air fed by the air feeder 7 under the action of the draught fan 4, the temperature of the flue gas is further reduced, and finally the flue gas is discharged through the chimney 6; and the heated air enters the high-temperature section air preheater 2 to exchange heat with high-temperature flue gas generated by the boiler, the temperature is further increased, and finally the heated air enters the boiler.

Example 2

As shown in fig. 2, the present embodiment is different from embodiment 1 in that a primary fan 8 is connected to the inlet end of the high-temperature stage air preheater 2. The primary air fan is mainly used for conveying pulverized coal in the boiler system, and in the embodiment, the high-temperature section air preheater is connected with the primary air fan, so that the pulverized coal can be heated, and the pulverized coal can be combusted after entering a hearth.

Example 3

As shown in fig. 3, the present embodiment is different from embodiment 1 in that a primary fan 8 is further connected to the inlet end of the low-temperature-stage air preheater 5. In this embodiment, through connecting low temperature section air heater with the primary air fan to communicate high temperature section air heater and carry out further heating to the buggy, make it get into furnace postcombustion more abundant.

Example 4

As shown in fig. 4, the present invention is different from the

embodiments

1 and 2 in that a blower 7 is connected to the inlet end of the high-temperature stage air preheater 2 through a cold air duct, and a primary air blower 8 is connected to the inlet end of the low-temperature stage air preheater 5.

The high-temperature section air preheater preferably adopts a rotary preheater or a tubular preheater; the low-temperature section air preheater preferably adopts a rotary preheater, a tubular preheater, a finned tube heat exchanger or a plate heat exchanger.

The utility model discloses a reasonable structural design has fully improved the utilization ratio of boiler flue gas heat energy to need not to heat up it alone before gas cleaning, reduced the energy consumption. And simultaneously, the utility model discloses the big problem of conventional living beings unit heat loss of discharging fume has still been solved.

The above embodiment is only one of the preferred embodiments of the present invention, and should not be used to limit the protection scope of the present invention, but all the insubstantial changes or modifications made in the spirit and the idea of the main design of the present invention, the technical problems solved by the embodiment are still consistent with the present invention, and all should be included in the protection scope of the present invention.

Claims

1. A multi-stage air preheater is characterized by comprising a high-temperature section air preheater (2), a flue gas purification system (3), an induced draft fan (4) and a low-temperature section air preheater (5) which are sequentially connected through pipelines; the inlet end of the high-temperature section air preheater (2) is connected with the flue gas outlet end of the boiler, and the outlet end of the high-temperature section air preheater (2) is connected with the air inlet of the boiler; the inlet end of the low-temperature section air preheater (5) is further connected with a blower (7), one outlet end of the low-temperature section air preheater (5) is connected with a chimney, and the other outlet end of the low-temperature section air preheater (5) is connected with the inlet end of the high-temperature section air preheater (2) through a hot air pipeline.

2. A multi-stage air preheater as claimed in claim 1, wherein the inlet end of the high temperature stage air preheater (2) is further connected to a primary air fan (8) via a cold air duct.

3. A multi-stage air preheater as claimed in claim 1, wherein a primary air fan (8) is also connected to the inlet end of the low temperature stage air preheater (5).

4. A multistage air preheater is characterized by comprising a high-temperature section air preheater (2), a flue gas purification system (3), an induced draft fan (4), a low-temperature section air preheater (5) and a blower (7) which are sequentially connected through pipelines; the inlet end of the high-temperature section air preheater (2) is connected with the flue gas outlet end of the boiler, and the outlet end of the high-temperature section air preheater (2) is connected with the air inlet of the boiler; the inlet end of the low-temperature section air preheater (5) is also connected with a primary fan (8), one outlet end of the low-temperature section air preheater (5) is connected with a chimney, and the other outlet end of the low-temperature section air preheater (5) is connected with the inlet end of the high-temperature section air preheater (2) through a hot air pipeline; the air feeder (7) is connected with the inlet end of the high-temperature section air preheater (2) through a cold air pipeline.

5. A multi-stage air preheater as claimed in any one of claims 1 to 4, wherein the high temperature section air preheater (2) is a rotary preheater or a tubular preheater.

6. A multi-stage air preheater according to any one of claims 1 to 4, wherein the low temperature section air preheater (5) is a rotary preheater, a tube preheater, a finned tube heat exchanger or a plate heat exchanger.