WO2023050702A1

WO2023050702A1 - Low-temperature desulfurization and denitrification method and system for flue gas from rotary kiln combustion furnace of refuse incineration power plant

Info

Publication number: WO2023050702A1
Application number: PCT/CN2022/078046
Authority: WO
Inventors: 李卫东; 汪世清; 梁鹤涛; 许世森; 郜时旺; 肖平; 刘练波; 牛红伟; 虢德军
Original assignee: 中国华能集团清洁能源技术研究院有限公司; 华能湖南岳阳发电有限责任公司
Priority date: 2021-09-28
Filing date: 2022-02-25
Publication date: 2023-04-06
Also published as: CN113769569A

Abstract

A low-temperature desulfurization and denitrification method and system for flue gas from a rotary kiln combustion furnace of a refuse incineration power plant. The method comprises the following steps: reducing the temperature of flue gas to 140ºC-170ºC; subjecting the flue gas to desulfurization; subjecting the flue gas to dust removal; reducing the temperature of the flue gas to 20ºC or below; subjecting the flue gas to desulfurization and denitrification; and discharging the flue gas.

Description

Low-temperature desulfurization and denitrification method and system for flue gas of rotary kiln combustion furnace in waste power plant

Cross References to Related Applications

This application is based on a Chinese patent application with application number No. 202111145564.0 and a filing date of September 28, 2021, and claims the priority of this Chinese patent application. The entire content of this Chinese patent application is hereby incorporated by reference into this application.

technical field

The disclosure relates to the technical field of gas purification, in particular to a method and system for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a waste power plant.

Background technique

The flue gas from the garbage power plant contains nitrogen oxides and sulfur dioxide, and the flue gas must be desulfurized and denitrified before being discharged. In related technologies, after the flue gas from the garbage power plant is discharged from the rotary kiln combustion furnace, the flue gas is directly denitrated at high temperature, and then desulfurized, and the denitrification efficiency is low.

Contents of the invention

The present disclosure aims to solve one of the technical problems in the related art at least to a certain extent.

For this reason, the embodiments of the present disclosure propose a method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a waste power plant.

Embodiments of the present disclosure also propose a low-temperature desulfurization and denitrification system for flue gas from a rotary kiln combustion furnace in a waste power plant.

The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant according to an embodiment of the present disclosure includes the following steps: lowering the temperature of the flue gas to 140°C-170°C; desulfurizing the flue gas; and removing dust from the flue gas ; The temperature of the flue gas is lowered to below 20° C.; The flue gas is desulfurized and denitrified; The flue gas is discharged.

The low-temperature desulfurization and denitrification method of the flue gas from the rotary kiln combustion furnace of the garbage power plant in the embodiment of the present disclosure reduces the temperature of the high-temperature flue gas discharged from the rotary kiln combustion furnace to 140°C-170°C, and then performs the first desulfurization treatment on the cooled flue gas , the desulfurization efficiency of the flue gas after cooling is high, thereby increasing the desulfurization rate of the method for low-temperature desulfurization and denitrification of flue gas from the rotary kiln combustion furnace of the waste power plant according to the embodiment of the present disclosure. The desulfurized flue gas is cooled again to reduce the temperature of the flue gas to below 20°C, and the desulfurized and denitrified flue gas is subjected to desulfurization and denitrification treatment. The desulfurization rate and denitrification rate of the low-temperature desulfurization and denitrification method for the flue gas of the rotary kiln combustion furnace of the garbage power plant according to the embodiment of the present disclosure are increased.

Therefore, the low-temperature desulfurization and denitrification method for the flue gas of the rotary kiln combustion furnace of the garbage power plant according to the embodiment of the present disclosure has the advantages of high desulfurization rate and high denitrification rate.

In some embodiments, reducing the temperature of the flue gas to 140°C-170°C includes: passing the flue gas into a waste heat boiler to reduce the temperature of the flue gas to 300°C-350°C; The flue gas is passed into the absorption refrigerating unit to exchange heat with the steam generator to reduce the temperature of the flue gas to 140°C-170°C.

In some embodiments, reducing the temperature of the flue gas to 140°C-170°C includes: passing the flue gas into a waste heat boiler to reduce the temperature of the flue gas to 300°C-350°C; The flue gas is passed into the absorption refrigeration unit to exchange heat with the steam generator, so that the temperature of the flue gas is reduced to 180°C-300°C; the flue gas is passed into the cooling tower, and the temperature of the flue gas is reduced to 140°C ℃-170℃.

In some embodiments, reducing the temperature of the flue gas to below 20°C includes: passing the flue gas into the absorption refrigerating unit to exchange heat with the evaporator so that the temperature of the flue gas is reduced to Below 20°C.

In some embodiments, before the flue gas is passed into the absorption refrigeration unit to exchange heat with the evaporator, the flue gas is passed into a precooler to reduce the temperature of the flue gas to 60 ℃-90℃.

In some embodiments, after the flue gas is desulfurized and denitrified, before the flue gas is discharged, the flue gas is passed into the precooler to precool the to cool down.

The low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant according to the embodiment of the present disclosure includes: a rotary kiln combustion furnace, the rotary kiln combustion furnace includes a flue gas discharge port; a waste heat boiler, and the waste heat boiler includes a first flue gas inlet and the first flue gas outlet, the flue gas discharge port communicates with the first flue gas inlet, so as to pass the flue gas into the waste heat boiler, so that the flue gas can heat the waste heat boiler, thereby reducing the The temperature of the flue gas; the absorption refrigeration unit, the absorption refrigeration unit includes a steam generator and an evaporator, the steam generator includes a second flue gas inlet and a second flue gas outlet, and the evaporator includes a third a flue gas inlet and a third flue gas outlet, the first flue gas outlet communicates with the second flue gas inlet, so that the flue gas can be passed into the steam generator, thereby reducing the temperature of the flue gas a desulfurization tower, the desulfurization tower includes a fourth flue gas inlet and a fourth flue gas outlet, the second flue gas outlet communicates with the fourth flue gas inlet, so that the flue gas is passed into the desulfurization tower In order to desulfurize the flue gas, the fourth flue gas outlet communicates with the third flue gas inlet so as to pass the flue gas into the evaporator, thereby reducing the temperature of the flue gas; low temperature An adsorption tower, the low-temperature adsorption tower includes a fifth flue gas inlet and a fifth flue gas outlet, and the third flue gas outlet communicates with the fifth flue gas inlet so that the flue gas can be passed into the low-temperature adsorption In the tower, the flue gas is desulfurized and denitrified.

The waste heat power plant rotary kiln combustion furnace flue gas low-temperature desulfurization and denitrification system of the embodiment of the present disclosure cools the flue gas through the waste heat boiler and the absorption refrigeration unit to reduce the temperature of the flue gas. After cooling, the flue gas is desulfurized in the desulfurization tower, and after cooling The desulfurization efficiency of the final flue gas is high, so the desulfurization rate of the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant according to the embodiment of the present disclosure is increased. The flue gas after the desulfurization treatment of the desulfurization tower is cooled again by the absorption refrigeration unit, and the flue gas after cooling is subjected to desulfurization and denitrification treatment in the low-temperature adsorption tower. The denitrification rate of the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant according to the embodiment of the present disclosure.

Therefore, the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant has the advantages of high desulfurization rate and high denitrification rate.

In some embodiments, the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant in the embodiment of the present disclosure further includes a cooling tower, the cooling tower includes a sixth flue gas inlet and a sixth flue gas outlet, and the sixth The flue gas inlet communicates with the second flue gas inlet so that the flue gas can be passed into the cooling tower to reduce the temperature of the flue gas, and the sixth flue gas outlet is connected to the fourth flue gas outlet The inlet is connected, so that the second flue gas outlet communicates with the fourth flue gas inlet.

In some embodiments, the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant in the embodiment of the present disclosure further includes a dust collector, the dust collector includes an air inlet and an air outlet, and the air inlet is connected to the first The four flue gas outlets communicate with each other so that the flue gas can pass into the dust collector, and the gas outlets communicate with the third flue gas inlet so that the fourth flue gas outlet communicates with the third flue gas inlet.

In some embodiments, the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant in the embodiment of the present disclosure further includes a precooler, the precooler includes a seventh flue gas inlet and a seventh flue gas outlet, the The seventh flue gas inlet communicates with the gas outlet so as to pass the flue gas into the precooler, thereby reducing the temperature of the flue gas; the seventh flue gas outlet communicates with the third flue gas The inlet is communicated so that the gas outlet communicates with the third flue gas inlet.

Description of drawings

Fig. 1 is a schematic structural diagram of a low-temperature desulfurization and denitrification system for flue gas of a rotary kiln combustion furnace in a waste-to-energy power plant according to an embodiment of the present disclosure.

Fig. 2 is a schematic structural diagram of a low-temperature desulfurization and denitrification system for flue gas from a rotary kiln combustion furnace in a waste-to-energy power plant according to an embodiment of the present disclosure.

Reference signs:

Rotary kiln combustion furnace 1; flue gas discharge port 11;

Waste heat boiler 2; first flue gas inlet 21; first flue gas outlet 22;

Absorption refrigeration unit 3; steam generator 31; second flue gas inlet 311; second flue gas outlet 312; evaporator 32; third flue gas inlet 321; third flue gas outlet 322;

Desulfurization tower 4; fourth flue gas inlet 41; fourth flue gas outlet 42;

Low temperature adsorption tower 5; fifth flue gas inlet 51; fifth flue gas outlet 52;

Cooling tower 6; sixth flue gas inlet 61; sixth flue gas outlet 62;

Dust collector 7; air inlet 71; air outlet 72; dust outlet 73;

induced draft fan 8; the ninth flue gas inlet 81; the ninth flue gas outlet 82;

Precooler 9 ; first heat exchange component 91 ; seventh flue gas inlet 911 ; seventh flue gas outlet 912 ; second heat exchange component 92 ; eighth flue gas inlet 921 ; eighth flue gas outlet 922 .

Detailed ways

Embodiments of the present disclosure are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the figures are exemplary and are intended to explain the present disclosure and should not be construed as limiting the present disclosure.

The present disclosure is made based on the inventors' discovery and recognition of the following facts and problems:

In the related technology, the reflection device for denitrification is installed in the waste heat boiler, and the raw material for denitrification is urea. The urea is configured into a urea solution with a certain concentration, and then the urea solution is sprayed into the waste heat boiler furnace with a pump. A spray gun is installed in the furnace. The urea solution entering the furnace can be atomized. The temperature in the furnace is around 1000°C. The high-temperature flue gas is fully mixed for a certain period of time in the furnace body of the misty urea solution. In the case of gaseous oxygen in the boiler, NOx reacts with misty urea solution; when the amount of NOx is half of the content of urea, the removal rate of nitrogen oxides is approximately 30%-50%.

The following describes the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant according to the embodiments of the present disclosure with reference to the accompanying drawings.

As shown in FIG. 1 , the low-temperature desulfurization and denitrification system for flue gas from a rotary kiln combustion furnace in a garbage power plant according to an embodiment of the present disclosure includes a rotary kiln combustion furnace 1 , a waste heat boiler 2 , an absorption refrigeration unit 3 , a desulfurization tower 4 and a low-temperature adsorption tower 5 .

The rotary kiln combustion furnace 1 includes a flue gas discharge port 11, specifically, the rotary kiln combustion furnace 1 has a flue gas discharge port 11, and then the high-temperature flue gas (the temperature of the high-temperature flue gas is at 1100°C) generated in the rotary kiln combustion furnace 1 -1200°C) is discharged from the flue gas discharge port 11 of the rotary kiln combustion furnace 1.

The waste heat boiler 2 includes a first flue gas inlet 21 and a first flue gas outlet 22, and the flue gas discharge port 11 communicates with the first flue gas inlet 21 so as to pass the flue gas into the waste heat boiler 2 so that the flue gas heats the waste heat boiler 2, thereby reducing the temperature of the flue gas. In some embodiments, the high-temperature flue gas discharged from the flue gas discharge port 11 of the rotary kiln combustion furnace 1 enters the waste heat boiler 2 through the first flue gas inlet 21 .

It can be understood that the heat exchange between the high-temperature flue gas and the waste heat boiler 2, and the heat exchange between the high-temperature flue gas and the water in the waste heat boiler 2 can reduce the temperature of the high-temperature flue gas, wherein the temperature of the high-temperature flue gas after reducing the temperature is 300°C -350°C, the cooled high-temperature flue gas is discharged from the first flue gas outlet 22 of the waste heat boiler 2 . In addition, the waste heat boiler 2 can absorb the heat of the high-temperature flue gas, thereby improving the utilization rate of the heat released by fuel combustion.

The absorption refrigeration unit 3 includes a steam generator 31 and an evaporator 32, the steam generator 31 includes a second flue gas inlet 311 and a second flue gas outlet 312, and the evaporator 32 includes a third flue gas inlet 321 and a third flue gas outlet 322, the first flue gas outlet 22 communicates with the second flue gas inlet 311, so as to pass the flue gas into the steam generator 31, thereby reducing the temperature of the flue gas.

In some embodiments, the flue gas discharged from the waste heat boiler 2 enters the steam generator 31 through the second flue gas inlet 311 of the steam generator 31, and the flue gas exchanges heat with the coolant in the steam generator 31, thereby making The coolant evaporates and absorbs the heat of the flue gas, and further, the cooled flue gas is discharged from the second flue gas outlet 312 of the steam generator 31 .

The desulfurization tower 4 includes a fourth flue gas inlet 41 and a fourth flue gas outlet 42, the second flue gas outlet 312 communicates with the fourth flue gas inlet 41, so that the flue gas is passed into the desulfurization tower 4, thereby desulfurizing the flue gas .

In some embodiments, the flue gas discharged from the steam generator 31 enters the desulfurization tower 4 through the fourth flue gas inlet 41, and the flue gas is desulfurized in the desulfurization tower 4 to remove sulfur compounds in the flue gas. After desulfurization treatment, the gas is discharged from the fourth flue gas outlet 42 of the desulfurization tower 4 .

The fourth flue gas outlet 42 communicates with the third flue gas inlet 321 so as to pass the flue gas into the evaporator 32 to reduce the temperature of the flue gas. In some embodiments, the desulfurized flue gas is discharged through the fourth flue gas outlet 42 of the desulfurization tower 4, enters the evaporator 32 from the third flue gas inlet 321 of the evaporator 32, and makes the flue gas in the evaporator 32 and The refrigerant performs heat exchange, thereby reducing the temperature of the flue gas.

The low-temperature adsorption tower 5 includes the fifth flue gas inlet 51 and the fifth flue gas outlet 52, and the third flue gas outlet 322 communicates with the fifth flue gas inlet 51, so that the flue gas is passed into the low-temperature adsorption tower 5, thereby the flue gas For desulfurization and denitrification.

In some embodiments, the cooled desulfurized flue gas is discharged through the third flue gas outlet 322 of the evaporator 32, and enters the low-temperature adsorption tower 5 from the fifth flue gas inlet 51 of the low-temperature adsorption tower 5 for desulfurization and denitration treatment. , the flue gas that has undergone desulfurization and denitrification treatment is discharged to the outside from the fifth flue gas outlet 52 .

The waste heat power plant rotary kiln combustion furnace flue gas low-temperature desulfurization and denitrification system of the embodiment of the present disclosure cools the flue gas through the waste heat boiler 2 and the absorption refrigeration unit 3, so that the temperature of the flue gas is reduced, and the flue gas is desulfurized in the desulfurization tower 4 after cooling , the desulfurization efficiency of the flue gas after cooling is high, so the desulfurization rate of the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant according to the embodiment of the present disclosure is increased. The flue gas desulfurized by the desulfurization tower 4 is cooled again by the absorption refrigeration unit 3, and the flue gas after cooling is subjected to desulfurization and denitrification treatment in the low-temperature adsorption tower 5, and the desulfurization and desulfurization efficiency of the flue gas after cooling again is high, so The denitrification rate of the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant in the embodiment of the present disclosure is increased.

In some embodiments, the waste heat boiler 2 includes a flue gas pipeline, the flue gas pipeline includes a first flue gas inlet 21 and a first flue gas outlet 22 , and the flue gas pipeline is used for heating the waste heat boiler 2 . In some embodiments, the high-temperature flue gas discharged from the rotary kiln combustion furnace 1 enters the flue gas pipe from the first flue gas inlet 21 of the flue gas pipe, and the high-temperature flue gas exchanges heat with the waste heat boiler 2 in the flue gas pipe, and then Reduce the temperature of high temperature flue gas.

In some embodiments, as shown in FIG. 2 , the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant in the embodiment of the present disclosure further includes a cooling tower 6, and the cooling tower 6 includes a sixth flue gas inlet 61 and a sixth flue gas inlet 61. The outlet 62, the sixth flue gas inlet 61 communicates with the second flue gas inlet 311, so as to pass the flue gas into the cooling tower 6, thereby reducing the temperature of the flue gas, and the sixth flue gas outlet 62 communicates with the fourth flue gas inlet 41 , so that the second flue gas outlet 312 communicates with the fourth flue gas inlet 41 .

In some embodiments, the flue gas cooled by the steam generator 31 is discharged from the second flue gas inlet 311 , enters the cooling tower 6 through the sixth flue gas inlet 61 , and the flue gas is cooled in the cooling tower 6 . After being cooled by the cooling tower 6 , the flue gas is discharged through the sixth flue gas outlet 62 and enters the desulfurization tower 4 through the fourth flue gas inlet 41 .

It can be understood that when the temperature of the flue gas cooled by the steam generator 31 is between 180°C and 300°C, and between 300°C and 500°C, harmful substances such as dioxins are likely to be formed in the flue gas, which will pass through the steam generator 31 The cooled flue gas is passed into the cooling tower 6 for cooling, thereby suppressing the generation of dioxins, so that the flue gas discharged to the outside does not contain harmful substances dioxins, thereby achieving the purpose of environmental protection.

Therefore, the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant in the embodiment of the present disclosure has the advantage of environmental protection.

In some embodiments, as shown in FIG. 2 , the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant in the embodiment of the present disclosure further includes a dust collector 7, and the dust collector 7 includes an air inlet 71 and an air outlet 72, and the air inlet The port 71 communicates with the fourth flue gas outlet 42 so as to pass the flue gas into the dust collector 7 , and the gas outlet 72 communicates with the third flue gas inlet 321 so that the fourth flue gas outlet 42 communicates with the third flue gas inlet 321 .

In some embodiments, the flue gas desulfurized by the desulfurization tower 4 is discharged from the fourth flue gas outlet 42, and enters the dust collector 7 through the air inlet 71 of the dust collector 7, and the flue gas is subjected to dust removal treatment in the dust collector 7 , and then remove the smoke and dust in the flue gas, so that there is no smoke and dust in the flue gas discharged to the outside world, and then achieve the purpose of environmental protection.

Further, the dust collector 7 has a dust outlet 73, through which the smoke and dust filtered by the dust collector 7 are discharged, and then the filtered smoke and dust are recycled to avoid secondary pollution to the environment.

In some embodiments, as shown in FIG. 2 , the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant in the embodiment of the present disclosure further includes a precooler 9, and the precooler 9 includes a seventh flue gas inlet 911 and a seventh flue gas inlet 911. The flue gas outlet 912 and the seventh flue gas inlet 911 communicate with the gas outlet 72 so as to pass the flue gas into the precooler 9 to reduce the temperature of the flue gas. The seventh flue gas outlet 912 communicates with the third flue gas inlet 321 , so that the gas outlet 72 communicates with the third flue gas inlet 321 .

In some embodiments, the flue gas dedusted by the dust collector 7 is discharged from the gas outlet 72 of the dust collector 7, enters the precooler 9 through the seventh flue gas inlet 911 of the precooler 9, and the flue gas enters the precooler 9 9, the cooling process is performed, and the cooled flue gas is discharged through the seventh flue gas outlet 912 and enters the evaporator 32 through the third flue gas inlet 321 .

Further, the precooler 9 includes a first heat exchange assembly 91 and a second heat exchange assembly 92, the first heat exchange assembly 91 includes a seventh flue gas inlet 911 and a seventh flue gas outlet 912, and the second heat exchange assembly 92 can The low-temperature fluid is passed through, and the seventh flue gas inlet 911 communicates with the gas outlet 72, so as to pass the flue gas into the first heat exchange component 91, thereby reducing the temperature of the flue gas.

In some embodiments, the flue gas dedusted by the dust collector 7 enters the first heat exchange assembly 91 through the seventh flue gas inlet 911, and the flue gas in the first heat exchange assembly 91 and the second heat exchange assembly 92 The low-temperature fluid conducts heat exchange, thereby reducing the temperature of the flue gas in the first heat exchange component 91 . The cooled flue gas is discharged through the seventh flue gas outlet 912 of the first heat exchange component 91 , and enters the evaporator 32 through the third flue gas inlet 321 to be cooled again.

Further, the second heat exchanging assembly 92 has an eighth flue gas inlet 921 and an eighth flue gas outlet 922, and the eighth flue gas inlet 921 communicates with the fifth flue gas outlet 52, so that the flue gas passes into the second heat exchanging assembly 92 , so that the flue gas forms a low-temperature fluid.

In some embodiments, the flue gas after the desulfurization and denitration treatment by the low-temperature adsorption tower 5 is discharged through the fifth flue gas outlet 52, and enters the second heat exchange assembly 92 through the eighth flue gas inlet 921 of the second heat exchange assembly 92 Inside. It can be understood that the flue gas in the cryogenic adsorption tower 5 is cooled again through the evaporator 32, and then the temperature of the flue gas discharged from the cryogenic adsorption tower 5 is lower than that of the flue gas in the first heat exchange assembly 91. 5 The exhausted flue gas forms a low-temperature fluid, and the low-temperature fluid formed by the flue gas exchanges heat with the flue gas of the first heat exchange component 91 in the second heat exchange component 92, thereby reducing the temperature of the flue gas in the first heat exchange component 91. temperature. Therefore, the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant in the embodiment of the present disclosure has the advantage of saving energy.

In some embodiments, as shown in FIG. 2 , the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant in the embodiment of the present disclosure further includes an induced draft fan 8, and the induced draft fan 8 is arranged between the precooler 9 and the dust collector 7 , the air inlet of the induced draft fan 8 communicates with the air outlet 72 , and the air outlet of the induced draft fan 8 communicates with the seventh flue gas inlet 911 , so that the seventh flue gas inlet 911 communicates with the air outlet 72 .

In some embodiments, the induced draft fan 8 has a ninth flue gas inlet 81 and a ninth flue gas outlet 82, wherein the ninth flue gas inlet 81 is the air inlet of the induced draft fan 8, and the ninth flue gas outlet 82 is the outlet of the induced draft fan 8. air outlet. In some embodiments, the ninth flue gas inlet 81 of the induced draft fan 8 communicates with the gas outlet 72 of the dust collector 7 , and the ninth flue gas outlet 82 of the induced draft fan 8 communicates with the seventh flue gas inlet 911 of the precooler 9 .

It can be understood that the induced draft fan 8 can speed up the flow velocity of the flue gas, thereby increasing the flue gas treatment efficiency in the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the waste power plant according to the embodiment of the present disclosure.

In other embodiments, the waste gas power plant rotary kiln combustion furnace flue gas low-temperature desulfurization and denitrification system of the embodiment of the present disclosure further includes a chimney, the chimney and the fifth flue gas outlet 52 or the eighth flue gas outlet 922 for discharging flue gas. In some embodiments, the chimney communicates with the fifth flue gas outlet 52 of the low-temperature adsorption tower 5, so that the flue gas discharged from the low-temperature adsorption tower 5 is discharged through the chimney. Alternatively, the chimney communicates with the eighth flue gas outlet 922 of the precooler 9, so that the flue gas discharged from the precooler 9 is discharged through the chimney.

The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a waste power plant according to an embodiment of the present disclosure will be described below with reference to the accompanying drawings. The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant according to an embodiment of the present disclosure is implemented by using the above-mentioned low-temperature desulfurization and denitrification system for flue gas from a rotary kiln combustion furnace in a garbage power plant.

The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant according to an embodiment of the present disclosure includes the following steps:

Reduce the temperature of the flue gas to 140°C-170°C;

Desulfurize the flue gas;

Dedust the flue gas;

Reduce the temperature of the flue gas to below 20°C;

Desulfurization and denitrification of flue gas;

Vent the fumes.

In some embodiments, as shown in FIG. 2 , reducing the temperature of the flue gas to 140°C-170°C includes passing the flue gas into the waste heat boiler 2 to lower the temperature of the flue gas to 300°C-350°C. In some embodiments, the rotary kiln combustion furnace 1 discharges high-temperature flue gas from the flue gas discharge port 11 , and enters the waste heat boiler 2 through the first flue gas inlet 21 . The high-temperature flue gas exchanges heat with the waste heat boiler 2, thereby reducing the temperature of the high-temperature flue gas to 300°C-350°C.

Pass the flue gas into the absorption refrigeration unit 3 to exchange heat with the steam generator 31, so that the temperature of the flue gas drops to 140°C-170°C. In some embodiments, the flue gas that has been cooled by the waste heat boiler 2 is discharged from the first flue gas outlet 22, enters the steam generator 31 of the absorption refrigerating unit 3 through the second flue gas inlet 311, and further treats the flue gas The temperature of the gas is lowered, so the temperature of the flue gas is reduced to 140°C-170°C.

In some embodiments, as shown in FIG. 2 , reducing the temperature of the flue gas to 140°C-170°C includes passing the flue gas into the waste heat boiler 2 to lower the temperature of the flue gas to 300°C-350°C. In some embodiments, the flue gas that has been cooled by the waste heat boiler 2 is discharged from the first flue gas outlet 22, enters the steam generator 31 of the absorption refrigerating unit 3 through the second flue gas inlet 311, and further treats the flue gas The temperature of the flue gas is lowered, so the temperature of the flue gas is reduced to 300°C-350°C.

Pass the flue gas into the absorption refrigerating unit 3 to exchange heat with the steam generator 31 to lower the temperature of the flue gas to 180°C-300°C. In some embodiments, the flue gas is passed into the absorption refrigeration unit 3 to exchange heat with the steam generator 31 to reduce the temperature of the flue gas to 180°C-300°C. In some embodiments, the flue gas that has been cooled by the waste heat boiler 2 is discharged from the first flue gas outlet 22, enters the steam generator 31 of the absorption refrigerating unit 3 through the second flue gas inlet 311, and further treats the flue gas The temperature of the flue gas is lowered, so the temperature of the flue gas is reduced to 180°C-300°C.

The flue gas is passed into the cooling tower 6 to reduce the temperature of the flue gas to 140°C-170°C. In some embodiments, the flue gas cooled by the steam generator 31 is discharged from the second flue gas outlet 312, and enters the cooling tower 6 through the sixth flue gas outlet 62 of the cooling tower 6, thereby reducing the temperature of the flue gas. to 140°C-170°C.

The flue gas whose temperature is lowered to 140°C-170°C enters the desulfurization tower 4 through the fourth flue gas inlet 41, so that the desulfurization tower 4 performs desulfurization treatment on the flue gas, and then removes sulfur compounds in the flue gas. Wherein, the desulfurization treatment of the flue gas by the desulfurization tower 4 includes dry desulfurization and semi-dry desulfurization.

In some embodiments, dry desulfurization is used to remove sulfur-containing compounds in flue dust, wherein dry slaked lime is used as an absorbent, and the flue gas in the desulfurization tower 4 is reacted with dry slaked lime, thereby removing sulfur-containing compounds in the flue gas. Alternatively, semi-dry desulfurization is used to remove sulfur compounds in the flue dust. Wherein, the slaked lime slurry is sprayed in the desulfurization tower 4, so that the slaked lime slurry is evenly distributed in the desulfurization tower 4, and the flue gas reacts with the slaked lime in the desulfurization tower 4, thereby removing sulfur compounds in the flue gas.

It can be understood that the height of the tower body of the desulfurization tower 4 is large, so that the flue gas in the desulfurization tower 4 can fully contact and react with the slaked lime. The desulfurization rate of gas low temperature desulfurization and denitrification method.

The desulfurized flue gas is discharged from the fourth flue gas outlet 42 of the desulfurization tower 4, and enters the dust collector 7 through the air inlet 71 of the dust collector 7 for dust removal.

In some embodiments, as shown in Figure 1, reducing the temperature of the flue gas to below 20°C includes passing the flue gas into the absorption refrigeration unit 3 to exchange heat with the evaporator 32, so that the temperature of the flue gas is reduced to below 20°C .

In some embodiments, the desulfurized flue gas is discharged through the fourth flue gas outlet 42, enters the evaporator 32 through the third flue gas inlet 321 of the evaporator 32, and the evaporator 32 exchanges heat with the flue gas, and then the The temperature of the flue gas is reduced below 20°C.

Further, the flue gas below 20° C. is discharged from the third flue gas outlet 322 of the evaporator 32 and enters the low-temperature adsorption tower 5 . The flue gas is desulfurized and denitrated in the low-temperature adsorption tower 5 .

In some embodiments, before the flue gas is passed into the absorption refrigeration unit 3 to exchange heat with the evaporator 32, the flue gas is passed into the precooler 9 to lower the temperature of the flue gas to 60°C-90°C.

In some embodiments, before the desulfurized flue gas is discharged into the evaporator 32 through the fourth flue gas outlet 42, the flue gas first enters the precooler 9 from the seventh flue gas inlet 911 of the precooler 9 In the first heat exchange component 91, the temperature of the flue gas is further reduced to 60°C-90°C.

In some embodiments, as shown in FIG. 2 , after the flue gas is desulfurized and denitrated, before the flue gas is discharged, the flue gas is passed into the pre-cooler 9 to cool the pre-cooler 9 .

In some embodiments, the flue gas discharged from the cryogenic adsorption tower 5 enters the second heat exchange assembly 92 of the precooler 9 through the eighth flue gas inlet 921 of the precooler 9, and then the second heat exchange assembly 92 The flue gas in the exhaust gas exchanges heat with the first heat exchange component 91 , which lowers the temperature of the first heat exchange component 91 of the precooler 9 , thus cooling the precooler 9 .

In describing the present disclosure, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial", The orientations or positional relationships indicated by "radial", "circumferential", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying the referred devices or elements Must be in a particular orientation, constructed, and operate in a particular orientation, and thus should not be construed as limiting on the present disclosure.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present disclosure, terms such as "installation", "connection", "connection" and "fixation" should be interpreted in a broad sense unless otherwise clearly specified and limited, for example, it may be a fixed connection or a detachable connection, or integrated; may be mechanically connected, may also be electrically connected or may communicate with each other; may be directly connected, or indirectly connected through an intermediary, may be internal communication between two components or an interactive relationship between two components, unless There are other clear restrictions. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present disclosure according to specific situations.

In the present disclosure, unless otherwise clearly stated and limited, a first feature being "on" or "under" a second feature may mean that the first and second features are in direct contact, or that the first and second features are indirect through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In this disclosure, the terms "one embodiment," "some embodiments," "example," "specific examples," or "some examples" mean a specific feature, structure, material, or feature described in connection with the embodiment or example. Features are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Claims

A method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant, characterized in that it includes the following steps:

Reduce the temperature of the flue gas to 140°C-170°C;

Desulfurizing the flue gas;

Dedusting the flue gas;

reducing the temperature of the flue gas to below 20°C;

Desulfurization and denitrification of the flue gas;

The flue gas is discharged.
The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant according to claim 1, wherein said reducing the temperature of the flue gas to 140°C-170°C includes:

Passing the flue gas into the waste heat boiler to reduce the temperature of the flue gas to 300°C-350°C;

The flue gas is passed into the absorption refrigeration unit to exchange heat with the steam generator, so that the temperature of the flue gas is reduced to 140°C-170°C.
The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant according to claim 1, wherein said reducing the temperature of the flue gas to 140°C-170°C includes:

Passing the flue gas into the waste heat boiler to reduce the temperature of the flue gas to 300°C-350°C;

Passing the flue gas into an absorption refrigeration unit to exchange heat with a steam generator, reducing the temperature of the flue gas to 180°C-300°C;

The flue gas is passed into a cooling tower to reduce the temperature of the flue gas to 140°C-170°C.
The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant according to claim 2 or 3, wherein said reducing the temperature of the flue gas to below 20°C comprises: passing the flue gas into the The absorption refrigerating unit exchanges heat with the evaporator to reduce the temperature of the flue gas to below 20°C.
The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant according to claim 4, wherein, before the flue gas is passed into the absorption refrigeration unit to exchange heat with the evaporator, the The flue gas is passed into the precooler to reduce the temperature of the flue gas to 60°C-90°C.
The method for low-temperature desulfurization and denitrification of flue gas from a rotary kiln combustion furnace in a garbage power plant according to claim 5, wherein after said flue gas is desulfurized and denitrified, before said flue gas is discharged, the The flue gas passes into the precooler to cool the precooler.
A low-temperature desulfurization and denitrification system for flue gas from a rotary kiln combustion furnace in a waste power plant, characterized in that it includes:

A rotary kiln combustion furnace, the rotary kiln combustion furnace includes a flue gas discharge port;

A waste heat boiler, the waste heat boiler includes a first flue gas inlet and a first flue gas outlet, and the flue gas discharge port communicates with the first flue gas inlet so as to pass flue gas into the waste heat boiler so that The flue gas heats the waste heat boiler, thereby reducing the temperature of the flue gas;

An absorption refrigerating unit, the absorption refrigerating unit includes a steam generator and an evaporator, the steam generator includes a second flue gas inlet and a second flue gas outlet, and the evaporator includes a third flue gas inlet and a third a flue gas outlet, the first flue gas outlet communicates with the second flue gas inlet, so as to pass the flue gas into the steam generator, thereby reducing the temperature of the flue gas;

A desulfurization tower, the desulfurization tower includes a fourth flue gas inlet and a fourth flue gas outlet, the second flue gas outlet communicates with the fourth flue gas inlet, so that the flue gas is passed into the desulfurization tower , so as to desulfurize the flue gas,

The fourth flue gas outlet communicates with the third flue gas inlet, so as to pass the flue gas into the evaporator, thereby reducing the temperature of the flue gas;

A low-temperature adsorption tower, the low-temperature adsorption tower includes a fifth flue gas inlet and a fifth flue gas outlet, and the third flue gas outlet communicates with the fifth flue gas inlet so that the flue gas can be passed into the low-temperature In the adsorption tower, the flue gas is desulfurized and denitrified.
The low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant according to claim 7 is characterized in that it also includes a cooling tower, the cooling tower includes a sixth flue gas inlet and a sixth flue gas outlet, and the sixth The flue gas inlet communicates with the second flue gas inlet, so that the flue gas is passed into the cooling tower, thereby reducing the temperature of the flue gas,

The sixth flue gas outlet communicates with the fourth flue gas inlet, so that the second flue gas outlet communicates with the fourth flue gas inlet.
According to claim 7 or 8, the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant is characterized in that it also includes a dust collector, and the dust collector includes an air inlet and an air outlet, and the air inlet is connected to the air outlet. The fourth flue gas outlet is communicated so that the flue gas is passed into the dust collector,

The gas outlet communicates with the third flue gas inlet, so that the fourth flue gas outlet communicates with the third flue gas inlet.
According to claim 9, the low-temperature desulfurization and denitrification system for the flue gas of the rotary kiln combustion furnace of the garbage power plant is characterized in that it also includes a pre-cooler, and the pre-cooler includes a seventh flue gas inlet and a seventh flue gas outlet. The seventh flue gas inlet communicates with the gas outlet, so as to pass the flue gas into the precooler, thereby reducing the temperature of the flue gas;

The seventh flue gas outlet communicates with the third flue gas inlet, so that the gas outlet communicates with the third flue gas inlet.