CN111495175A - Exhaust gas treatment device - Google Patents
Exhaust gas treatment device Download PDFInfo
- Publication number
- CN111495175A CN111495175A CN202010040654.2A CN202010040654A CN111495175A CN 111495175 A CN111495175 A CN 111495175A CN 202010040654 A CN202010040654 A CN 202010040654A CN 111495175 A CN111495175 A CN 111495175A
- Authority
- CN
- China
- Prior art keywords
- exhaust gas
- water
- heat exchanger
- drum
- heat medium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000007789 gas Substances 0.000 claims abstract description 108
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 63
- 239000003054 catalyst Substances 0.000 claims abstract description 41
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 20
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 18
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 12
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 10
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000004202 carbamide Substances 0.000 claims abstract description 9
- 238000000746 purification Methods 0.000 claims description 8
- 238000011084 recovery Methods 0.000 claims description 7
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 abstract description 17
- 229910052921 ammonium sulfate Inorganic materials 0.000 abstract description 17
- 235000011130 ammonium sulphate Nutrition 0.000 abstract description 17
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 239000002351 wastewater Substances 0.000 description 27
- 238000002485 combustion reaction Methods 0.000 description 11
- 238000010248 power generation Methods 0.000 description 7
- 238000002347 injection Methods 0.000 description 6
- 239000007924 injection Substances 0.000 description 6
- 238000001514 detection method Methods 0.000 description 4
- 239000000446 fuel Substances 0.000 description 4
- 238000009833 condensation Methods 0.000 description 3
- 230000005494 condensation Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000010349 pulsation Effects 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000002918 waste heat Substances 0.000 description 2
- 238000003809 water extraction Methods 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- BIGPRXCJEDHCLP-UHFFFAOYSA-N ammonium bisulfate Chemical compound [NH4+].OS([O-])(=O)=O BIGPRXCJEDHCLP-UHFFFAOYSA-N 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 239000002817 coal dust Substances 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
- B01D53/8631—Processes characterised by a specific device
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2067—Urea
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/0283—Flue gases
Landscapes
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Chimneys And Flues (AREA)
- Catalysts (AREA)
Abstract
An exhaust gas treatment device, wherein a denitration catalyst filling layer using ammonia or urea as a reducing agent to reduce and remove nitrogen oxides in exhaust gas is disposed in a gas flow path (18) through which exhaust gas discharged from a furnace of a circulation-type drum boiler (1) in which water led out from a drum (4) is heated by the furnace and the heated water is returned to the drum (4) is made to flow, and ammonia or urea is injected into the exhaust gas flowing through the gas flow path on the upstream side of the denitration catalyst filling layer. The heat exchanger (30) is disposed in a gas flow passage (18) on the upstream side of the denitration catalyst-packed layer (denitration device (20)), and a heat medium introduction pipe (33) introduces water in the steam drum (4) into the heat exchanger (30). The water introduced from the heat medium introduction pipe (33) flows through the heat exchanger (30) as a heat medium. According to this configuration, the formation of ammonium sulfate at low exhaust gas temperatures is appropriately suppressed by a simple configuration.
Description
Technical Field
The present invention relates to an exhaust gas treatment device for purifying exhaust gas from a boiler.
Background
In a thermal power plant that generates power by burning fuel in a boiler, exhaust gas from the boiler is purified by an exhaust gas treatment system and discharged to the atmosphere. The exhaust gas treatment system is provided with a device for removing Nitrogen Oxides (NO) in the exhaust gasx) A denitration device for reduction removal, an air preheater for heating combustion air by heat exchange with exhaust gas, an electric dust collector for collecting and removing coal dust (combustion ash) in exhaust gas, and the like.
Further, patent document 1 describes two examples (a first example and a second example) of a boiler starting device that raises the temperature of exhaust gas at an inlet of a denitration device at the time of starting a boiler in which the denitration device is provided in a flue of an outlet portion of the boiler. In the first example, the bypass damper that bypasses a part of the heat transfer surface is opened at the start-up of the boiler to raise the temperature of the exhaust gas at the inlet of the denitration device. In the second example, a part of the steam supplied from the steam-water separator to the turbine side is supplied to the exhaust gas superheater provided at the inlet of the denitration device.
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 3-51601
In the case of a denitration apparatus using a catalyst containing ammonia or urea as a reducing agent, when the temperature of the exhaust gas flowing into the denitration apparatus (the temperature of the exhaust gas before passing through the denitration catalyst) is low, the S component contained in the exhaust gas reacts with the ammonia as the reducing agent to produce ammonium sulfate (ammonium bisulfate: NH)4HSO4). This results in a decrease in the performance of the denitration catalyst. Further, the generated ammonium sulfate adheres to and accumulates in equipment (for example, an air preheater) on the downstream side of the denitration device, and there is a possibility that deterioration or functional failure of the equipment (for example, clogging of the air preheater) may occur. For example, during low load operation of the boiler for adjusting the power supply amount (suppressing to a low level), the exhaust gas temperature decreases, and ammonium sulfate is easily generated.
In contrast, in the exhaust gas treatment device in which the bypass duct that bypasses a part of the heat transfer surface (for example, economizer) is provided as in the first example of patent document 1 and the bypass damper is capable of opening and closing the bypass duct, when the temperature of the exhaust gas flowing into the denitration device is low, the temperature of the exhaust gas at the inlet of the denitration device can be raised by opening the bypass damper. In addition, in the exhaust gas treatment apparatus as in the second example, in which a part of the steam supplied from the steam separator (steam drum) to the turbine side is supplied to the exhaust gas superheater (heat exchanger) on the inlet side of the denitration device, when the temperature of the exhaust gas flowing into the denitration device is low, the temperature of the exhaust gas at the inlet of the denitration device can be raised by the heat exchanger. Therefore, ammonium sulfate is not easily generated, and the adhesion and accumulation of ammonium sulfate to equipment on the downstream side of the denitration device can be suppressed.
However, when the exhaust gas treatment device of the first example is applied to a conventional boiler that does not include a bypass duct, a large amount of labor such as addition of the bypass duct is required. In addition, there is a problem in terms of space for arranging the large bypass duct. For this reason, it is often difficult to apply the exhaust gas treatment device of the first example to a conventional boiler that does not include a bypass duct, and therefore an exhaust gas treatment device that can be easily applied to a conventional boiler that does not include a bypass duct is desired.
In the exhaust gas treatment device of the second example, since steam from the drum is used as a heat medium, a reduction in the amount of power generation is likely to occur, and pulsation may be caused by condensation in the heat exchanger.
Disclosure of Invention
Problems to be solved by the invention
Accordingly, an object of the present invention is to appropriately suppress the generation of ammonium sulfate at a low temperature of exhaust gas with a simple configuration.
Means for solving the problems
In order to achieve the above object, an exhaust gas purifying apparatus according to the present invention is provided in a circulation-type drum boiler that heats water guided out from a drum by a furnace and returns the heated water to the drum. A denitration catalyst-filled layer is disposed in a gas flow path through which an exhaust gas discharged from a furnace flows, the denitration catalyst-filled layer being formed by using ammonia or urea as a reducing agent to reduce and remove nitrogen oxides in the exhaust gas, and ammonia or urea is injected into the exhaust gas flowing through the gas flow path upstream of the denitration catalyst-filled layer.
An exhaust gas purification device according to a first aspect of the present invention includes: a heat exchanger disposed in a gas flow path on the upstream side of the denitration catalyst-packed layer; and a heat medium inlet pipe for introducing water in the steam drum to the heat exchanger. The water introduced from the heat medium introduction pipe flows through the heat exchanger as a heat medium.
In the above configuration, since the water in the drum becomes high temperature by the operation of the circulation type drum boiler (boiler), the high temperature water (wastewater, precipitation water) in the drum is extracted from the drum and introduced into the heat exchanger through the heat medium introduction pipe, and therefore the temperature of the exhaust gas before passing through the denitration catalyst (denitration catalyst packed layer) is raised by heat exchange with the high temperature wastewater. For example, in a low-load operation of the boiler, the exhaust gas temperature is lowered as compared with a non-low-load operation (for example, in a normal operation), but in a circulation-type drum boiler for power generation, the steam pressure is increased to improve the efficiency of the plant. Therefore, the temperature of the high-temperature water in the steam drum is higher than the temperature of the exhaust gas passing through the denitration catalyst, and the exhaust gas whose temperature has been raised by the heat exchanger can be introduced into the denitration catalyst during the low-load operation.
Further, by disposing the heat exchanger in the gas flow passage on the upstream side of the denitration catalyst and providing the heat medium introduction pipe for introducing water in the drum into the heat exchanger, a wide disposition space as the bypass pipe is not required due to such a simple structure, and therefore, the present invention can be easily applied to a conventional circulation-type drum boiler not having a bypass pipe.
Further, since the high-temperature waste water from the steam drum is used as the heat medium, the amount of power generation is less likely to be reduced than in the case of using steam as the heat medium, and pulsation due to condensation of the heat exchanger is not caused.
A second aspect of the present invention is the exhaust gas treatment device according to the first aspect, further comprising a heat medium recovery pipe that returns water flowing out of the heat exchanger to a water supply line or a water circulation line of the circulation-type drum boiler.
In the above configuration, the waste water flowing out of the heat exchanger is returned to the water supply line or the water circulation line of the boiler, so that the waste heat of the waste water passing through the heat exchanger can be recovered to improve the boiler efficiency.
A third aspect of the present invention is the exhaust gas treatment device according to the first or second aspect, further comprising an introduction amount control valve provided in the heat medium introduction pipe and controlling an introduction amount of the water introduced into the heat exchanger.
In the above configuration, the amount of wastewater introduced can be increased or decreased (may include fully closing the circulation boiler without introducing wastewater) according to the operating state of the circulation boiler, and the boiler efficiency can be improved while suppressing the generation of ammonium sulfate. For example, the upper limit (threshold temperature) of a temperature range in which the possibility of generating ammonium sulfate is high is obtained in advance, the temperature of the exhaust gas passing through the denitration catalyst is detected, the wastewater is introduced when the detected temperature (exhaust gas detection temperature) of the exhaust gas is equal to or lower than the threshold temperature (or is lower than the threshold temperature), and the introduction of the wastewater is stopped when the exhaust gas detection temperature exceeds the threshold temperature (or is equal to or higher than the threshold temperature), whereby the boiler efficiency can be improved while suppressing the generation of ammonium sulfate.
Effects of the invention
According to the present invention, the production of ammonium sulfate at low exhaust gas temperatures can be suitably suppressed with a simple configuration.
Drawings
Fig. 1 is a schematic diagram showing a flue gas treatment system according to an embodiment of the present invention.
Fig. 2 is a schematic view showing the heat exchanger and the denitration apparatus of fig. 1.
Description of reference numerals:
1: a circulating drum boiler;
2: a combustion chamber;
3: a water wall tube;
4: a steam drum;
5: a downcomer;
6: a riser pipe;
7: a saturated steam pipe;
8: a superheater;
9: superheating the steam pipe;
10: a water supply pipe;
11: a water supply pump;
12: economizers (economizers);
13: a primary air duct;
14: a burner;
15: an air preheater (air heater);
16: a secondary air duct;
17: a flue;
18: a gas flow path;
20: a denitration device;
21: a catalyst layer (denitration catalyst-filled layer);
22: a reducing agent injection nozzle;
23: a gas temperature sensor;
30: a heat exchanger;
31: a heating medium inlet;
32: a heat medium outlet;
33: a heat medium inlet pipe;
34: a lead-in amount control valve;
35: a heat medium recovery pipe;
36: a waste water extraction pipe.
Detailed Description
An exhaust gas treatment device according to an embodiment of the present invention will be described with reference to the drawings. The hollow arrows in the figure indicate the flow direction of the exhaust gas. In the present embodiment, an example in which the exhaust gas treatment device of the present invention is applied to a coal-fired natural circulation drum boiler (hereinafter, simply referred to as a boiler) 1 for power generation will be described. The boiler 1 may be a boiler other than a power generation boiler, a boiler other than a coal-fired boiler, or a forced circulation drum boiler.
As shown in fig. 1, water in a drum (steam-water separation drum, steam-water separator) 4 is introduced into a waterwall tube 3 forming a furnace of a boiler 1 through a downcomer 5. The water in the waterwall tubes 3 receives the heat of combustion of the fuel in the combustion chamber 2 of the furnace to generate steam, and the steam is returned to the drum 4 through the riser 6 and separated into water and steam in the drum 4. The drum 4, the downcomer 5, the waterwall tubes 3, and the riser 6 constitute a water circulation path of the boiler 1, and water separated in the drum 4 is introduced from the downcomer 5 into the waterwall tubes 3 again to circulate. The steam separated in the steam drum 4 passes through the saturation steam pipe 7, the superheater 8, and the superheated steam pipe 9, and is supplied to a turbine (not shown) for power generation. In fig. 1, the connection portions between the downcomer 5 and the riser 6 and the waterwall tubes 3 are not shown.
Water in a water supply tank (not shown) is supplied to the steam drum 4 through a water supply pipe 10 by a water supply pump 11. An economizer (economizer) 12 is provided in the middle of the water supply pipe 10, and water heated by the economizer 12 is supplied to the steam drum 4. That is, the water supply pipe 10, the water supply pump 11, and the economizer 12 constitute a water supply route of the boiler 1.
The fuel (coal) is finely pulverized by a mill (not shown), and is carried by primary air flowing through a primary air duct 13 and is introduced into the combustion chamber (internal space of furnace) 2 from the burner 14 together with the primary air. The secondary air (combustion air) heated by the air preheater (air heater) 15 is circulated through a secondary air duct 16 and supplied from the combustor 14 to the combustion chamber 2. The air preheater 15 may heat a part or all of the primary air, or the secondary air may be supplied to the combustion chamber 2 from a mechanism other than the combustor 14 (for example, a secondary air port or the like).
Exhaust gas generated by the combustion of the fuel flows through the flue 17 and is discharged from a stack (not shown). In a flow path (gas flow path 18) of the exhaust gas from the furnace of the boiler 1 to the chimney, the superheater 8, the economizer 12, the heat exchanger 30, the denitration device 20, and the air preheater 15 are arranged from the upstream side to the downstream side.
In the superheater 8, the saturated steam separated in the steam drum 4 is heated by the exhaust gas to generate superheated steam. In the economizer 12, water supplied to the drum 4 is heated by the exhaust gas, and in the air preheater 15, secondary air supplied to the combustion chamber 2 is heated by the exhaust gas.
As shown in fig. 2, the denitration device 20 includes a catalyst layer (denitration catalyst-packed layer) 21 and a plurality of reducing agent injection nozzles (reducing agent injection means) 22. The catalyst layer 21 and the reducing agent injection nozzle 22 are fixedly provided in the gas flow passage 18.
The catalyst layer 21 is composed of a denitration catalyst for reducing and removing nitrogen oxides in the exhaust gas by using ammonia or urea as a reducing agent, and a carrier on which the denitration catalyst is supported. The catalyst layer 21 may be one layer (one stage) or may be a plurality of layers (plural stages).
The reducing agent injection nozzle 22 is disposed in the gas flow passage 18 on the upstream side of the catalyst layer 21, and injects ammonia or urea into the exhaust gas flowing through the gas flow passage 18. The reducing agent injection nozzle 22 may be disposed in the gas flow passage 18 in the flue 17 between the boiler 1 and the denitration device 20.
A gas temperature sensor (exhaust gas temperature detection means) 23 that detects the temperature of the exhaust gas passing through the denitration catalyst is provided on the upstream side of the catalyst layer 21. The location where the gas temperature sensor 23 is disposed is not limited to the upstream side of the catalyst layer 21, and may be, for example, the downstream side of the catalyst layer 21.
As shown in fig. 1 and 2, the heat exchanger 30 is disposed in the gas flow passage 18 on the upstream side of the denitration device 20 (catalyst layer 21), and the heat medium inlet 31 of the heat exchanger 30 is connected to the downstream end of the heat medium introduction pipe 33. The heat medium introduction pipe 33 has one or more waste water extraction pipes 36 at an upstream end that extract water in the drum 4, and introduces the water in the drum 4 into the heat exchanger 30. The high-temperature water (wastewater, descending water) introduced from the heat medium introduction pipe 33 flows as the heat medium inside the heat exchanger 30. The upstream end of the heat medium introduction pipe 33 may be connected to the downcomer 5 without being connected to the drum 4.
An introduction amount control valve 34 for controlling the introduction amount of water into the heat exchanger 30 is provided in the middle of the heat medium introduction pipe 33. The introduction amount control valve 34 is set to an arbitrary opening degree between full-open and full-close, for example. The opening degree of the introduction amount control valve 34 (the introduction amount of wastewater per unit time) may be set based on the temperature of the exhaust gas passing through the denitration catalyst (catalyst layer 21) (the temperature of the exhaust gas detected by the gas temperature sensor 23 (exhaust gas detection temperature)). The introduction amount control valve 34 may be opened or closed by manual operation or automatic control.
The heat medium outflow port 32 of the heat exchanger 30 is connected to the upstream end of the heat medium recovery pipe 35. The downstream end of the heat medium recovery pipe 35 is connected to the water supply pipe 10 on the upstream side of the water supply pump 11, and the waste water flowing out of the heat exchanger 30 is returned to the water supply route of the boiler 1 through the heat medium recovery pipe 35. The downstream end of the heat medium recovery pipe 35 may be connected to a pipe of the water circulation line or the drum 4 so as to return the waste water flowing out of the heat exchanger 30 to the water circulation line of the boiler 1.
The heat exchanger 30 is arranged at a lower level than the steam drum 4 so that the wastewater flows down from the steam drum 4 to the heat exchanger 30 by gravity. It is preferable that the heat medium outlet 32 is disposed at a position lower than the heat medium inlet 31 (see fig. 2) so that the wastewater flows through the heat exchanger 30 by gravity. It is preferable that the heat exchanger 30 is disposed so that the flow direction of the exhaust gas and the flow direction of the wastewater (heat medium) intersect each other.
According to the present embodiment, since the water in the drum 4 becomes high temperature due to the operation of the boiler 1, the high temperature water (wastewater) in the drum 4 is extracted from the drum 4 and introduced into the heat exchanger 30 through the heat medium introduction pipe 33, and therefore the temperature of the exhaust gas before passing through the denitration catalyst (catalyst layer 21) is raised by heat exchange with the high temperature wastewater. For example, during low-load operation of the boiler 1, the temperature of the exhaust gas is lower than during non-low-load operation (e.g., during normal operation), but the temperature of the water in the drum 4 is higher than the temperature of the exhaust gas before passing through the denitration catalyst (upstream side of the heat exchanger 30) because the steam pressure is increased to improve the efficiency of the plant. Therefore, during this low load operation, the exhaust gas whose temperature has been raised by the heat exchanger 30 can be introduced into the denitration catalyst. This can prevent or suppress precipitation of ammonium sulfate in the pores of the denitration catalyst, and can suppress adhesion and deposition of ammonium sulfate to equipment (for example, the air preheater 15) on the downstream side of the denitration catalyst.
By arranging the heat exchanger 30 in the gas flow path 18 on the upstream side of the denitration catalyst and providing the heat medium introduction pipe 33 for introducing the water in the drum 4 into the heat exchanger 30, a wide arrangement space such as a bypass pipe is not required with such a simple structure, and therefore, the present invention can be easily applied to a conventional circulation-type drum boiler not having a bypass pipe.
Since the high-temperature wastewater from the steam drum 4 is used as the heat medium, the amount of power generation is less likely to be reduced than in the case of using steam as the heat medium, and pulsation due to condensation of the heat exchanger 30 is not caused.
Since the waste water flowing out of the heat exchanger 30 is returned to the water supply line of the boiler 1, the waste heat of the waste water passing through the heat exchanger 30 can be recovered to improve the boiler efficiency.
Since the heat supplied from the heat exchanger 30 to the exhaust gas is recovered by the air preheater 15 and introduced into the boiler 1, the amount of heat lost can be reduced, and a decrease in boiler efficiency can be suppressed.
When switching from the low-load operation to the high-load operation (normal operation), the temperature of the exhaust gas passing through the denitration catalyst can be increased in a short time, and therefore the time until performance during the high-load operation is obtained can be shortened.
In the low load operation, since the boiler load increasing operation for the purpose of removing ammonium sulfate is not required, the low load operation can be continued.
Further, by opening and closing the introduction amount control valve 34, the introduction amount of the high-temperature wastewater can be increased or decreased (may include fully closing without introducing the wastewater) according to the operating state of the boiler 1, and the boiler efficiency can be improved while suppressing the generation of ammonium sulfate. For example, the upper limit (threshold temperature) of the temperature range in which the possibility of generating ammonium sulfate is high is obtained in advance, the temperature of the exhaust gas passing through the denitration catalyst is detected by the gas temperature sensor 23, the wastewater is introduced when the detected temperature of the exhaust gas detected by the gas temperature sensor 23 is equal to or lower than the threshold temperature (or is lower than the threshold temperature), and the introduction of the wastewater is stopped when the detected temperature of the exhaust gas exceeds the threshold temperature (or is equal to or higher than the threshold temperature), whereby the boiler efficiency can be improved while suppressing the generation of ammonium sulfate.
The present invention is not limited to the above-described embodiments and modifications described as examples, and various modifications may be made in accordance with design and the like without departing from the technical spirit of the present invention. For example, the circulation-type drum boiler 1 includes a natural circulation type and a forced circulation type, and the present invention can be applied to both of them.
Claims (3)
1. An exhaust gas purification device in which a denitration catalyst-filled layer for reducing and removing nitrogen oxides in exhaust gas using ammonia or urea as a reducing agent is disposed in a gas flow passage through which exhaust gas discharged from a furnace of a circulation-type drum boiler is allowed to flow, and ammonia or urea is injected into the exhaust gas flowing through the gas flow passage on the upstream side of the denitration catalyst-filled layer, wherein the circulation-type drum boiler heats water discharged from a drum by the furnace and returns the heated water to the drum, the exhaust gas purification device being characterized in that,
the exhaust gas purification device is provided with:
a heat exchanger disposed in the gas flow passage on the upstream side of the denitration catalyst-packed layer; and
a heat medium inlet pipe for introducing water in the steam drum to the heat exchanger,
the water introduced from the heat medium introduction pipe flows as a heat medium inside the heat exchanger.
2. The exhaust gas purification apparatus according to claim 1,
the exhaust gas purification device further includes a heat medium recovery pipe that returns water flowing out of the heat exchanger to a water supply line or a water circulation line of the circulation-type drum boiler.
3. The exhaust gas purification apparatus according to claim 1 or 2,
the exhaust gas purification apparatus further includes an introduction amount control valve provided in the heat medium introduction pipe and configured to control an introduction amount of the water introduced into the heat exchanger.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019014479A JP2020121267A (en) | 2019-01-30 | 2019-01-30 | Exhaust gas treatment equipment |
| JP2019-014479 | 2019-06-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111495175A true CN111495175A (en) | 2020-08-07 |
Family
ID=71865410
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010040654.2A Pending CN111495175A (en) | 2019-01-30 | 2020-01-14 | Exhaust gas treatment device |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2020121267A (en) |
| CN (1) | CN111495175A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113893683B (en) * | 2021-08-17 | 2023-10-20 | 华能重庆珞璜发电有限责任公司 | Subcritical coal-fired boiler full-load denitration system |
| CN113546511A (en) * | 2021-08-26 | 2021-10-26 | 房保忠 | Biomass boiler afterbody low temperature spouts calcium sweetener |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103170230A (en) * | 2013-03-01 | 2013-06-26 | 大连易世达新能源发展股份有限公司 | Selective non-catalytic reduction reaction denitration system for cement kiln |
| CN206709040U (en) * | 2017-03-21 | 2017-12-05 | 苏州海陆重工股份有限公司 | It is matched in the HTHP denitration waste heat boiler of catalytic cracking unit |
| CN109196277A (en) * | 2016-05-31 | 2019-01-11 | 日立造船株式会社 | Exhaust gas denitration device, incinerator and exhaust gas denitration method |
-
2019
- 2019-01-30 JP JP2019014479A patent/JP2020121267A/en active Pending
-
2020
- 2020-01-14 CN CN202010040654.2A patent/CN111495175A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103170230A (en) * | 2013-03-01 | 2013-06-26 | 大连易世达新能源发展股份有限公司 | Selective non-catalytic reduction reaction denitration system for cement kiln |
| CN109196277A (en) * | 2016-05-31 | 2019-01-11 | 日立造船株式会社 | Exhaust gas denitration device, incinerator and exhaust gas denitration method |
| CN206709040U (en) * | 2017-03-21 | 2017-12-05 | 苏州海陆重工股份有限公司 | It is matched in the HTHP denitration waste heat boiler of catalytic cracking unit |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2020121267A (en) | 2020-08-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100366873B1 (en) | Reheating Flue Gas for Selective Catalytic Systems | |
| JP5260585B2 (en) | Coal-fired power plant and method for operating coal-fired power plant | |
| RU2543096C1 (en) | METHOD AND DEVICE FOR SELECTIVE CATALYTIC REDUCTION OF NOx IN POWER BOILER | |
| RU2688078C2 (en) | Coaling welded electric installation with oxy-ignition with heat integrating | |
| JP2009008365A (en) | Steam power plant | |
| JPH11108334A (en) | Waste heat recovering boiler | |
| CN105318313B (en) | A kind of smoke waste heat utilization system based on SCR denitration device | |
| JP7420941B2 (en) | Arrangement and method for operating a steam boiler system | |
| CN111649349A (en) | Full-load denitration system for deep peak shaving of boiler and operation method thereof | |
| JP6632198B2 (en) | Heat exchanger and heat exchanger control method | |
| CN111495175A (en) | Exhaust gas treatment device | |
| JP2002206701A (en) | Exhaust gas heat recovering device and method | |
| EP2716880A1 (en) | Steam Power Plant with Steam Turbine Extraction Control | |
| CN112303604A (en) | Economizer temperature governing system that unit start-up process denitration was put into | |
| EP3232022B1 (en) | System and method for improving the performance of a heat recovery steam generator | |
| JP2013189883A (en) | Thermal power generation plant | |
| CN105889899A (en) | Superheated steam temperature adjusting system and method suitable for SCR low-load operation | |
| CN111306526B (en) | Drainage main pipe system recycling and discharging device of auxiliary system of coal-fired steam drum boiler | |
| JP2000065313A (en) | Boiler apparatus and boiler starting operation method | |
| JP7516275B2 (en) | Waste heat recovery boiler | |
| JP2019090559A (en) | Temperature controller of heat exchanger for boiler exhaust gas | |
| JP2024080906A (en) | Exhaust gas bypass device, exhaust heat recovery boiler, and exhaust gas bypass method | |
| CN110230520A (en) | A kind of biomass/rubbish direct combustion coupling coal-burning boiler master is to water generating system and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: Kanagawa Prefecture, Japan Applicant after: Mitsubishi Power Co.,Ltd. Address before: Kanagawa Prefecture, Japan Applicant before: MITSUBISHI HEAVY INDUSTRIES, Ltd. |
|
| CB02 | Change of applicant information | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200807 |
|
| WD01 | Invention patent application deemed withdrawn after publication |