CN214051165U - Denitration exhaust-heat boiler - Google Patents

Denitration exhaust-heat boiler Download PDF

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CN214051165U
CN214051165U CN202022983432.2U CN202022983432U CN214051165U CN 214051165 U CN214051165 U CN 214051165U CN 202022983432 U CN202022983432 U CN 202022983432U CN 214051165 U CN214051165 U CN 214051165U
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ammonia
shaped
main pipe
heat boiler
pipe
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耿明山
任乐
郭豪
向继涛
金锐
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MCC Capital Engineering and Research Incorporation Ltd
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MCC Capital Engineering and Research Incorporation Ltd
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Abstract

The utility model provides a denitration exhaust-heat boiler, include exhaust-heat boiler casing, high-pressure evaporator, middling pressure evaporimeter, spout ammonia equipartition device, flue and chimney, wherein, spout ammonia equipartition device and include: an ammonia spraying main pipe; the inlet of the ammonia spraying branch pipe group is communicated with the ammonia spraying main pipe; the ammonia spraying branch pipe group comprises an I-shaped branch pipe, a plurality of ammonia spraying branch pipes and a plurality of ammonia spraying branch pipes, wherein the I-shaped branch pipe is provided with a first inlet and a plurality of first outlets, the first inlet is positioned at the symmetrical center of the I-shaped branch pipe, the plurality of first outlets are in one-to-one correspondence with the end parts of the I-shaped branch pipe, and the outlets of the ammonia spraying branch pipe group are connected with the first inlets; the X-shaped distributors are connected with the first outlets in a one-to-one correspondence mode, each X-shaped distributor comprises a second inlet and a plurality of second outlets, the second inlets are located at the symmetrical centers of the X-shaped distributors, the second outlets are in one-to-one correspondence with the end portions of the X-shaped distributors, and the second inlets of the X-shaped distributors are communicated with the corresponding first outlets; and each second outlet is correspondingly connected with one nozzle.

Description

Denitration exhaust-heat boiler
Technical Field
The utility model relates to a flue gas or industry tail gas denitration field, concretely relates to denitration exhaust-heat boiler.
Background
Nitrogen oxides (NOx) are a major class of atmospheric pollutants and are one of the major contributors to the formation of acid rain, photochemical smog, and PM2.5 pollution. A large amount of SO is generated in the process of burning coal2And the air pollutants such as NOx are easy to cause serious air pollution and economic loss. The denitration in the prior art mainly aims at removing Nitric Oxide (NO) and nitrogen dioxide (NO)2)。
In SO2And NOx removal is greater than SO removal2Therefore, the simultaneous desulfurization and denitrification techniques can be roughly classified into two types from the viewpoint of NOx. The first type is a catalytic reduction method, which mainly utilizes a catalyst, a reducing agent and the like to reduce NOx so as to realize simultaneous desulfurization and denitrification; the second type is oxidation absorption method, which mainly uses various strong oxidants and active free radicals to oxidize NO insoluble in water to generate NO2,SO2And NO2Subsequent simultaneous absorption, strong oxidants include NaClO2、ClO2、HClO3、KMnO4、H2O2Etc., the free radicals include O2 -、OH-、O3And the like, and the generation technologies thereof include electron beam technology, pulsed corona discharge, and radical cluster lamp. The nitrogen oxide is difficult to remove, and the nitrogen dioxide is easy to remove. Therefore, the technology for converting nitric oxide into nitrogen dioxide is more critical.
At present, the desulfurization and denitrification technologies widely used at home and abroad comprise wet limestone and gypsum Flue Gas Desulfurization (FGD) and NH3Group of selective catalytic reduction denitration technologies (SCR)And synthesizing and adsorbing and catalyzing with active carbon.
Wherein the SCR is widely applied to denitration of coal-fired power plants, a temperature window of 300-400 ℃ is needed, and NOx is in a catalyst and NH3Is reduced to N2The denitration efficiency can reach more than 90%; the activated carbon adsorption catalysis method utilizes the adsorption and catalysis effects of activated carbon, the application temperature is about 200 ℃, and the denitration efficiency is about 50-70% under the condition of ammonia spraying; in the field of low-temperature denitration, SCR needs to heat flue gas, and the technical cost of activated carbon is high.
Although the desulfurization and denitrification efficiency of the technology is high, the investment and operation cost are high, the requirements of the catalyst in the SCR denitrification process on the process conditions are strict, the special requirements including the flue gas temperature and the dust characteristics in the flue gas exist, and the catalyst is easy to be poisoned and failed, so that the operation cost of an SCR system is high.
For a selective catalytic reduction method, two performance parameters of denitration efficiency and ammonia escape rate are mainly improved by two means: 1. the catalytic reduction capability of the catalyst is improved; 2. improving the flue gas distribution and NOx/NH at the inlet of the catalyst layer3(NOx means nitrogen oxide, NH)3Representing ammonia) uniformity.
The catalytic reduction capability of the catalyst is improved mainly by means of improving the formula of the catalyst, increasing the dosage of the catalyst and the like; and catalyst layer inlet flue gas distribution and NOx/NH3The uniformity of the ammonia injection grid is realized by optimizing a flue guide plate of the denitration device and adjusting the design of the ammonia injection grid, wherein the ammonia injection grid is used for treating NOx/NH in flue gas of the denitration device3Is particularly critical.
In an SCR flue gas denitration system, the injection and mixing of a reducing agent ammonia gas are important components of the whole system. Usually, the ammonia injection and mixing adopts an ammonia injection grid or a static mixer so as to achieve the purpose of uniformly mixing the ammonia gas and the flue gas. In the design of a denitration system, the sufficient mixing of ammonia and nitrogen oxides is a key factor, and the uneven mixing can cause lower denitration rate or higher escape ammonia amount. The effect of this mixing is only a rough type of control, while the distribution of ammonia is significantly uneven and cannot be controlled locally and fine tuned.
The ammonia injection grid commonly used in the prior art is composed of a plurality of parallel ammonia injection pipes, and each ammonia injection pipe is provided with a plurality of ammonia gas nozzles. In actual industrial production, the ammonia spraying amount of different ammonia nozzles on different ammonia spraying pipes is greatly different, and the distribution of ammonia on the cross section of a flue is extremely uneven due to the influence of comprehensive factors such as on-way resistance of a pipeline and uneven distribution of flue gas flow velocity on the cross section of the flue, so that the denitration efficiency is seriously influenced, and the ammonia escape rate is increased.
The common ammonia injection device configuration type of current SCR denitrification facility is the ammonia injection grid of equipartition formula. The basic principle is that a plurality of subareas with the same size are designed and planned in the denitration inlet flue, and a plurality of groups of nozzles are uniformly distributed in the subareas. Each partition corresponds to an ammonia injection branch pipe, and a valve is arranged on the ammonia injection branch pipe and used for manual adjustment.
But along with the continuous improvement of the environmental protection requirement, the requirement of ultra-clean and even ultra-clean flue gas denitration is provided, when the requirement of the flue gas denitration device on the denitration efficiency is more than 90%, the efficiency can not be further improved by simply increasing the dosage of the catalyst, and the NOx/NH is required to be carried out3Higher requirements for uniformity, NH3/NOXThe deviation of the molar ratio distribution needs to be up to + -3% or even less.
In the face of such high NH3/NOXThe requirement for the deviation of the molar ratio distribution, the current ammonia-injection grid pattern, begins to expose its disadvantages:
1. when the deviation of the flue gas flow field is large, the ammonia gas flow required by a plurality of local injection branch pipes is too large or too small and exceeds the adjustment range; the flow rate of the locally sprayed ammonia gas is too much or too little relative to the flow rate of the flue gas, so that the denitration efficiency is not high.
2. Ammonia is unevenly distributed on the cross section, and the dynamic adjustment of local ammonia flow cannot be realized; the ordinary stop valve that the valve of ammonia injection branch pipe adopted, the regulation performance is relatively poor, can't satisfy the regulation required precision.
3. The flow distribution of each nozzle on a single branch pipe is uneven, the air flow velocity near the inlet of the branch pipe is high, the flow is high, and the air flow velocity at the tail end of the branch pipe is low and the air flow is insufficient.
4. Flue gas and ammonia gas are not well mixed in laminar flow and turbulent flow states.
5. The spoiler is arranged, so that resistance loss of air flow is increased, the equipment is high in processing and manufacturing difficulty, high in mounting precision requirement and inconvenient to maintain and overhaul.
6. The mode of adopting the tapered branch pipe can only be suitable for gas distribution under a certain flow condition, the gas distribution under different flow conditions still has nonuniformity, the processing and manufacturing difficulty of the branch pipe is large, and the precision requirement is high.
The increase of the escape rate of ammonia not only reduces the denitration efficiency, but also causes the blockage and corrosion of the denitration device. Therefore, a new ammonia injection grid which is reasonable in design and suitable for application is urgently needed, the uniform mixing of ammonia gas and nitric oxide in a flue is ensured, the denitration efficiency is further improved, and the ammonia escape rate is reduced.
SUMMERY OF THE UTILITY MODEL
The utility model provides a denitration exhaust-heat boiler to reach the purpose that improves denitration efficiency.
The utility model provides a technical scheme that its technical problem adopted is: the utility model provides a denitration exhaust-heat boiler, includes exhaust-heat boiler casing, high-pressure evaporimeter, middling pressure evaporimeter, spouts ammonia equipartition device, flue and chimney, high-pressure evaporimeter and middling pressure evaporimeter interval set up in exhaust-heat boiler casing, spout ammonia equipartition device and lie in between high-pressure evaporimeter and the middling pressure evaporimeter, the flue is close to high-pressure evaporimeter one side with the exhaust-heat boiler casing and is connected, the chimney is close to middling pressure evaporimeter one side with the exhaust-heat boiler casing and is connected, wherein, spout ammonia equipartition device and include: an ammonia spraying main pipe; the inlet of the ammonia spraying branch pipe group is communicated with the ammonia spraying main pipe; the ammonia spraying branch pipe group comprises an I-shaped branch pipe, a plurality of ammonia spraying branch pipes and a plurality of ammonia spraying branch pipes, wherein the I-shaped branch pipe is provided with a first inlet and a plurality of first outlets, the first inlet is positioned at the symmetrical center of the I-shaped branch pipe, the plurality of first outlets are in one-to-one correspondence with the end parts of the I-shaped branch pipe, and the outlets of the ammonia spraying branch pipe group are connected with the first inlets; the X-shaped distributors are connected with the first outlets in a one-to-one correspondence mode, each X-shaped distributor comprises a second inlet and a plurality of second outlets, the second inlets are located at the symmetrical centers of the X-shaped distributors, the second outlets are in one-to-one correspondence with the end portions of the X-shaped distributors, and the second inlets of the X-shaped distributors are communicated with the corresponding first outlets; and each second outlet is correspondingly connected with one nozzle.
Further, the ammonia spraying main pipe comprises a first main pipe, a second main pipe, a third main pipe and a fourth main pipe which are sequentially connected, wherein the inner diameter of the first main pipe is larger than that of the second main pipe, the inner diameter of the second main pipe is larger than that of the third main pipe, and the inner diameter of the third main pipe is larger than that of the fourth main pipe.
Further, first being responsible for, the second is responsible for, the third is responsible for and the fourth is responsible for and all corresponds and is provided with an ammonia injection branch pipe group, and ammonia injection branch pipe group includes: the ammonia spraying distribution pipe is provided with an ammonia spraying distribution pipe inlet and a plurality of ammonia spraying distribution pipe outlets, and the ammonia spraying distribution pipe inlet is connected with the corresponding ammonia spraying main pipe; the inlets of the plurality of ammonia spraying branch pipe bodies are correspondingly connected with the outlets of the plurality of ammonia spraying distribution pipes one by one; and the inlets of the plurality of partition branch pipes are connected with the outlets of the plurality of ammonia spraying branch pipe bodies in a one-to-one correspondence manner, and each partition branch pipe is connected to the corresponding first inlet.
Furthermore, the inlet end side of the first main pipe is provided with a first regulating valve, and a second regulating valve is arranged between each ammonia spraying distribution pipe and the corresponding ammonia spraying main pipe.
Further, the ammonia spraying and uniformly distributing device also comprises a control assembly which is connected with the first regulating valve and the second regulating valve.
Further, the nozzle includes: the small-diameter end of the circular truncated cone-shaped spray pipe is connected with the second outlet; the arc guide plate is fixedly connected with the large-diameter end of the circular truncated cone-shaped spray pipe through the circular seam supporting piece.
Furthermore, the nozzle also comprises a flow equalizing plate which is provided with a plurality of through holes which are uniformly distributed at intervals, and the outer wall of the flow equalizing plate is fixedly connected with the inner wall of the large-diameter end of the circular truncated cone-shaped spray pipe.
Furthermore, the circular seam supporting piece comprises a top edge, a bottom edge and an inner side edge, the top edge is connected with the arc-shaped guide plate, the bottom edge is connected with the large-diameter end of the circular truncated cone-shaped spray pipe, and the inner side edge is parallel to the central line of the circular truncated cone-shaped spray pipe.
Further, denitration exhaust-heat boiler still includes the catalyst layer, sets up between ammonia injection equipartition device and medium pressure evaporimeter.
Further, denitration exhaust-heat boiler still includes: the nitrogen oxide detection unit is arranged between the high-pressure evaporator and the ammonia spraying uniform distribution device; the ammonia gas detection unit is arranged between the catalyst layer and the medium-pressure evaporator; and the smoke detection unit is arranged at an inlet of the chimney.
The beneficial effects of the utility model are that, adopt the mode of arranging and the X shape distributor of I-shaped branch pipe, can realize that each nozzle spouts the evenly distributed of ammonia volume in every independent subregion, realize the speed, the pressure evenly distributed of each nozzle ammonia, realize the homogeneous mixing of flue gas and ammonia, eliminate the too big phenomenon that causes the ammonia escape of local ammonia concentration.
Drawings
The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 is a schematic structural diagram of an embodiment of the present invention;
FIG. 2 is a schematic structural view of an ammonia injection main pipe and an ammonia injection branch pipe group;
FIG. 3 is a schematic view of the assembly of the ammonia injection main pipe and the I-shaped branch pipe;
FIG. 4 is a schematic structural view of an ammonia injection branch pipe group;
FIG. 5 is a schematic structural view of an I-shaped branch pipe;
FIG. 6 is a schematic structural view of an X-shaped distributor and a nozzle in an embodiment of the present invention;
FIG. 7 is a cross-sectional view of FIG. 6;
FIG. 8 is a schematic structural view of a nozzle according to an embodiment of the present invention;
fig. 9 is a side view of a nozzle in an embodiment of the invention.
Reference numbers in the figures: 10. an ammonia spraying main pipe; 101. a first main tube; 102. a second main pipe; 103. a third main pipe; 104. a fourth main pipe; 11. an ammonia injection branch pipe group; 111. an ammonia spraying distribution pipe; 112. an ammonia injection branch pipe body; 113. partitioning branch pipes; 12. an I-shaped branch pipe; 121. a first-stage I-shaped branch pipe; 122. a second-stage I-shaped branch pipe; 123. three-stage I-shaped branch pipes; 13. an X-shaped distributor; 14. a nozzle; 141. a truncated cone-shaped nozzle; 142. an arc-shaped guide plate; 143. a circumferential seam support; 144. a flow equalizing plate; 15. a first regulating valve; 17. a second regulating valve; 71. a waste heat boiler housing; 72. a high pressure evaporator; 73. a medium pressure evaporator; 74. an ammonia spraying uniform distribution device; 75. a flue; 76. a chimney; 77. a catalyst layer; 78. a nitrogen oxide detection unit; 79. an ammonia gas detection unit; 80. a smoke detection unit; 81. a primary baffle; 82. a secondary baffle; 83. a high pressure superheater; 84. a high pressure steam drum; 85. a medium pressure steam drum; 86. a low pressure steam drum; 87. a low pressure evaporator; 88. a low-pressure economizer; 89. an exhaust gas outlet; 90. and (4) a measuring device.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
As shown in fig. 1 to 9, the embodiment of the utility model provides a denitration exhaust-heat boiler, including exhaust-heat boiler casing 71, high-pressure evaporator 72, medium-pressure evaporator 73, ammonia injection equipartition device 74, flue 75 and chimney 76, high-pressure evaporator 72 and medium-pressure evaporator 73 interval set up in exhaust-heat boiler casing 71, ammonia injection equipartition device 74 is located between high-pressure evaporator 72 and the medium-pressure evaporator 73, flue 75 is close to high-pressure evaporator 72 one side with exhaust-heat boiler casing 71 and is connected, chimney 76 is close to medium-pressure evaporator 73 one side with exhaust-heat boiler casing 71 and is connected, wherein, ammonia injection equipartition device 74 is responsible for 10 including the ammonia injection, ammonia injection branch pipe group 11, i-shaped branch pipe 12, a plurality of X-shaped distributors 13 and a plurality of nozzle 14. The inlet of the ammonia injection branch pipe group 11 is communicated with the ammonia injection main pipe 10. The I-shaped branch pipe 12 is provided with a first inlet and a plurality of first outlets, the first inlet is positioned at the symmetrical center of the I-shaped branch pipe 12, the plurality of first outlets are in one-to-one correspondence with the end parts of the I-shaped branch pipe 12, and the outlets of the ammonia injection branch pipe group 11 are connected with the first inlets. The plurality of X-shaped distributors 13 are connected with the plurality of first outlets in a one-to-one correspondence manner, each X-shaped distributor 13 comprises a second inlet and a plurality of second outlets, the second inlet is located at the symmetrical center of the X-shaped distributor 13, the second outlets are in one-to-one correspondence with the end portions of the X-shaped distributors 13, and the second inlet of each X-shaped distributor 13 is communicated with the corresponding first outlet. Each second outlet is correspondingly connected with a nozzle 14.
By adopting the arrangement mode of the I-shaped branch pipes 12 and the X-shaped distributor 13, the ammonia spraying amount of each nozzle 14 in each independent subarea can be uniformly distributed, the ammonia gas speed and pressure of each nozzle 14 can be uniformly distributed, the flue gas and the ammonia gas can be uniformly mixed, and the phenomenon of ammonia escape caused by overlarge local ammonia gas concentration can be eliminated.
It should be noted that the i-shaped branch pipe 12, the plurality of X-shaped distributors 13, and the plurality of nozzles 14 form one ammonia injection unit, and in this embodiment, a plurality of symmetrically distributed ammonia injection units may be provided to achieve overall coverage of the whole flue.
As shown in fig. 5, in the embodiment of the present invention, the i-shaped branch pipe 12 includes an one-level i-shaped branch pipe 121, a two-level i-shaped branch pipe 122 and a three-level i-shaped branch pipe 123, an outlet of the one-level i-shaped branch pipe 121 is connected to an inlet of the X-shaped distributor 13, an inlet of the one-level i-shaped branch pipe 121 is connected to an outlet of the two-level i-shaped branch pipe 122, an inlet of the two-level i-shaped branch pipe 122 is connected to an outlet of the three-level i-shaped branch pipe 123, and an inlet of the three-level i-shaped branch pipe 123 is connected to an outlet of the ammonia spraying branch pipe set 11.
The structure is only one of the ammonia spraying uniform distribution units, and a plurality of I-shaped branch pipes can be added according to different requirements so as to cover the section of the whole waste heat boiler shell 71.
The ammonia injection main pipe 10 comprises a first main pipe 101, a second main pipe 102, a third main pipe 103 and a fourth main pipe 104 which are connected in sequence, wherein the inner diameter of the first main pipe 101 is larger than that of the second main pipe 102, the inner diameter of the second main pipe 102 is larger than that of the third main pipe 103, and the inner diameter of the third main pipe 103 is larger than that of the fourth main pipe 104. The ammonia spraying main pipe 10 adopts a plurality of sections of pipelines with different pipe diameters for connection so as to realize the uniform and stable flow rate of ammonia gas.
The first main pipe 101, the second main pipe 102, the third main pipe 103 and the fourth main pipe 104 are respectively provided with an ammonia injection branch pipe group 11, and the ammonia injection branch pipe group 11 comprises an ammonia injection distribution pipe 111, a plurality of ammonia injection branch pipe bodies 112 and a plurality of partition branch pipes 113. The ammonia spraying distribution pipe 111 is provided with an ammonia spraying distribution pipe inlet and a plurality of ammonia spraying distribution pipe outlets, and the ammonia spraying distribution pipe inlet is connected with the corresponding ammonia spraying main pipe 10. The inlets of the plurality of ammonia injection branch pipe bodies 112 are correspondingly connected with the outlets of the plurality of ammonia injection distribution pipes. The inlets of the plurality of partition branch pipes 113 are correspondingly connected with the outlets of the plurality of ammonia injection branch pipe bodies 112, and each partition branch pipe 113 is connected with the corresponding first inlet.
Through setting up above-mentioned structure can adjust and control the ammonia volume of spouting of every subregion respectively for it is adjustable to spout the ammonia volume subregion on the flue cross-section, optimizes ammonia and nitrogen oxide's in the air homogeneous mixing effect, has improved denitration efficiency, and has effectively reduced ammonia escape rate.
It should be noted that the ammonia injection main pipe 10 is arranged outside the waste heat boiler shell 71, at least two ammonia injection main pipes 10 are arranged, the two ammonia injection main pipes 10 are designed in a symmetrical structure, and the ammonia concentration in the ammonia injection main pipes 10 is lower than 5%.
The inlet end side of the first main pipe 101 is provided with a first regulating valve 15, and a second regulating valve 17 is provided between each ammonia injection distribution pipe 111 and the corresponding ammonia injection main pipe 10. The ammonia spraying and uniform distributing device also comprises a control component which is connected with the first regulating valve 15 and the second regulating valve 17. The embodiment of the utility model provides an in first governing valve 15 and second governing valve 17 are aperture governing valve, including executor and electromagnetic flow control valve body, the execution is used for receiving the aperture signal from the control assembly and adjusts the aperture of electromagnetic flow control valve body, realizes spouting the automatically regulated of ammonia volume.
In this embodiment, each ammonia injection branch pipe body 112 is provided with a flow meter, which is an electromagnetic flow meter, an ultrasonic flow meter or a rotameter.
Furthermore, the control assembly comprises a flue gas speed measuring module, a flue gas component measuring module, an ammonia injection amount calculating module, an ammonia injection amount monitoring module and a measured data summarizing and analyzing module; the system comprises a speed measuring module, a smoke component analyzing module, a measured data summarizing and analyzing module, a nitrogen oxide spraying amount adjusting valve, an ammonia spraying amount adjusting module and a flow meter, wherein the speed measuring module is used for measuring the smoke flow speed in different areas in a smoke channel, the smoke component analyzing module is used for measuring the content of nitrogen oxide in smoke, the removal load of nitrogen oxide is calculated by utilizing a computer program, the measured data summarizing and analyzing module is used for calculating the load of nitrogen oxide according to the smoke flow and the smoke component of each area, the ammonia spraying amount required by each area is calculated according to the load of nitrogen oxide, the ammonia spraying amount of each area is adjusted through an electric or pneumatic subarea flow adjusting valve on an ammonia spraying branch pipe, and the actual ammonia spraying amount is monitored according to the flow meter on the ammonia spraying branch pipe; the ammonia gas monitoring module is used for detecting the amount of unreacted ammonia gas at the downstream of the catalyst, and controlling the ammonia spraying amount according to the ammonia escape amount feedback in each area, when the ammonia escape amount exceeds a set value, the system prompts that the ammonia spraying amount of the corresponding area is too large, the ammonia spraying amount of the area is correspondingly reduced, and the minimum ammonia consumption and ammonia escape amount are realized.
Specifically, the nozzle 14 includes a frustoconical lance 141 and an arcuate baffle 142. The small diameter end of the circular truncated cone-shaped nozzle 141 is connected to the second outlet. The arc-shaped guide plate 142 is fixedly connected with the large-diameter end of the circular truncated cone-shaped spray pipe 141 through the circular seam support 143, and a strip-shaped gap for gas to pass through is formed between the arc-shaped guide plate 142 and the circular truncated cone-shaped spray pipe 141.
The nozzle 14 provided by the embodiment of the utility model can realize the annular distribution of ammonia around the truncated cone-shaped nozzle 141, thereby enlarging the spatial distribution range of ammonia; the arc-shaped guide plate 142 can prevent the circular truncated cone-shaped spray pipe 141 from being blocked by deposited dust, and can disturb the flue gas, so that the flue gas and the ammonia gas can be rapidly and uniformly mixed.
The center of the arc-shaped guide plate 142 coincides with the center of the circular truncated cone-shaped spray pipe 141, the bottom end of the arc-shaped guide plate 142 faces the large-diameter end of the circular truncated cone-shaped spray pipe 141, and the diameter of the bottom end of the arc-shaped guide plate 142 is larger than that of the large-diameter end of the circular truncated cone-shaped spray pipe 141. The arrangement can prevent the circular truncated cone-shaped spray pipe 141 from being blocked by dust deposition, and can disturb the flue gas to realize rapid and uniform mixing of the flue gas and ammonia gas.
Preferably, the nozzle 14 further includes a flow equalizing plate 144 having a plurality of through holes spaced uniformly, and an outer wall of the flow equalizing plate 144 is fixedly connected to an inner wall of the large diameter end of the circular truncated cone-shaped nozzle 141. The provision of the flow equalizing plate 144 enables even distribution of the air flow.
The central line of the circular truncated cone-shaped nozzle 141 is perpendicular to the flow equalizing plate 144, and the distance between the flow equalizing plate 144 and the large-diameter section of the circular truncated cone-shaped nozzle 141 is smaller than the distance between the flow equalizing plate 144 and the small-diameter section of the circular truncated cone-shaped nozzle 141, so that the gas can be fully equalized.
The plurality of circular seam supports 143 are uniformly distributed along the circumferential direction of the circular truncated cone-shaped nozzle 141, the circular seam supports 143 are located in the circular truncated cone-shaped nozzle 141, and the circular seam supports 143 are located between the arc-shaped flow guide plate 142 and the flow equalizing plate 144. The circular seam support 143 includes a top edge, a bottom edge, and an inner side edge, the top edge is connected to the arc-shaped baffle 142, the bottom edge is connected to the large diameter end of the frustoconical spout 141, the inner side edge is parallel to the centerline of the frustoconical spout 141, and the distance from the inner side edge to the centerline of the frustoconical spout 141 is less than the radius of the flow equalizing plate 144.
The flow equalizing plate 144 is fixed by the circumferential seam support 143, and the circumferential seam support 143 and the arc-shaped guide plate 142 can be separated from and assembled with the circular truncated cone-shaped nozzle 141, so that the flow equalizing plate 144 can be conveniently installed and replaced.
It should be noted that the direction of the arrows shown in fig. 7 is the flow direction of the flue gas, and as can be seen from fig. 7, the flow direction of the flue gas is opposite to the spraying direction of the nozzles 14.
As shown in fig. 1, the denitration exhaust-heat boiler further includes a catalyst layer 77 disposed between the ammonia injection uniform distribution device 74 and the medium-pressure evaporator 73.
Further, the denitration exhaust-heat boiler also comprises a nitrogen oxide detection unit 78, an ammonia gas detection unit 79 and a flue gas detection unit 80. The nitrogen oxide detection unit 78 is arranged between the high-pressure evaporator 72 and the ammonia spraying uniform distribution device 74; the ammonia gas detection unit 79 is provided between the catalyst layer 77 and the medium-pressure evaporator 73; and a smoke detection unit 80 disposed at an inlet of the chimney 76.
The flue gas detection units 80 are arranged on the cross section of the waste heat boiler, the positions of the flue gas detection units 80 and the centers of the three-stage I-shaped branch pipes 123 are on the same horizontal axis, the flue gas velocity of each flue gas detection unit 80 represents the flue gas velocity distribution of the independent subarea, and at least one flue gas detection unit 80 is arranged in each ammonia spraying unit. In this embodiment, the two smoke detection units 80 are respectively disposed in front of the inlet of the chimney 76 and at the inlet of the waste heat boiler casing 71.
The nitrogen oxide detecting units 78 are arranged on the section of the waste heat boiler, the positions of the nitrogen oxide detecting units 78 and the center of the three-stage I-shaped branch pipe 123 are on the same horizontal axis, the nitrogen oxide concentration of each nitrogen oxide detecting unit 78 represents the concentration distribution of nitrogen oxide in the independent subarea, and at least one nitrogen oxide detecting unit 78 is arranged in each ammonia spraying uniform distribution unit. In this embodiment, the nitrogen oxide detecting unit 78 is respectively disposed in front of the ammonia spraying and uniformly distributing device 74 and in front of the inlet of the chimney 76.
The ammonia gas detection unit 79 is provided with a plurality of sampling measurement points, the positions of the ammonia gas measurement points and the center of the three-stage I-shaped branch pipe 123 are on the same horizontal axis, and each ammonia spraying uniform distribution unit is at least provided with one ammonia gas detection unit 79.
Further, the denitration exhaust-heat boiler also comprises a primary guide plate 81, a secondary guide plate 82, a high-pressure superheater 83, a low-pressure evaporator 87, a low-pressure economizer 88, a high-pressure steam drum 84, a medium-pressure steam drum 85, a low-pressure steam drum 86, an exhaust gas outlet 89 and a measuring device 90. The above structures are the same as those in the prior art, and are not described in detail here.
Further, the primary guide plate 81 and the secondary guide plate 82 can rotate around respective horizontal axes to realize different horizontal inclination angles, so that the dynamic adjustment of the turning angle of the flue gas is realized.
The embodiment of the utility model can combine the concentration of nitrogen oxides at each measuring point of the smoke components and the flow velocity of the smoke, according to the area covered by each ammonia spraying unit, the removal load of nitrogen oxides in each ammonia spraying unit area is calculated, the ammonia spraying amount required in each ammonia spraying unit area is calculated, the calculated ammonia spraying amount is the ammonia spraying amount required to be set by the ammonia spraying branch pipe in the area, the opening regulating valve is regulated by a controller, the accurate setting and control of the ammonia spraying amount are realized, meanwhile, the actual ammonia spraying amount of the ammonia spraying branch pipe in the area is monitored by a flowmeter, if the deviation between the monitored ammonia injection amount and the set value is smaller than the allowable deviation range, the ammonia injection amount regulating valve is kept set, the ammonia injection amount is stabilized, and if the deviation between the monitored ammonia injection amount and the set value is larger than the allowable deviation range, continuously adjusting the ammonia injection regulating valve until the deviation between the monitored ammonia injection amount and the set value is smaller than the allowable deviation range.
Evaluating whether the ammonia spraying amount in the corresponding ammonia spraying unit is proper or not by utilizing the ammonia concentration measured in each area, if the ammonia concentration of a certain monitored ammonia spraying unit exceeds the required ammonia spraying amount, indicating that the ammonia spraying amount in the corresponding ammonia spraying distribution area is too large, reducing the ammonia spraying amount by the corresponding calculation model, and automatically adjusting the ammonia spraying amount by an ammonia spraying adjusting valve until the concentration value of the monitored ammonia reaches the required ammonia spraying amount requirement; if the ammonia concentration in a certain distribution area is lower than the required ammonia spraying amount, the ammonia spraying amount in the ammonia spraying distribution area corresponding to the certain distribution area is insufficient, the corresponding calculation model is increased aiming at the ammonia spraying amount, and the ammonia spraying amount is adjusted by automatically adjusting an ammonia spraying adjusting valve until the monitored ammonia concentration value reaches the required ammonia spraying amount requirement, so that the condition that the ammonia spraying and the nitrogen oxide have enough complete reaction is ensured.
From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: by adopting the arrangement mode of the I-shaped branch pipes and the X-shaped distributor, the ammonia spraying amount of each nozzle in each independent subarea can be uniformly distributed, the ammonia gas speed and pressure of each nozzle can be uniformly distributed, the flue gas and the ammonia gas can be uniformly mixed, and the phenomenon of ammonia escape caused by overlarge local ammonia gas concentration can be eliminated.
The above description is only for the specific embodiments of the present invention, and the scope of the present invention can not be limited by the embodiments, so that the replacement of the equivalent components or the equivalent changes and modifications made according to the protection scope of the present invention should still belong to the scope covered by the present patent. In addition, the utility model provides an between technical feature and the technical feature, between technical feature and the technical scheme, all can the independent assortment use between technical scheme and the technical scheme.

Claims (10)

1. The utility model provides a denitration exhaust-heat boiler, a serial communication port, including exhaust-heat boiler casing (71), high pressure evaporimeter (72), medium pressure evaporimeter (73), spout ammonia equipartition device (74), flue (75) and chimney (76), high pressure evaporimeter (72) and medium pressure evaporimeter (73) interval set up in exhaust-heat boiler casing (71), it is located between high pressure evaporimeter (72) and medium pressure evaporimeter (73) to spout ammonia equipartition device (74), flue (75) are close to high pressure evaporimeter (72) one side with exhaust-heat boiler casing (71) and are connected, chimney (76) are close to medium pressure evaporimeter (73) one side with exhaust-heat boiler casing (71) and are connected, wherein, spout ammonia equipartition device (74) and include:
an ammonia injection main pipe (10);
the inlet of the ammonia spraying branch pipe group (11) is communicated with the ammonia spraying main pipe (10);
the ammonia spraying device comprises an I-shaped branch pipe (12) and a plurality of ammonia spraying branch pipes, wherein the I-shaped branch pipe (12) is provided with a first inlet and a plurality of first outlets, the first inlet is positioned at the symmetrical center of the I-shaped branch pipe (12), the first outlets correspond to the end parts of the I-shaped branch pipe (12) one by one, and the outlets of an ammonia spraying branch pipe group (11) are connected with the first inlets;
a plurality of X-shaped distributors (13) connected with the first outlets in a one-to-one correspondence manner, wherein each X-shaped distributor (13) comprises a second inlet and a plurality of second outlets, the second inlet is positioned at the symmetrical center of the X-shaped distributor (13), the second outlets are in one-to-one correspondence with the end parts of the X-shaped distributor (13), and the second inlet of each X-shaped distributor (13) is communicated with the corresponding first outlet;
and each second outlet is correspondingly connected with one nozzle (14).
2. The denitration exhaust-heat boiler of claim 1, characterized in that the ammonia injection main pipe (10) comprises a first main pipe (101), a second main pipe (102), a third main pipe (103) and a fourth main pipe (104) which are connected in sequence, the inner diameter of the first main pipe (101) is larger than that of the second main pipe (102), the inner diameter of the second main pipe (102) is larger than that of the third main pipe (103), and the inner diameter of the third main pipe (103) is larger than that of the fourth main pipe (104).
3. The denitration exhaust-heat boiler of claim 2, characterized in that the first main pipe (101), the second main pipe (102), the third main pipe (103) and the fourth main pipe (104) are respectively provided with an ammonia injection branch pipe group (11), and the ammonia injection branch pipe group (11) comprises:
the ammonia spraying distribution pipe (111) is provided with an ammonia spraying distribution pipe inlet and a plurality of ammonia spraying distribution pipe outlets, and the ammonia spraying distribution pipe inlet is connected with the corresponding ammonia spraying main pipe (10);
a plurality of ammonia injection branch pipe bodies (112), inlets of which are correspondingly connected with outlets of the ammonia injection distribution pipes one by one;
and inlets of the plurality of partition branch pipes (113) are correspondingly connected with outlets of the plurality of ammonia injection branch pipe bodies (112) one by one, and each partition branch pipe (113) is connected to the corresponding first inlet.
4. The denitration exhaust-heat boiler of claim 3, characterized in that the inlet end side of the first main pipe (101) is provided with a first regulating valve (15), and a second regulating valve (17) is arranged between each ammonia injection distribution pipe (111) and the corresponding ammonia injection main pipe (10).
5. The denitration exhaust-heat boiler of claim 4, characterized in that, the ammonia injection uniform distribution device further comprises a control component, and the control component is connected with the first regulating valve (15) and the second regulating valve (17).
6. The denitration exhaust heat boiler of claim 1, wherein the nozzle (14) comprises:
a circular truncated cone-shaped nozzle (141) having a small diameter end connected to the second outlet;
the arc-shaped guide plate (142) is fixedly connected with the large-diameter end of the circular truncated cone-shaped spray pipe (141) through the circular seam supporting piece (143).
7. The denitration exhaust-heat boiler of claim 6, characterized in that the nozzle (14) further comprises a flow equalizing plate (144) having a plurality of through holes spaced uniformly, and the outer wall of the flow equalizing plate (144) is fixedly connected with the inner wall of the large diameter end of the truncated cone-shaped nozzle (141).
8. The denitration exhaust-heat boiler of claim 6, characterized in that the circumferential seam support (143) comprises a top edge, a bottom edge and an inner side edge, the top edge is connected with the arc-shaped guide plate (142), the bottom edge is connected with the large diameter end of the truncated cone-shaped nozzle (141), and the inner side edge is parallel to the central line of the truncated cone-shaped nozzle (141).
9. The denitration exhaust-heat boiler of claim 1, characterized in that the denitration exhaust-heat boiler further comprises a catalyst layer (77) disposed between the ammonia injection equi-distribution device (74) and the medium-pressure evaporator (73).
10. The denitration exhaust-heat boiler of claim 9, further comprising:
the nitrogen oxide detection unit (78) is arranged between the high-pressure evaporator (72) and the ammonia spraying uniform distribution device (74);
an ammonia gas detection unit (79) provided between the catalyst layer (77) and the medium-pressure evaporator (73);
and the smoke detection unit (80) is arranged at the inlet of the chimney (76).
CN202022983432.2U 2020-12-14 2020-12-14 Denitration exhaust-heat boiler Active CN214051165U (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112657334A (en) * 2020-12-14 2021-04-16 中冶京诚工程技术有限公司 Denitration exhaust-heat boiler
CN115854367A (en) * 2023-02-15 2023-03-28 山西鑫瑞华机电设备有限公司 Sled dress formula VOC exhaust-gas treatment equipment

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112657334A (en) * 2020-12-14 2021-04-16 中冶京诚工程技术有限公司 Denitration exhaust-heat boiler
CN112657334B (en) * 2020-12-14 2024-04-16 中冶京诚工程技术有限公司 Denitration waste heat boiler
CN115854367A (en) * 2023-02-15 2023-03-28 山西鑫瑞华机电设备有限公司 Sled dress formula VOC exhaust-gas treatment equipment

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