Integrated energy-saving SCR (selective catalytic reduction) system for waste incineration flue gas

Abstract

The utility model belongs to the technical field of household garbage flue gas treatment, and particularly relates to an integrated energy-saving SCR (Selective Catalytic Reduction) system for garbage incineration flue gas. The waste incineration flue gas integrated energy-saving SCR system comprises a support, and a flue gas inlet pipeline, a GGH heat exchanger, an SGH heat exchanger, a reactor inlet pipeline, a reactor and a flue gas outlet pipeline which are arranged on the support. The GGH heat exchanger can exchange heat with the denitrated flue gas, the flue gas before denitration is preheated, the steam consumed by the SGH heat exchanger is reduced, and the operation cost is saved; due to heat exchange of the GGH heat exchanger, the temperature of flue gas discharged by the system is reduced after denitration, so that the utilization rate of overall energy is increased; the integrated GGH heat exchanger and the reactor save the space, reduce the consumption of steel structures and flue gas pipelines, and reduce the cost of a newly added waste heat utilization system.

Description

Technical Field

[0001] The utility model belongs to the technical field of domestic waste flue gas treatment, and specifically relates to an integrated energy-saving SCR system for waste incineration flue gas. Background Art

[0002] Waste incineration, as an effective waste disposal method, not only reduces the volume of waste but also generates energy through the incineration process. However, this process is accompanied by the emission of harmful gases such as nitrogen oxides (NOx), posing a challenge to the environment. To address this issue, the waste incineration industry has begun to introduce SCR (Selective Catalytic Reduction) technology. Selective Catalytic Reduction (SCR) is a process for treating NOx in flue gas emissions. In this process, a reducing agent, ammonia or urea, is injected over a catalyst to reduce NOx in the exhaust gas to N2 and H2O.

[0003] In existing SCR flue gas treatment systems, flue gas is heated to the optimum temperature for the catalytic reaction by the SGH system (steam direct heating system), then passes through the catalyst layer and directly enters the next system. This approach consumes a lot of steam to heat the flue gas before it enters the catalyst layer, and the flue gas temperature at the SCR system outlet is high, resulting in inefficient energy utilization. Furthermore, the existing SCR system is arranged horizontally, occupying a large area. Utility Model Content

[0004] The purpose of the utility model is to provide an integrated energy-saving SCR system for waste incineration flue gas, so as to solve the technical problems in the existing SCR flue gas treatment system that a lot of steam is consumed in heating the flue gas before it enters the catalyst layer, the flue gas temperature at the outlet of the SCR system is high, and energy is not effectively utilized.

[0005] The present application provides an integrated energy-saving SCR system for waste incineration flue gas. The integrated energy-saving SCR system for waste incineration flue gas includes:

[0006] The bracket, and the flue gas inlet pipeline, GGH heat exchanger, SGH heat exchanger, reactor inlet pipeline, reactor, and flue gas outlet pipeline installed on the bracket;

[0007] The flue gas inlet pipeline is connected to the shell side inlet of the GGH heat exchanger, and the shell side outlet of the GGH heat exchanger is connected to the SGH heat exchanger and the reactor inlet pipeline in sequence;

[0008] The outlet of the reactor is communicated with the tube side inlet of the GGH heat exchanger, and the tube side outlet of the GGH heat exchanger is communicated with the flue gas outlet pipeline.

[0009] In one embodiment of the present application, the waste incineration flue gas integrated energy-saving SCR system further includes a flue gas bypass pipe;

[0010] The flue gas bypass pipe is connected to the flue gas inlet pipe and the flue gas outlet pipe;

[0011] The flue gas bypass pipe is provided with a first control valve.

[0012] In one embodiment of the present application, a second control valve is provided at the connection point between the tube side outlet of the GGH heat exchanger and the flue gas outlet pipeline.

[0013] In one embodiment of the present application, the bracket includes a first column and a second column arranged in parallel;

[0014] The flue gas inlet pipeline, SGH heat exchanger, and reactor inlet pipeline are arranged in the first row and arranged in sequence from bottom to top;

[0015] The reactor, GGH heat exchanger, and flue gas outlet pipeline are arranged in the second row and arranged in sequence from top to bottom.

[0016] The beneficial effects of the present invention are as follows: the integrated energy-saving SCR system for waste incineration flue gas comprises a bracket, a flue gas inlet pipeline, a GGH heat exchanger, an SGH heat exchanger, a reactor inlet pipeline, a reactor, and a flue gas outlet pipeline mounted on the bracket. The GGH heat exchanger can exchange heat with the flue gas after denitration, preheating the flue gas before denitration, reducing steam consumption by the SGH heat exchanger and saving operating costs. The heat exchange of the denitration flue gas by the GGH heat exchanger reduces the exhaust temperature of the system, thereby improving overall energy utilization. The integrated GGH heat exchanger and reactor save space, reduce the use of steel structures and flue gas piping, and reduce the cost of adding a new waste heat utilization system.

[0017] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1It is a schematic diagram of the utility model of the integrated energy-saving SCR system for waste incineration flue gas.

[0021] In the picture:

[0022] Flue gas inlet pipeline 1, GGH heat exchanger 2, SGH heat exchanger 3, reactor inlet pipeline 4, reactor 5, flue gas outlet pipeline 6, second control valve 61, flue gas bypass pipe 7, first control valve 71, bracket 100, first column 101, second column 102. DETAILED DESCRIPTION

[0023] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0024] Glossary:

[0025] SGH heat exchanger: Steam-flue gas heat exchanger (SGH) is a shell and tube heat exchanger. The flowing medium in the shell side is flue gas, the medium on the inlet tube side is low-pressure saturated or supersaturated steam, and the medium on the outlet tube side is saturated water. The latent heat of vaporization of steam is used to heat the flue gas.

[0026] GGH heat exchanger: The GGH heat exchanger for incineration flue gas, also known as a flue gas-to-flue gas heat exchanger, primarily utilizes heat exchange between high-temperature flue gas and low-temperature flue gas to achieve heat recovery and reuse. In the incinerator system, the high-temperature flue gas passes through the GGH heat exchanger in countercurrent contact with the low-temperature flue gas, transferring heat to the low-temperature flue gas, thereby lowering the temperature of the high-temperature flue gas and raising the temperature of the low-temperature flue gas, achieving the goal of energy conservation and emission reduction.

[0027] This application provides an integrated energy-saving SCR system for waste incineration flue gas, which is described in detail below. It should be noted that the order of description of the following embodiments does not limit the preferred order of the embodiments of this application. In the following embodiments, the description of each embodiment has its own focus. For parts not detailed in one embodiment, please refer to the relevant description of other embodiments.

[0028] See also Figure 1In one embodiment of the present application, an integrated energy-saving SCR system for waste incineration flue gas includes: a bracket 100, and a flue gas inlet pipeline 1, a GGH heat exchanger 2, an SGH heat exchanger 3, a reactor inlet pipeline 4, a reactor 5, and a flue gas outlet pipeline 6 installed on the bracket 100; wherein the flue gas inlet pipeline 1 is connected to the shell-side inlet of the GGH heat exchanger 2, and the shell-side outlet of the GGH heat exchanger 2 is connected to the SGH heat exchanger 3 and the reactor inlet pipeline 4 in sequence; the outlet of the reactor 5 is connected to the tube-side inlet of the GGH heat exchanger 2, and the tube-side outlet of the GGH heat exchanger 2 is connected to the flue gas outlet pipeline 6.

[0029] In this embodiment, flue gas first enters GGH heat exchanger 2 via flue gas inlet pipe 1, exchanging heat with the denitrified flue gas discharged from reactor 5, thereby raising the temperature of the pre-denitrified flue gas. The pre-denitrified flue gas from GGH heat exchanger 2 is then fed into SGH heat exchanger 3 for heating, further raising its temperature. After being heated to a suitable temperature for the catalytic reaction by SGH heat exchanger 3, the pre-denitrified flue gas is fed into the reactor via reactor inlet pipe 4 for denitrification. The denitrified flue gas then flows into GGH heat exchanger 2, exchanging heat with the pre-denitrified flue gas, preheating the pre-denitrified flue gas and reducing the temperature of the denitrified flue gas.

[0030] In this embodiment, the reactor 5 is an SCR reactor, and a catalyst is arranged inside the reactor.

[0031] In one application scenario, the inlet flue gas temperature entering from the flue gas inlet pipe 1 can be 145°C; after heat exchange in the GGH heat exchanger 2, it is raised to 164°C; then after passing through the SGH heat exchanger 3, it is raised to 175°C and enters the reactor 5; the flue gas after the denitrification reaction is heat exchanged with the flue gas before denitrification through the GGH heat exchanger 2, and the temperature of the flue gas after denitrification is reduced from 170°C to 150°C before being discharged.

[0032] It should be noted that the structures of the GGH heat exchanger 2, SGH heat exchanger 3 and SCR reactor in this embodiment are improved, and those skilled in the art can purchase the above-mentioned heat exchangers or reactors on the market.

[0033] In this embodiment, optionally, the integrated energy-saving SCR system for waste incineration flue gas further includes a flue gas bypass pipe 7 ; the flue gas bypass pipe 7 connects the flue gas inlet pipe 1 and the flue gas outlet pipe 6 ; and a first control valve 71 is provided on the flue gas bypass pipe 7 .

[0034] Furthermore, a second control valve 61 is provided at the connection point between the tube outlet of the GGH heat exchanger 2 and the flue gas outlet pipeline 6 .

[0035] In some application scenarios, the first control valve 71 may be opened and the second control valve 61 may be closed, so that the flue gas is discharged directly from the flue gas outlet pipeline 6 .

[0036] In order to save equipment space, in this embodiment, preferably, the bracket 100 includes a first column 101 and a second column 102 arranged in parallel; the flue gas inlet pipeline 1, the SGH heat exchanger 3, and the reactor inlet pipeline 4 are arranged in the first column 101 and arranged in sequence from bottom to top; the reactor 5, the GGH heat exchanger 2, and the flue gas outlet pipeline 6 are arranged in the second column 102 and arranged in sequence from top to bottom.

[0037] In this embodiment, the flue gas inlet pipeline 1 and the flue gas outlet pipeline 6 can effectively utilize the width of the bracket 100, and the reactor 5, the GGH heat exchanger 2, and the SGH heat exchanger 3 can fully utilize the longitudinal space.

[0038] In summary, the integrated energy-saving SCR system for waste incineration flue gas of the present invention includes heat exchange with the flue gas after denitrification through the GGH heat exchanger. The flue gas before denitrification is preheated, and the steam consumption of the SGH heat exchanger is reduced, saving operating costs; the flue gas after denitrification is cooled by the heat exchange of the GGH heat exchanger, which reduces the exhaust temperature of the system, thereby improving the overall energy utilization rate; the integrated GGH heat exchanger and reactor save space, reduce the use of steel structures and flue gas pipelines, and reduce the cost of the new waste heat utilization system.

[0039] The various devices selected in this application (components whose specific structures are not described) are all universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0040] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection.

[0041] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] Based on the above-mentioned ideal embodiment of the present invention, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. An integrated energy-saving SCR system for waste incineration flue gas, characterized in that: include: A support (100), and a flue gas inlet pipeline (1), a GGH heat exchanger (2), an SGH heat exchanger (3), a reactor inlet pipeline (4), a reactor (5), and a flue gas outlet pipeline (6) installed on the support (100); wherein The flue gas inlet pipeline (1) is connected to the shell side inlet of the GGH heat exchanger (2), and the shell side outlet of the GGH heat exchanger (2) is connected to the SGH heat exchanger (3) and the reactor inlet pipeline (4) in sequence; The outlet of the reactor (5) is communicated with the tube-side inlet of the GGH heat exchanger (2), and the tube-side outlet of the GGH heat exchanger (2) is communicated with the flue gas outlet pipeline (6).

2. The integrated energy-saving SCR system for waste incineration flue gas according to claim 1 is characterized in that: Also includes a flue gas bypass pipe (7); The flue gas bypass pipe (7) is connected to the flue gas inlet pipe (1) and the flue gas outlet pipe (6); The flue gas bypass pipe (7) is provided with a first control valve (71).

3. The integrated energy-saving SCR system for waste incineration flue gas according to claim 2 is characterized in that: A second control valve (61) is provided at the connection point between the tube-side outlet of the GGH heat exchanger (2) and the flue gas outlet pipeline (6).

4. The integrated energy-saving SCR system for waste incineration flue gas according to claim 1 is characterized in that: The bracket (100) includes a first column (101) and a second column (102) arranged in parallel; The flue gas inlet pipeline (1), the SGH heat exchanger (3), and the reactor inlet pipeline (4) are arranged in the first row (101) and arranged in sequence from bottom to top; The reactor (5), the GGH heat exchanger (2), and the flue gas outlet pipeline (6) are arranged in the second row (102) and arranged in sequence from top to bottom.

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