Waste heat boiler coupling tail gas system

Abstract

The invention relates to a waste heat boiler coupling tail gas system, which belongs to the technical field of waste heat boilers, and comprises an inlet flue gas control module (1), a combustor (3), a waste heat boiler hearth (400), an air feeder (8), an induced draft fan (9), a first console (6), a second console (5) and a tail gas control module (7), a plurality of heat exchangers are arranged in the waste heat boiler hearth (400), and a smoke inlet (2), a smoke outlet, a tail gas inlet, a cold air inlet, a heat exchange medium inlet and a heat exchange medium outlet are formed in the waste heat boiler hearth (400); the inlet flue gas control module (1) is connected with the flue gas inlet (2); the first console (6) is connected with the cold air inlet and the air feeder (8), and is connected with the heat exchanger through the cold air inlet; and the second console (5) is connected with the heat exchange medium inlet and is connected with the heat exchanger through the heat exchange medium inlet. According to the system, high-temperature flue gas waste heat and tail gas are efficiently utilized, and emission pollution is reduced.

Description

Technical Field

[0001] This invention relates to the field of waste heat boiler technology, and in particular to a waste heat boiler coupled with exhaust gas system. Background Technology

[0002] In modern industrial processes, different devices produce byproduct gases with varying properties:

[0003] One type is high-temperature flue gas (such as the 400-600℃ flue gas discharged from catalytic cracking units), which carries a large amount of sensible heat; the other type is tail gas containing combustible components (such as the tail gas containing 15%-20% carbon monoxide produced by coking units), which contains chemical energy.

[0004] Traditional treatment methods for these two types of by-product gases have significant drawbacks: 1. High-temperature flue gas is often cooled by direct water spraying, which not only wastes sensible heat (each 100°C drop is equivalent to a 2.5% loss of heat energy), but also increases the volume of flue gas due to water evaporation, thus increasing the load on subsequent treatment; 2. Combustible exhaust gases are usually released directly or flared, which neither recovers chemical energy (each cubic meter of CO exhaust gas can release about 3MJ of heat when burned) nor can it generate secondary pollution due to incomplete combustion.

[0005] In summary, existing technologies result in low energy efficiency, high operating costs (requiring additional water and electricity resources to treat waste gas), and difficulties in pollutant control (decentralized treatment increases regulatory complexity). Particularly for small and medium-sized chemical industrial parks, treating waste gas from multiple units separately would significantly increase equipment investment and land occupation. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a waste heat boiler coupled with exhaust gas system.

[0007] A waste heat boiler coupled with exhaust gas system includes an inlet flue gas control module, a burner, a waste heat boiler furnace, a forced draft fan, an induced draft fan, a first control console, a second control console, and an exhaust gas control module. The waste heat boiler furnace is equipped with multiple heat exchangers and includes a flue gas inlet, a flue gas outlet, an exhaust gas inlet, a cold air inlet, a heat exchange medium inlet, and a heat exchange medium outlet. The inlet flue gas control module is connected to the flue gas inlet. The induced draft fan is connected to the flue gas outlet. The exhaust gas control module is connected to the exhaust gas inlet and, through the exhaust gas inlet, to the heat exchangers. The first control console is connected to the cold air inlet and the forced draft fan, and, through the cold air inlet, to the heat exchangers. The second control console is connected to the heat exchange medium inlet and, through the heat exchange medium inlet, to the heat exchangers. The burner is connected to the waste heat boiler furnace and the heat exchangers.

[0008] Furthermore, the waste heat boiler furnace has an inverted U-shaped structure, with the burner connected to the left side of the waste heat boiler furnace and the heat exchanger located inside the right side of the waste heat boiler furnace.

[0009] Furthermore, on the right side of the waste heat boiler furnace, from top to bottom, are the heat exchange medium outlet, heat exchange medium inlet, cold air inlet, exhaust gas inlet, and flue gas outlet.

[0010] Furthermore, the heat exchanger includes a first heat exchanger, a second heat exchanger, a third heat exchanger, and a fourth heat exchanger; the first heat exchanger is connected to the heat exchange medium outlet; the second heat exchanger is connected to the heat exchange medium inlet; the first heat exchanger is connected to the second heat exchanger; the third heat exchanger is connected to the cold air inlet and the burner; and the fourth heat exchanger is connected to the exhaust gas inlet and the burner.

[0011] Furthermore, the induced draft fan is connected to a flue gas treatment module or a chimney.

[0012] The beneficial effects of this invention are reflected in:

[0013] 1. The utilization of waste heat from high-temperature flue gas improves energy utilization efficiency;

[0014] 2. The combustible exhaust gas is coupled with a waste heat boiler, which enables the reuse of exhaust gas and saves energy;

[0015] 3. The flue gas exhaust is reused to generate steam needed for industrial equipment, thus achieving recycling;

[0016] 4. After coupled combustion, pollutants such as NOx and SO2 can be effectively treated and reduced. Attached Figure Description

[0017] Figure 1 This is a system structure diagram of the present invention;

[0018] Figure descriptions: 1. Inlet flue gas control module; 2. Flue gas inlet; 3. Burner; 400. Waste heat boiler furnace; 401. First heat exchanger; 402. Second heat exchanger; 403. Third heat exchanger; 404. Fourth heat exchanger; 5. Second control console; 6. First control console; 7. Exhaust gas control module; 8. Forced draft fan; 9. Exhaust draft fan. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Reference Figure 1As shown in the figure, this application provides a waste heat boiler coupled with exhaust gas system, including an inlet flue gas control module 1, a burner 3, a waste heat boiler furnace 400, a forced draft fan 8, an induced draft fan 9, a first control console 6, a second control console 5, and an exhaust gas control module 7. The waste heat boiler furnace 400 is internally equipped with multiple heat exchangers and includes a flue gas inlet 2, a flue gas outlet, an exhaust gas inlet, a cold air inlet, a heat exchange medium inlet, and a heat exchange medium outlet. The inlet flue gas control module 1 is connected to the flue gas inlet 2; the induced draft fan 9 is connected to the flue gas outlet; the exhaust gas control module 7 is connected to the exhaust gas inlet and, through the exhaust gas inlet, to the heat exchangers; the first control console 6 is connected to the cold air inlet and the forced draft fan 8, and, through the cold air inlet, to the heat exchangers; the second control console 5 is connected to the heat exchange medium inlet and, through the heat exchange medium inlet, to the heat exchangers; the burner 3 is connected to the waste heat boiler furnace 400 and the heat exchangers. The exhaust outlet of the induced draft fan 9 is connected to a flue gas treatment module or a chimney.

[0021] In this embodiment, the waste heat boiler furnace 400 adopts an inverted U-shaped structure. The burner 3 is connected to the left side of the waste heat boiler furnace 400, and the heat exchanger is located inside the right side of the waste heat boiler furnace 400. From top to bottom, the right side of the waste heat boiler furnace 400 consists of a heat exchange medium outlet, a heat exchange medium inlet, a cold air inlet, a tail gas inlet, and a flue gas outlet.

[0022] In this embodiment, the heat exchanger includes a first heat exchanger 401, a second heat exchanger 402, a third heat exchanger 403, and a fourth heat exchanger 404; the first heat exchanger 401 is connected to the heat exchange medium outlet; the second heat exchanger 402 is connected to the heat exchange medium inlet; the first heat exchanger 401 and the second heat exchanger 402 are connected; the third heat exchanger 403 is connected to the cold air inlet and the burner 3; and the fourth heat exchanger 404 is connected to the exhaust gas inlet and the burner 3.

[0023] In this embodiment, the first heat exchanger 401 and the second heat exchanger 402 are designed in series to form the main steam generation system. The first stage preheats the feedwater to saturation, and the second stage completes evaporation and superheating, with the pressure level matching industrial requirements. The third heat exchanger 403 is specifically used to preheat the combustion air, heating the cold air before delivering it to the burner 3, thereby improving combustion efficiency. The fourth heat exchanger 404 is located in the exhaust gas preheating section, preheating the combustible exhaust gas to above its ignition point before injecting it into the burner 3, ensuring stable combustion and reducing the generation of harmful gases.

[0024] In this embodiment, the first control console 6 dynamically adjusts the air supply volume by monitoring the flue gas temperature in real time (by arranging thermocouples at key points in the furnace), ensuring that the wall temperature of the heat exchange surface is always higher than the acid dew point, effectively preventing low-temperature corrosion. The second control console 5 controls the flow rate of the heat exchange medium (such as water) to keep the steam production fluctuation range within a reasonable range.

[0025] In this embodiment, based on the temperature, pressure, and flow rate parameters of various waste gases, including high-temperature flue gas and combustible tail gas, generated by different chemical plants, a waste heat boiler with appropriate pressure and flow rates is designed. Simultaneously, the waste gases from different chemical plants are comprehensively treated in a single boiler, which not only expands the boiler capacity but also allows the generated steam to be used for industrial applications or power generation, thus improving the overall energy utilization rate of the system. It effectively utilizes not only the sensible heat of the high-temperature flue gas but also the chemical energy in the combustible tail gas. Furthermore, it decomposes harmful components in the tail gas through high-temperature combustion. Depending on the tail gas composition, if combustion may produce pollutants such as SO2 and NOx, simply adding appropriate high-efficiency desulfurization and denitrification equipment to the boiler can achieve pollution-free emissions.

[0026] In the description of embodiments of the present invention, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of embodiments of the present invention, the term "and / or" is used only to describe the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " generally indicates that the preceding and following associated objects are in an "or" relationship.

[0028] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waste heat boiler coupled with exhaust gas system, characterized in that, The system includes an inlet flue gas control module (1), a burner (3), a waste heat boiler furnace (400), a blower (8), an induced draft fan (9), a first control console (6), a second control console (5), and a tail gas control module (7). The waste heat boiler furnace (400) is equipped with multiple heat exchangers and includes a flue gas inlet (2), a flue gas outlet, a tail gas inlet, a cold air inlet, a heat exchange medium inlet, and a heat exchange medium outlet. The inlet flue gas control module (1) is connected to the flue gas inlet (2). The induced draft fan (9) is connected to the flue gas outlet. The tail gas control module (7) is connected to the tail gas inlet and is connected to the heat exchanger through the tail gas inlet. The first control console (6) is connected to the cold air inlet and the blower (8) and is connected to the heat exchanger through the cold air inlet. The second control console (5) is connected to the heat exchange medium inlet and is connected to the heat exchanger through the heat exchange medium inlet. The burner (3) is connected to the waste heat boiler furnace (400) and the heat exchanger.

2. The waste heat boiler coupled tail gas system according to claim 1, characterized in that, The waste heat boiler furnace (400) has an inverted U-shaped structure. The burner (3) is connected to the left side of the waste heat boiler furnace (400), and the heat exchanger is located inside the right side of the waste heat boiler furnace (400).

3. The waste heat boiler coupled tail gas system according to claim 1, characterized in that, The waste heat boiler furnace (400) has, from top to bottom, heat exchange medium outlet, heat exchange medium inlet, cold air inlet, tail gas inlet and flue gas outlet on the right side.

4. The waste heat boiler coupled tail gas system according to claim 1, characterized in that, The heat exchangers include a first heat exchanger (401), a second heat exchanger (402), a third heat exchanger (403), and a fourth heat exchanger (404); the first heat exchanger (401) is connected to the heat exchange medium outlet; the second heat exchanger (402) is connected to the heat exchange medium inlet; the first heat exchanger (401) and the second heat exchanger (402) are connected; the third heat exchanger (403) is connected to the cold air inlet and the burner (3); the fourth heat exchanger (404) is connected to the exhaust gas inlet and the burner (3).

5. A waste heat boiler coupled with tail gas system according to claim 1, characterized in that, The induced draft fan (9) is connected to the flue gas treatment module or the chimney.

Images