System and method for producing ammonia by coupling waste heat of flue gas of ammonium bicarbonate pyrolysis device and boiler

Abstract

The invention discloses an ammonium bicarbonate pyrolysis device coupled boiler flue gas waste heat ammonia production system and method, a smoke suction port on a boiler tail flue is communicated with a heat release side inlet of an internal heating type rotary pyrolysis reactor, and an outlet of an ammonium bicarbonate bin is communicated with a heat absorption side inlet of the internal heating type rotary pyrolysis reactor; a heat absorption side outlet of the internal heat type rotary pyrolysis reactor is communicated with an inlet of a condenser, a gas outlet of the condenser is communicated with an inlet of a mixer through a fan, an outlet of the mixer is communicated with an inlet of an SCR reactor in a boiler tail flue, a heat exchange pipe is arranged in the boiler tail flue, and the SCR reactor is communicated with the heat exchange pipe. An inlet of the heat exchange pipe is communicated with the external environment, an outlet of the heat exchange pipe is communicated with an inlet of the mixer, and the system and the method can efficiently utilize ammonium bicarbonate to prepare ammonia gas.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection, and relates to an ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat to produce ammonia system and method. Background Art

[0002] At present, the commonly used reducing agents in the denitrification system of thermal power plants include liquid ammonia, ammonia water and urea. Liquid ammonia, as a Class B hazardous substance stipulated by the state, has major safety hazards; although ammonia water is relatively safe, it has high transportation costs and requires large storage equipment; the investment and operation costs of the urea system are relatively high, and the system energy consumption is large. In order to improve safety and economy, and at the same time respond to the country's requirements for comprehensive management and transformation of hazardous chemicals in the power industry, it is urgent to develop new denitrification reducing agent preparation technology.

[0003] Ammonium bicarbonate is the second largest nitrogen fertilizer in my country after urea. It has a wide source and is inexpensive. It is stored in solid particles at room temperature and pressure, and there is no safety problem. More importantly, ammonium bicarbonate can begin to decompose and produce ammonia at around 100°C, and the pyrolysis rate increases rapidly with increasing temperature. These characteristics make ammonium bicarbonate a potential ideal substitute. However, there is currently a lack of industrial technology solutions for the efficient use of ammonium bicarbonate to prepare ammonia, especially how to organically combine it with the existing system of thermal power plants to achieve efficient use of energy. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a system and method for producing ammonia by coupling an ammonium bicarbonate pyrolysis device with boiler flue gas waste heat. The system and method can efficiently utilize ammonium bicarbonate to prepare ammonia.

[0005] To achieve the above-mentioned purpose, the present invention discloses an ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system, comprising a boiler tail flue, an internal heat rotary pyrolysis reactor, an ammonium bicarbonate silo, a condenser, a fan and a mixer;

[0006] The smoke extraction port on the boiler tail flue is connected to the heat release side inlet of the internal heating rotary pyrolysis reactor, the outlet of the ammonium bicarbonate silo is connected to the heat absorption side inlet of the internal heating rotary pyrolysis reactor, the heat absorption side outlet of the internal heating rotary pyrolysis reactor is connected to the inlet of the condenser, the gas outlet of the condenser is connected to the inlet of the mixer via the fan, the outlet of the mixer is connected to the inlet of the SCR reactor in the boiler tail flue, a heat exchange tube is arranged in the boiler tail flue, the inlet of the heat exchange tube is connected to the external environment, and the outlet of the heat exchange tube is connected to the inlet of the mixer.

[0007] The further improvement of the ammonium bicarbonate pyrolysis device coupled with the boiler flue gas waste heat ammonia production system of the present invention is:

[0008] Furthermore, the internal heat rotary pyrolysis reactor includes a shell and a plurality of heat transfer tubes, wherein each heat transfer tube is connected to the smoke outlet, the inlet of the shell is connected to the ammonium bicarbonate silo, and the outlet of the shell is connected to the condenser.

[0009] Furthermore, the heat transfer tubes are arranged and distributed in parallel.

[0010] Furthermore, the drain port of the condenser is connected to an external boiler water supply system.

[0011] Furthermore, the heat exchange tube and the air preheater are placed side by side.

[0012] Furthermore, the heat release side outlet of the internal heat rotary pyrolysis reactor is connected to the inlet of the external dry dust collector.

[0013] Furthermore, the outlet of the ammonium bicarbonate silo is connected to the heat absorption side inlet of the internal heating rotary pyrolysis reactor via a powder conveyor.

[0014] The invention discloses a method for producing ammonia by coupling an ammonium bicarbonate pyrolysis device with boiler flue gas waste heat, comprising the following steps:

[0015] The ammonium bicarbonate particles enter the internal heating rotary pyrolysis reactor and move downward under the rotation of the cylinder. At the same time, the high-temperature flue gas enters the heat transfer tube from the center axis of the cylinder. As the cylinder rotates, the ammonium bicarbonate particles in the heat transfer tube are constantly turned over to enhance the heat transfer effect. The generated ammonia, water vapor and carbon dioxide mixture is discharged from the outlet of the internal heating rotary pyrolysis reactor and sent to the boiler denitrification system for use after dust removal and condensation.

[0016] The further improvement of the method for producing ammonia by coupling the ammonium bicarbonate pyrolysis device with boiler flue gas waste heat of the present invention is:

[0017] Furthermore, the dimension design formula of the internal heating rotary pyrolysis reactor is:

[0018]

[0019] Wherein, t is the residence time of the material, L is the length of the internal heating rotary pyrolysis reactor, D is the diameter of the internal heating rotary pyrolysis reactor, and γ=0.75.

[0020] Furthermore, the heat transfer tubes are arranged and distributed in parallel.

[0021] The present invention has the following beneficial effects:

[0022] In the specific operation of the ammonium bicarbonate pyrolysis device coupled with the boiler flue gas waste heat ammonia production system and method described in the present invention, ammonium bicarbonate particles enter the internal heating rotary pyrolysis reactor and move downward under the rotation of the cylinder. At the same time, the high-temperature flue gas enters the heat transfer tube from the center axis of the cylinder. As the cylinder rotates, the ammonium bicarbonate particles in the heat transfer tube are constantly turned over to enhance the heat transfer effect, thereby achieving efficient coupling of ammonium bicarbonate pyrolysis and flue gas waste heat of thermal power units, which not only improves the ammonia production efficiency and reduces energy consumption, but also significantly improves the safety and economy of the system. The generated ammonia, water vapor and carbon dioxide mixture is discharged from the outlet of the internal heating rotary pyrolysis reactor, and is sent to the boiler denitration system for use after dust removal and condensation treatment, thereby efficiently utilizing ammonium bicarbonate to prepare ammonia. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 is a system structure diagram of the present invention;

[0025] Figure 2 It is a schematic structural diagram of the internal heating rotary pyrolysis reactor 2 of the present invention;

[0026] Figure 3 This is the structural diagram of the rotary sealing device at the heat source inlet and outlet.

[0027] Among them, 1 is an ammonium bicarbonate silo, 2 is an internal heat rotary pyrolysis reactor, 3 is a condenser, 4 is a fan, 5 is a mixer, and 6 is an SCR reactor. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0030] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0031] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0032] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0033] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0036] Embodiment 1

[0037] refer to Figure 1 , Figure 2 and Figure 3 The ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system of the present invention comprises a boiler tail flue, an ammonium bicarbonate silo 1, an internal heat rotary pyrolysis reactor 2, a condenser 3, a fan 4, a mixer 5 and an SCR reactor 6;

[0038] The smoke extraction port on the flue at the tail end of the boiler is connected to the heat release side inlet of the internal heating rotary pyrolysis reactor 2, and the heat release side outlet of the internal heating rotary pyrolysis reactor 2 is connected to the inlet of the dry dust collector;

[0039] The outlet of the ammonium bicarbonate silo 1 is connected to the inlet of the endothermic side of the internal heating rotary pyrolysis reactor 2 via a powder conveyor, the outlet of the endothermic side of the internal heating rotary pyrolysis reactor 2 is connected to the inlet of the condenser 3, the gas outlet of the condenser 3 is connected to the inlet of the mixer 5 via a fan 4, the outlet of the mixer 5 is connected to the inlet of the SCR reactor 6 in the tail flue of the boiler, and a heat exchange tube is arranged in the tail flue of the boiler, the inlet of the heat exchange tube is connected to the external environment, and the outlet of the heat exchange tube is connected to the inlet of the mixer 5.

[0040] The drain port of the condenser 3 is connected to the boiler feed water system.

[0041] The heat exchange tube and the air preheater are placed side by side.

[0042] Ammonium bicarbonate silo 1: It adopts a sealed design, is equipped with a temperature and humidity control system, and is equipped with a heat exchange pipeline. The low-temperature flue gas discharged from the internal heating rotary pyrolysis reactor 2 is used to slightly heat the ammonium bicarbonate silo 1 to prevent the raw materials from getting damp and agglomerating. A one-way ventilation safety valve is set on the top of the ammonium bicarbonate silo 1 to prevent pressure increase caused by decomposition of a small amount of ammonium bicarbonate.

[0043] Powder conveyor: It adopts a screw conveyor design with anti-clogging function to ensure that the ammonium bicarbonate particles are evenly transported to the internal heating rotary pyrolysis reactor 2.

[0044] Internal heating rotary pyrolysis reactor 2: It adopts an innovative tubular design with multiple parallel heat transfer tubes inside. The outside of the heat transfer tubes is filled with ammonium bicarbonate particles, and the inside of the heat transfer tubes is high-temperature flue gas. The rotation of the cylinder allows the particles to fully contact the heat transfer tubes, thereby improving the heat transfer efficiency.

[0045] In addition, during operation, flue gas at about 280°C is drawn out from the SCR outlet of the thermal power unit and the temperature is reduced to about 120°C through the heat transfer tube.

[0046] Condenser 3: Ammonia is condensed through condenser 3, and the condensed supercooled water enters the boiler feed water system. A mixer 5 is configured to fully mix the pyrolysis ammonia. An ammonia concentration online monitoring device is set to ensure product quality.

[0047] Control system: Distributed control system (DCS) is used to realize full process automation control. It is equipped with intelligent PID control algorithm, optimizes system operation parameters, and sets multiple safety protection mechanisms, including over-temperature alarm, emergency shutdown and other functions.

[0048] The SCR reactor 6 is equipped with an ammonia injection system: an ammonia injection grid is set up according to the requirements of precise ammonia injection modification, and an ammonia flow precision control device is equipped to achieve ammonia injection on demand.

[0049] Embodiment 2

[0050] refer to Figure 1 , Figure 2 and Figure 3 The present embodiment discloses a method for producing ammonia by coupling an ammonium bicarbonate pyrolysis device with waste heat from boiler flue gas. The method for producing ammonia by coupling an ammonium bicarbonate pyrolysis device with waste heat from boiler flue gas is realized based on a system for producing ammonia by coupling an ammonium bicarbonate pyrolysis device with waste heat from boiler flue gas. The system for producing ammonia by coupling an ammonium bicarbonate pyrolysis device with waste heat from boiler flue gas comprises a boiler tail flue, an ammonium bicarbonate silo 1, an internally heated rotary pyrolysis reactor 2, a condenser 3, a fan 4, a mixer 5 and an SCR reactor 6; a smoke extraction port on the boiler tail flue is connected to the internally heated rotary pyrolysis reactor 2. The inlet of the exothermic side is connected, the outlet of the ammonium bicarbonate silo 1 is connected to the inlet of the endothermic side of the internal heating rotary pyrolysis reactor 2, the outlet of the endothermic side of the internal heating rotary pyrolysis reactor 2 is connected to the inlet of the condenser 3, the gas outlet of the condenser 3 is connected to the inlet of the mixer 5 through the fan 4, the outlet of the mixer 5 is connected to the inlet of the SCR reactor 6 in the boiler tail flue, and a heat exchange tube is arranged in the boiler tail flue, the inlet of the heat exchange tube is connected to the external environment, and the outlet of the heat exchange tube is connected to the inlet of the mixer 5.

[0051] Specifically, the method for producing ammonia by coupling the ammonium bicarbonate pyrolysis device with the waste heat of boiler flue gas comprises the following steps:

[0052] The working principle of the present invention is as follows: ammonium bicarbonate particles (particle size 1-3 mm) enter the internal heating rotary pyrolysis reactor 2 and slowly move downward under the rotation of the cylinder. At the same time, high-temperature flue gas enters the heat transfer tube from the center axis of the cylinder. As the cylinder rotates, the ammonium bicarbonate particles in the heat transfer tube are constantly turned over, which enhances the heat transfer effect. Ammonium bicarbonate is pyrolyzed at 120-150°C, and the reaction equation is:

[0053] NH4HCO3→NH3+H2O+CO2

[0054] The generated ammonia, water vapor and carbon dioxide mixture is discharged from the outlet of the internal heating rotary pyrolysis reactor 2, and is sent to the boiler denitration system for use after dust removal and condensation. The entire pyrolysis process is carried out under normal pressure, and the reaction temperature is accurately adjusted by controlling the heat source parameters and the rotation speed of the cylinder to ensure that the conversion rate of ammonium bicarbonate reaches more than 95%.

[0055] Embodiment 3

[0056] refer to Figure 1 , Figure 2 and Figure 3 , this embodiment takes the condition that the ammonia mass flow rate provided by the ammonia production system required by a single 300MW unit is about 170kg / h as an example. With an ammonia production of 170kg / h and a conversion rate of 95% as the target, 832kg / h of ammonium bicarbonate raw material is required, and the feed is fed at normal temperature and pressure (feed temperature 25°C, pressure 1bar). In this embodiment, the feed rate of the rotary inlet is 0.832t / h, and the outlet is 0.17t / h, and the average value is G m =0.5t / h. Set the material filling rate to 15% and the material residence time to 20 minutes. Set the inclination angle of the cylinder to 3° and the rotation speed of the cylinder to 1r / min. Substitute the above known quantities into the size design formula of the internal heating rotary pyrolysis reactor 2.

[0057]

[0058] Among them, γ=0.75, the length L of the internal heating rotary pyrolysis reactor 2 is 6m, the diameter D is 0.75m, and referring to the design regulations of the rotary kiln, the wall thickness of the cylinder is selected to be 8mm.

[0059] The internal heating rotary pyrolysis reactor 2 adopts an innovative tubular design, with multiple parallel heat transfer tubes inside. The outside of the tubes is filled with ammonium bicarbonate particles, and the inside of the tubes is high-temperature flue gas. The rotation of the cylinder allows the particles to fully contact the heat transfer tubes, thereby improving the heat transfer efficiency.

[0060] In addition, the decomposition reaction enthalpy required for the thermal decomposition of ammonium bicarbonate is 167.92 kJ / mol. Taking into account the reaction heat and air temperature rise, the system requires external heating power of about 900 kW.

[0061] Flue gas at about 280°C is drawn out from the SCR outlet of the thermal power unit, and the temperature is reduced to about 120°C through a multi-stage heat exchanger, and then enters the internal heating rotary pyrolysis reactor 2. According to calculations, the required flue gas volume is about 18t / h.

[0062] The heat exchange system adopts an 8-tube pass layout, with a heat transfer tube diameter of φ25×2.5mm, a tube length of 5m, and a tube spacing of 32mm. According to the heat exchange area calculation, 300 heat transfer tubes are required, and 75 rows of 4-tube pass heat transfer tubes are arranged circumferentially.

[0063] To meet the heat exchange area requirements, if space permits, the length L of the internal heating rotary pyrolysis reactor 2 can be increased to 10m, and the pipe diameter can be increased to 1m to simplify the arrangement of the heat transfer pipes inside the pyrolysis device.

[0064] In addition, in this embodiment, a condenser 3 is added to achieve dehumidification, reduce the moisture content in the product ammonia, and improve the ammonia separation efficiency. After the product gas leaves the internal heat rotary pyrolysis reactor 2, it is sent to the mixer 5 through the metering and distribution module to be diluted with hot dilution air, and then sent to the denitrification flue to participate in the denitrification reaction. An online monitoring device for ammonia concentration is provided to ensure product quality.

[0065] The working process of this embodiment is:

[0066] 1) Start: Start the flue gas induced draft fan 4 to introduce the boiler flue gas into the heat exchange system, and at the same time start the rotary drive device to make the cylinder start to rotate.

[0067] 2) Preheating: Use flue gas to gradually heat the rotation until it reaches the working temperature (120-150°C).

[0068] 3) Feeding: Start the ammonium bicarbonate feeding system and feed the material evenly into the internal heating rotary pyrolysis reactor 2.

[0069] 4) Pyrolysis reaction: Ammonium bicarbonate is pyrolyzed in the internal heating rotary pyrolysis reactor 2 to generate a mixture of ammonia, water vapor and carbon dioxide.

[0070] 5) Product collection: After the pyrolysis products are dusted and condensed, the ammonia is separated and sent to the boiler denitrification system for use.

[0071] 6) Monitoring and adjustment: The control system monitors various parameters in real time, such as temperature, pressure, speed, etc., and makes necessary adjustments to keep the system running stably.

[0072] 7) Shutdown: Gradually reduce the heat source input according to the preset program, stop feeding, and stop rotating after the system cools down.

[0073] Through the above design and optimization, the present invention can operate safely and efficiently, provide a reliable source of ammonia for the denitration system of a thermal power plant, and significantly improve energy utilization efficiency.

[0074] The present invention has the following characteristics:

[0075] The present invention makes full use of the waste heat of flue gas from thermal power plants, significantly reduces the energy consumption of ammonia production, and realizes the cascade utilization of energy.

[0076] The present invention adopts solid pyrolysis, which avoids the heat absorption of solution evaporation, further reduces energy consumption and has high thermal efficiency.

[0077] The system equipment of the present invention is simple, the floor space occupied is only about half of that of the traditional urea hydrolysis system, and the investment cost is low.

[0078] The raw material cost of the invention is low, and the operation cost is reduced by about 23% compared with the scheme of preparing ammonia by hydrolyzing urea.

[0079] The present invention improves the safety of the denitration system and eliminates the risk of using dangerous chemicals such as liquid ammonia.

[0080] The pyrolysis reaction temperature of the present invention is low, about 110° C. to 150° C., the equipment has low corrosion, and the service life of the equipment is prolonged.

[0081] The system of the present invention has a fast response speed and can quickly adjust the ammonia production according to the denitrification demand.

[0082] The raw materials of the present invention have a wide range of sources, which reduces the dependence on a single raw material and improves the stability of the supply chain.

[0083] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and disclosure of the invention. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention is indicated by the following claims.

[0084] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0085] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system, characterized in that: It comprises a boiler tail flue, an internal heating rotary pyrolysis reactor (2), an ammonium bicarbonate silo (1), a condenser (3), a fan (4) and a mixer (5); The smoke extraction port on the flue at the rear of the boiler is connected to the inlet of the heat release side of the internal heating rotary pyrolysis reactor (2), the outlet of the ammonium bicarbonate silo (1) is connected to the inlet of the heat absorption side of the internal heating rotary pyrolysis reactor (2), the outlet of the heat absorption side of the internal heating rotary pyrolysis reactor (2) is connected to the inlet of the condenser (3), the gas outlet of the condenser (3) is connected to the inlet of the mixer (5) via the fan (4), the outlet of the mixer (5) is connected to the inlet of the SCR reactor (6) in the flue at the rear of the boiler, and a heat exchange tube is arranged in the flue at the rear of the boiler, the inlet of the heat exchange tube is connected to the external environment, and the outlet of the heat exchange tube is connected to the inlet of the mixer (5).

2. The ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system according to claim 1 is characterized in that: The internal heat rotary pyrolysis reactor (2) comprises a shell and a plurality of heat transfer tubes, wherein each heat transfer tube is connected to a smoke extraction port, the inlet of the shell is connected to an ammonium bicarbonate silo (1), and the outlet of the shell is connected to a condenser (3).

3. The ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system according to claim 2 is characterized in that: The heat transfer tubes are arranged in parallel.

4. The ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system according to claim 1, characterized in that: The drain port of the condenser (3) is connected to an external boiler water supply system.

5. The ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system according to claim 1, characterized in that: The heat exchange tube and the air preheater are placed side by side.

6. The ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system according to claim 1, characterized in that: The heat release side outlet of the internal heat rotary pyrolysis reactor (2) is connected to the inlet of an external dry dust collector.

7. The ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system according to claim 1, characterized in that: The outlet of the ammonium bicarbonate silo (1) is connected to the heat absorption side inlet of the internal heating rotary pyrolysis reactor (2) via a powder conveyor.

8. A method for producing ammonia by coupling an ammonium bicarbonate pyrolysis device with waste heat from boiler flue gas, characterized in that: The ammonium bicarbonate pyrolysis device coupled with boiler flue gas waste heat ammonia production system according to claim 2 comprises the following steps: The ammonium bicarbonate particles enter the internal heating rotary pyrolysis reactor (2) and move downward under the rotation of the cylinder. At the same time, the high-temperature flue gas enters the heat transfer tube from the center axis of the cylinder. As the cylinder rotates, the ammonium bicarbonate particles in the heat transfer tube are constantly turned over to enhance the heat transfer effect. The generated ammonia, water vapor and carbon dioxide mixture is discharged from the outlet of the internal heating rotary pyrolysis reactor (2) and sent to the boiler denitration system for use after dust removal and condensation.

9. The method for producing ammonia by coupling the ammonium bicarbonate pyrolysis device with the waste heat of boiler flue gas according to claim 8, characterized in that: The heat transfer tubes are arranged in parallel.

10. The method for producing ammonia by coupling the ammonium bicarbonate pyrolysis device with boiler flue gas waste heat according to claim 8, characterized in that: The heat exchange tube and the air preheater are placed side by side.

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