Ammonia complete combustion system

Abstract

An ammonia complete combustion system according to one embodiment of the present invention comprises: an ammonia-fueled burner, composed of a primary burner or a secondary burner, for elevating the temperature of ammonia supplied into a combustion chamber to a preset temperature; an ammonia water spray nozzle for injecting ammonia water into the combustion chamber heated in the ammonia-fueled burner to vaporize the ammonia water; a combustion chamber for accommodating the ammonia vaporized in the ammonia water spray nozzle and combustion gas, maintaining an internal temperature, and providing a stable combustion environment; an ammonia oxidation catalyst for completely combusting a trace amount of ammonia generated from the combustion chamber and including the combustion gas generated in the combustion process to completely burn the ammonia before discharging the ammonia to the atmosphere; and a combustion air-heating preheater for preheating combustion air required for the ammonia-fueled burner by recovering heat from the combustion gas discharged from the ammonia oxidation catalyst.

Description

Ammonia complete combustion system

[0001] The present invention relates to an ammonia complete combustion system, and more specifically, to an ammonia complete combustion system capable of maximizing combustion efficiency by burning ammonia using an ammonia complete combustion burner, vaporizing waste ammonia water by raising the temperature in the combustion chamber, completely combusting a small amount of ammonia through an ammonia oxidation catalyst (AOC) to treat it before it is discharged into the atmosphere, and recovering the heat of the combustion gas to preheat the combustion air and reusing it in the ammonia complete combustion burner.

[0002] As a carbon-free energy source, ammonia is showing increasing potential for utilization in the power generation and industrial sectors and is considered an important alternative for achieving carbon neutrality. However, due to its high ignition energy and slow combustion rate, ammonia exhibits low combustion stability, and there is a possibility of generating trace amounts of pollutants, such as ammonia and nitrogen oxides (NOx), during the combustion process, thus requiring technical improvements.

[0003] Accordingly, existing ammonia combustion technologies primarily adopt co-firing methods with other fuels to compensate for ammonia's ignition characteristics. For example, typical methods involve mixing and burning ammonia with natural gas (NG) or ammonia with hydrogen. While this co-firing method improves ammonia's low ignition characteristics and enables stable combustion, it has limitations, such as system complexity and the need for additional infrastructure due to the use of mixed fuels.

[0004] The present invention proposes a method to improve the ignition properties of ammonia and further induce complete combustion of ammonia by raising the temperature of ammonia or combustion air to lower the ignition energy of ammonia and facilitate ignition. This provides the possibility to more efficiently realize the standalone combustion of ammonia without relying on a co-firing method, and enables simplification and economic efficiency of the ammonia combustion system.

[0005] Based on this technical background, the present invention focuses on solving technical challenges to maximize the combustion performance of ammonia and achieve substantially complete combustion.

[0006] The objective of the present invention is to provide an ammonia complete combustion system that maximizes energy efficiency through the complete combustion of ammonia and effectively treats trace amounts of ammonia emitted during the combustion process.

[0007] In addition, the invention provides an ammonia complete combustion system that maintains the stable operation of key components even in the high-temperature environment generated during ammonia combustion, and increases combustion efficiency and minimizes energy waste by recovering heat from the combustion gases and recycling it for preheating the combustion air.

[0008] An ammonia complete combustion system according to one embodiment of the present invention may comprise a primary burner or a secondary burner, an ammonia total combustion burner that raises the temperature of ammonia supplied into the combustion chamber to a preset temperature, an ammonia water spray nozzle that sprays ammonia water into the combustion chamber raised in the ammonia total combustion burner to vaporize it, a combustion chamber that receives the ammonia vaporized from the ammonia water spray nozzle and combustion gas, maintains an internal temperature, and creates a stable combustion environment, an ammonia oxidation catalyst that completely combusts a small amount of ammonia generated from the combustion chamber and completely combusts the ammonia including the combustion gas generated during the combustion process before releasing it into the atmosphere, and a preheater for raising the temperature of combustion air that recovers the heat of the combustion gas discharged from the ammonia oxidation catalyst and preheats the combustion air required in the ammonia total combustion burner.

[0009] Additionally, the ammonia total burner may include a primary burner that burns ammonia supplied through a primary ammonia gas inlet through a primary ammonia burner nozzle, a secondary burner that burns ammonia supplied through a secondary ammonia gas inlet through a secondary ammonia burner nozzle, a primary combustion air inlet and a secondary combustion air inlet that supply air necessary for ammonia combustion to each of the primary burner and the secondary burner, and an ammonia ignition pilot burner that injects initial combustion gas to start the ignition of the ammonia total burner, induces ignition through a high-voltage spark, and is controlled to maintain a stable flame after ignition.

[0010] In addition, the first burner and the second burner may be characterized by operating during the initial combustion process to raise the temperature inside the combustion chamber to a preset condition, and when the preset condition is satisfied, controlling either one of the first burner and the second burner to operate or both to stop operating.

[0011] In addition, the ammonia oxidation catalyst may be characterized by including a catalyst section that completely burns a small amount of ammonia generated in the ammonia burner and ammonia water spray nozzle, and an overheating prevention cooling device to maintain stable operation of the catalyst section in a high-temperature environment generated when a large amount of ammonia is incinerated.

[0012] Additionally, the preheater for heating the combustion air may include a combustion gas inlet for introducing combustion gas discharged from the combustion chamber and the ammonia oxidation catalyst into the heat exchange process, a heat exchanger comprising a plurality of heat transfer fins for recovering heat from the combustion gas introduced through the combustion gas inlet to raise the temperature of the combustion air, and a combustion air outlet for supplying the combustion air preheated by the heat exchanger to the ammonia burner and the combustion chamber.

[0013] An ammonia complete combustion system according to one embodiment of the present invention performs the complete combustion of anhydrous ammonia and completely burns trace amounts of ammonia and pollutants that may be generated during the combustion process of ammonia, thereby minimizing environmental pollution and having the effect of significantly improving combustion efficiency by recovering heat from the combustion gas to preheat the combustion air.

[0014] In addition, by vaporizing waste ammonia water through an ammonia water spray nozzle and integrating it into the combustion process for effective treatment, it enhances the efficiency of waste management and enables the implementation of a simplified system that does not require separate treatment equipment.

[0015] In addition, by maintaining the stability of key components, particularly the ammonia oxidation catalyst (AOC), through an overheat prevention cooling device in the high-temperature environment generated during ammonia combustion, the reliability of the system is enhanced, and long-term continuous operation is possible.

[0016] In addition, by recovering heat from combustion gases through a preheater for heating combustion air and recycling the combustion air, it reduces energy waste and maximizes energy efficiency, thereby improving economic feasibility.

[0017] FIG. 1 is a drawing for explaining the overall shape of an ammonia complete combustion system according to an embodiment of the present invention.

[0018] FIG. 2 is a drawing for explaining the configuration of an ammonia burner according to an embodiment of the present invention.

[0019] FIG. 3 is a drawing for explaining the configuration of an ammonia water spray nozzle according to an embodiment of the present invention.

[0020] FIG. 4 is a diagram illustrating the composition of an ammonia oxidation catalyst (AOC) according to an embodiment of the present invention.

[0021] FIG. 5 is a drawing for explaining the configuration of a preheater for heating combustion air according to an embodiment of the present invention.

[0022] Specific embodiments of the present invention will be described in detail below with reference to the drawings. However, the concept of the present invention is not limited to the embodiments presented. Those skilled in the art who understand the concept of the present invention may easily propose other inventions that are inferior or other embodiments included within the scope of the concept of the present invention by adding, changing, or deleting other components within the same scope of the concept, and such are also to be considered to be included within the scope of the concept of the present invention.

[0023] Hereinafter, the ammonia complete combustion system (100) of the present invention will be described in detail with reference to the attached FIGS. 1 to 5.

[0024]

[0025] FIG. 1 is a drawing for explaining the overall formation of an ammonia complete combustion system according to an embodiment of the present invention.

[0026] Referring to FIG. 1, an ammonia complete combustion system (100) according to one embodiment of the present invention includes an ammonia complete combustion burner (110), an ammonia water spray nozzle (120), a combustion chamber (130), an ammonia oxidation catalyst (AOC) (140), and a preheater (150) for heating combustion air, and through the interaction of these, stable and efficient combustion can be achieved.

[0027] The above-mentioned ammonia burner (110) is formed with a cylindrical burner body structure and can be designed with a heat-resistant or high-temperature corrosion-resistant metal material to ensure durability in a high-temperature environment. The interior of the body is divided into two combustion spaces to efficiently handle primary and secondary combustion processes and is separated by an internal partition. The partition includes a suitable passage for the smooth movement of air and combustion gases.

[0028] The primary combustion space is the front section where the primary burner (111) is positioned, and is the area where initial combustion takes place. The primary burner (111) is positioned parallel to the central axis and is designed to uniformly spray a gas mixed with ammonia and air into the combustion space.

[0029] More specifically, referring to FIG. 2, a primary ammonia gas inlet (113) and a primary combustion air inlet (117) are installed on the outside of the main body, through which ammonia and combustion air are supplied into the primary burner (111). A primary ammonia burner nozzle (114) is positioned in the front center of the main body to spray the mixed gas into the combustion space.

[0030] The secondary combustion space is an intermediate section where a secondary burner (112) is placed, and serves to further burn the mixed gas remaining after the primary combustion.

[0031] More specifically, a secondary ammonia gas inlet (115) and a secondary combustion air inlet (118) are installed in the middle of the outer part of the main body, and the ammonia gas and combustion air supplied therefrom are injected through the secondary ammonia burner nozzle (116). Through this, the gas generated from the primary combustion naturally flows into the secondary combustion space, maximizing combustion efficiency and minimizing unburned gas.

[0032] The first burner (111) and the second burner (112) are arranged in series in the axial direction, and each burner (111, 112) is individually controlled through an independent air inlet and a control system. In the initial combustion stage, both burners (111, 112) operate to rapidly raise the internal temperature of the combustion chamber to a preset condition.

[0033] During a continuous combustion process, the internal temperature of the combustion chamber rises sufficiently, and heat accumulation occurs inside the combustion chamber at high temperatures, so that a stable combustion environment can be maintained even if the primary burner (111) and the secondary burner (112) do not operate.

[0034] At this point, the control system may operate only one of the primary burner (111) and the secondary burner (112) or stop the operation of both burners (111, 112) for fuel saving and efficient operation. This process can be performed automatically by a control system that monitors the combustion temperature, ammonia supply amount, combustion air flow rate, etc., in real time.

[0035] Additionally, an ammonia ignition pilot burner (119) is installed at the front of the main body and is used to stably start initial combustion. The ammonia ignition pilot burner (119) continuously maintains the flame generated during the combustion process and ensures that the internal temperature of the combustion chamber is maintained stably. During the initial combustion stage, it supplies the energy required for the complete combustion of ammonia and creates a stable combustion environment inside the combustion chamber.

[0036] When the combustion chamber temperature drops below a set condition, the control system automatically restarts the primary burner (111) and the secondary burner (112) to raise the temperature again. This start-stop cycle is designed to maintain the combustion chamber temperature stably while efficiently using energy and fuel.

[0037] Referring to FIG. 3, the ammonia water spray nozzle (120) is positioned in the connecting section between the ammonia burner (110) and the combustion chamber (130). Generally, it may be symmetrically positioned near the central axis of the combustion chamber (130), or a plurality of nozzles may be installed on the wall of the combustion chamber (130) to ensure uniform spraying throughout.

[0038] The above ammonia water spray nozzle (120) is a device capable of vaporizing ammonia water inside the combustion chamber (130), which is heated to a high temperature by the above ammonia burner (110), and can be designed to spray an appropriate amount of ammonia water according to the temperature conditions of the combustion chamber (130).

[0039] Ammonia water is finely sprayed to come into contact with the high-temperature gas inside the combustion chamber (130), thereby rapidly vaporizing the ammonia water. The vaporized ammonia is mixed with the combustion gas and integrated into the combustion process.

[0040] Ammonia water is vaporized and participates in the combustion process inside the combustion chamber (130), thereby increasing its utility as fuel and maximizing combustion efficiency. By integrating waste ammonia water into the combustion process, it can be effectively processed without additional treatment processes.

[0041] The vaporized ammonia is converted into energy through a combustion reaction, and a small amount of ammonia is transferred to an ammonia oxidation catalyst (AOC) (140) for complete combustion.

[0042] The ammonia water spray nozzle (120) detects the temperature conditions inside the combustion chamber (130) in real time and automatically controls and sprays an appropriate amount of ammonia water. This optimizes the vaporization process and maintains a balance between combustion efficiency and energy consumption.

[0043] For example, the amount of ammonia water injected is reduced when the temperature of the combustion chamber (130) is low, and the amount injected is increased when the temperature is high, so that appropriate vaporization is achieved.

[0044] The combustion chamber (130) is a space where high-temperature combustion gas generated from the ammonia burner (110) and ammonia water are mixed and combusted, and is a component that provides a stable combustion environment. The combustion chamber (130) induces complete combustion by mixing the combustion gas generated from the ammonia burner (110) and the ammonia water vaporized from the ammonia water spray nozzle (120).

[0045] For flow optimization, a mixing device (e.g., induction fins or porous structure) may be installed inside. The temperature and pressure inside the combustion chamber (130) can be measured in real time and transmitted to a control system. Based on the data, adjustments can be made to maintain combustion stability.

[0046] The completely combusted gas is transferred to the ammonia oxidation catalyst (AOC) (140), and the heat generated during the combustion process maintains or raises the internal temperature of the combustion chamber, providing a stable combustion environment. This minimizes the generation of harmful substances such as nitrogen oxides (NOx) and unburned ammonia, thereby preparing the ammonia oxidation catalyst (AOC) (140) to operate effectively in subsequent processes.

[0047] Referring to FIG. 4, the ammonia oxidation catalyst (AOC) (140) is installed at the rear of the combustion chamber (130), where combustion gas naturally flows in. It can be designed to be placed at an optimal location considering the flow of combustion gas so that both the combusted gas and unburned ammonia can undergo a catalytic reaction.

[0048] The trace amounts of ammonia and other combustion gases that are not processed in the combustion chamber (130) are completely burned to prevent the emission of substances harmful to the environment. Nitrogen oxides that may be generated during the combustion process are reduced through chemical reactions, thereby minimizing air pollution.

[0049] The above ammonia oxidation catalyst (AOC) (140) may include a catalyst section (141) and an overheating prevention cooling device (142). The catalyst section (141) is a core component of the AOC and includes a porous or honeycomb structure coated with a catalytic material that induces a stable chemical reaction even in a high-temperature environment. Generally, precious metal catalysts or oxide catalysts such as platinum (Pt), palladium (Pd), and ruthenium (Ru) are used.

[0050] The catalyst part (141) is designed to be modular so that it can be replaced, and maintenance is easy.

[0051] Combustion gas and a small amount of ammonia discharged from the combustion chamber (130) are introduced into the catalyst section (141) through the inlet of the ammonia oxidation catalyst (AOC) (140). Inside the catalyst section (141), a high-temperature gas comes into contact with the catalyst material, and a chemical reaction occurs. The stabilized gas is discharged to the outside through the outlet, and in this process, there is almost no emission of harmful substances.

[0052] The above-mentioned overheating prevention cooling device (142) is an essential component for maintaining the stable operation of the catalyst section (141) within the ammonia oxidation catalyst (AOC) (140), and serves to prevent thermal damage and degradation of catalyst performance by preventing the temperature of the catalyst section (141) from rising excessively. The above-mentioned overheating prevention cooling device (142) can be designed in various ways, such as cooling fluid circulation, external air intake, and integration with a temperature sensing and control system.

[0053] The above-mentioned preheater (150) for heating combustion air is positioned at the top of the combustion chamber (130). It serves to recover heat by introducing high-temperature combustion gas discharged from the combustion chamber (130) and the ammonia oxidation catalyst (AOC) (140).

[0054] Referring to FIG. 5, the preheater (150) for heating combustion air may include a combustion gas inlet (151), a heat exchanger (152), and a combustion air outlet (153).

[0055] The combustion gas inlet (151) is connected to the outlet of the combustion chamber (130) and the ammonia oxidation catalyst (AOC) (140), and serves as a passage through which the discharged combustion gas flows directly into the preheater (150) for heating the combustion air.

[0056] The combustion gas inlet (151) is installed in the front part of the preheater (150) for heating the combustion air and is positioned so that high-temperature combustion gas can be efficiently introduced.

[0057] The heat exchanger (152) has a plurality of heat transfer fins installed inside, which increases the contact area with the combustion gas to improve heat transfer efficiency. The fins can be designed in a straight, curved, or sawtooth shape. The heat exchanger (152) can be designed in various forms that optimize the heat transfer area and the turbulence generation effect, such as a porous fin structure, a plate-type heat exchanger, or a tube-type heat exchanger.

[0058] The combustion gas flows into the heat exchanger (152) through the combustion gas inlet (151) and begins to release thermal energy upon contact with porous fins or heat exchange plates. Induction fins or guide structures are installed inside the heat exchanger (152) to align the flow of the combustion gas and are designed to maximize the heat transfer area. The combustion gas moves along the fins or plates, gradually decreasing in temperature, and the released heat is transferred to the combustion air.

[0059] The combustion air flowing inside the heat exchanger (152) absorbs thermal energy received from the combustion gas and gradually increases in temperature, and is finally supplied to the ammonia burner (110) and the combustion chamber (130) through the combustion air outlet (153) in a preheated state. The heat exchanger (152) adopts a multi-layer structure and a high-conductivity material to maximize heat transfer efficiency, and is designed in a cross-flow or counter-flow manner so that the heat exchange process can be optimized.

[0060] The combustion gas passes through the heat exchanger (152), where its temperature is lowered, and after heat recovery, it is adjusted to a set discharge temperature and delivered to the ammonia oxidation catalyst (AOC) (140) or the discharge port. This allows for meeting environmental regulatory standards and preventing heat pollution during discharge. A temperature sensor is installed in the heat exchanger (152) to measure the temperature of the combustion gas and combustion air in real time, and is linked with a control system to continuously maintain heat transfer efficiency.

[0061] Preheated combustion air can quickly meet reaction conditions in the combustion chamber to increase combustion efficiency and effectively recover excess heat from the combustion gases, thereby reducing additional fuel consumption while maximizing energy utilization.

[0062] Additionally, a combustion air fan (160) may be further provided to supply the combustion air required inside the ammonia burner (110) and the combustion chamber (130). It serves to control the flow of combustion air and deliver the required amount of air to the preheater (150) for heating the combustion air.

[0063] The above combustion air fan (160) is generally made of a material with excellent heat resistance so that it can operate stably even in a high-temperature environment, and a high-efficiency motor is used to minimize power consumption. The design of the fan can be axial or centrifugal, taking into account the optimization of air flow.

[0064] The operation of the combustion air fan (160) is linked to a control system, allowing the temperature and flow rate of the combustion air to be adjusted in real time. Preheated combustion air is stably supplied to the required ammonia burner (110) or combustion chamber (130), and combustion efficiency can be maximized by adjusting the fan's rotation speed and air flow according to combustion conditions.

[0065]

[0066] As described above, although an embodiment of the present invention has been explained by limited embodiments and drawings, the embodiment of the present invention is not limited to the embodiments described above, and various modifications and variations are possible from this description by those skilled in the art to which the present invention pertains. Accordingly, an embodiment of the present invention should be understood only by the claims described below, and all equivalent or analogous variations thereof shall be considered to be within the scope of the inventive concept.

[0067]

[0068] 100: Ammonia complete combustion system

[0069] 110: Ammonia full burner 111: Primary burner

[0070] 112: Secondary burner

[0071] 113: Primary ammonia gas inlet

[0072] 114: Primary ammonia burner nozzle

[0073] 115: Secondary ammonia gas inlet

[0074] 116: Secondary ammonia burner nozzle

[0075] 117: Primary combustion air inlet

[0076] 118: Secondary combustion air inlet

[0077] 119: Ammonia Ignition Pilot Burner

[0078] 120: Ammonia solution spray nozzle

[0079] 130: Combustion chamber

[0080] 140: Ammonia Oxidation Catalyst (AOC) 141: Catalyst section

[0081] 142: Overheating prevention cooling device

[0082] 150: Preheater for heating combustion air 151: Combustion gas inlet

[0083] 152: Heat exchanger

[0084] 153: Combustion air exhaust

[0085] 160: Combustion air fan

Claims

1. In an ammonia complete combustion system, An ammonia total combustion burner comprising a primary burner or a secondary burner, which raises the temperature of ammonia supplied into the combustion chamber to a preset temperature; A combustion chamber for accommodating high-temperature combustion gas generated by the combustion action of the above-mentioned ammonia burner, maintaining an internal temperature, and creating a stable combustion environment; An ammonia water spray nozzle that sprays and vaporizes ammonia water inside the combustion chamber; An ammonia oxidation catalyst that completely burns a trace amount of ammonia generated from the combustion chamber and completely burns the ammonia, including the combustion gas generated during the combustion process, before releasing it into the atmosphere; A preheater for heating combustion air that recovers heat from the combustion gas discharged from the ammonia oxidation catalyst and preheats the combustion air required in the ammonia total combustion burner; comprising, The above ammonia burner is, A primary burner that burns ammonia supplied through a primary ammonia gas inlet through a primary ammonia burner nozzle, and, A secondary burner that burns ammonia supplied through a secondary ammonia gas inlet through a secondary ammonia burner nozzle; A primary combustion air inlet and a secondary combustion air inlet for supplying air necessary for ammonia combustion to each of the primary burner and the secondary burner; Ammonia ignition pilot burner that injects initial combustion gas to start ignition of the above-mentioned ammonia total combustion burner and induces ignition through a high-voltage spark, and is controlled to maintain a stable flame after ignition; The above-mentioned primary burner and secondary burner are, It operates during the initial combustion process to raise the temperature inside the combustion chamber to a preset condition, and When preset conditions are satisfied, either one of the primary burner and the secondary burner is automatically controlled to operate, or both are stopped from operating. The above ammonia water spray nozzle detects the temperature inside the combustion chamber and automatically adjusts the amount of ammonia water sprayed according to the temperature, and The above ammonia oxidation catalyst comprises: a catalyst section that completely burns a small amount of ammonia generated in the ammonia burner and the ammonia water spray nozzle; and It includes an overheat prevention cooling device for maintaining stable operation of the catalyst unit in a high-temperature environment generated during the incineration of a large amount of ammonia; The above-described preheater for heating combustion air comprises: a combustion gas inlet that introduces and heat-exchanges combustion gas discharged from the combustion chamber and the ammonia oxidation catalyst; A heat exchanger comprising a plurality of heat transfer fins for recovering heat from combustion gas introduced through the combustion gas inlet and raising the temperature of the combustion air; A combustion air outlet that supplies combustion air preheated by the heat exchanger above to an ammonia full-burner and a combustion chamber; and Ammonia complete combustion system characterized by including a temperature sensor for controlling the exhaust temperature of combustion gases to a set level.

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