Glass furnace for supplying heat by adopting ammonia oxygen-enriched combustion method

Abstract

The invention discloses a glass furnace for supplying heat by adopting an ammonia oxygen-enriched combustion method, which belongs to the field of glass furnaces and comprises an oxygen pipeline, an air distributor, a carbon dioxide pipeline, a carbon dioxide detector, a cyclone, an ammonia pipeline, a mixing pipeline, a flame arrester, an igniter, a combustion melting chamber, a carbon dioxide trapping device and a nitrogen oxide treatment device. An air distributor is mounted at a fork of an oxygen pipeline, a cyclone is mounted on a mixing pipeline, flame arresters are mounted at the tail end of the mixing pipeline and the tail end of a branch of the oxygen pipeline, and a carbon dioxide trapping device and a nitrogen oxide treatment device are sequentially mounted behind an outlet of a combustion melting chamber. Wrapping by mixed gas of low-temperature oxygen and carbon dioxide, and carrying out dense-thin two-stage combustion; carbon dioxide is used for replacing nitrogen, generation of a large amount of thermal nitrogen oxide is reduced, radiation heat transfer in the combustion melting chamber is enhanced, and the heating effect is more ideal.

Description

Technical Field

[0001] The invention belongs to the field of glass furnaces and relates to a glass furnace which adopts an ammonia-oxygen-enriched combustion method for heating. Background Art

[0002] To achieve the goal of carbon neutrality, it is necessary to prioritize solving the main contradictions and focus on promoting decarbonization in the industrial sector, which is a major energy consumer. In the industrial sector, more than 20% of energy is used to generate heat in industrial furnaces to process materials such as glass, and industrial furnaces mainly rely on natural gas as fuel, which poses a challenge to emission reduction.

[0003] As an ideal carbon-free alternative fuel, ammonia is widely used in power generation, transportation, industrial processing and other fields. The products of its complete combustion are only water and nitrogen, which will not aggravate the greenhouse effect. However, the chemical properties of ammonia limit its development as a new fuel. For example, the flame speed and temperature of ammonia are lower than those of traditional hydrocarbon fuels, and because the flame does not contain carbon dioxide, its radiation heat transfer capacity is weak, which makes it difficult to directly apply ammonia to industrial equipment that requires high-temperature smelting, such as glass furnaces.

[0004] Compared with traditional air combustion, oxygen-enriched combustion technology has higher flame temperature and combustion speed, lower ignition temperature and burnout time, less smoke volume after combustion, and less nitrogen oxides generated. Summary of the invention

[0005] In combination with the above background technology, the present invention proposes a glass furnace that uses ammonia-oxygen-enriched combustion method to provide heat. The glass furnace uses ammonia as fuel and pure oxygen as a combustion aid to provide heat through swirl non-premixed oxygen-enriched combustion.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0007] A glass furnace using an ammonia-oxygen-enriched combustion method for heating, comprising an oxygen pipeline, a carbon dioxide pipeline, an ammonia pipeline, a mixing pipeline, a combustion and melting chamber, a carbon dioxide capture device and a nitrogen oxide treatment device;

[0008] After the oxygen pipeline and the carbon dioxide pipeline are converged, they are connected to the inlet end of the combustion and melting chamber at the same position through the mixing pipeline and the ammonia pipeline. The outlet end of the combustion and melting chamber is connected to a carbon dioxide capture device and a nitrogen oxide treatment device in sequence. The middle part of the oxygen pipeline is connected to the middle and rear part of the combustion and melting chamber through an oxygen pipeline branch, and the middle part of the carbon dioxide pipeline is connected to the carbon dioxide capture device through a carbon dioxide pipeline branch.

[0009] In the above technical solution, the glass furnace further includes an air distributor, which is arranged at a branching point of the oxygen pipeline.

[0010] In the above technical solution, the glass furnace further includes a carbon dioxide detector, which is arranged at the starting section of a branch of the carbon dioxide pipeline.

[0011] In the above technical solution, the glass furnace further comprises a cyclone, and the cyclone is arranged behind the intersection of the oxygen pipeline and the carbon dioxide pipeline on the mixing pipeline.

[0012] In the above technical solution, the glass furnace further includes a first flame arrester, which is arranged at the ends of the ammonia pipeline and the mixing pipeline.

[0013] In the above technical solution, the glass furnace further includes a second flame arrester, which is arranged at the end of a branch of the oxygen pipeline.

[0014] In the above technical solution, the glass furnace further comprises an igniter, which is arranged in the combustion and melting chamber on a side close to the first flame arrester.

[0015] In the above technical solution, the inner wall of the ammonia pipeline has been pre-treated for corrosion protection.

[0016] In the above technical solution, the ammonia gas introduced into the ammonia gas pipeline is preheated to above 600K.

[0017] In the above technical solution, the volume ratio of oxygen to carbon dioxide in the mixing pipeline is 3:2.

[0018] Beneficial effects:

[0019] The present invention proposes a glass furnace that uses ammonia-oxygen-enriched combustion method for heating, including an oxygen pipeline, an air distributor, a carbon dioxide pipeline, a carbon dioxide detector, a cyclone, an ammonia pipeline, a mixing pipeline, a first flame arrester, an igniter, a second flame arrester, a combustion and melting chamber, a carbon dioxide capture device, and a nitrogen oxide treatment device. When the present invention is working, the input ammonia is preheated, and most of the oxygen and carbon dioxide form a new mixed gas in the mixing pipeline, which shows a slightly rich combustion state in the inlet section of the combustion and melting chamber, significantly enhancing the propagation speed and adiabatic temperature of the ammonia flame, so that the interior of the combustion and melting chamber reaches the required working temperature; the remaining oxygen is sent to the rear part of the combustion and melting chamber through a branch of the oxygen pipeline to show a lean combustion state, so that the ammonia introduced is fully burned; using carbon dioxide instead of the original nitrogen can not only reduce the generation of a large amount of thermal nitrogen oxides, but also enhance the radiation heat transfer process in the combustion and melting chamber, and the heating effect is more ideal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the flame arrester in the present invention;

[0022] In the figure: 1 is an oxygen pipeline, 2 is an air distributor, 3 is a carbon dioxide pipeline, 4 is a carbon dioxide detector, 5 is a cyclone, 6 is an ammonia pipeline, 7 is a mixing pipeline, 8 is a first flame arrester, 9 is an igniter, 10 is a second flame arrester, 11 is a combustion and melting chamber, 12 is a carbon dioxide capture device, and 13 is a nitrogen oxide treatment device. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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, 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.

[0024] Example

[0025] A glass furnace using an ammonia-oxygen-enriched combustion method for heating, comprising an oxygen pipeline 1, an air distributor 2, a carbon dioxide pipeline 3, a carbon dioxide detector 4, a cyclone 5, an ammonia pipeline 6, a mixing pipeline 7, a first flame arrester 8, an igniter 9, a second flame arrester 10, a combustion and melting chamber 11, a carbon dioxide capture device 12 and a nitrogen oxide treatment device 13;

[0026] The end of the oxygen pipeline 1 is connected to the starting section of the mixing pipeline 7, and the middle part of the pipeline is connected to the middle and rear part of the combustion and melting chamber 11 through an oxygen pipeline branch; the end of the carbon dioxide pipeline 3 is connected to the starting section of the mixing pipeline 7, and the middle part of the pipeline is connected to the carbon dioxide capture device 12 through a carbon dioxide pipeline branch; the air distributor 2 is arranged at the bifurcation of the oxygen pipeline 1, the carbon dioxide detector 4 is arranged at the starting section of the carbon dioxide pipeline branch, and the cyclone 5 is arranged behind the intersection of the oxygen pipeline 1 and the carbon dioxide pipeline 3 on the mixing pipeline 7; the first flame arrester 8 and the second flame arrester 10 are respectively arranged at the ends of the ammonia pipeline 6 and the mixing pipeline 7 and the end of the oxygen pipeline branch; the igniter 9 is arranged in the combustion and melting chamber 11 on the side close to the first flame arrester 8; the carbon dioxide capture device 12 is arranged behind the outlet of the combustion and melting chamber 11, and the nitrogen oxide treatment device 13 is arranged behind the carbon dioxide capture device 12.

[0027] In this embodiment, the oxygen pipeline 1 has an air inlet and two air outlets, and the inner wall of the pipeline has been pre-treated for rust prevention to prevent the circulating oxygen from corroding the pipeline.

[0028] In this embodiment, the air distributor 2 keeps most of the oxygen in the original oxygen pipeline 1 in the original channel, distributes the remaining oxygen to the oxygen branch pipeline, and finally introduces it into the middle and rear part of the combustion and melting chamber 11.

[0029] In this embodiment, the carbon dioxide pipeline 3 has two air inlets and one air outlet, and the carbon dioxide is supplied from an external air source and captured by a carbon dioxide capture device.

[0030] In this embodiment, the carbon dioxide detector 4 can monitor the amount of captured and recovered carbon dioxide, and then adjust the amount of externally supplied carbon dioxide to ensure that the total amount of supplied carbon dioxide remains unchanged.

[0031] In this embodiment, the cyclone 5 can fully mix the introduced oxygen and carbon dioxide to form a new mixed gas, in which the volume ratio of oxygen to carbon dioxide is 3:2, that is, the volume fraction of oxygen is 60%.

[0032] In this embodiment, the inner wall of the ammonia pipeline 6 has been pre-treated for corrosion prevention to avoid reaction with the introduced ammonia gas, and the introduced ammonia gas is pre-heated above 600K.

[0033] In this embodiment, the carbon dioxide capture device 12 can capture a large amount of carbon dioxide that does not participate in the combustion reaction at the outlet of the combustion and melting chamber and introduce it into a branch of the carbon dioxide pipeline for recycling.

[0034] In this embodiment, the nitrogen oxide treatment device 13 reduces the nitrogen oxides in the tail gas to meet the emission standards before discharging them.

[0035] In this embodiment, the introduced ammonia maintains a slightly rich combustion state with an equivalence ratio of 1.05-1.20 at the outlet of the ammonia pipeline 6, and maintains a chemical equivalence ratio combustion with a global equivalence ratio of 1, realizing a "rich combustion + lean combustion" two-stage combustion mode, ensuring that the amount of unburned ammonia and generated nitrogen oxides in the combustion and melting chamber 11 is minimized.

[0036] In this embodiment, oxygen-enriched combustion reduces the difficulty of preheating ammonia combustion and increases the speed and temperature of the ammonia flame in the combustion melting chamber 11, which is suitable for industrial equipment such as glass furnaces that require high-temperature melting.

[0037] In this embodiment, the combination gas of "oxygen + carbon dioxide" is used instead of the widely used air combination of "oxygen + nitrogen", so as to avoid the excessively high temperature in the combustion and melting chamber 11 from oxidizing a large amount of nitrogen to generate thermal nitrogen oxides; at the same time, as a triatomic gas, carbon dioxide has strong radiation and absorption capabilities, and can transfer the heat released in the ammonia flame to the entire combustion and melting chamber 11, thereby promoting the uniformity of heat transfer.

[0038] like Figure 1 As shown, this embodiment provides a glass furnace that adopts ammonia-enriched oxygen combustion method for heating. The volume ratio of supplied oxygen, carbon dioxide and ammonia is 3:2:4. The air distributor 2 keeps most of the oxygen in the original channel, distributes the remaining oxygen to the oxygen branch pipeline, and finally introduces it into the combustion and melting chamber, so that the introduced ammonia maintains a slightly rich combustion state with an equivalence ratio of 1.05-1.20 at the outlet of the ammonia pipeline, and maintains a chemical equivalence ratio combustion with a global equivalence ratio of 1 in the combustion and melting chamber, implementing rich and thin two-stage combustion.

[0039] like Figure 1 As shown, the swirl number of the cyclone 5 is 0.8, which can generate a strong turbulent mixing intensity, so that the oxygen and carbon dioxide introduced can be fully and evenly mixed.

[0040] like Figure 1 As shown, the ammonia pipeline 6 passes through the center of the mixing pipeline 7, the original swirl flame will become a slender flame, and the mixed gas composed of lower temperature oxygen and carbon dioxide will wrap the preheated ammonia, isolating the ammonia from the high temperature area, making the pyrolysis reaction the main way of ammonia consumption, the reducing atmosphere in the combustion and melting chamber 11 is strong, and the concentration of nitrogen oxides at the outlet of the combustion and melting chamber 11 is significantly reduced.

[0041] like Figure 2 As shown, the flame arrester contains many tiny channels that allow the mixed gas to flow, but the retreating flame will be divided into many thin flames by the flame arrester; the heat generated by the combustion in the channel is much less than the heat dissipated to the channel wall, and the flame temperature drops sharply; when it drops to a certain temperature, the flame will be extinguished in the flame arrester channel.

[0042] The working principle of a glass furnace using ammonia-oxygen-combustion method for heating is as follows:

[0043] When the present invention is working, the input ammonia is preheated, and most of the oxygen in the oxygen pipeline forms a mixed gas with carbon dioxide, and a slightly rich combustion organization is realized in the inlet section of the combustion and melting chamber, which can significantly enhance the propagation speed and adiabatic temperature of the ammonia flame, so that the interior of the combustion and melting chamber reaches the required working temperature; the remaining oxygen is sent to the rear part of the combustion and melting chamber through a branch of the oxygen pipeline to implement a lean combustion organization to ensure the full combustion of the introduced ammonia; the use of carbon dioxide instead of the original nitrogen can not only reduce the generation of a large amount of thermal nitrogen oxides, but also enhance the radiation heat transfer process in the combustion and melting chamber, and the heating effect is more ideal.

[0044] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A glass furnace using ammonia-oxygen-enriched combustion method for heating, characterized in that: It includes oxygen pipelines, carbon dioxide pipelines, ammonia pipelines, mixing pipelines, combustion and melting chambers, carbon dioxide capture devices and nitrogen oxide treatment devices; After the oxygen pipeline and the carbon dioxide pipeline are converged, they are connected to the inlet end of the combustion and melting chamber at the same position through the mixing pipeline and the ammonia pipeline. The outlet end of the combustion and melting chamber is connected to a carbon dioxide capture device and a nitrogen oxide treatment device in sequence. The middle part of the oxygen pipeline is connected to the middle and rear part of the combustion and melting chamber through an oxygen pipeline branch, and the middle part of the carbon dioxide pipeline is connected to the carbon dioxide capture device through a carbon dioxide pipeline branch.

2. A glass furnace using ammonia-oxygen-combustion method for heating according to claim 1, characterized in that: The glass furnace further comprises an air distributor, which is arranged at a bifurcation of the oxygen pipeline.

3. A glass furnace using ammonia-oxygen combustion method for heating according to claim 1, characterized in that: The glass furnace further comprises a carbon dioxide detector, which is arranged at the starting section of a branch of the carbon dioxide pipeline.

4. A glass furnace using ammonia-oxygen-combustion method for heating according to claim 1, characterized in that: The glass furnace further comprises a cyclone, which is arranged behind the intersection of the oxygen pipeline and the carbon dioxide pipeline on the mixing pipeline.

5. A glass furnace using ammonia-oxygen-combustion method for heating according to claim 1, characterized in that: The glass furnace further comprises a first flame arrester, which is arranged at the ends of the ammonia pipeline and the mixing pipeline.

6. A glass furnace using ammonia-oxygen combustion method for heating according to claim 1, characterized in that: The glass furnace further comprises a second flame arrester, which is arranged at the end of a branch of the oxygen pipeline.

7. The glass furnace using ammonia-oxygen-combustion method for heating according to claim 1, characterized in that: The glass furnace further comprises an igniter, which is arranged in the combustion and melting chamber at a side close to the first flame arrester.

8. The glass furnace using ammonia-oxygen-combustion method for heating according to claim 1, characterized in that: The inner wall of the ammonia pipeline has been pre-treated for corrosion resistance.

9. The glass furnace using ammonia-oxygen-combustion method for heating according to claim 1, characterized in that: The ammonia gas introduced into the ammonia gas pipeline is preheated to above 600K.

10. The glass furnace using ammonia-oxygen-combustion method for heating according to claim 1, characterized in that: The volume ratio of oxygen to carbon dioxide in the mixing pipeline is 3:2.

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