Ammonia gas supply system for ammonia-fired glass melting furnace

Abstract

The present invention provides an ammonia gas supply system for an ammonia-fired glass melting furnace, and relates to the technical field of glass production, the ammonia gas supply system comprises: a gasification device respectively connected with a liquid ammonia storage tank and an ammonia gas buffer tank and used for gasifying liquid ammonia conveyed from the liquid ammonia storage tank and then conveying the gasified liquid ammonia into the ammonia gas buffer tank; the gas mixing device is respectively connected with the ammonia buffer tank and the gas preheating device, the gas preheating device is connected with the ammonia-fired glass melting furnace, and the gas mixing device is used for mixing hydrogen conveyed from the outside and ammonia conveyed by the ammonia buffer tank to obtain mixed gas and conveying the mixed gas into the gas preheating device; and the gas preheating device exchanges heat between the mixed gas and flue gas released by the ammonia-fired glass melting furnace and then conveys the mixed gas to the ammonia-fired glass melting furnace for combustion and use. The energy utilization efficiency of a glass factory is effectively improved; the defects that the ignition temperature is high, large ignition energy is needed, the combustion speed is low, the combustion stability is poor, the combustion temperature is low and the like due to the fact that ammonia serves as fuel in ammonia combustion are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of glass production, and in particular to an ammonia supply system for an ammonia-fired glass melting furnace. Background Art

[0002] Driven by the country's urgent needs for "carbon peak" and "carbon neutrality", the exploration of carbon-free or low-carbon fuel technologies, ammonia, as a zero-carbon fuel, may become an indispensable part of the diversified fuel of glass melting furnaces.

[0003] At present, compared with hydrogen, which is difficult to store and has a higher transportation cost, the production, storage and transportation technology of ammonia is relatively mature, which is conducive to the storage and transportation of renewable energy and greatly reduces the cost of fuel use.

[0004] However, as a fuel, ammonia has a high ignition temperature, requires a large ignition energy, has a slow combustion speed, poor combustion stability, low combustion temperature, and a large amount of ammonia is used in glass factory melting furnaces. In order to solve the defects of glass factory melting furnaces using ammonia as fuel, large gas consumption, and ammonia combustion process, and to make full use of energy recovery in glass factories, a safe and reliable ammonia supply system for glass melting furnaces burning ammonia is extremely important. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides an ammonia supply system for an ammonia-fired glass melting furnace, comprising:

[0006] A gasification device, connected to the liquid ammonia storage tank and the ammonia buffer tank, respectively, for gasifying the liquid ammonia transported from the liquid ammonia storage tank and then sending it into the ammonia buffer tank;

[0007] A gas mixing device, connected to the ammonia buffer tank and the gas preheating device respectively, the gas preheating device is connected to the ammonia-burning glass melting furnace, and the gas mixing device is used to mix the hydrogen delivered from the outside with the ammonia delivered from the ammonia buffer tank to obtain a mixed gas and deliver it to the gas preheating device;

[0008] The gas preheating device exchanges heat between the mixed gas and the flue gas released by the ammonia-fired glass melting furnace and then transports the mixed gas to the ammonia-fired glass melting furnace for combustion.

[0009] Preferably, the gasification device includes a circulating water heat exchange system and an air-temperature gasification device.

[0010] Preferably, the circulating water heat exchange system comprises a plurality of cooling towers and hot water pools arranged on the glass production line, and each of the cooling towers and the hot water pool is provided with a liquid ammonia hot water heat exchanger;

[0011] Liquid ammonia is transported to the liquid ammonia hot water heat exchanger and is sequentially heat-exchanged and gasified through the cooling tower and the hot water tank to obtain the ammonia gas.

[0012] Preferably, a liquid ammonia pump is provided on the liquid delivery pipeline between the liquid ammonia storage tank and the gasification device, for extracting the liquid ammonia from the liquid ammonia storage tank and delivering it to the gasification device for gasification.

[0013] Preferably, an ammonia pressure reducing valve group is provided on the gas pipeline between the ammonia buffer tank and the gas mixing device.

[0014] Preferably, it also includes a hydrogen buffer tank connected to the gas mixing device and used to store the hydrogen.

[0015] Preferably, a hydrogen pressure reducing valve group is provided on the gas transmission pipeline between the hydrogen buffer tank and the gas mixing device.

[0016] Preferably, a gas distribution system is provided between the gas preheating device and the ammonia-fired glass melting furnace, and the gas distribution system divides the preheated mixed gas into the number of combustion branches required by the melting furnace spray gun, and then transports it to the ammonia-fired glass melting furnace for combustion.

[0017] Preferably, an ammonia and hydrogen pressure-stabilizing metering valve group is respectively provided on each of the combustion branches.

[0018] Preferably, it also includes a nitrogen oxide recovery device connected to the gas preheating device for recovering the flue gas after heat exchange.

[0019] The above technical solution has the following advantages or beneficial effects:

[0020] 1) By making full use of the thermal energy of the gasification device on the glass production line and the flue gas of the ammonia-fired glass melting furnace, the ammonia supply system of the present invention is provided with energy to achieve gasification of liquid ammonia and preheating of ammonia, thereby effectively improving the energy utilization efficiency of the glass factory;

[0021] 2) Preheating the mixed gas through flue gas solves the shortcomings of ammonia combustion such as high ignition temperature, large ignition energy, slow combustion speed, poor combustion stability and low combustion temperature when ammonia is used as fuel;

[0022] 3) Make full use of the melting furnace’s own nitrogen oxide recovery device to recover nitrogen oxides during ammonia combustion and achieve zero nitrogen oxide emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a schematic structural diagram of an ammonia supply system for an ammonia-fired glass melting furnace in a preferred embodiment of the present invention;

[0024] Figure 2 This is a structural schematic diagram of a circulating water heat exchange system in a preferred embodiment of the present invention;

[0025] Figure 3 for Figure 2 Schematic diagram of the structure in the A direction. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment, and other embodiments may also fall within the scope of the present invention as long as they conform to the gist of the present invention.

[0027] In a preferred embodiment of the present invention, based on the above problems existing in the prior art, an ammonia supply system for an ammonia-fired glass melting furnace is provided. Figure 1 As shown, including:

[0028] The gasification device 1 is connected to the liquid ammonia storage tank 2 and the ammonia buffer tank 3 respectively, and is used to gasify the liquid ammonia transported from the liquid ammonia storage tank 1 and then transport it to the ammonia buffer tank 3;

[0029] The gas mixing device 4 is connected to the ammonia buffer tank 3 and the gas preheating device 5 respectively. The gas preheating device 5 is connected to the ammonia-burning glass melting furnace 6. The gas mixing device 4 is used to mix the hydrogen delivered from the outside with the ammonia delivered from the ammonia buffer tank 3 to obtain a mixed gas and send it to the gas preheating device 5;

[0030] The gas preheating device 5 exchanges heat with the flue gas released by the ammonia-fired glass melting furnace 6 and then transports the mixed gas to the ammonia-fired glass melting furnace 6 for combustion.

[0031] Specifically, in this embodiment, as ammonia is used as a fuel for the glass factory melting furnace, due to the large amount of ammonia gas, in order to ensure the continuous stability of the fuel and facilitate fuel transportation and storage, the glass factory mainly uses liquid ammonia, which is transported by a liquid ammonia tanker 15 and stored in a liquid ammonia storage tank 2. The liquid ammonia storage tank 2 can be composed of multiple storage tanks.

[0032] In a preferred embodiment of the present invention, a liquid ammonia pump 7 is provided on the liquid delivery pipeline between the liquid ammonia storage tank 2 and the gasification device 1, which is used to extract liquid ammonia from the liquid ammonia storage tank 2 and deliver it to the gasification device 1 for gasification. Figure 2 and Figure 3 As shown, the gasification device 1 includes a circulating water heat exchange system 11 and an air-temperature gasification device 12 .

[0033] In a preferred embodiment of the present invention, the circulating water heat exchange system 11 includes a plurality of cooling towers and hot water pools arranged on the glass production line, and each cooling tower and hot water pool is provided with a liquid ammonia hot water heat exchanger;

[0034] Liquid ammonia is transported to a liquid ammonia hot water heat exchanger and is successively heat exchanged and gasified through a cooling tower and a hot water tank to obtain ammonia gas.

[0035] Specifically, the liquid ammonia in the liquid ammonia storage tank 2 enters the circulating water heat exchange system 11 and the air-temperature gasification device 12 through the liquid ammonia pump 7, and the liquid ammonia is gasified by using the heat energy of the circulating return water of the main line and the public factory, air, etc., and the gasified ammonia enters the ammonia buffer tank 3. While using the circulating water heat energy, the circulating return water temperature of the main line and the public factory is reduced, and the energy consumption of the circulating water heat exchange system is reduced.

[0036] In a preferred embodiment of the present invention, an ammonia pressure reducing valve group 8 is provided on the gas pipeline between the ammonia buffer tank 3 and the gas mixing device 4 .

[0037] In a preferred embodiment of the present invention, a hydrogen buffer tank 9 is further included, which is connected to the gas mixing device 4 and is used to store hydrogen.

[0038] In a preferred embodiment of the present invention, a hydrogen pressure reducing valve group 10 is provided on the gas pipeline between the hydrogen buffer tank 9 and the gas mixing device 4 .

[0039] Specifically, in this embodiment, hydrogen and other fuel gases enter the hydrogen buffer tank 9, and after being stabilized, reduced and metered by the hydrogen pressure reducing valve group 10, enter the gas mixing device 4. At the same time, ammonia from the ammonia buffer tank 3, after being stabilized, reduced and metered by the ammonia pressure reducing valve group 8, also enters the gas mixing device 4 to be mixed with hydrogen and other fuel gases. Among them, the mixing ratio of ammonia and hydrogen and other fuels is allocated according to the Wobbe number and the combustion characteristics of the glass melting furnace, which will not be repeated here.

[0040] After ammonia and hydrogen and other fuel gases are mixed in proportion, they enter the gas preheating device 5 and exchange heat with the flue gas released by the ammonia-fired glass melting furnace 6, thereby increasing the temperature of the mixed gas, thereby increasing the combustion speed and combustion stability of the fuel gas.

[0041] In a preferred embodiment of the present invention, a gas distribution system is provided between the gas preheating device 5 and the ammonia-fired glass melting furnace 6. The gas distribution system divides the preheated mixed gas into the number of combustion branches required by the furnace spray gun, and then transports the mixed gas to the ammonia-fired glass melting furnace 6 for combustion. An ammonia and hydrogen pressure-stabilizing metering valve group 13 is provided on each combustion branch.

[0042] Specifically, in this embodiment, the high-temperature ammonia-hydrogen mixture from the gas preheating device 5 enters the fuel gas distribution system and is divided into the number of combustion branches required by the melting furnace spray gun. After each branch is pressure-stabilized and metered by the ammonia-hydrogen pressure-stabilizing and metering valve group 13, it enters the ammonia-fired glass melting furnace 6 for combustion.

[0043] Further preferably, the ammonia supply system of the present invention is an intelligent system, using PLC or DCS15, all parameters of the device, such as temperature, pressure, flow, alarm, liquid ammonia pump, heat exchanger, pressure stabilizing system, preheating device, gas distribution and other operating parameters, ammonia valve, hydrogen valve opening, ammonia flow, hydrogen flow, mixed gas ratio and other signals are connected to the control system, so that the ammonia system of the glass factory can automatically supply ammonia according to the actual needs of the glass melting furnace, the device can be intelligently controlled, and the signal can be transmitted remotely.

[0044] In a preferred embodiment of the present invention, a nitrogen oxide recovery device 14 is further included, which is connected to the gas preheating device 5 and is used to recover the flue gas after heat exchange.

[0045] Specifically, in this embodiment, the nitrogen oxide recovery device 14 is the nitrogen oxide recovery device 14 of the ammonia-fired glass melting furnace 6 itself, which recovers nitrogen oxides in the ammonia combustion process to achieve zero nitrogen oxide emissions.

[0046] In summary, the ammonia supply system of the present invention provides energy for the ammonia supply system of the present invention by making full use of the thermal energy of the gasification device on the glass production line and the flue gas of the ammonia-burning glass melting furnace, so as to gasify the liquid ammonia and preheat the ammonia, thereby effectively improving the energy utilization efficiency of the glass factory.

[0047] Preheating the mixed gas through flue gas solves the shortcomings of ammonia combustion such as high ignition temperature, large ignition energy, slow combustion speed, poor combustion stability and low combustion temperature when ammonia is used as fuel;

[0048] Make full use of the melting furnace's own nitrogen oxide recovery device to recover nitrogen oxides in the ammonia combustion process and achieve zero nitrogen oxide emissions.

[0049] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. An ammonia supply system for an ammonia-fired glass melting furnace, characterized in that: include: A gasification device, connected to the liquid ammonia storage tank and the ammonia buffer tank, respectively, for gasifying the liquid ammonia transported from the liquid ammonia storage tank and then sending it into the ammonia buffer tank; A gas mixing device, connected to the ammonia buffer tank and the gas preheating device respectively, the gas preheating device is connected to the ammonia-burning glass melting furnace, and the gas mixing device is used to mix the hydrogen delivered from the outside with the ammonia delivered from the ammonia buffer tank to obtain a mixed gas and deliver it to the gas preheating device; The gas preheating device exchanges heat between the mixed gas and the flue gas released by the ammonia-fired glass melting furnace and then transports the mixed gas to the ammonia-fired glass melting furnace for combustion.

2. The ammonia supply system according to claim 1, characterized in that: The gasification device comprises a circulating water heat exchange system and an air-temperature gasification device.

3. The ammonia supply system according to claim 2, characterized in that: The circulating water heat exchange system comprises a plurality of cooling towers and hot water pools arranged on the glass production line, each of the cooling towers and the hot water pool is provided with a liquid ammonia hot water heat exchanger; Liquid ammonia is transported to the liquid ammonia hot water heat exchanger and is sequentially heat-exchanged and gasified through the cooling tower and the hot water tank to obtain the ammonia gas.

4. The ammonia supply system according to claim 1, characterized in that: A liquid ammonia pump is provided on the liquid delivery pipeline between the liquid ammonia storage tank and the gasification device, which is used to extract the liquid ammonia from the liquid ammonia storage tank and send it to the gasification device for gasification.

5. The ammonia supply system according to claim 1, characterized in that: An ammonia pressure reducing valve group is provided on the gas transmission pipeline between the ammonia buffer tank and the gas mixing device.

6. The ammonia supply system according to claim 1, characterized in that: It also includes a hydrogen buffer tank connected to the gas mixing device and used to store the hydrogen.

7. The ammonia supply system according to claim 6, characterized in that: A hydrogen pressure reducing valve group is provided on the gas transmission pipeline between the hydrogen buffer tank and the gas mixing device.

8. The ammonia supply system according to claim 1, characterized in that: A gas distribution system is provided between the gas preheating device and the ammonia-fired glass melting furnace. The gas distribution system divides the preheated mixed gas into the number of combustion branches required by the furnace spray gun, and then transports the mixed gas to the ammonia-fired glass melting furnace for combustion.

9. The ammonia supply system according to claim 8, characterized in that: Each of the combustion branches is respectively provided with an ammonia and hydrogen pressure-stabilizing metering valve group.

10. The ammonia supply system according to claim 1, characterized in that: It also includes a nitrogen oxide recovery device connected to the gas preheating device for recovering the flue gas after heat exchange.

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