Natural gas ammonia-doped distributed heating furnace based on ammonia gas cracking

Abstract

The invention discloses a natural gas ammonia-doped distributed heating furnace based on ammonia gas cracking, relates to the technical field of distributed heating, and solves the problem that a large amount of carbon dioxide and other greenhouse gases are generated in the fuel combustion process of a traditional heating system. An ammonia thermal cracking system, a mixing system and a heating furnace heat supply system are communicated in sequence; the ammonia thermal cracking system comprises an ammonia storage tank and an ammonia gas cracking chamber; the ammonia storage tank is communicated with one end of the ammonia gas cracking chamber; a catalyst and a heater are arranged in the ammonia gas cracking chamber; the other end of the ammonia gas cracking chamber communicates with the mixing system, and hydrogen generated by ammonia gas cracking is mixed with natural gas in the mixing system and introduced into a heating furnace of the heating furnace heating system to be combusted. The proportion of natural gas in combustion is reduced through hydrogen generated by ammonia gas cracking, and the problem of high emission of nitric oxide is avoided while emission of carbon dioxide is reduced; and waste heat of flue gas after combustion is used for providing heat for thermal cracking of ammonia gas, so that the energy utilization efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of distributed heating, and in particular to a natural gas-ammonia-blended distributed heating furnace based on ammonia cracking. Background Art

[0002] Faced with the severe challenge of global climate change, it is imperative to find efficient and clean heating solutions. Traditional heating systems rely on fossil fuels such as coal and natural gas, which produce a large amount of carbon dioxide and other greenhouse gases during combustion, exacerbating global warming. In addition, with the increase in energy demand and the improvement of environmental protection awareness, the development of efficient and clean heating technology has become an urgent problem to be solved. Ammonia is a carbon-free fuel that only produces nitrogen and water after combustion, and does not release carbon dioxide. It is one of the ideal clean energy sources. Summary of the invention

[0003] In order to solve the problem that a large amount of carbon dioxide and other greenhouse gases will be generated during the combustion of fuel in the traditional heating system mentioned above, the present invention proposes a natural gas-ammonia-blended distributed heating furnace based on ammonia cracking. The present invention generates hydrogen by cracking ammonia and then mixes it with natural gas for combustion, which not only improves the combustion stability but also achieves low carbon emissions, thereby solving the problem of gradually increasing carbon emissions from existing heating furnaces.

[0004] The present invention proposes a natural gas ammonia-blended distributed heating furnace based on ammonia cracking, which specifically comprises an ammonia thermal cracking system, a blending system and a heating furnace heating system, wherein the ammonia thermal cracking system, the blending system and the heating furnace heating system are connected in sequence; the ammonia thermal cracking system comprises an ammonia storage tank and an ammonia cracking chamber, wherein the ammonia storage tank is connected to one end of the ammonia cracking chamber; a catalyst and a heater are arranged in the ammonia cracking chamber; the other end of the ammonia cracking chamber is connected to the blending system, and hydrogen generated by ammonia cracking is mixed with natural gas in the blending system and introduced into the heating furnace of the heating furnace heating system for combustion.

[0005] Furthermore, the blending system includes a regulating valve, a natural gas tank and a blending chamber, the outlet of the ammonia cracking chamber is connected to the inlet of the regulating valve, the outlet of the regulating valve is connected to one inlet of the blending chamber, the natural gas tank is connected to another inlet of the blending chamber, and the outlet of the blending chamber is connected to the heating furnace.

[0006] Furthermore, a valve is provided between the natural gas tank and the mixing chamber.

[0007] Furthermore, the heating furnace includes an air inlet pipe, a burner, a water inlet pipe, a heat exchanger, a water outlet pipe and a combustion furnace. A burner is arranged at the bottom of the combustion furnace, an air inlet pipe is arranged on the burner, and the air inlet pipe is connected to the mixing system; a heat exchanger is arranged in the combustion furnace; the inlet of the heat exchanger is connected to the water inlet pipe, and the outlet is connected to the water outlet pipe; a flue gas pipe is arranged at the upper end of the combustion furnace.

[0008] Furthermore, the flue gas pipe is connected to the heater.

[0009] Furthermore, a flue gas fan is provided on the flue gas pipe.

[0010] Furthermore, a plurality of combustion ports are arranged on the surface of the burner facing the interior of the combustion furnace, and a burner regulating valve is arranged on the burner.

[0011] Furthermore, the water outlet pipe is provided with a water pump, a temperature gauge and a pressure gauge.

[0012] Furthermore, the heating furnace heating system also includes a controller, which is connected to the burner control valve, temperature gauge, pressure gauge and flue gas fan.

[0013] Furthermore, the catalyst is a Ni-based catalyst, and is disposed in a wall coating manner.

[0014] The beneficial effects of the natural gas-ammonia-blended distributed heating furnace based on ammonia cracking described in the present invention are:

[0015] (1) The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking described in the present invention adopts a distributed energy supply mode, closely combines energy production and use, and improves energy utilization efficiency. This flexible and efficient heating method not only reduces the loss during energy transmission, but also meets the personalized heating needs of different regions and users, and improves the quality of life of residents. This technology provides a new technical path for achieving carbon peak and carbon neutrality goals, and is of great significance for building a green, low-carbon and sustainable energy system.

[0016] (2) The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking described in the present invention uses a catalyst in an ammonia cracking chamber to crack ammonia into hydrogen, and then mixes the hydrogen with natural gas for combustion, thereby improving the calorific value and combustion efficiency of the fuel, thereby improving the heating efficiency of the heating furnace;

[0017] (3) The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking described in the present invention utilizes a catalyst to catalyze the thermal cracking of ammonia to produce hydrogen that is mixed with natural gas, thereby reducing the combustion ratio of hydrocarbons and reducing carbon dioxide emissions. At the same time, it avoids direct combustion of ammonia and reduces the emission of pollutants such as nitrogen oxides.

[0018] (4) The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking described in the present invention can provide heating according to the needs of the heating area, thereby improving the flexibility of heating and realizing distributed heating.

[0019] (5) The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking described in the present invention utilizes combustion flue gas to provide the required heat for thermal cracking of ammonia, thereby improving the thermal energy utilization efficiency by utilizing waste heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] In the attached picture:

[0022] Figure 1 It is a structural schematic diagram of a natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to the present invention;

[0023] Among them: 1-ammonia storage tank; 2-catalyst; 3-ammonia cracking chamber; 4-heater; 5-regulating valve; 6-natural gas tank; 7-mixing chamber; 8-air inlet; 9-burner; 10-burning port; 11-burner regulating valve; 12-water inlet pipe; 13-heat exchanger; 14-water outlet pipe; 15-combustion furnace; 16-water pump; 17-temperature gauge; 18-pressure gauge; 19-controller; 20-flue gas pipe; 21-flue gas fan. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0025] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0027] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Specific implementation method 1: See Figure 1 The embodiment is described in detail. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking described in the embodiment specifically includes an ammonia thermal cracking system, a blending system and a heating furnace heating system, which are connected in sequence; ammonia is cracked into hydrogen in the ammonia thermal cracking system, the hydrogen is introduced into the blending system to mix with natural gas, and the mixed gas is introduced into the heating furnace heating system to burn, and the heat generated by the combustion is used to heat the heating water.

[0029] The ammonia thermal cracking system includes an ammonia storage tank 1 and an ammonia cracking chamber 3, and the ammonia storage tank 1 is connected to one end of the ammonia cracking chamber 3; a catalyst 2 and a heater 4 are arranged in the ammonia cracking chamber 3, and the heater 4 provides heat for ammonia cracking; the other end of the ammonia cracking chamber 3 is connected to the mixing system, and the hydrogen produced by the cracking of ammonia is mixed with natural gas in the mixing system and introduced into the heating furnace of the heating furnace heating system for combustion. The ammonia cracking chamber 3 adopts a plate reactor type, and the channel adopts a serpentine channel and only adds cylindrical fins in the front section of the reactor, and the number of fins gradually decreases. The new type of ammonia decomposition plate reactor improves the effect of the ammonia decomposition rate and can obtain a higher ammonia decomposition rate at the same reactor volume. At the same time, the ammonia decomposition plate reactor can reduce the reactor volume at the same ammonia decomposition rate and reduce the space required for the overall system. The catalyst 2 adopts a Ni-based catalyst (NiO-Al 2 O 3 -additives) and the use of wall-coated catalysts improves the reactor heat transfer limitations and achieves low pressure drop and high catalyst activity.

[0030] The blending system includes a regulating valve 5, a natural gas tank 6 and a blending chamber 7. The outlet of the ammonia cracking chamber 3 is connected to the inlet of the regulating valve 5, the outlet of the regulating valve 5 is connected to one inlet of the blending chamber 7, the natural gas tank 6 is connected to another inlet of the blending chamber 7, and the outlet of the blending chamber 7 is connected to the heating furnace. The regulating valve 5 controls the gas produced after the cracking of ammonia and the natural gas to enter the blending chamber to mix in different blending ratios in the blending chamber 7, so as to meet the requirements of the hydrogen blending ratio (5% to 20%) in different occasions, achieve the purpose of carbon emission requirements in different regions, and ensure that the mixed gas is stably burned in the burner 9, improve the instability of ammonia combustion and high nitrogen oxide emissions, and reduce the carbon dioxide emissions of burning natural gas;

[0031] A valve is provided between the natural gas tank 6 and the mixing chamber 7 to control the input of natural gas.

[0032] The heating furnace includes an air inlet pipe 8, a burner 9, a water inlet pipe 12, a heat exchanger 13, a water outlet pipe 14 and a combustion furnace 15. The burner 9 is arranged at the bottom of the combustion furnace 15, and the air inlet pipe 8 is arranged on the burner 9. The air inlet pipe 8 is connected to the mixing system; a heat exchanger 13 is arranged in the combustion furnace 15, and the heat exchanger 13 adopts a spiral winding type, which increases the heat exchange area, improves the heat utilization rate, and accelerates the water temperature rising rate; the inlet of the heat exchanger 13 is connected to the water inlet pipe 12, and circulating water is provided to the heat exchanger 13 through the water inlet pipe 12, and the outlet is connected to the water outlet pipe 14; a flue gas pipe 20 is arranged at the upper end of the combustion furnace 15.

[0033] The flue gas pipe 20 is connected to the heater 4, and the waste heat of the combustion flue gas generated in the combustion furnace 15 is used to provide the required heat for the thermal cracking of ammonia, so as to achieve the purpose of waste heat utilization and improve the efficiency of energy utilization. The flue gas pipe 20 is provided with a flue gas fan 21, and the purpose of regulating the flue gas flux is achieved by adjusting the speed of the flue gas fan 21, and the purpose of controlling the flue gas flux is to meet the thermal cracking temperature requirement of ammonia in the ammonia cracking chamber 3.

[0034] The surface of the burner 9 facing the inside of the combustion furnace 15 is provided with a plurality of combustion ports 10, and the burner 9 is provided with a burner control valve 11. The burner control valve 11 controls the fuel flux of the air inlet 8 and the opening size of the combustion ports 10 to control the combustion of the gas.

[0035] The outlet pipe 14 is provided with a water pump 16, a thermometer 17 and a pressure gauge 18. The heating furnace heating system also includes a controller 19, which is connected to the burner control valve 11, the thermometer 17, the pressure gauge 18 and the flue gas fan 21 respectively. The thermometer 17 uses a Celsius temperature scale, and the specific water temperature is observed by observing the dial, and the specific water temperature is fed back to the controller 19, and then the burner 9 is controlled by the controller 19 to achieve the purpose of controlling the water temperature. By observing the dial of the pressure gauge 18 to check whether the pressure meets the equipment requirements, after feeding back to the controller 19, the controller 19 controls the water pump 16 to meet the water pressure requirements. The burner control valve 11 is controlled by the controller 19, and the burner control valve 11 controls the fuel flux of the air inlet 8 and the opening size of the combustion port 10 to accurately ensure the heating temperature. The controller 19 adjusts the flue gas flux by controlling the speed of the flue gas fan 21.

[0036] Summarizing the above implementation cases, the natural gas ammonia distributed heating furnace based on ammonia cracking described in the present invention adopts a distributed energy supply mode, closely combines energy production and use, and improves energy utilization efficiency. This flexible and efficient heating method not only reduces the loss in the energy transmission process, but also meets the personalized heating needs of different regions and different users, and improves the quality of life of residents. This technology provides a new technical path for achieving carbon peak and carbon neutrality goals, and is of great significance for building a green, low-carbon and sustainable energy system. The natural gas ammonia distributed heating furnace based on ammonia cracking described in the present invention improves the calorific value and combustion efficiency of the fuel by using catalyst 2 in the ammonia cracking chamber 3 to crack ammonia into hydrogen, and mixes hydrogen and natural gas for combustion, thereby improving the heating efficiency of the heating furnace; the natural gas ammonia distributed heating furnace based on ammonia cracking described in the present invention uses catalyst 2 to catalyze the thermal cracking of ammonia to produce hydrogen and mix with natural gas to reduce the combustion ratio of hydrocarbons, reduce carbon dioxide emissions, and avoid direct combustion of ammonia, reducing the emission of pollutants such as nitrogen oxides. The distributed heating furnace with natural gas and ammonia mixed with ammonia based on ammonia cracking described in the present invention can provide heating according to the needs of the heating area, thereby improving the flexibility of heating and realizing distributed heating. The distributed heating furnace with natural gas and ammonia mixed with ammonia based on ammonia cracking described in the present invention utilizes combustion flue gas to provide the required heat for thermal cracking of ammonia, and the utilization of waste heat improves the utilization efficiency of thermal energy.

[0037] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the invention. It can also be a reasonable combination of the features recorded in the above implementation methods. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A natural gas ammonia-blended distributed heating furnace based on ammonia cracking, characterized in that: The invention comprises an ammonia thermal cracking system, a blending system and a heating furnace heating system, wherein the ammonia thermal cracking system, the blending system and the heating furnace heating system are connected in sequence; the ammonia thermal cracking system comprises an ammonia storage tank (1) and an ammonia cracking chamber (3), wherein one end of the ammonia storage tank (1) and the ammonia cracking chamber (3) are connected; a catalyst (2) and a heater (4) are arranged in the ammonia cracking chamber (3); the other end of the ammonia cracking chamber (3) is connected to the blending system, and hydrogen generated by ammonia cracking is mixed with natural gas in the blending system and introduced into the heating furnace of the heating furnace heating system for combustion.

2. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 1 is characterized in that: The blending system comprises a regulating valve (5), a natural gas tank (6) and a blending chamber (7); the outlet of the ammonia cracking chamber (3) is connected to the inlet of the regulating valve (5), the outlet of the regulating valve (5) is connected to one inlet of the blending chamber (7), the natural gas tank (6) is connected to the other inlet of the blending chamber (7), and the outlet of the blending chamber (7) is connected to a heating furnace.

3. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 2 is characterized in that: A valve is provided between the natural gas tank (6) and the mixing chamber (7).

4. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 1 is characterized in that: The heating furnace comprises an air inlet pipe (8), a burner (9), a water inlet pipe (12), a heat exchanger (13), a water outlet pipe (14) and a combustion furnace (15); the burner (9) is arranged at the bottom of the combustion furnace (15); the burner (9) is arranged with an air inlet pipe (8); the air inlet pipe (8) is connected to a mixing system; a heat exchanger (13) is arranged in the combustion furnace (15); the inlet of the heat exchanger (13) is connected to the water inlet pipe (12), and the outlet is connected to the water outlet pipe (14); and a smoke pipe (20) is arranged at the upper end of the combustion furnace (15).

5. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 4 is characterized in that: The flue gas pipe (20) is in communication with the heater (4).

6. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 4 is characterized in that: The smoke pipe (20) is provided with a smoke fan (21).

7. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 6 is characterized in that: A plurality of combustion ports (10) are arranged on the surface of the burner (9) facing the interior of the combustion furnace (15), and a burner regulating valve (11) is arranged on the burner (9).

8. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 7 is characterized in that: The water outlet pipe (14) is provided with a water pump (16), a temperature gauge (17) and a pressure gauge (18).

9. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 8 is characterized in that: The heating furnace heating system also includes a controller (19), which is connected to the burner control valve (11), the temperature gauge (17), the pressure gauge (18) and the flue gas fan (21).

10. The natural gas-ammonia-blended distributed heating furnace based on ammonia cracking according to claim 1, characterized in that: The catalyst (2) is a Ni-based catalyst, and is disposed in a wall coating manner.

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