Ammonia gas modified fuel and combustion device and method thereof

Abstract

The invention provides an ammonia gas modified fuel and a combustion device and method thereof. The ammonia gas modified fuel comprises an igniter, and the igniter is fixed in an ignition mechanism; a heating mechanism for evaporating and gasifying a methanol solution is mounted on the side wall of the first conveying pipe; a preheating and mixing mechanism for uniformly mixing and heating ammonia gas and methanol is mounted on the side wall of the heating mechanism; feeding mechanisms for conveying methanol or nitromethane are mounted on the side walls of the heating mechanism and the ignition mechanism, a mixing mechanism for preliminarily mixing gasified methanol and ammonia gas is mounted between the heating mechanism and the preheating and mixing mechanism, and a hearth for sufficiently combusting the ammonia gas is mounted at one end of the preheating and mixing mechanism; the ammonia gas modified fuel, the combustion device and the combustion method have the advantages that the ammonia gas is rapidly ignited, and sufficient combustion of the ammonia gas is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of ammonia combustion, and in particular to an ammonia modified fuel, a combustion device and a method thereof. Background Art

[0002] Excessive exploitation and consumption of fossil fuels have severely restricted the sustainable development of my country's economy. The combustion of fossil fuels releases large amounts of CO2, SO2, NO2 and particulate matter PM, leading to acid rain, haze and respiratory diseases. Ammonia, as a zero-carbon fuel, can be directly used as fuel for coal-fired boilers. Compared with traditional fossil fuels, it can significantly reduce carbon dioxide emissions. Ammonia, as a carrier of hydrogen energy, is a new type of renewable zero-carbon fuel.

[0003] The auto-ignition point of ammonia is 651°C, which is much higher than the auto-ignition point of diesel at 210°C. This makes ammonia difficult to ignite and the ignition delay is as long as 3-5 times, which seriously reduces the efficiency of the boiler. In addition, the combustion speed of ammonia is extremely slow and the flame propagation is unstable, which can easily lead to incomplete combustion of ammonia, reduce the utilization efficiency of ammonia, and produce pollutants such as nitric oxide and nitrogen dioxide.

[0004] Therefore, it is necessary to provide a new ammonia modified fuel, combustion device and method thereof to solve the above technical problems. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide an ammonia modified fuel, a combustion device and a method thereof which can quickly ignite ammonia and ensure full combustion of ammonia.

[0006] In order to solve the above technical problems, the ammonia modified fuel combustion device provided by the present invention includes: an igniter, the igniter is fixed inside the ignition mechanism, the ignition mechanism includes a first delivery pipe, the igniter is installed at the center of the interior of the first delivery pipe, the interior of the first delivery pipe is rotatably connected to the blades, a plurality of the blades are obliquely installed on the side wall of the fixed shaft, and the fixed shaft is rotatably connected to the side wall of the igniter; one end of the first delivery pipe is fixedly connected to the mounting pipe, a second porous medium layer is arranged inside the mounting pipe, and the interior of the second porous medium layer is fixedly connected to a fixed rod with hemispherical ends; a third porous medium layer is arranged at one end of the mounting pipe, and the second porous medium layer is connected to the third porous medium layer; a heating mechanism for evaporating and gasifying the methanol solution is installed on the side wall of the heating mechanism, and a preheating mixing mechanism for uniformly mixing and heating ammonia and methanol is installed on the side wall of the heating mechanism; the preheating mixing mechanism includes a third delivery pipe, the heating mechanism The side wall of the structure is covered with the third delivery pipe, and one end of the third delivery pipe is obliquely installed with an air inlet pipe for conveying ammonia; a fourth porous medium layer is arranged inside the third delivery pipe, and the other end of the third delivery pipe is fixedly connected to a partition, and a plurality of nozzles are obliquely installed on the side wall of the partition, and the air outlets of the nozzles are obliquely aligned with the side wall of the third porous medium layer; at the connection between the partition and the nozzle, the side wall of the partition is an arc-shaped structure; a fixing ring with an arc-shaped side wall is installed on the inner side wall of the third delivery pipe, and a plurality of return pipes are installed on the side wall of the third delivery pipe, one end of the return pipe abuts against the fixing ring, and the other end side wall of the return pipe is hook-shaped; the side walls of the heating mechanism and the ignition mechanism are both installed with a feeding mechanism for conveying methanol or nitromethane, a mixing mechanism for preliminarily mixing gasified methanol and ammonia is installed between the heating mechanism and the preheating mixing mechanism, and a furnace for fully burning ammonia is installed at one end of the preheating mixing mechanism.

[0007] Preferably, the heating mechanism includes a second conveying pipe, the side wall of the first conveying pipe is sleeved with the second conveying pipe, and a spiral ring is installed between the first conveying pipe and the second conveying pipe; a plurality of spiral coils are installed inside the first conveying pipe, and one end of the spiral coil enters the interior of the first conveying pipe.

[0008] Preferably, the mixing mechanism includes a first blocking ring, a first blocking ring with an arc-shaped side wall is installed at one end of the second conveying pipe, a second blocking ring with an arc-shaped side wall is installed on the side wall of the first conveying pipe, and the first blocking ring is located inside the second blocking ring; a third blocking ring with a triangular cross-section is installed on the side wall of the second conveying pipe, a slide groove with an arc-shaped side wall is provided inside the third blocking ring, and one end of the second blocking ring is located inside the slide groove.

[0009] Preferably, one end of the mounting tube, one end of the second delivery tube, the center of the side wall of the first delivery tube, and the center of the side wall of the third delivery tube are all funnel-shaped structures, and the side wall of the third delivery tube in the funnel shape is aligned with the air inlet end of the second blocking ring.

[0010] Preferably, the feeding mechanism includes a feeding pipe, and the side walls of the first conveying pipe and the second conveying pipe are both installed with feeding pipes, the side walls of the feeding pipes are installed with water pipes with "L"-shaped side walls, and an atomizing nozzle is installed at one end of the water pipe; a dispersion net is installed at the connection between the feeding pipe and the first conveying pipe, and the dispersion net is a hollow conical structure.

[0011] Preferably, the air inlet of the return pipe is located between the fourth porous medium layer and the nozzle, and the air outlet of the return pipe is aligned with the first blocking ring.

[0012] Preferably, there is a mounting tube between the fourth porous medium layer and the second porous medium layer, and the size of the internal voids of the fourth porous medium layer gradually increases along the outer side toward the inner side of the third conveying tube, and the size of the internal voids of the second porous medium layer gradually increases along the inner side toward the outer side of the first conveying tube.

[0013] Preferably, the spiral coil is located between the second porous medium layer and the igniter, and the spiral coil is located obliquely inside the first delivery pipe and the second delivery pipe.

[0014] Preferably, one end of the furnace is fixedly connected to the partition, and the center of the interior of the partition is fixedly connected to the mounting pipe; the smoke exhaust pipe is installed at the top of the furnace, and a first porous medium layer with an arc-shaped end is installed inside the furnace, and the center of the first porous medium layer is aligned with the third porous medium layer.

[0015] A combustion method of an ammonia modified fuel comprises the following steps: Step 1: delivering nitromethane and oxygen into the ignition mechanism through one of the feeding mechanisms, delivering methanol and oxygen into the heating mechanism through another of the feeding mechanisms, and delivering ammonia into the third water pipe; Step 2: The vortex generated by the rotation of the blades evenly mixes the nitromethane and oxygen, which are then ignited by the igniter, rapidly increasing the temperature inside the first delivery pipe; the methanol and oxygen inside the second water delivery pipe are heated, and the methanol solution quickly evaporates and vaporizes into gas in the oxygen, so that the two are evenly mixed. The spiral coils create turbulence, improving heat exchange efficiency, thereby further increasing the temperature of the gas inside the second delivery pipe; Step 3: The high-temperature gas in the second delivery pipe enters the third water delivery pipe through the mixing mechanism. The mixing mechanism increases the mixing distance and time of ammonia, oxygen and methanol, thereby improving the uniformity of the mixing of the three. Step 4: The mixed gas inside the third water pipe enters the interior of the fourth porous medium layer. As the burning nitromethane enters the interior of the second porous medium layer and burns, the temperature inside the second porous medium layer continues to rise. The heat dissipated by the second porous medium layer causes the temperature of the fourth porous medium layer to continue to rise. The mixed gas is continuously mixed in the fourth porous medium layer through continuous vortexes, diversions and other disturbances, and the gas temperature inside the fourth porous medium layer continues to rise. By improving the size of the internal gap between the second porous medium layer and the fourth porous medium layer, the heat exchange efficiency between the two is improved and the temperature of the gas inside the fourth porous medium layer is increased. The fourth porous medium layer enters the interior of the nozzle, and the mixed gas outside the fourth porous medium layer enters the interior of the return pipe, so that part of the gas heated by the fourth porous medium layer re-enters the interior of the fourth porous medium layer for reheating and mixing, thereby increasing the temperature of the gas ejected from the fourth porous medium layer and improving the uniformity of the mixing of ammonia, oxygen and methanol. Step 5: The mixed gas ejected from the inside of the nozzle rotates along the side wall of the third porous medium layer, and the flame on the surface of the third porous medium layer is drawn into the mixed gas flow. The mixed gas flow is preheated and is in a high-temperature state, so that the methanol gas is evenly distributed in the mixed gas flow. Methanol gas is flammable. The flame first ignites the methanol, and the burning methanol quickly ignites the surrounding preheated ammonia. The burning ammonia then ignites the surrounding methanol, so that the flame propagates stably and quickly inside the mixed gas, quickly igniting the ammonia, and the ignited gas enters the interior of the first porous medium layer and is fully burned.

[0016] An ammonia modified fuel consists of methanol, ammonia and nitromethane. The molar fraction of nitromethane in the ammonia modified fuel ranges from 16.7% to 28.6%, and the molar ratio of ammonia to methanol is 4:1.

[0017] Compared with related technologies, the ammonia modified fuel, combustion device and method provided by the present invention have the following beneficial effects: The present invention provides an ammonia modified fuel, a combustion device, and a method thereof. During use, nitromethane burns inside the first water pipe. Nitromethane is flammable and generates high temperatures during combustion, thereby rapidly increasing the temperature inside the first water pipe, heating methanol and oxygen inside the second water pipe. The methanol solution rapidly evaporates and vaporizes in the oxygen to form a gas, and the two are evenly mixed. After combustion, the nitromethane enters the interior of the second porous medium layer, causing the temperature inside the second porous medium layer to continuously increase. Through heat exchange, the heat dissipated by the second porous medium layer causes the temperature of the fourth porous medium layer to continuously increase. And because the fixed rod and the second porous medium layer block, the combustion time of nitromethane inside the first delivery pipe is increased, thereby increasing the temperature of the gas inside the second delivery pipe; the high-temperature gas inside the second delivery pipe enters the interior of the third water pipe through the mixing mechanism, and the mixing mechanism increases the mixing distance and time of ammonia, oxygen and methanol, thereby improving the uniformity of the mixing of the three. Part of the methanol is liquefied due to the decrease in temperature, and the liquefied methanol dissolves ammonia, so that part of the ammonia is stored in the methanol droplets; the mixed gas inside the third water pipe is continuously mixed through continuous vortex, diversion and other disturbances inside the fourth porous medium layer, and at the same time, the gas temperature inside the fourth porous medium layer is continuously rising, and the methanol is gasified again while releasing the ammonia therein, increasing the gas The fluidity between the flows is improved, and methanol is evaporated and gasified multiple times, which is conducive to the uniform distribution of methanol inside the ammonia; by improving the size of the internal gaps between the second porous medium layer and the fourth porous medium layer, the heat exchange efficiency of the two is improved and the temperature of the gas inside the fourth porous medium layer is increased; and by setting the return pipe, the mixed gas with the highest temperature on the innermost side of the fourth porous medium layer enters the interior of the nozzle, and the mixed gas outside the fourth porous medium layer enters the interior of the fourth porous medium layer again through the return pipe, so that part of the gas heated by the fourth porous medium layer each time enters the interior of the fourth porous medium layer again for reheating and mixing, thereby increasing the temperature of the gas ejected from the interior of the fourth porous medium layer and improving the uniformity of the mixing of ammonia, oxygen and methanol; The burning nitromethane enters the interior of the third porous medium layer through the second porous medium layer. The third porous medium layer is cylindrical, so that the flame of the nitromethane combustion is evenly distributed on the surface of the third porous medium layer, and the heat generated by the combustion of nitromethane quickly increases the internal temperature of ammonia, oxygen and methanol and allows the three to mix evenly, which is convenient for the ignition of ammonia; the multiple mixed gases sprayed from the nozzle rotate along the side wall of the third porous medium layer, and the mixed gases increase the contact area with the third porous medium layer after being diverted by the nozzle, and the flame on the surface of the third porous medium layer is drawn into the mixed gas flow, so that the nitromethane in the combustion process is quickly integrated into the mixed gas flow. The mixed gas flow is in a high temperature state after preheating, and the methanol gas is evenly distributed in the mixed gas flow. The methanol gas is flammable, and the flame first ignites the methanol, and the burning methanol quickly ignites the surrounding preheated ammonia. The burning ammonia then ignites the surrounding methanol. The methanol causes the flame to spread stably and quickly inside the mixed gas and quickly ignites the ammonia. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of a preferred embodiment of the ammonia modified fuel, combustion device and method provided by the present invention; Figure 2 for Figure 1 An enlarged schematic diagram of the structure at point A is shown; Figure 3 for Figure 1 An enlarged schematic diagram of the structure at point B is shown; Figure 4 for Figure 1 An enlarged schematic diagram of the structure at position C is shown; Figure 5 for Figure 1 An enlarged schematic diagram of the structure at D is shown; Figure 6 for Figure 1 A side view of the partition structure shown; Figure 7 for Figure 1 Schematic diagram of the blade structure shown; Figure 8 Schematic diagram of laminar flame speed of the blended fuel at different equivalence ratios and nitromethane addition amounts; Figure 9 Figure 2 is a graph showing the ignition delay time data at different ammonia / methanol / nitromethane mixture ratios.

[0019] Numbers in the figure: 1. igniter, 2. furnace, 21. first porous medium layer, 22. exhaust pipe, 3. feeding mechanism, 31. feeding pipe, 32. water pipe, 33. atomizing nozzle, 34. dispersion network, 4. ignition mechanism, 41. first conveying pipe, 42. fixed shaft, 43. blade, 44. fixed rod, 45. second porous medium layer, 46. third porous medium layer, 47. mounting pipe, 5. heating mechanism, 51. second conveying pipe, 52. spiral ring, 53. spiral ring, 6. preheating mixing mechanism, 61. third conveying pipe, 62. air inlet pipe, 63. reflux pipe, 64. fourth porous medium layer, 65. nozzle, 66. partition, 67. fixed ring, 7. mixing mechanism, 71. first blocking ring, 72. second blocking ring, 73. third blocking ring, 74. slide groove. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] See also Figures 1 to 7 , Figure 1 A schematic structural diagram of a preferred embodiment of the ammonia modified fuel, combustion device and method provided by the present invention; Figure 2 for Figure 1 An enlarged schematic diagram of the structure at point A is shown; Figure 3 for Figure 1 An enlarged schematic diagram of the structure at point B is shown; Figure 4 for Figure 1 An enlarged schematic diagram of the structure at position C is shown; Figure 5 for Figure 1 An enlarged schematic diagram of the structure at D is shown; Figure 6 for Figure 1 The partition structure shown is a side view; Figure 7 for Figure 1The blade structure diagram shown in the figure. The ammonia modified fuel combustion device includes: an igniter 1, which is fixed inside the ignition mechanism 4, and the ignition mechanism 4 includes a first delivery pipe 41. The igniter 1 is installed in the center of the first delivery pipe 41. The first delivery pipe 41 is internally connected to the blade 43, and the plurality of blades 43 are obliquely installed on the side wall of the fixed shaft 42, and the fixed shaft 42 is rotatably connected to the side wall of the igniter 1; when nitromethane and oxygen enter the first delivery pipe 41, the mixed gas and the inclined blade 43 are rotated. 3 contacts, pushing the blades 43 and the fixed shaft 42 to rotate. The rotation of the blades 43 forms a vortex on the mixed gas, which evenly mixes the nitromethane droplets with the oxygen. The side wall of the first delivery pipe 41 is funnel-shaped in the middle, so that the mixed gas is accelerated again inside the first gas delivery pipe 41 and ignited by the igniter 1. The flame generated by the ignition rotates inside the first gas delivery pipe 41 and moves toward the mounting pipe 47. Nitromethane is flammable and generates high temperature during combustion, thereby rapidly increasing the temperature inside the first delivery pipe 41.

[0022] A heating mechanism 5 for evaporating and gasifying the methanol solution is installed on the side wall of the first delivery pipe 41, and the heating mechanism 5 includes a second delivery pipe 51. The side wall of the first delivery pipe 41 is covered with the second delivery pipe 51, and a spiral ring 52 is installed between the first delivery pipe 41 and the second delivery pipe 51; the spiral ring 53 is located between the second porous medium layer 45 and the igniter 1, and the spiral ring 53 is tilted inside the first delivery pipe 41 and the second delivery pipe 51; when the methanol solution and oxygen enter the interior of the second delivery pipe 51, the solution and oxygen perform a spiral motion along the spiral ring 52 inside the second delivery pipe 51, so that the methanol solution and oxygen are fully mixed, and the solution and oxygen rotate inside the second delivery pipe 51 and move toward the direction of the spiral ring 64. At this time, due to the rapid increase in the temperature of the side wall of the first delivery pipe 41 when nitromethane burns, the high-temperature first The contact with the delivery pipe 41 causes the temperature of the mixed gas to continue to rise, and the mixed gas rotates continuously, which facilitates the heat on the surface of the first delivery pipe 41 to dissipate into the mixed gas, causing the methanol solution to quickly evaporate and gasify into gas in the oxygen. During the evaporation of methanol, the volume increases and expands outward, causing the methanol gas and oxygen to mix again, thereby improving the uniformity of the mixing of the two; a plurality of spiral coils 64 are installed inside the first delivery pipe 41, and one end of the spiral coil 64 enters the interior of the first delivery pipe 41; the spiral coils 64 turbulently affect the gas inside the first delivery pipe 41 and the second delivery pipe 51 respectively, thereby increasing the heat exchange efficiency of the internal gas of the two, and rapidly increasing the temperature of the gas inside the second delivery pipe 51, which is beneficial to the evaporation and gasification of methanol, and the spiral coils 64 are inclined to increase the contact area between the spiral coils 64 and the gas, thereby further improving the heat exchange efficiency and further increasing the temperature of the gas inside the second delivery pipe 51.

[0023] The side wall of the heating mechanism 5 is installed with a preheating mixing mechanism 6 for uniformly mixing and heating ammonia and methanol, and a mixing mechanism 7 for preliminarily mixing gasified methanol and ammonia is installed between the heating mechanism 5 and the preheating mixing mechanism 6; the preheating mixing mechanism 6 includes a third delivery pipe 61, the side wall of the heating mechanism 5 is covered with the third delivery pipe 61, and one end of the third delivery pipe 61 is obliquely installed with an intake pipe 62 for delivering ammonia; the mixing mechanism 7 includes a first blocking ring 71, one end of the second delivery pipe 51 is installed with a first blocking ring 71 with an arc-shaped side wall, and the side wall of the first delivery pipe 41 is installed with a second blocking ring 72 with an arc-shaped side wall, and the first blocking ring 71 is located inside the second blocking ring 72; the side wall of the second delivery pipe 51 is installed with a third blocking ring 73 with a triangular cross-section, and the interior of the third blocking ring 73 is provided with a slide groove 74 with an arc-shaped side wall, and one end of the second blocking ring 72 is located inside the slide groove 74; when ammonia passes through the intake pipe 62 in the During the movement inside the third delivery pipe 61, the heated gas inside the second delivery pipe 51 enters between the first blocking ring 71 and the second blocking ring 72 through the second delivery pipe 51. One end of the second delivery pipe 51 is funnel-shaped. The gas output from the second delivery pipe 51 converges and enters between the first blocking ring 71 and the second blocking ring 72. After changing direction through the first blocking ring 71 and the second blocking ring 72, it is ejected through the chute 74. After changing direction again inside the chute 74, the gas flows in the same direction as the ammonia gas inside the third delivery pipe 51. The ammonia, oxygen and methanol gases collide and mix with each other inside the third delivery pipe 51. The mixing distance and time of ammonia, oxygen and methanol are increased through the mixing mechanism 7, and the uniformity of the mixing of the three is improved. The heated oxygen and methanol increase the temperature of the ammonia, and part of the methanol is liquefied due to the temperature drop. The liquefied methanol dissolves the ammonia, so that part of the ammonia is stored in the methanol droplets.

[0024] One end of the first delivery pipe 41 is fixedly connected to the mounting pipe 47, and a second porous medium layer 45 is provided inside the mounting pipe 47, and the interior of the second porous medium layer 45 is fixedly connected to a hemispherical fixed rod 44 at both ends; a third porous medium layer 46 is provided at one end of the mounting pipe 47, and the second porous medium layer 45 is connected to the third porous medium layer 46; a fourth porous medium layer 64 is provided inside the third delivery pipe 61; the nitromethane burning in the first delivery pipe 41 contacts the fixed rod 44 and the second porous medium layer 45, and due to the obstruction of the fixed rod 44 and the second porous medium layer 45, the combustion time of the nitromethane in the first delivery pipe 41 is increased, thereby increasing the temperature of the gas inside the second delivery pipe 51; one end of the mounting pipe 47 is funnel-shaped, which facilitates the burning nitromethane to enter the interior of the mounting pipe 47, and the burning nitromethane enters the third delivery pipe 61 due to the obstruction of the fixed rod 44 Inside the second porous medium layer 45, nitromethane and oxygen are fully mixed through continuous vortexes, diversions and other disturbances inside the second porous medium layer 45, so that nitromethane burns efficiently in the second porous medium layer 45, thereby causing the temperature inside the second porous medium layer 45 to continue to rise. The fourth porous medium layer 64 is separated from the second porous medium layer 45 by a layer of the mounting tube 47. When the second porous medium layer 45 dissipates heat, the temperature of the fourth porous medium layer 64 continues to rise, and the mixed gas formed by ammonia, oxygen and methanol inside the third delivery pipe 61 enters the fourth porous medium layer 64. The mixed gas is fully mixed through continuous vortexes, diversions and other disturbances inside the fourth porous medium layer 64. At the same time, the fourth porous medium layer 64 causes the temperature of the mixed gas to continue to rise. As the temperature of the mixed gas continues to rise, the liquefied methanol evaporates and gasifies again, further improving the uniformity of the mixing of the three.

[0025] The size of the internal voids of the second porous medium layer 45 gradually increases along the inner side of the first delivery pipe 41 toward the outer side, so that the porosity of the outer side of the second porous medium layer 45 is large, and more nitromethane is ignited outside the outer side of the second porous medium layer 45, thereby increasing the temperature inside the mounting pipe 47 and the fourth porous medium layer 64; the size of the internal voids of the fourth porous medium layer 64 gradually increases along the outer side of the third delivery pipe 61 toward the inner side, and the porosity of the inner side of the fourth porous medium layer 64 is large, so that the mixed gas inside the third delivery pipe 61 converges toward the inner side of the fourth porous medium layer 64, where the temperature is the highest, thereby increasing the temperature of the mixed gas inside the third delivery pipe 61.

[0026] The inner side wall of the third delivery pipe 61 is installed with a fixed ring 67 with an arc-shaped side wall, and the side wall of the third delivery pipe 61 is installed with multiple return pipes 63, one end of the return pipe 63 contacts the fixed ring 67, and the other end of the return pipe 63 has a hook-shaped side wall; the air inlet of the return pipe 63 is located between the fourth porous medium layer 64 and the nozzle 65, and the air outlet of the return pipe 63 is aligned with the first blocking ring 71. The mixed gas heated by the fourth porous medium layer 64 enters between the partition 66 and the fourth porous medium layer 64, and the mixed gas with the highest temperature on the innermost side of the fourth porous medium layer 64 flows along the arc-shaped side wall of the partition 66. 6 enters the interior of the nozzle 65, and the mixed gas on the outside of the fourth porous medium layer 64 contacts the fixed ring 67 with an arc-shaped side wall, so that the mixed gas enters the interior of the return pipe 63, and is sprayed between the third delivery pipe 61 and the second blocking ring 72 through the return pipe 63. This part of the mixed gas enters the interior of the fourth porous medium layer 64 again for heating, so that the gas heated by the fourth porous medium layer 64 each time enters the interior of the fourth porous medium layer 64 again for heating and mixing, thereby increasing the temperature of the gas ejected from the inside of the fourth porous medium layer 64 and improving the uniformity of the mixing of ammonia, oxygen and methanol.

[0027] The first porous medium layer 21, the second porous medium layer 45, the third porous medium layer 46 and the fourth porous medium layer 64 are composed of silicon carbide ceramics. The other end of the third delivery pipe 61 is fixedly connected to the partition 66, and a plurality of nozzles 65 are installed obliquely on the side wall of the partition 66, and the gas outlet of the nozzle 65 is obliquely aligned with the side wall of the third porous medium layer 46; at the connection between the partition 66 and the nozzle 65, the side wall of the partition 66 is an arc-shaped structure; the mixed gas output from the inside of the third delivery pipe 61 is diverted by the plurality of nozzles 65 to reduce the volume of the mixed gas, and the diverted gas is sprayed obliquely toward the side wall of the third porous medium layer 46 through the nozzle 65, so that the gas rotates along the side wall of the third porous medium layer 46 and enters Inside the furnace 1, the burning nitromethane passes through the second porous medium layer 45 and enters the inside of the third porous medium layer 46. The third porous medium layer 46 is cylindrical, so that the flame of the burning nitromethane 46 is evenly located on the surface of the third porous medium layer 46. At this time, multiple streams of mixed gas ejected from the inside of the nozzle 65 move along the side wall of the third porous medium layer 46, and multiple streams of air ejected from the nozzle 65 are sprayed toward the surface of the third porous medium layer 46 from different angles. The air streams interact and cooperate with each other to rotate along the surface of the third porous medium layer 46 (as shown in the attached figure). Figure 6As shown), the flame on the surface of the third porous medium layer 46 is drawn into the mixed airflow, so that the nitromethane in the combustion process is quickly integrated into the mixed airflow. The mixed airflow is preheated and is in a high temperature state, so that the methanol gas is evenly distributed in the mixed airflow. Methanol gas is flammable. The flame generated by the combustion of nitromethane in the mixed airflow first ignites the methanol. The burning methanol quickly ignites the surrounding preheated ammonia. The burning ammonia then ignites the surrounding methanol, so that the flame propagates stably and quickly in the mixed airflow, and the ammonia is quickly ignited.

[0028] One end of the furnace 2 is fixedly connected to the partition 66, and the center of the interior of the partition 66 is fixedly connected to the mounting pipe 47; a smoke exhaust pipe 22 is installed at the top of the furnace 2, and a first porous medium layer 21 with an arc-shaped end is installed inside the furnace 2, and the center of the first porous medium layer 21 is aligned with the third porous medium layer 46. After the mixed gas is diverted by the nozzle 65, it rotates along the third porous medium layer 46, and the volume of the mixed gas is reduced to facilitate ignition. The ignited gas moves toward the side wall of the first porous medium layer 21, and the mixed gas contacts the first porous medium layer 21 with an arc-shaped side wall. The ignited mixed gas expands outward along the side wall of the first porous medium layer 21, so that the mixed gas evenly enters the first porous medium layer 21 for combustion. Due to the existence of three heat exchange modes of convection, heat conduction and radiation inside the first porous medium layer 21, the temperature of the nitrogen combustion area tends to be uniform, maintaining a relatively stable temperature gradient, and allowing the ammonia to fully burn in the first porous medium layer 21.

[0029] The side walls of the third delivery pipe 61 are all funnel-shaped in the center, and the side walls of the third delivery pipe 61 at the funnel-shaped part are aligned with the air inlet end of the second blocking ring 72; when the mixed gas inside the third delivery pipe 61 passes through the funnel and enters the fourth porous medium layer 64 along the side walls of the second blocking ring 72, the funnel-shaped structure increases the flow velocity of the mixed gas inside the fourth porous medium layer 64.

[0030] The side walls of the heating mechanism 5 and the ignition mechanism 4 are both equipped with a feeding mechanism 3 for conveying methanol or nitromethane, and one end of the preheating mixing mechanism 6 is equipped with a furnace 2 for fully burning ammonia; the feeding mechanism 3 includes a feeding pipe 31, and the side walls of the first delivery pipe 41 and the second delivery pipe 51 are both equipped with feeding pipes 31, and the side wall of the feeding pipe 31 is equipped with a water pipe 32 with an "L"-shaped side wall, and one end of the water pipe 32 is equipped with an atomizing nozzle 33; when nitromethane or methanol enters the first delivery pipe 41 and the second delivery pipe 51 through the water pipe 32, oxygen passes through the feeding pipe 31 at this time. 31 enters the interior of the delivery pipe, and the solution is atomized by the atomizing nozzle 33 and enters the oxygen, so that the oxygen and the solution are preliminarily mixed; and a dispersion net 34 is installed at the connection between the feeding pipe 31 and the first delivery pipe 41. After the oxygen and the nitromethane solution are preliminarily mixed, they contact the heat dissipation net 34, and the solution and the nitromethane solution form a turbulent flow on the side wall of the dispersion net 34, and the dispersion net 34 breaks up the solution again, thereby improving the uniformity of the mixing of the oxygen and nitromethane solution; the dispersion net 34 has a hollow conical structure, which increases the contact area of ​​the dispersion net 34 with the oxygen and nitromethane, further improving the uniformity of the mixing of the two.

[0031] A combustion method of an ammonia modified fuel comprises the following steps: Step 1: Nitromethane and oxygen are delivered to the interior of the first water pipe 41 through one of the feed mechanisms 3, methanol and oxygen are delivered to the interior of the second water pipe 51 through another feed mechanism 3, and ammonia is delivered to the interior of the third water pipe 61 through the air intake pipe 62; the molar ratio of ammonia in the third water pipe 61 to methanol in the second water pipe 51 is fixed at 4:1; in the fuel combination of methanol, ammonia, and nitromethane, the molar fraction of nitromethane ranges from 16.7% to 28.6%; the oxygen in the first water pipe 41 is sufficient for the combustion of nitromethane, and the oxygen in the second water pipe 51 is sufficient for the combustion of methanol and ammonia; Step 2: When nitromethane and oxygen enter the interior of the first delivery pipe 41, the mixed gas contacts the inclined blade 43, pushing the blade 43 and the fixed shaft 42 to rotate. The rotation of the blade 43 forms a vortex on the mixed gas, and the vortex makes the nitromethane droplets and oxygen mix evenly. The side wall of the first delivery pipe 41 is funnel-shaped in the middle, so that the mixed gas is accelerated again inside the first gas delivery pipe 41 and ignited by the igniter 1. The flame generated by the ignition rotates inside the first gas delivery pipe 41 and moves toward the mounting pipe 47. Nitromethane It is flammable and burns to generate high temperature, thereby rapidly increasing the temperature inside the first delivery pipe 41; at this time, the methanol solution and oxygen enter the interior of the second delivery pipe 51, and the solution and oxygen make a spiral motion along the spiral ring 52 inside the second delivery pipe 51, so that the methanol solution and oxygen are fully mixed, and the solution and oxygen rotate inside the second delivery pipe 51 and move toward the direction of the spiral ring 64. At this time, due to the rapid increase in the temperature of the side wall of the first delivery pipe 41 when the nitromethane burns, it contacts the high-temperature first delivery pipe 41, causing the temperature of the mixed gas to continue to rise, and the mixed gas The mixed gas continuously rotates, facilitating the heat on the surface of the first delivery pipe 41 to dissipate into the mixed gas, causing the methanol solution to quickly evaporate and vaporize in the oxygen to become gas. During the evaporation process, the volume of methanol increases and expands outward, causing the methanol gas and oxygen to mix again, thereby improving the uniformity of the mixing of the two. A plurality of spiral coils 64 are installed inside the first delivery pipe 41, and one end of the spiral coil 64 enters the interior of the first delivery pipe 41. The spiral coils 64 turbulently ... Step 3: The heated gas inside the second delivery pipe 51 enters between the first blocking ring 71 and the second blocking ring 72 through the second delivery pipe 51. One end of the second delivery pipe 51 is funnel-shaped. The gas output through the second delivery pipe 51 converges and enters between the first blocking ring 71 and the second blocking ring 72. After passing through the first blocking ring 71 and the second blocking ring 72, it changes direction and is then ejected through the chute 74. After changing direction again inside the chute 74, the gas flows in the same direction as the ammonia gas inside the third delivery pipe 51. The ammonia, oxygen and methanol gases collide and mix with each other inside the third delivery pipe 51. The mixing distance and time of the ammonia, oxygen and methanol are increased by the mixing mechanism 7, thereby improving the uniformity of the mixing of the three. The heated oxygen and methanol increase the temperature of the ammonia, and part of the methanol is liquefied due to the decrease in temperature. The liquefied methanol dissolves the ammonia, so that part of the ammonia is stored in the methanol droplets. Step 4: The gas inside the third water pipe 61 enters the interior of the fourth porous medium layer 64. Since the burning nitromethane enters the interior of the mounting pipe 47, and the burning nitromethane enters the interior of the second porous medium layer 45 due to the obstruction of the fixing rod 44, the nitromethane and oxygen are fully mixed in the second porous medium layer 45 through continuous vortex, diversion and other disturbances, so that the nitromethane burns efficiently in the second porous medium layer 45, thereby continuously increasing the temperature inside the second porous medium layer 45. There is a layer of the mounting pipe 47 between the fourth porous medium layer 64 and the second porous medium layer 45. The heat emitted by the second porous medium layer 45 is the heat of the fourth porous medium layer 64. The temperature of the porous medium layer 64 continues to rise, and the mixed gas formed by ammonia, oxygen and methanol in the third delivery pipe 61 enters the interior of the fourth porous medium layer 64. The mixed gas is continuously mixed in the fourth porous medium layer 64 through continuous vortex, diversion and other disturbances. At the same time, the fourth porous medium layer 64 continuously increases the temperature of the mixed gas, and the liquefied methanol evaporates and gasifies again as the temperature of the mixed gas continues to rise, further improving the uniformity of the mixing of the three. The size of the internal gap of the second porous medium layer 45 gradually increases along the direction from the inside of the first delivery pipe 41 to the outside, so that the porosity of the outside of the second porous medium layer 45 is large, and more of the nitromethane The alkane is ignited outside the second porous medium layer 45, increasing the temperature inside the mounting tube 47 and the fourth porous medium layer 64; the size of the internal gap of the fourth porous medium layer 64 gradually increases from the outside of the third delivery pipe 61 to the inside, the porosity of the inner side of the fourth porous medium layer 64 is large, and the mixed gas inside the third delivery pipe 61 converges toward the inner side of the fourth porous medium layer 64, where the temperature is the highest, thereby increasing the temperature of the mixed gas inside the third delivery pipe 61; the mixed gas heated by the fourth porous medium layer 64 enters between the partition 66 and the fourth porous medium layer 64, and the mixed gas with the highest temperature on the innermost side of the fourth porous medium layer 64 The mixed gas enters the interior of the nozzle 65 along the partition 66 with an arc-shaped side wall, and the mixed gas outside the fourth porous medium layer 64 contacts the fixed ring 67 with an arc-shaped side wall, so that the mixed gas enters the interior of the return pipe 63, and is sprayed between the third delivery pipe 61 and the second blocking ring 72 through the return pipe 63. This part of the mixed gas enters the interior of the fourth porous medium layer 64 again for heating, so that part of the gas heated by the fourth porous medium layer 64 enters the interior of the fourth porous medium layer 64 again for reheating and mixing, thereby increasing the temperature of the gas ejected from the interior of the fourth porous medium layer 64 and improving the uniformity of the mixing of ammonia, oxygen and methanol. Step 5: Multiple streams of mixed gas ejected from the inside of the nozzle 65 move along the side wall of the third porous medium layer 46, and multiple streams of gas ejected from the nozzle 65 are sprayed onto the surface of the third porous medium layer 46 from different angles. The gas streams interact and cooperate with each other to rotate along the surface of the third porous medium layer 46, and the flame on the surface of the third porous medium layer 46 is drawn into the mixed gas stream, so that the nitromethane in the combustion process is quickly integrated into the mixed gas stream. The mixed gas stream is preheated to a high temperature state, so that the methanol gas is evenly distributed in the mixed gas stream. The methanol gas is flammable, and the flame ignites the methanol first, and the burning methanol quickly ignites the surrounding preheated ammonia gas. The burning ammonia ignites the surrounding methanol, and the flame propagates stably and rapidly inside the mixed gas, igniting the ammonia quickly. The ignited gas moves toward the side wall of the first porous medium layer 21, and the mixed gas contacts the first porous medium layer 21 with an arc-shaped side wall, so that the ignited mixed gas expands outward along the side wall of the first porous medium layer 21, so that the mixed gas evenly enters the first porous medium layer 21 and burns. Due to the existence of the three heat exchange modes of convection, heat conduction and radiation inside the first porous medium layer 21, the temperature of the nitrogen combustion area tends to be uniform, maintaining a relatively stable temperature gradient, and allowing the ammonia to fully burn in the first porous medium layer 21.

[0032] An ammonia modified fuel consists of methanol, ammonia and nitromethane. The molar fraction of nitromethane in the ammonia modified fuel ranges from 16.7% to 28.6%, and the molar ratio of ammonia to methanol is 4:1.

[0033] The laminar combustion velocity of ammonia mixed fuel was tested at an ammonia to methanol molar ratio of 4:1, atmospheric pressure (1 atm), and 400K. Figure 8 As shown in the figure, the laminar combustion velocity of the ammonia / methanol fuel mixture increases significantly with the increase of nitromethane content. When the nitromethane mole fraction is 28.6%, the laminar combustion velocity reaches a maximum of 45 cm / s, which is a significant increase of about 80% compared with the case without nitromethane (about 25 cm / s). According to experimental data, the addition ratio of nitromethane is controlled within the mole fraction range of 16.7%-28.6%. The ignition delay time of ammonia mixed fuel was tested under high pressure conditions of 10 atm and 20 atm with a molar ratio of ammonia to methanol of 4:1. Figure 9 As shown in the figure, the ignition delay time significantly decreases with increasing nitromethane mole fraction. For example, at 20 atm and 800 K, the ignition delay time of the fuel mixture without nitromethane is approximately 90 ms. However, after adding 50% nitromethane, the ignition delay time is significantly shortened to approximately 20 ms, significantly improving the rapid ignition capability of the fuel mixture.

[0034] To better understand the combustion optimization of methanol / ammonia blends by the addition of nitromethane, we constructed the oxidation mechanism of ammonia / methanol / nitromethane and elaborated in detail the effect of nitromethane on the ammonia / methanol oxidation process. The main reason why the addition of nitromethane improves combustion characteristics is that free radicals such as NO2 and CH3 are released after the decomposition of nitromethane; these active free radicals effectively promote the occurrence of chain reactions, increase the activity of the overall fuel mixture, and thus significantly reduce the initial reaction temperature of the fuel. In addition, the decomposition of nitromethane also significantly increases the concentration of OH and H radicals in the system through free radical reaction pathways, accelerating the decomposition and combustion of ammonia and methanol. Specific reaction pathway analysis shows that: at lower temperatures (such as 740K), the NO2 radical introduced by nitromethane significantly promotes the oxidation of ammonia. At higher temperatures (such as 1020K), most of the nitromethane decomposes through the reaction CH3NO2(+M)→CH3+NO2(+M), which further increases NO x emissions, but also speeds up the oxidation rate of the fuel.

[0035] In summary, through a reasonable nitromethane ratio, the ignition performance and flame propagation speed of the methanol / ammonia mixed fuel are effectively improved while improving the fuel combustion performance, thereby enhancing the practicality and combustion stability of the overall fuel, and has good engineering application potential.

[0036] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An ammonia modified fuel combustion device, characterized in that: include: An igniter (1), wherein the igniter (1) is fixed inside an ignition mechanism (4), wherein the igniter (1) is installed at the center of the inside of the first delivery pipe (41), wherein the inside of the first delivery pipe (41) is rotatably connected to blades (43), wherein a plurality of blades (43) are obliquely installed on the side wall of a fixed shaft (42), and wherein the fixed shaft (42) is rotatably connected to the side wall of the igniter (1); wherein one end of the first delivery pipe (41) is fixedly connected to a mounting pipe (47), wherein a second porous medium layer (45) is provided inside the mounting pipe (47), wherein the inside of the second porous medium layer (45) is fixedly connected to a fixing rod (44) having hemispherical ends; wherein a third porous medium layer (46) is provided at one end of the mounting pipe (47), and wherein the second porous medium layer (45) is connected to the third porous medium layer (46); A heating mechanism (5) for evaporating and gasifying the methanol solution is installed on the side wall of the first delivery pipe (41), and a preheating mixing mechanism (6) for uniformly mixing and heating the ammonia gas and the methanol is installed on the side wall of the heating mechanism (5); The preheating mixing mechanism (6) includes a third delivery pipe (61), the side wall of the heating mechanism (5) is sleeved with the third delivery pipe (61), one end of the third delivery pipe (61) is obliquely installed with an air inlet pipe (62) for delivering ammonia; a fourth porous medium layer (64) is provided inside the third delivery pipe (61), the other end of the third delivery pipe (61) is fixedly connected to a partition (66), and a plurality of nozzles (65) are obliquely installed on the side wall of the partition (66), and the nozzles (65) The gas outlet is tilted and aligned with the side wall of the third porous medium layer (46); at the connection between the partition (66) and the nozzle (65), the side wall of the partition (66) is in an arc-shaped structure; the inner side wall of the third delivery pipe (61) is installed with a fixing ring (67) with an arc-shaped side wall, and the side wall of the third delivery pipe (61) is installed with a plurality of return pipes (63), one end of the return pipe (63) abuts against the fixing ring (67), and the other end of the return pipe (63) has a hook-shaped side wall; A feeding mechanism (3) for conveying methanol or nitromethane is installed on the side walls of the heating mechanism (5) and the ignition mechanism (4), a mixing mechanism (7) for preliminarily mixing vaporized methanol with ammonia is installed between the heating mechanism (5) and the preheating mixing mechanism (6), and a furnace (2) for fully burning ammonia is installed at one end of the preheating mixing mechanism (6).

2. The ammonia reformed fuel combustion device according to claim 1, characterized in that: The heating mechanism (5) comprises a second delivery pipe (51), the second delivery pipe (51) is sleeved on the side wall of the first delivery pipe (41), and a spiral ring (52) is installed between the first delivery pipe (41) and the second delivery pipe (51); a plurality of spiral coils (64) are installed inside the first delivery pipe (41), and one end of the spiral coil (64) enters the interior of the first delivery pipe (41).

3. The ammonia reformed fuel combustion device according to claim 2, characterized in that: The mixing mechanism (7) comprises a first blocking ring (71), one end of the second delivery pipe (51) is installed with the first blocking ring (71) having an arc-shaped side wall, the side wall of the first delivery pipe (41) is installed with a second blocking ring (72) having an arc-shaped side wall, and the first blocking ring (71) is located inside the second blocking ring (72); the side wall of the second delivery pipe (51) is installed with a third blocking ring (73) having a triangular cross-section, the interior of the third blocking ring (73) is provided with a sliding groove (74) having an arc-shaped side wall, and one end of the second blocking ring (72) is located inside the sliding groove (74).

4. The ammonia reformed fuel combustion device according to claim 3, characterized in that: One end of the mounting tube (47), one end of the second delivery tube (51), the center of the side wall of the first delivery tube (41), and the center of the side wall of the third delivery tube (61) are all funnel-shaped structures, and the side wall of the third delivery tube (61) in the funnel shape is aligned with the air inlet end of the second blocking ring (72).

5. The ammonia reformed fuel combustion device according to claim 4, characterized in that: The feeding mechanism (3) comprises a feeding pipe (31), the side walls of the first conveying pipe (41) and the second conveying pipe (51) are both equipped with the feeding pipe (31), the side wall of the feeding pipe (31) is equipped with a water pipe (32) with an "L"-shaped side wall, and one end of the water pipe (32) is equipped with an atomizing nozzle (33); a dispersion net (34) is installed at the connection between the feeding pipe (31) and the first conveying pipe (41), and the dispersion net (34) has a hollow conical structure.

6. The ammonia reformed fuel combustion device according to claim 5, characterized in that: The air inlet of the return pipe (63) is located between the fourth porous medium layer (64) and the nozzle (65), and the air outlet of the return pipe (63) is aligned with the first blocking ring (71); a layer of the mounting tube (47) is located between the fourth porous medium layer (64) and the second porous medium layer (45), and the size of the internal gap of the fourth porous medium layer (64) gradually increases from the outside to the inside of the third delivery pipe (61), and the size of the internal gap of the second porous medium layer (45) gradually increases from the inside to the outside of the first delivery pipe (41).

7. The ammonia reformed fuel combustion device according to claim 6, characterized in that: The spiral coil (53) is located between the second porous medium layer (45) and the igniter (1), and the spiral coil (53) is located obliquely inside the first delivery pipe (41) and the second delivery pipe (51).

8. The ammonia reformed fuel combustion device according to claim 7, characterized in that: One end of the furnace (2) is fixedly connected to the partition (66), and the center of the interior of the partition (66) is fixedly connected to the mounting pipe (47); a smoke exhaust pipe (22) is installed at the top of the furnace (2), and a first porous medium layer (21) with an arc-shaped end is installed inside the furnace (2), and the center of the first porous medium layer (21) is aligned with the third porous medium layer (46).

9. The ammonia reformed fuel combustion device according to claim 8, characterized in that: A combustion method of an ammonia modified fuel comprises the following steps: Step 1: During the combustion of the ammonia modified fuel, nitromethane and oxygen are transported to the interior of the ignition mechanism (4) through one of the feed mechanisms (3), methanol and oxygen are transported to the interior of the heating mechanism (5) through another of the feed mechanisms (3), and ammonia is transported to the interior of the third water pipe (61); Step 2: The vortex generated by the rotation of the blades (43) causes the nitromethane and oxygen to mix evenly, and then the mixture is ignited by the igniter (1), causing the temperature inside the first delivery pipe (41) to rise rapidly; the methanol and oxygen inside the second water delivery pipe (51) are heated, and the methanol solution is quickly evaporated and gasified in the oxygen, so that the two are mixed evenly, and the flow is disturbed by the spiral ring (64), thereby improving the heat exchange efficiency, thereby further increasing the temperature of the gas inside the second delivery pipe (51); Step 3: The high-temperature gas inside the second delivery pipe (51) enters the interior of the third water delivery pipe (61) through the mixing mechanism (7). The mixing mechanism (7) increases the mixing distance and time of ammonia, oxygen and methanol, thereby improving the uniformity of the mixing of the three. Step 4: The mixed gas inside the third water pipe (61) enters the interior of the fourth porous medium layer (64). Due to the burning nitromethane, the temperature inside the second porous medium layer (45) is continuously increased, and the temperature of the fourth porous medium layer (64) is continuously increased. The mixed gas is fully mixed and heated in and out through continuous vortex, diversion and other disturbances inside the fourth porous medium layer (64); by improving the size of the internal gap between the second porous medium layer (45) and the fourth porous medium layer (64), the heat exchange efficiency of the two is improved and the temperature of the gas inside the fourth porous medium layer (64) is increased; and part of the gas discharged from the fourth porous medium layer (64) enters the interior of the fourth porous medium layer (64) again through the return pipe (63) to be heated and mixed again, thereby increasing the temperature of the gas ejected from the fourth porous medium layer (64) and improving the uniformity of the mixing of ammonia, oxygen and methanol; Step 5: The mixed gas ejected from the nozzle (65) rotates along the side wall of the third porous medium layer (46), and the flame on the surface of the third porous medium layer (46) is drawn into the mixed gas flow. The mixed gas flow is preheated to a high temperature state, so that the methanol gas is evenly distributed in the mixed gas flow. The methanol gas is flammable, and the flame first ignites the methanol. The burning methanol quickly ignites the surrounding preheated ammonia gas, and the burning ammonia then ignites the surrounding methanol, so that the flame propagates stably and quickly inside the mixed gas, quickly igniting the ammonia gas. The ignited gas enters the interior of the first porous medium layer (21) and is fully burned.

10. The combustion method of ammonia-modified fuel according to claim 9, characterized in that: The invention comprises an ammonia modified fuel, which is composed of methanol, ammonia and nitromethane. The molar fraction of nitromethane in the ammonia modified fuel ranges from 16.7% to 28.6%, and the molar ratio of ammonia to methanol is 4:1.

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