A methanol porous media burner, its working method and application

Abstract

The application discloses a kind of methanol porous medium combustor and its working method and application, including fan, methanol pump, combustion chamber, ignition needle, metal fiber felt and porous medium, the methanol pump is connected methanol supply pipeline, the outlet of the methanol supply pipeline is located in the mixing cavity of the combustion chamber, to introduce liquid methanol into the mixing cavity;The fan passes through the air inlet on the combustion chamber and introduces air into the mixing cavity, in mixing cavity, air and methanol gas are mixed, the ignition needle passes through the shell of the combustion chamber and inserts into the mixing cavity;The mixing cavity is equipped with the metal fiber felt and porous medium, the outlet of the methanol supply pipeline is in contact with the metal fiber felt.Porous medium combustion chamber inside temperature distribution is more uniform, effectively solve the "partial burning" problem of traditional free flame combustor.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle technology, and in particular to a methanol porous media burner, its operating method, and its application. Background Technology

[0002] Burners are widely used in daily life and national industrial production. Tests have found that the combustion flue gas from several commercially available diesel burners contains high concentrations of carbon monoxide, nitrogen oxides, and other pollutants, and their thermal efficiency is not very satisfactory.

[0003] Currently, my country's energy structure urgently needs adjustment. To quickly break free from dependence on traditional fossil fuels, the promotion and application of low-carbon fuels and related combustion technologies has become an inevitable trend. Methanol, with its low carbon content, high energy density, high combustion efficiency, ability to be regenerated from biomass energy using renewable energy sources, and absence of pollutants such as nitrogen and sulfur, has received widespread attention as a low-carbon clean fuel in recent years. These advantages of methanol fuel make it highly suitable for the current energy situation and contribute to the transformation of my country's energy structure. Therefore, a new type of clean energy burner urgently needs further research and development.

[0004] In addition, my country's electric vehicle industry is developing rapidly, and the number of electric vehicles on the road continues to rise. However, in winter, in cold regions of my country, the normal operation of electric vehicle batteries is difficult to guarantee, starting becomes very difficult, and the driving range is greatly reduced, sometimes by more than half. This problem not only seriously hinders the normal travel of electric vehicles, but also poses a major obstacle to the implementation of my country's dual-carbon goals. Therefore, solving the problem of normal operation of electric vehicle batteries in cold weather is urgent.

[0005] To address these issues, various thermal management methods for electric vehicles have emerged in recent years. "PTC electric heating," as a relatively mature technology, can basically ensure the normal operation of the battery, but it requires the battery's own electrical energy for heating, making it difficult to fundamentally solve the range problem. While "air conditioning heat pump" technology can enhance battery range on top of the former, its complex system structure and high cost make it difficult to meet practical applications, and neither of these methods improves the cold start problem. Summary of the Invention

[0006] The purpose of this invention is to address the technical deficiencies of existing burners by providing a methanol porous media burner.

[0007] Another object of the present invention is to provide a method of operating the methanol porous media burner.

[0008] Another object of the present invention is to provide the application of the methanol porous media burner in the battery thermal management system of an electric vehicle.

[0009] The technical solution adopted to achieve the purpose of this invention is:

[0010] A methanol porous media burner includes a fan, a methanol pump, a combustion chamber, an ignition needle, a metal fiber felt, and a porous media, wherein:

[0011] The methanol pump is connected to a methanol supply pipeline, the outlet of which is located in the mixing chamber of the combustion chamber to introduce liquid methanol into the mixing chamber; the blower introduces air into the mixing chamber through the air inlet on the combustion chamber, where air and methanol gas are mixed; and the ignition needle passes through the housing of the combustion chamber and is inserted into the mixing chamber.

[0012] The mixing chamber is provided with the metal fiber felt and the porous medium. The outlet of the methanol supply pipeline is in contact with the metal fiber felt. The metal fiber felt is located in the mixing chamber on the side near the air inlet and the outlet of the methanol supply pipeline. The porous medium is inserted into the mixing chamber adjacent to the metal fiber felt.

[0013] In the above technical solution, the combustion chamber is disposed inside the combustion chamber shell, the combustion chamber shell is provided with an air inlet, and the fan is disposed inside the combustion chamber shell.

[0014] In the above technical solution, the porous medium is cylindrical, and the pore sizes in the porous medium are different.

[0015] In the above technical solution, the porous medium is coaxially arranged with the combustion chamber, and two or more layers of the porous medium are arranged side by side, with different pore densities between adjacent layers of porous medium.

[0016] In the above technical solution, the front end of the combustion chamber is provided with a cylindrical protrusion, and the cylindrical protrusion is provided with annularly distributed air inlet holes. The metal fiber felt is arranged around the cylindrical protrusion. When the ignition needle passes through the housing of the combustion chamber and is inserted into the mixing chamber, it does not come into contact with the metal fiber felt.

[0017] In the above technical solution, the methanol porous media burner further includes a control system. The control system is located within the combustion chamber and is electrically connected to the fan, methanol pump, ignition needle, heat dissipation temperature sensor, and cavity temperature sensor. The heat dissipation temperature sensor is located at the rear end of the combustion chamber, and the cavity temperature sensor is located at the front end of the combustion chamber.

[0018] In another aspect of the present invention, the method of operating the methanol porous media burner includes the following steps:

[0019] Step 1: After powering on, set the target temperature through the control system. Once the target temperature is set, the ignition needle is energized and heated, and the fan starts working.

[0020] Step 2: After the control system detects that the temperature of the ignition needle has risen to the predetermined temperature, it controls the methanol pump to work. The glow plug heats up, vaporizing some of the methanol around the ignition needle and igniting it. At this time, a mixture is ignited in the mixing chamber of the burner. After the methanol liquid fuel enters the metal fiber felt, the capillary action of the metal fiber felt can quickly and evenly distribute the fuel throughout the entire fiber felt. The ignited mixture heats the metal fiber felt. The methanol that has entered the metal fiber felt is heated and vaporized, and then continues to mix with the air blown in by the blower in the mixing chamber and is ignited to form a flame. The flame enters the porous medium and continues to burn and heat the porous medium. At this time, the ignition process is completed, and the ignition needle stops working.

[0021] Step 3: The flame surface expands fully and gradually fills the entire porous medium evenly. Combustion enters a stable state, and the porous medium becomes red-hot. The radiant heat of the porous medium and the heat of the combustion chamber wall are transferred to the metal fiber felt and mixing chamber upstream of the burner. The temperature of the metal fiber felt continuously vaporizes the pumped liquid methanol. The radiant heat of the high-temperature porous medium heats the premixed gas entering the mixing chamber. The mixed gas entering the porous medium can also be continuously ignited, so that the combustion process in the burner continues smoothly and the combustion in the porous medium is stable.

[0022] Step 4: As the burner continues to work, the heat dissipation temperature sensor of the control system receives feedback from the heat dissipation system. After the burner has worked, the expected set target has been achieved. The fuel pump flow rate has been reduced and the fan speed has been matched. However, the feedback temperature from the heat dissipation temperature sensor is still maintained at around the set target. If the set temperature or power is increased or decreased at this time, the control system will make the fuel supply and intake and exhaust of the burner respond and change in a timely manner.

[0023] Step 5: The control system executes the shutdown command, the fuel pump stops working, but the intake and exhaust system continues to operate at maximum speed to purge the combustion chamber. After the temperature sensor at the front of the combustion chamber reports that the temperature has dropped to a certain level, the entire machine stops working.

[0024] In another aspect of the present invention, the methanol porous media burner is used in a battery thermal management system.

[0025] In the above technical solution, a heat exchange coil is provided outside the combustion chamber. The heat exchange coil is connected to a water heat exchange system. The water heat exchange system is used to heat the battery of the electric vehicle. The water heat exchange system includes a circulation pipeline and a water pump installed on the circulation pipeline. Part of the circulation pipeline is arranged in a serpentine bend around the battery, preferably located below the battery.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. Due to the porous structure of porous media, the flow resistance of gas is increased, resulting in a strong flow equalization effect. Therefore, it can promote the formation of combustible mixture in the combustion chamber, and the mixing of fuel and air is more thorough and uniform. By comparing the temperature distribution inside the combustion chamber before and after adding porous media, it can be seen that the temperature distribution inside the porous media combustion chamber is more uniform, effectively solving the "uneven burning" problem of traditional free flame burners.

[0028] 2. High combustion rate and intensity in porous media: The specific heat of porous media is much greater than that of air, and the heat accumulated during continuous combustion is also greater. Porous media acts as a "heat pool", which greatly enhances the heat transfer in the burner, significantly improves the combustion intensity and uniformity of combustion distribution in the combustion chamber, and makes combustion more complete and efficient. While maintaining stable combustion, it also has high volumetric heat intensity and power density.

[0029] 3. Significantly Optimized Start-up of Porous Media Burners: Most liquid porous media burners have complex start-up processes. Most employ two systems: gaseous fuel for heating during startup, followed by switching to liquid fuel. This necessitates preparing two fuels and two fuel supply systems, and the simultaneous use of two fuels involves the coordination of these systems, making the entire system very complex. The methanol porous media burner, however, uses only one fuel. During startup, the ignition needle rises to 1100°C to vaporize part of the methanol and ignite the premixed gas. After ignition, the ignition needle closes. This device utilizes the heat storage and enhanced heat transfer characteristics of porous media; the heat transferred upstream by the porous media is sufficient to vaporize the methanol, allowing the combustion process within the burner to continue.

[0030] 4. When methanol porous media burners are applied to the thermal management of electric vehicles, they employ "auxiliary fuel heating" technology to maintain a suitable operating temperature for the battery system, thereby ensuring battery performance and significantly extending driving range. Activating this device before a cold start directly heats the battery, allowing it to quickly reach a suitable operating environment and making starting smoother. Attached Figure Description

[0031] Figure 1 The image shown is an exploded view of a methanol porous media burner.

[0032] Figure 2 This is a front view of a methanol porous media burner.

[0033] Figure 3 This is a schematic diagram of the combustion chamber and its connecting structure (combustion chamber shell omitted).

[0034] Figure 4 Is Figure 3 Heat exchange coils are added to the existing structure.

[0035] Figure 5This is a schematic diagram of the internal structure of the combustion chamber.

[0036] Figure 6 This is a schematic diagram of the battery thermal management system.

[0037] Figure 7 This is a flowchart of the battery thermal management system.

[0038] Figure 8 It refers to the temperature distribution in the combustion chamber under different equivalence ratios.

[0039] Figure 9 Whether to add a porous media combustion chamber for temperature distribution.

[0040] Figure 10 The burner did not contain a porous medium.

[0041] Figure 11 It is a porous medium in physical form.

[0042] Figure 12 It is a burner with a porous medium.

[0043] Figure 13 It refers to the extreme temperature difference of the second porous medium in the burner.

[0044] Figure 14 It is the average temperature of the second layer of porous media in the burner.

[0045] Figure 15 The third layer uses a 15ppi porous media burner outlet flame.

[0046] Figure 16 The third layer uses a >15ppi porous media burner outlet flame.

[0047] In the diagram: 1-fan, 2-methanol pump, 3-combustion chamber, 4-ignition needle, 5-porous medium, 6-methanol supply pipeline, 7-mixing chamber, 8-air inlet, 9-air inlet, 10-cylindrical protrusion, 11-heat exchange coil, 12-circulation pipeline, 13-water pump, 14-battery, 15-control system, 16-insulation cylinder, 17-combustion chamber shell, 18-exhaust port. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0049] Example 1

[0050] A methanol porous media burner includes a fan 1, a methanol pump 2, a combustion chamber 3, an ignition needle 4, a metal fiber felt, and a porous media 5, wherein:

[0051] The methanol pump 2 is connected to a methanol supply pipeline 6, and the outlet of the methanol supply pipeline 6 is located in the mixing chamber 7 of the combustion chamber 3 to introduce liquid methanol into the mixing chamber 7; the blower 1 introduces air into the mixing chamber 7 through the air inlet 8 on the combustion chamber 3. In the mixing chamber 7, air and methanol gas are mixed, and the ignition needle 4 passes through the housing of the combustion chamber 3 and is inserted into the mixing chamber 7.

[0052] The mixing chamber 7 is provided with the metal fiber felt and the porous medium 5. The outlet of the methanol supply pipeline 6 is in contact with the metal fiber felt. The metal fiber felt is located in the mixing chamber 7 on the side near the air inlet 8 and the outlet of the methanol supply pipeline 6. The porous medium 5 is inserted into the mixing chamber 7 adjacent to the metal fiber felt.

[0053] The combustion chamber 3 is equipped with an ignition needle 4. The ignition needle 4 is heated first, and the methanol vaporizes. When the temperature continues to rise, the ignition needle 4 ignites, and the methanol burns in the presence of oxygen in the air. The methanol combustion reaction adopts a two-step overall reaction: in the first step, methanol reacts with oxygen to produce carbon monoxide, and in the second step, carbon monoxide reacts with oxygen to produce carbon dioxide.

[0054] After methanol liquid fuel enters the metal fiber felt, the capillary action of the metal fiber felt can quickly and evenly distribute the fuel throughout the entire fiber felt. When the ignited mixture enters the mixing chamber 7, the metal fiber felt is heated. After the methanol entering the metal fiber felt is heated and vaporized, it continues to mix with the incoming air and burn.

[0055] The porous medium 5 fills the mixing chamber 7 of the combustion chamber 3. This structure acts as a "heat pool," significantly enhancing heat transfer within the burner and greatly improving the combustion intensity and uniformity of combustion distribution within the combustion chamber. Combustion is more complete and efficient, exhibiting both stable combustion and high volumetric heat intensity and power density, thus reducing CO and NO emissions. x The emission of particulate matter has been greatly reduced, effectively reducing pollution emissions, and the problem of "uneven burning" of the original burner has been basically solved.

[0056] Preferably, the combustion chamber 3 is disposed inside the combustion chamber shell 17, and the combustion chamber shell 17 is provided with an air inlet 9. The fan 1 is disposed inside the combustion chamber shell 17. When the fan 1 is started, air enters the combustion chamber shell 17 through the air inlet 9, and then enters the mixing chamber 7 through the air inlet 8 on the combustion chamber 3.

[0057] Preferably, the porous medium 5 is cylindrical, with varying pore sizes. The porous medium 5 possesses a vortex structure and a high coefficient of friction, causing vortexing, flow splitting, and turbulence in the fuel-gas mixture. This prolongs the combustion time or path within the combustion zone, enhancing heat and mass transfer and accelerating the combustion rate. This results in high combustion efficiency and low emissions (CO < 15 mg / Nm³). 3 NOx < 30 mg / Nm 3 It also has advantages such as wide fuel compatibility.

[0058] More preferably, the porous medium 5 is coaxially arranged with the combustion chamber 3, and two or more layers of the porous medium 5 are arranged side by side, with adjacent layers of porous medium 5 having different pore densities. The combination of multiple layers of porous medium 5 with different pore densities causes the flame velocity to change at the interface of porous medium 5 with different pore sizes, the flame remains stably within the porous medium 5, combustion becomes stable, no flame drift phenomenon was observed, and the flame surface is perpendicular to the axis of the combustion chamber 3, with no flame surface deflection or instability observed.

[0059] Preferably, the combustion chamber 3 has a cylindrical protrusion 10 at its front end, and the cylindrical protrusion 10 has annularly distributed air inlets 8. The metal fiber felt is arranged around the cylindrical protrusion 10. When the ignition needle 4 passes through the housing of the combustion chamber 3 and is inserted into the mixing chamber 7, it does not come into contact with the metal fiber felt, thus avoiding affecting ignition.

[0060] Preferably, the methanol porous medium burner further includes a control system 15, which is installed in the combustion chamber 3 and electrically connected to the fan 1, methanol pump 2 and ignition needle 4 respectively. The control system 15 controls the operation of the fan 1, methanol pump 2 and ignition needle 4.

[0061] Furthermore, the methanol porous media burner also includes a heat dissipation temperature sensor and a cavity temperature sensor electrically connected to the control system 15. The heat dissipation temperature sensor is located at the rear end of the combustion chamber 3 (the side of the combustion chamber 3 closer to the fan 1 is the front end, and the side closer to the porous media 5 is the rear end). When the temperature sensed by the heat dissipation temperature sensor exceeds a certain value, the ignition needle 4 stops working to prevent overheating. The cavity temperature sensor is located at the front end of the combustion chamber 3. When the fuel pump stops working, the air intake fan 1 still operates at its maximum speed to purge the combustion chamber 3. After the cavity temperature sensor at the front end of the combustion chamber 3 reports that the temperature has dropped to a certain level, the entire unit stops working.

[0062] Example 2

[0063] The operating method of the methanol porous media burner as described in Example 1 includes the following steps:

[0064] Step 1: After powering on, set the target temperature through the control system 15 (different targets will correspond to different air intake and alcohol consumption). After setting the target temperature, the ignition needle 4 is powered on and heated, and the fan 1 starts to work.

[0065] Step 2: After the control system 15 detects that the temperature of the ignition needle 4 has risen to 1100℃, it controls the methanol pump 2 to work. The glow plug heats up, vaporizing some of the methanol around the ignition needle 4 and igniting it. At this time, the mixed gas in the mixing chamber 7 of the burner is ignited. After the methanol liquid fuel enters the metal fiber felt, the capillary action of the metal fiber felt can quickly and evenly distribute the fuel throughout the entire fiber felt. The ignited mixed gas heats the metal fiber felt. The methanol that enters the metal fiber felt is heated and vaporized, and then it continues to mix with the air blown in by the blower 1 in the mixing chamber 7 and is ignited to form a flame. The flame enters the porous medium 5 and continues to burn and heat the porous medium 5. At this time, the ignition process is completed, and the ignition needle 4 stops working.

[0066] Step 3: The flame surface fully expands, gradually and evenly filling the entire porous medium 5. Combustion stabilizes, and the porous medium 5 becomes red-hot. The radiant heat from the porous medium 5 and the heat from the combustion chamber 3 wall are transferred to the upstream metal fiber felt and mixing chamber (fuel side, i.e., the side near the air inlet 8 and the outlet of the methanol supply pipe 6). The temperature of the metal fiber felt continuously vaporizes the pumped liquid methanol, and the radiant heat from the high-temperature porous medium 5 heats the premixed gas entering the mixing chamber. The heat storage and heat transfer characteristics of the porous medium 5 perfectly solve the vaporization of liquid methanol, and the mixed gas entering the porous medium 5 can also be continuously ignited, ensuring a continuous and smooth combustion process within the burner. Furthermore, combustion within the porous medium 5 is stable, with no flame drift.

[0067] Step 4: As the burner continues to operate, the heat dissipation temperature sensor in the control system 15 receives feedback from the heat dissipation system, indicating that the burner has reached the expected set target. The fuel pump flow rate decreases, and the fan 1 speed matches it, but the feedback temperature from the heat dissipation temperature sensor remains around the set target. If the set temperature or power is increased or decreased at this time, the control system 15 will promptly respond and change the fuel supply and intake / exhaust of the burner.

[0068] Step 5: The control system 15 executes the shutdown command, the fuel pump stops working, but the intake and exhaust system continues to work at maximum speed to purge the combustion chamber 3. After the temperature sensor at the front end of the combustion chamber 3 reports that the temperature has dropped to a certain level, the entire machine stops working.

[0069] After the burner is ignited and started, it enters normal operation. Due to the large heat capacity of the porous medium 5, the start-up time is longer than that of the free flame burner, about 150 to 200 seconds. The characteristic of the start-up is that the temperature of the porous medium 5 in the combustion chamber 3 is uniform, the temperature of the porous medium 5 is about 1400 K, and the temperature of the burner wall is about 1200 K.

[0070] When the porous media burner is operating normally, the radiant heat from the porous media 5 and the heat from the combustion chamber 3 wall are transferred to the upstream (fuel side) metal fiber felt and mixing chamber 7. The temperature of the metal fiber felt continuously vaporizes the pumped liquid methanol, and the radiant heat from the high-temperature porous media 5 heats the premixed gas entering the mixing chamber 7. The heat storage and heat transfer characteristics of the porous media 5 perfectly solve the disadvantage of the large latent heat of vaporization of liquid methanol. The smokeless combustion of methanol is an advantage, and as long as there is sufficient air during combustion, carbon deposits will not be produced to pollute the porous media 5. As methanol fuel is continuously pumped into the burner, the above process will continue, and the device will operate continuously.

[0071] Example 3

[0072] Preferably, a heat exchange coil 11 is provided on the outside of the combustion chamber 3. The heat exchange coil 11 is connected to a water heat exchange system to transfer the heat released by combustion to the circulating water in the pipeline and to the required area, such as the electric vehicle battery 14. More preferably, a portion of the heat exchange coil 11 is coiled around the outside of the combustion chamber 3, and another portion is coiled with a smaller diameter. The two ends of the heat exchange coil 11 are a water inlet and a water outlet, respectively. The heat exchange coil 11 is disposed inside an insulation cylinder 16. One end of the insulation cylinder 16 is connected to the opening of the combustion chamber shell 17, and the other end is provided with an exhaust port 18 for discharging the gases produced after combustion. The two ends of the heat exchange coil 11 extend out from the side wall of the insulation cylinder 16.

[0073] Preferably, the water heat exchange system is used to heat the battery 14 of the electric vehicle. The water heat exchange system includes a circulation pipe 12 and a water pump 13 disposed on the circulation pipe 12. A portion of the circulation pipe 12 is arranged in a serpentine bend around the battery 14, preferably disposed below the battery 14. The water pump 13 promotes the flow of water in the circulation pipe 12. The combustion chamber 3 transfers heat to the water in the circulation pipe 12 and then to the electric vehicle battery 14.

[0074] The battery 14 is equipped with a temperature sensor for collecting temperature signals. When the temperature sensor detects that the temperature of the battery 14 is less than or equal to 15°C, the methanol porous medium burner starts to work until the temperature of the battery 14 is greater than 25°C, at which point the methanol porous medium burner stops working.

[0075] Example 4

[0076] This embodiment verifies the performance of the methanol porous media burner described in Example 1.

[0077] First, a numerical simulation was performed on the flow combustion process of the original burner design that did not use porous media 5. Figure 8 The simulation results show the temperature distribution within combustion chamber 3 under different equivalence ratios. It can be seen that the temperature distribution within the chamber is uneven under all equivalence ratios, causing the high-temperature flame at the outlet of combustion chamber 3 to be distributed only in a localized area on one side, i.e., a "partial combustion" phenomenon. To address this issue, the calculation results of the internal structure and flow distribution of combustion chamber 3 were analyzed. It was found that because the fuel enters tangentially from the fuel nozzle on one side of the burner, entering the larger cavity of combustion chamber 3 along with air, the cavity design of combustion chamber 3 makes it difficult for the fuel and air to fully mix and fill the entire space of combustion chamber 3 before flowing out. Therefore, the combustion reaction only occurs in the localized area where the fuel flows through and mixes with air within combustion chamber 3, leading to the "partial combustion" phenomenon and severely affecting the complete combustion of the fuel.

[0078] When porous medium 5 is introduced, compared with free space combustion, the combustion of premixed gas in porous medium 5 has the advantages of high power density, low pollutant emissions and compact structure. Figure 9 By comparing the temperature distribution inside the combustion chamber 3 before and after adding porous medium 5, it can be seen that the temperature distribution inside the combustion chamber 3 with porous medium 5 is more uniform, effectively solving the problem of "uneven burning" of the burner.

[0079] In this embodiment, the combustion chamber 3 is cylindrical, with an outer shell made of 316 stainless steel, and contains a porous medium 5 with a diameter of 50mm and a length of 90mm. The porous medium 5 is made of silicon carbide and can withstand high temperatures of 1500℃+.

[0080] Extensive experiments were conducted on the selection of the porous medium 5 within the burner, revealing that the burner performance was optimal when the porous medium 5 was designed with different combinations of pore densities. Based on the experimental structure, a porous medium 5 with a total length of 90mm (30mm 30ppi + 30mm 25ppi + 30mm 15ppi) was ultimately selected. The first layer (near the air inlet 8 of the combustion chamber 3) was chosen with a pore density of 30ppi to significantly increase the uniformity of fuel gas and air mixing and to effectively address the issue of uneven combustion within the burner. Figure 10 The flame distribution at the burner outlet observed when no porous medium was added to the burner shows that the high-temperature flame only appeared on the left side of the burner, indicating a severe "disproportionate burning" phenomenon; while Figure 12 The flame distribution after adding porous medium 5 to the burner shows that the uniformity of flame distribution in combustion chamber 3 has been greatly improved, basically solving the problem of "uneven burning" of the original burner.

[0081] The second layer, 25ppi porous medium 5, is mainly selected based on the combustion temperature distribution within the combustion chamber 3. Figure 13 and Figure 14 The experimental results of the average temperature and temperature range in combustion chamber 3 under different pore densities were compared. Figure 13 This indicates that the combustion chamber 3 uses a 25ppi porous medium 5, resulting in a higher average temperature inside the combustion chamber 3 and therefore more intense combustion; Figure 14 The results show that, under all power conditions, the use of 25ppi porous medium 5 results in a lower temperature range within combustion chamber 3, indicating a more uniform temperature distribution within combustion chamber 3.

[0082] The third layer (near the outlet side of combustion chamber 3) uses 15ppi porous medium 5 primarily based on the burner's internal resistance and airflow uniformity. Burner resistance and the uniformity of flow distribution within it are strongly influenced by the pore density of the porous medium. Comparative experiments revealed that using 15ppi porous medium 5 resulted in a more uniform flow distribution within combustion chamber 3, and no visible flame was emitted from the burner outlet. Figure 15 When using porous media with a pore density >15ppi, flames can be seen ejected from the outlet. Figure 16 This indicates that there is a local high-speed zone at the outlet of combustion chamber 3.

[0083] The thermal efficiency of the burner under different conditions during normal operation was determined experimentally (as shown in Table 1).

[0084] Note: The thermal efficiency is calculated as follows: Thermal efficiency = Heat supply / Fuel heat release * 100%. The heat supply is calculated from the data measured by thermocouples, flow meters and stopwatches. The fuel heat release can be obtained from the fuel consumption corresponding to each power. Each power is tested five times and the average value is taken.

[0085] Table 1. Thermal efficiency test results of burners operating normally under different conditions.

[0086]

[0087]

[0088] As shown in Table 1, the thermal efficiency of the methanol porous media burner is significantly improved compared to that of the traditional diesel burner, with an increase of about 10%, which greatly reduces energy waste and improves the energy efficiency of the device.

[0089] The composition and content of pollutants in flue gas under different conditions during stable operation were determined experimentally (as shown in Table 2).

[0090] Note: The flue gas testing instrument is Testo350. Five tests were conducted for each power condition, and the average value of the results was taken.

[0091] Table 2. Measurement results of burner flue gas component content under different conditions

[0092]

[0093] As shown in Table 2, the methanol porous media burner significantly reduces emissions compared to traditional diesel burners. In the flue gas: the average concentration of carbon monoxide decreases by 37%; methanol combustion is more complete and safer; the average NOx emission concentration decreases by 84%; and the total pollutant emissions are reduced by approximately 65%, a substantial decrease. Therefore, the burner of this invention has significant energy-saving and emission-reduction effects and is worthy of application and promotion.

[0094] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0095] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0096] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A methanol porous media burner, characterized in that, It includes a fan, methanol pump, combustion chamber, ignition needle, metal fiber felt, and porous media, among which: The methanol pump is connected to a methanol supply pipeline, the outlet of which is located in the mixing chamber of the combustion chamber to introduce liquid methanol into the mixing chamber; the blower introduces air into the mixing chamber through the air inlet on the combustion chamber, and the ignition needle passes through the housing of the combustion chamber and is inserted into the mixing chamber; The mixing chamber is provided with the metal fiber felt and the porous medium. The outlet of the methanol supply pipeline is in contact with the metal fiber felt. The metal fiber felt is arranged in the mixing chamber on the side near the air inlet and the outlet of the methanol supply pipeline. The porous medium is inserted into the mixing chamber adjacent to the metal fiber felt. The combustion chamber is disposed inside the combustion chamber shell, the combustion chamber shell is provided with an air inlet, and the fan is disposed inside the combustion chamber shell; The porous medium is cylindrical, and the pore sizes in the porous medium are different. The porous medium is coaxially arranged with the combustion chamber, and two or more layers of the porous medium are arranged side by side, with different pore densities between adjacent layers of porous medium. The combustion chamber has a cylindrical protrusion at the front end, and the cylindrical protrusion has annularly distributed air inlets. The metal fiber felt is arranged around the cylindrical protrusion. When the ignition needle passes through the housing of the combustion chamber and is inserted into the mixing chamber, it does not come into contact with the metal fiber felt. The methanol porous medium burner also includes a control system, which is connected to the fan, methanol pump, and ignition needle respectively.

2. The methanol porous media burner as described in claim 1, characterized in that, The methanol porous medium burner also includes a heat dissipation temperature sensor and a cavity temperature sensor, which are electrically connected to the control system. The heat dissipation temperature sensor is located at the rear end of the combustion chamber, and the cavity temperature sensor is located at the front end of the combustion chamber.

3. The operating method of the methanol porous media burner as described in claim 2, characterized in that, Includes the following steps: Step 1: After powering on, set the target temperature through the control system. Once the target temperature is set, the ignition needle is energized and heated, and the fan starts working. Step 2: After the control system detects that the temperature of the ignition needle has risen to the predetermined temperature, it controls the methanol pump to work. The glow plug heats up and vaporizes some of the methanol around the ignition needle and ignites it. At this time, the mixed gas in the mixing chamber of the burner is ignited. After the methanol liquid fuel enters the metal fiber felt, the capillary action of the metal fiber felt can quickly and evenly distribute the fuel throughout the entire fiber felt. The ignited mixed gas heats the metal fiber felt. After the methanol that enters the metal fiber felt is heated and vaporized, it continues to mix with the air blown in by the blower in the mixing chamber and is ignited to form a flame. The flame enters the porous medium and continues to burn and heat the porous medium. At this time, the ignition process is completed and the ignition needle stops working. Step 3: The flame surface expands fully and gradually fills the entire porous medium evenly. Combustion enters a stable state, and the porous medium becomes red-hot. The radiant heat of the porous medium and the heat of the combustion chamber wall are transferred to the metal fiber felt and mixing chamber upstream of the burner. The temperature of the metal fiber felt continuously vaporizes the pumped liquid methanol. The radiant heat of the high-temperature porous medium heats the premixed gas entering the mixing chamber. The mixed gas can also be continuously ignited when it enters the porous medium, so that the combustion process in the burner continues smoothly and the combustion in the porous medium is stable. Step 4: As the burner continues to work, the heat dissipation temperature sensor of the control system receives feedback from the heat dissipation system. After the burner has worked, the expected set target has been achieved. The methanol pump flow rate has been reduced and the fan speed has been matched. However, the feedback temperature of the heat dissipation temperature sensor is still maintained at around the set target. If the set temperature or power is increased or decreased at this time, the control system will make the fuel supply and intake and exhaust of the burner respond and change in a timely manner. Step 5: The control system executes the shutdown command, the methanol pump stops working, but the intake and exhaust system continues to operate at maximum speed to purge the combustion chamber. After the temperature sensor at the front of the combustion chamber reports that the temperature has dropped to a certain level, the entire machine stops working.

4. The application of the methanol porous media burner as described in claim 1 or 2 in a battery thermal management system.

5. The application as described in claim 4, characterized in that, A heat exchange coil is provided outside the combustion chamber. The heat exchange coil is connected to a water heat exchange system. The water heat exchange system is used to heat the battery of the electric vehicle. The water heat exchange system includes a circulation pipeline and a water pump installed on the circulation pipeline. Part of the circulation pipeline is arranged in a serpentine bend around the battery.

6. The application as described in claim 5, characterized in that, Part of the circulation pipeline is arranged in a serpentine bend below the battery.

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