Mobile intelligent hot air furnace for biomass

Abstract

The utility model discloses a mobile biomass intelligence hot -blast furnace, the casing is equipped with combustion chamber and combustion cylinder, the combustion cylinder is equipped with hearth subassembly, the hearth subassembly is by fire grate, conical furnace bridge, hearth sleeve and intake pipe is formed, the conical furnace bridge is the small cone cylinder structure of big up, and erects on the air outlet of hearth sleeve, the fire grate is blocked in the bottom opening of conical furnace bridge, and with hearth sleeve sliding dismounts connection, the fire grate and conical furnace bridge all are evenly provided with the air hole, compared with prior art, the utility model discloses the structure's design of hot -blast furnace, the heat hot -blast temperature has been improved obviously, and the air heat exchange rate is higher and more reasonable, through the structural design of combustion cylinder, hearth subassembly's conical fire grate, can realize the suspension of material and fully combustion, make biomass granule and oxygen combination combustion more fully, improve the combustion efficiency of biomass.

Description

Technical Field

[0001] This utility model relates to the field of energy equipment, and in particular to a mobile biomass intelligent hot air furnace. Background Technology

[0002] Currently, supported by dual-carbon goals and environmental policies, the biomass hot blast stove industry is increasingly replacing traditional coal-fired and oil-fired hot blast stoves. The overall industry background shows a positive development trend, mainly due to the promotion of environmental policies and changes in market demand. As a green and environmentally friendly heat source equipment, biomass hot blast stoves have the characteristics of good combustion effect, high thermal efficiency, and zero pollution, and are widely used in agriculture, chemical industry, animal husbandry, and other fields. Current status of traditional technologies: Traditional biomass hot blast stoves are mostly large, fixed-furnace combustion devices with poor reliability and low levels of intelligent and refined operation, gradually becoming out of touch with market demands. Their operation is relatively rudimentary, their functions are limited, and they have high fuel requirements, posing a risk of supply chain disruption. The main technical shortcomings of traditional biomass hot blast stoves are as follows: 1. Low level of intelligence: Combustion control relies on experience to adjust various parameters, resulting in large temperature deviations, high fuel waste rate, and the need for personnel to be on duty regularly; 2. Inefficient combustion mode: Traditional equipment mostly adopts grate direct combustion design, which uses oil injection for ignition and combustion. The grate structure is prone to deformation, fuel is easily damaged, and the air supply and oxygen ratio adjustment is not precise enough, resulting in frequent fluctuations in furnace temperature, generally low thermal efficiency, and high CO emission concentration. 3. Poor thermal insulation of the equipment: The steel structure of the equipment has a high thermal conductivity, and the insulation and heat insulation layers are simple, resulting in a large amount of heat waste; 4. Low heat transfer ratio in ordinary tube heat exchange chambers: The air exchanged in ordinary tube heat exchange chambers is laminar flow, resulting in a low air heat transfer coefficient; 5. Hot air furnace without waste heat recovery device and dehumidification function: Traditional equipment mostly provides hot air function but has no waste heat and dehumidification function; 6. Limited fuel adaptability: Fuel pretreatment relies on simple equipment, which cannot be compatible with raw materials with a moisture content >25% or a particle size >10mm, and is mostly limited to biomass pellet form, resulting in a narrow range of fuel applications and a tendency to clog. 7. Poor equipment installation and reliability: Traditional equipment is mostly a single and independent device. To be compatible with other functions, additional equipment needs to be added, resulting in poor compatibility, inconvenient installation, and high maintenance costs. 8. The lack of remote control methods results in long delays in responding to equipment malfunctions, increasing the risk of escalating the fault. Utility Model Content

[0003] The purpose of this invention is to provide a mobile intelligent biomass hot air furnace that solves the above-mentioned problems and improves the combustion efficiency and heat exchange efficiency of biomass.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A mobile biomass intelligent hot air furnace includes a shell, a combustion chamber inside the shell, a combustion cylinder inside the combustion chamber, and a furnace assembly inside the combustion cylinder. The furnace assembly consists of a grate, a conical furnace bridge, a furnace sleeve, and an air inlet pipe. The conical furnace bridge is a cone-shaped structure, smaller at the bottom and larger at the top, and is mounted on the air outlet of the furnace sleeve. The grate is sealed at the bottom opening of the conical furnace bridge and is slidably and detachably connected to the furnace sleeve. Air outlet holes are evenly distributed on the grate and the conical furnace bridge. This invention, through the structural design of the furnace assembly, enables the suspension and complete combustion of materials. During combustion, lighter materials rise with the rotation of the vortex airflow and are fully combusted, while heavier materials are suspended up and down in the vortex airflow until complete combustion.

[0005] Preferably, the furnace sleeve is composed of a square air inlet section and a circular cyclone section. The air inlet section is connected to the bottom side of the cyclone section, and an air outlet is provided above the cyclone section. A conical furnace bridge is mounted on the air outlet. The air inlet pipe is arranged laterally on the side of the furnace sleeve and is connected to the middle of the air inlet section.

[0006] This invention, based on the principles of air viscosity and fluid mechanics, utilizes the aforementioned structural design of the grate, conical furnace bridge, and furnace sleeve to cause the air injected by the centrifugal fan to separate and alternate within the furnace sleeve, thus forming a vortex flow. When the airflow passes over the combustion medium, the vortex creates a low-pressure zone below the combustion medium. The vortex amplifies the material, giving it an upward buoyancy. While the material is pulled downwards by gravity, the mass loss during combustion causes this gravitational pull to decrease as the solid mass of the combustion medium decreases. Based on Archimedes' principle, a critical value is calculated, achieving levitation and reaching a balanced state of complete combustion.

[0007] The vortex airflow generated and its direction in the furnace assembly of this utility model are as follows: When the airflow enters the furnace sleeve from the inlet pipe and impacts the inner wall of the furnace sleeve, it is divided into two parts. One part of the airflow rotates clockwise at the rear end of the inlet section to form a swirling airflow. The swirling airflow can cool the furnace door (i.e., the inspection door) to facilitate maintenance in case of malfunction. Another part of the airflow enters the cyclone section and forms a spiraling upward airflow along the arc-shaped outer wall. Part of the spiraling upward airflow is ejected from the air outlets around the conical furnace bridge to form a vortex airflow, and another part is ejected upward from the air outlets at the bottom of the grate to provide an upward lifting force for the vortex airflow.

[0008] Because the furnace components can generate a stable vortex airflow, the material can be suspended and fully combusted. Through the PLC control system and temperature and humidity acquisition transmitter, combined with the adaptive PID algorithm, the dynamic matching of material conveying speed, air volume and temperature control can be achieved, realizing unmanned operation and remote real-time control, and ensuring the heating temperature requirements of different scenarios.

[0009] Preferably, the conical furnace bridge is also equipped with an alumina ceramic igniter for ignition.

[0010] Preferably, the combustion cylinder is vertically installed in the combustion chamber, and a ventilation channel is provided between the outer wall of the combustion cylinder and the combustion chamber. The furnace assembly is mounted at the lower center of the combustion cylinder, the bottom of the combustion cylinder is an ash chamber, and gaps are provided around the furnace assembly to facilitate the falling of ash into the ash chamber after combustion.

[0011] Because the furnace components are built into the combustion chamber, the lighter dust particles from the combustion ash enter the heat exchange chamber with the high-temperature flue gas, where they settle further, reducing the pressure on subsequent environmental protection equipment for flue gas dust removal. Heavier ash, when it reaches the upper part of the combustion chamber, is blown out due to the reduced vortex binding force and falls along the inner wall of the combustion chamber into the ash chamber for automatic collection. Furthermore, since the combustion chamber is completely integrated within the combustion chamber, it can directly reheat the fresh air heated in the heat exchange chamber, further improving heat utilization and the exhaust temperature of the heating duct.

[0012] Preferably, the housing also includes a heat exchange chamber and a fresh air duct. A heating duct and a turbine fan are located at the top of the housing. The top of the combustion chamber is connected to the flue gas inlet of the heat exchange chamber, the turbine fan is connected to the flue gas outlet of the heat exchange chamber, the fresh air duct is connected to the fresh air inlet of the heat exchange chamber, the fresh air outlet of the heat exchange chamber is connected to the lower part of the ventilation channel inside the combustion chamber, and the heating duct is connected to the top of the ventilation channel inside the combustion chamber. Through the structural design of the heat exchange chamber and the fresh air duct, a heat exchange channel is formed between the hot flue gas and the fresh air after connecting with the combustion chamber, allowing the fresh air to be heated for heating purposes.

[0013] Preferably, the outer wall of the combustion chamber is further provided with heat exchange fins, which are evenly spaced along the outer wall of the combustion chamber. By adding heat exchange fins to the combustion chamber, the contact area between the fresh air and the combustion chamber can be further increased, the hot air outlet temperature can be further increased, and the heat utilization rate can be improved.

[0014] Preferably, the shell is also equipped with an observation window, a maintenance door, and a slag removal door. The observation window is connected to the inside of the combustion cylinder and is directly opposite the vortex combustion part of the furnace assembly. The combustion stability can be observed through the observation window, which facilitates dynamic adjustment of the air intake and feed rate as needed. The maintenance door is connected to the furnace sleeve of the furnace assembly, which facilitates the inspection and maintenance of the furnace assembly. The slag removal door is connected to the ash chamber at the bottom of the combustion cylinder. The design of the slag removal door is twofold: first, to facilitate the cleaning of ash after combustion; and second, because a negative pressure cavity is formed at the bottom of the combustion cylinder under the action of vortex combustion, when the centrifugal fan cannot meet the oxygen supply conditions at its maximum power, the slag removal door can be opened to form a secondary oxygen supply channel, increasing the oxygen in the combustion cylinder and ensuring that the material can be fully oxidized and burned.

[0015] Preferably, the combustion chamber is wrapped with two layers of fireproof and heat-insulating material to insulate the combustion chamber. An air gap is arranged between the fireproof and heat-insulating material and the shell to achieve a multi-layer heat insulation effect and prevent the shell from getting hot.

[0016] Preferably, the shell is equipped with a hopper, a feeding assembly and a centrifugal fan. The hopper continuously conveys the material to the top of the conical furnace bridge through the feeding assembly for feeding operations. The centrifugal fan blows oxygen into the furnace sleeve through the air inlet pipe and forms a vortex airflow above the conical furnace bridge, so that the material is suspended and burned in the vortex airflow.

[0017] Preferably, the feeding assembly is located at the bottom of the hopper and consists of a motor, chain, sprocket, feeding cylinder, infeed cylinder, and discharge cylinder. The feeding cylinder is located above the infeed cylinder, with one end connected to the bottom of the hopper and the other end connected to the upper end of the discharge cylinder. The lower end of the discharge cylinder is connected to the middle of the infeed cylinder. The front end of the infeed cylinder extends through the combustion chamber to the top of the conical furnace bridge. Both the feeding cylinder and the infeed cylinder are equipped with auger spiral blades. The motor drives the auger spiral blades to rotate and feed material through the chain and sprocket.

[0018] The feeding assembly has the following structural design and layout characteristics: 1. Adopting a dual-dragon automatic feeding system, it can accurately feed materials quantitatively while crushing them into 3-5mm fragments; 2. Because the space between the combustion chamber and the combustion cylinder is a high-temperature gas chamber, the material entering through the feed cylinder can be dried at high temperature, ensuring that the moisture content is ≤15%; 3. At the same time, the hollow feeding cylinder design forms a physical separation between the material discharge from the hopper and the feeding from the combustion chamber. When the material in the feeding cylinder is ignited due to high temperature, it will not spread to the feeding cylinder and the hopper, effectively isolating safety risks and greatly improving the safety of the equipment.

[0019] Preferably, the front end of the feed cylinder is provided with a feeding chute to facilitate the dispersion of material. The material discharged from the auger spiral blades can be dispersed through the feeding chute so that it can be better lifted by the vortex airflow.

[0020] Preferably, the heat exchange chamber consists of a heat exchange chamber shell and a partition plate. The partition plate divides the heat exchange chamber shell into an upper high-temperature smoke chamber and a low-temperature smoke chamber, a middle fresh air heat exchange chamber, and a lower circulating smoke chamber. The high-temperature smoke chamber and the low-temperature smoke chamber are separated left and right by the partition plate. The side of the high-temperature smoke chamber has a flue gas inlet connected to the top of the combustion cylinder, and the top of the low-temperature smoke chamber has a flue gas outlet connected to the turbine fan. The fresh air heat exchange chamber has multiple sets of tubes arranged vertically. The high-temperature smoke chamber and the low-temperature smoke chamber are respectively connected to the circulating smoke chamber through the tubes to form a U-shaped flue. The left side of the fresh air heat exchange chamber has a fresh air inlet connected to the fresh air duct, and the right side has a fresh air outlet connected to the combustion chamber. The fresh air heat exchange chamber has a vertical baffle plate, which divides the fresh air heat exchange chamber into an inverted U-shaped fresh air channel. The heat exchanger is a combined heat exchanger formed by the design of the heat exchange chamber, tubes, spiral heat exchange fins, and baffles. The heat exchange path is increased by the design of the U-shaped flue and the inverted U-shaped fresh air channel. The air anisotropic velocity and a large number of vortex structures are realized by the turbulence principle in engineering fluid mechanics. The air in this state has nonlinear characteristics, which can enhance the heat transfer. Compared with laminar flow, the turbulent heat transfer coefficient is 40% higher than that of traditional design.

[0021] Preferably, the outer wall of the tube is fitted with spiral heat exchange fins, the inner wall of the tube is a non-smooth surface, the tube has a Venturi effect inlet at the flue gas inlet, and a turbulence plate is installed inside the tube, with the turbulence plate located away from the flue gas inlet. This invention incorporates turbulence design both inside and outside the tube to create turbulence within the heat exchange chamber. The spiral heat exchange fins on the outer wall of the tube not only increase the contact area between the tube and the fresh air, but also generate numerous vortices as the fresh air flows through them, creating an irregular, mixed state that breaks away from the original flow layer. This causes the fresh air to transition from advection to turbulence, ensuring sufficient contact and heat exchange between the fresh air and the tube and spiral heat exchange fins. The Venturi effect nozzle structure at the flue gas inlet end of the tube can generate the Venturi effect, causing the high-temperature flue gas to accelerate and impact the turbulent plate. Combined with the non-smooth inner wall of the tube, this creates a large amount of turbulence in the high-temperature flue gas within the tube, thereby improving the heat exchange efficiency between the high-temperature flue gas and the tube.

[0022] Preferably, each of the housings is provided with a smoke chamber access door that connects to the high-temperature smoke chamber, the circulating smoke chamber, and the low-temperature smoke chamber. Since lighter dust particles will enter the heat exchange chamber with the high-temperature flue gas, dust will accumulate in the high-temperature smoke chamber, the circulating smoke chamber, and the low-temperature smoke chamber over time. The opening of the smoke chamber access door facilitates the regular cleaning of dust in the heat exchange chamber.

[0023] Preferably, the housing also includes a waste heat exchange chamber, mainly composed of a waste heat exchange chamber shell, hydrophilic aluminum foil exchange cores, a humid heat pipe assembly, and an exhaust gas pipe. The hydrophilic aluminum foil exchange cores are arranged in two sets, upper and lower, both sets being rhomboidally positioned within the square waste heat exchange chamber shell, dividing the waste heat exchange chamber shell into six independent air chambers. The air chambers on the left side of the waste heat exchange chamber, from top to bottom, are the first fresh air intake chamber, the exhaust gas intake chamber, and the second fresh air intake chamber; the air chambers on the right side, from top to bottom, are the first exhaust gas exhaust chamber, the fresh air outlet chamber, and the second exhaust gas exhaust chamber. Both the first and second fresh air intake chambers have fresh air inlets on their sides. These chambers are connected to the fresh air outlet chamber via two sets of hydrophilic aluminum foil exchange cores. The fresh air outlet chamber is connected to the fresh air inlet of the heat exchange chamber via a fresh air duct, forming a fresh air preheating intake channel. The humid heat pipe assembly is connected to the exhaust gas intake chamber, which is also connected to the first and second exhaust gas exhaust chambers via two sets of hydrophilic aluminum foil exchange cores. The first and second exhaust gas exhaust chambers are connected to the outside of the casing via exhaust gas exhaust pipes. Since biomass hot air furnaces generally require a large supply of hot air, and the hot air, after being dried and used within the plant equipment, carries a large amount of water vapor and production waste gas, the resulting humid hot air needs to be dehydrated before being discharged into the waste gas treatment equipment for further processing. This invention incorporates a waste heat exchange chamber within the hot air furnace. This chamber not only preheats the fresh air with the waste heat from the humid air, achieving heat recovery and utilization, but also condenses and recovers water vapor from the humid air. The recovered water vapor can then be directly discharged into waste gas treatment equipment for further processing. To achieve the utilization of waste heat and steam condensation from a large volume of humid air, this invention employs two sets of rhomboid-arranged hydrophilic aluminum foil exchange cores, dividing the waste heat exchange chamber into six independent compartments. Due to the cross-arranged heat exchange tube structure within the hydrophilic aluminum foil exchange cores, the humid air path and fresh air path can exchange heat alternately, achieving connectivity between the relevant compartments. This enables a unique cross-heat exchange method where the humid air is split in two and the fresh air is combined into one. While meeting the requirement of handling a large volume of humid air, the heat utilization rate is improved through heat exchange with the fresh air. Simultaneously, the water condensed from the humid air can naturally flow back along the first exhaust chamber to the exhaust inlet chamber, and then to the second exhaust chamber, easily achieving gravity-flow water recovery.

[0024] Preferably, the fresh air inlet is equipped with an air filter to filter dust and impurities in the air, making the incoming fresh air cleaner; the exhaust duct is equipped with an axial flow fan, which can transport the heat-exchanged exhaust gas through the exhaust duct to the next stage of exhaust gas treatment equipment; after the heating duct delivers high-temperature hot air to the plant equipment, the resulting humid and hot exhaust gas is drawn back to the waste heat exchange chamber through the humid and hot gas pipe assembly for fresh air preheating, improving energy utilization efficiency and achieving the purpose of energy saving and emission reduction. At the same time, water vapor is condensed and recycled through the condensate drainage pipe at the bottom of the second exhaust chamber.

[0025] Compared with the prior art, the advantages of this utility model are: (1) By designing the structure of the hot air furnace and the heat exchange channel, this utility model significantly improves the temperature of the hot air discharged from the heating air pipe from 58.3% to 79.9% compared with the traditional hot air furnace, and the heat carried out by the flue gas of the turbine fan from 18.8% to 9.2%, resulting in a higher and more reasonable air heat exchange rate.

[0026] (2) Through the conical grate structure design of the combustion tube and furnace components, this utility model can achieve material suspension and full combustion, so that biomass particles can combine with oxygen to burn more fully, effectively reducing the generation of carbon monoxide, carbon black and ash, and improving the combustion efficiency of biomass; through the designed feeding slide, the biomass fuel is evenly distributed, avoiding local material accumulation or dry burning; and the configuration of multi-channel oxygen supply channels improves combustion efficiency, so that it burns fully and reduces CO emission concentration. The heat source is burned more fully. Compared with the traditional hot air furnace B, the heat loss due to incomplete chemical combustion is reduced from 14.6% to 6.1%, which proves the advanced nature of the furnace structure and secondary oxygen supply of this utility model.

[0027] (3) The double auger automatic feeding system is adopted. While feeding, the fuel is crushed into 3-5mm pieces. The heat provided by the metal cylinder in the built-in combustion chamber dries the fuel moisture, ensuring that the moisture content is ≤15%. The fuel is compatible with various forms such as pellets, briquettes, and sawdust. At the same time, the hollow feeding cylinder forms a physical barrier, effectively isolating the safety risks caused by the high temperature ignition of biomass, and greatly improving the safety of the equipment.

[0028] (4) The various structures of this utility model are modular and integrated into one, the combustion chamber and the heat exchange chamber are directly connected, and the whole steel multi-layer sleeve welded structure reduces the floor area and saves installation and manual maintenance costs; moreover, it can ensure the temperature requirements of different scenarios through dynamic matching of fuel delivery speed, air volume and temperature control and unmanned operation. Attached Figure Description

[0029] Figure 1 and Figure 2This is a schematic diagram of the external structure of this utility model; Figure 3 and Figure 4 This is a schematic diagram of the internal structure of this utility model; Figure 5 This is a schematic diagram of the internal structure of the combustion chamber and heat exchange chamber of this utility model; Figure 6 This is a schematic diagram of the internal structure of the waste heat exchange chamber of this utility model; Figure 7 This is an overall schematic diagram of the furnace assembly and feeding assembly of this utility model; Figure 8 This is a schematic diagram of the internal structure of the furnace assembly of this utility model; Figure 9 This is a schematic diagram of the internal structure of the feeding assembly of this utility model; Figure 10 This is a schematic diagram of the internal structure of the tube of this utility model; Figure 11 This is a diagram showing the airflow trajectory of the furnace assembly of this utility model; Figure 12 A diagram showing the structure and airflow trajectory of a traditional furnace assembly; Figure 13 This is a diagram illustrating the thermal diffusion effect of high-temperature flue gas in the furnace assembly of this utility model. Figure 14 This is a comparison diagram of the combustion effects of the furnace assembly of this utility model and a traditional furnace; Figure 15 and 16 This invention provides a diagram showing the airflow trajectory and turbulent airflow principle within the tube of the present invention. Figure 17 and 18 The diagram shows the airflow trajectory and turbulent airflow principle within a traditional heat exchanger tube. Figure 19 This is a comparison diagram of the high-temperature heat flow distribution between the tube array of this utility model and the traditional heat exchange tube; Figure 20 and Figure 21 This is a gaseous cloud image of the flue gas and heat exchange air of this utility model; Figure 22 This is a thermal phase diagram of the air cross-section of the heat exchange chamber of this utility model; Figure 23 This is a gaseous cloud image of the heat exchange air in a traditional hot blast stove. Figure 24 This is a thermal phase diagram of the air cross-section in the heat exchange chamber of a traditional hot blast stove. Detailed Implementation

[0030] The present invention will be further described below. I. Equipment Composition This utility model relates to a mobile biomass intelligent hot air furnace, see [link to relevant documentation]. Figures 1 to 10 The main equipment consists of the following components: shell 1, hopper 5, feeding assembly 4, centrifugal fan 2, combustion chamber 6, heat exchange chamber 9, fresh air duct 11, heating air duct 8, and turbine fan 10. The combustion chamber 6 is composed of the following components: It is encased in fireproof and heat-insulating material 67, contains a combustion cylinder 61, has heat exchange fins 66 on its exterior, and a bottom ash chamber 62. The combustion chamber 6 also contains a furnace assembly 7. The furnace assembly 7 consists of a grate 71, a conical furnace bridge 72, a furnace sleeve 73, an air inlet pipe 75, and an alumina ceramic igniter 74. The furnace sleeve 73 consists of an air inlet section 731 and a cyclone section 732.

[0031] The feeding assembly 4 is composed of the following components: a motor 41, a chain 42, a sprocket 43, a feeding cylinder 45, an infeed cylinder 46, a discharge cylinder 47, a feeding slide 48, and a auger spiral blade 44.

[0032] The heat exchange chamber 9 is composed of the following components: a heat exchange chamber shell 91, a high-temperature smoke chamber 92, a low-temperature smoke chamber 95, a fresh air heat exchange chamber 93, and a circulating smoke chamber 94. The fresh air heat exchange chamber 93 contains multiple sets of tubes 96 and baffles 97. Spiral heat exchange fins 98 are mounted on the tubes 96. The tubes 96 also contain Venturi effect inlets 961 and turbulence vanes 962. A fresh air motor 17 is mounted on the fresh air duct 11.

[0033] The waste heat exchange chamber 12 is composed of the following components: a waste heat exchange chamber shell 121, a hydrophilic aluminum foil exchange core 122, a humid heat pipe assembly 13, an exhaust gas pipe 14, an air filter 129, a condensate drain pipe 16, and an axial flow fan 15. The hydrophilic aluminum foil exchange core 122 divides the waste heat exchange chamber shell 121 into six independent air chambers. From top to bottom on the left, these are the first fresh air intake chamber 123, the exhaust gas intake chamber 124, and the second fresh air intake chamber 125. From top to bottom on the right, these are the first exhaust gas exhaust chamber 126, the fresh air outlet chamber 127, and the second exhaust gas exhaust chamber 128.

[0034] It also includes maintenance auxiliary equipment, such as the observation window 63, maintenance door 64 and slag removal door 65 on the combustion tube 61, and the smoke chamber maintenance door 99 on the heat exchange chamber 9.

[0035] This invention enhances turbulent heat transfer and increases the heat transfer rate by modifying the furnace structure of the combustion chamber 6 and the flue gas flow path of the heat exchange chamber 9. The intelligent control system precisely regulates the combustion process, effectively reducing incomplete combustion losses. Simultaneously, the integrated waste heat recovery device uses the heat from the used hot air to preheat the dehumidification system, further improving energy utilization and significantly addressing the problems of low thermal efficiency, high emission temperature, and high energy consumption inherent in traditional hot air furnaces.

[0036] II. Thermal Effect Test To quantitatively understand the heat usage and thermal efficiency changes of the new type of hot air furnace, evaluate its thermal characteristics, and reveal the application effect of turbulent heat transfer, field tests were conducted on the biomass intelligent hot air furnace A of this invention and the traditional hot air furnace B with the same furnace type and size. The data collected from the field tests were subjected to thermal diagnosis and quantitative analysis, and the effect was verified through comparative analysis.

[0037] 1. Experimental subjects The utility model of this biomass intelligent hot air furnace A: cylindrical, with a diameter of 500 (mm) and a height of 1800 (mm); Traditional equipment hot air furnace B: cylindrical, diameter 500 (600) and height 1800 (1900).

[0038] 2. Experiment content and data The test data records include: flue gas composition, fuel medium consumption; flue gas temperature and pressure; combustion air temperature, pressure, and flow rate; cold air temperature, pressure, and flow rate; hot air temperature, pressure, and flow rate. The flue gas data are all from actual factory measurements. Flue gas data A is the average of nine sets of data from intermittent tests, and flue gas data B is the gas data at the time of the test. Flue gas composition was measured on-site using a VarioPlus industrial gas continuous analyzer manufactured by MRU GmbH, Germany. The test data tables contain averages from multiple on-site tests. The dimensions of the hot blast stove mainly refer to its external dimensions.

[0039] (1) Meteorological parameters for the day: Date: 2025.3.30, Atmospheric temperature: 14℃, Wind speed: <5m / s, Weather condition: Cloudy to sunny.

[0040] (2) Flue gas composition test data (%), see Table 1 below:

[0041] (3) The combustion period parameters of the hot blast stove during the test period are shown in Table 2 below:

[0042] (4) Parameters for the hot blast stove air supply period during the test period, see Table 3 below:

[0043] (5) Parameters for the hot blast stove air supply period during the test period, see Table 4 below:

[0044] (6) Operating parameters of the hot blast stove during the test period are shown in Table 5 below:

[0045] 3. Data processing for thermal diagnostics (1) Basic parameters a. Based on experience, the moisture content of biomass pellets is taken as 5% (equivalent to 37g / m³). 3 Biomass pellets), the low calorific value of fuel D WQ It is 18653 kJ / kg; b. Calculations yielded a theoretical dry air volume of 57.83, a theoretical flue gas generation of 145.68, and an air coefficient of 0.98. c. Based on the ambient temperature, the moisture content of the dry air is as follows: Hot air furnace A (6℃) has a moisture content of 7.48; Hot air furnace B (14℃) has a moisture content of 12.9. d. Based on the above parameters, calculate the actual flue gas generation: 145.05 for hot blast stove A; 153.60 for hot blast stove B. e. The actual amount of flue gas generated is converted into the wet composition of the flue gas (%), as shown in Table 6 below:

[0046] (2) Heat income items Measurements showed that during the testing period, the actual biomass pellet usage for hot blast stove A was 12.3 kg, and for hot blast stove B it was 12.2 kg. Based on the lower heating value (LHC) of the biomass pellets, D... WQ Calculate the chemical heat of fuel Q1, physical heat of fuel Q2, physical heat of combustion air and fuel Q3, heat brought in by cold air Q4, and the total heat received ∑Q, as shown in Table 7 below:

[0047] (3) Heat expenditure items The heat carried out by hot air Q1′, the heat carried out by flue gas Q2′, the heat loss due to incomplete combustion Q3′, the heat absorbed by moisture in biomass pellets Q4′, the heat dissipation from the furnace surface Q5′, and the total heat expenditure ∑Q′ are shown in Table 8 below:

[0048] Calculate the thermal diagnostic difference ΔQ. The formula for calculating the thermal diagnostic difference is as follows: △Q=∑Q -∑Q′=∑Q -(Q1′+Q2′+Q3′+Q4′+Q5′) Calculations show that the thermal diagnostic difference of hot blast stove A is ΔQ = 27971.6 - 26879.3 = 1092.3 kJ / m³. 3 ; The thermal diagnostic difference of hot blast stove B, ΔQ = 27702.1 - 26769.8 = 932.3 kJ / m³ 3 ; (4) Perform thermal diagnosis of the hot blast stove system based on the above parameters. a. Before performing thermal diagnostics, the relative error δ should be calculated. The calculation formula is...

[0049] Calculations show that the relative error of hot blast stove A is δ = |1092.3 / 27971.6| × 100% ≈ 3.9%; The relative error of hot blast stove B is δ = |932.3 / 27702.1| × 100% ≈ 3.3%; It can be seen that the relative error δ of the heat balance calculation for both hot blast stoves is less than 5%, which is within the ±5% range of the allowable relative difference for heat balance, and the calculation results are valid.

[0050] b. Calculate the thermal efficiency η of the hot blast stove system. Thermal efficiency has two characteristics: the body thermal efficiency η1, which does not include heat loss from piping and furnace body, and η2, which includes heat loss. The calculation formulas are as follows:

[0051]

[0052] This embodiment takes the calculation of the thermal efficiency η2 of the hot blast stove system as an example. The calculation results are shown in Table 9 below:

[0053] 4. Analysis of the results of thermal diagnosis (1) Increased hot air temperature As can be seen from Table 8, compared with the traditional hot air furnace B, the heat carried out by the hot air of this utility model A is increased from 58.3% to 79.9%, while the heat carried out by the flue gas is decreased from 18.8% to 9.2%. The air heat exchange is more reasonable, the effective heat utilization is increased, and the heat loss is reduced.

[0054] (2) Flue gas temperature decreases As can be seen from Table 8, compared with the traditional hot air furnace B, the heat carried out by the flue gas in the hot air furnace A of this utility model is reduced from 18.8% to 9.2%, indicating that the heat conduction capacity of the high-temperature flue gas in the heat exchange tube of the heat exchange chamber is stronger, which improves the heat storage capacity of the heat storage body during the combustion period and reduces the flue gas temperature.

[0055] (3) The heat source burns more completely As can be seen from Table 8, compared with the traditional hot air furnace B, the heat loss due to incomplete chemical combustion of the hot air furnace A of this utility model is reduced from 14.6% to 6.1%, which proves the advanced nature of the furnace structure and secondary oxygen supply of this utility model. The biomass pellets combine with oxygen and react fully to generate carbon dioxide, effectively reducing the generation of carbon monoxide, carbon black and ash.

[0056] (4) Better heat source isolation As can be seen from Table 8, compared with the traditional hot air furnace B, the heat dissipation of the furnace body surface of the present invention A is reduced from 7.7% to 4.2%. The fireproof and heat-insulating plate on the surface effectively blocks ineffective heat conduction and heat source radiation loss, thereby improving the heat energy utilization rate.

[0057] 5. Conclusion Comparing the data in Table 9, the thermal efficiency of the hot blast stove A system of this invention is 74.6%, while the thermal efficiency of the traditional hot blast stove B system is 51.5%. The results show that the thermal efficiency of stove A is 23.1% higher than that of stove B.

[0058] Note: This experiment did not involve testing waste heat recovery. According to theoretical calculations, using a waste heat recovery system to increase the air temperature can further improve thermal efficiency by 15% (affected by space volume and environmental factors).

[0059] III. Heat Source Analysis of the Equipment Structure of this Utility Model 1. Furnace assembly The structural design of the furnace chamber assembly 7 of the hot blast stove of this utility model is described in [reference needed]. Figure 7 and Figure 8 The conical furnace bridge 72 structure, designed using the principles of air viscosity and fluid mechanics, enables the separation and alternation of oxygen supply air, thus forming a vortex flow. When the airflow passes over the combustion medium, the vortex creates a low-pressure zone below the combustion medium, giving it an upward buoyancy. When the combustion medium is pulled downward by gravity, the mass loss during combustion causes the gravitational pull to decrease with the solid mass loss of the combustion medium. Based on Archimedes' principle, its critical value is calculated, thus achieving a state of suspension and complete combustion. Therefore, it can achieve material suspension and complete combustion. The airflow trajectory is shown in [reference needed]. Figure 11 For the thermal diffusion effect of high-temperature flue gas, please refer to [reference needed]. Figure 13 The highest temperature near the furnace assembly 7 can reach 800℃, the temperature of the circulating smoke chamber 94 is about 313℃, and the inlet temperature of the heating air duct 8 is about 236℃.

[0060] Traditional hot blast stoves use a flat grate as the combustion device, where the combustion medium burns on the grate. See [link to relevant documentation] for the structure and airflow trajectory. Figure 12 See the comparison diagram of combustion effect with that of this utility model. Figure 14 .

[0061] Conclusion: Through comparison of combustion effects, the hot blast stove of this invention exhibits no dark areas, indicating complete combustion, uniform oxygen supply, and no black smoke formation. The main emissions are CO2 and H2O, significantly reducing CO, CH4, SO2, NOx, and H2. In contrast, traditional hot blast stoves show obvious piled-up combustion and distinct dark areas, indicating incomplete combustion, uneven oxygen supply, poor combustion conditions, incomplete combustion of carbides, and the formation of carbon black particles. These particles rise with the hot air to form black smoke, and incomplete combustion increases the probability of CO, CH4, SO2, NOx, and H2 production.

[0062] The main reasons for this are: the vortex airflow of this invention provides sufficient oxygen, suspending the combustion medium while supplying oxygen for combustion. In contrast, traditional hot blast stove designs feature turbulent flow, which, while providing oxygen, suffers from insufficient uniformity and incomplete combustion in certain areas, leading to frequent fluctuations in furnace temperature, generally low thermal efficiency, and high CO emission concentrations. Furthermore, the conical grate of this invention features a diffusion-type deformation design with small deformation and more uniform distribution. The point of maximum deformation under high-temperature thermal stress is located on the fixed top ring surface, dispersing outwards and easily recovering after cooling and contraction. Traditional grate structures, made of flat metal, are prone to plastic deformation due to combustion thermal stress, causing the transported fuel medium to easily deposit and accumulate during combustion, resulting in incomplete combustion.

[0063] 2. Heat exchanger - tube and shell The Venturi effect nozzle 961 structure at the flue gas inlet end of the tube 96 of this utility model can generate a Venturi effect, causing the high-temperature flue gas to accelerate and impact the turbulence vane 962. Simultaneously, the inner wall of the tube 96 is a non-smooth surface, causing vortices to be generated in the fluid and detach from the original flow layer. When the Reynolds number exceeds the critical value, inertial force overcomes the fluid viscosity, and inertial force becomes dominant, sufficient to overcome the inhibitory effect of viscosity on vortex motion, allowing the vortex to continue to develop and triggering fluid particle mixing. The airflow state changes from laminar flow to transitional flow and then to turbulent flow. See [reference needed] for the airflow trajectory inside the tube. Figure 15 For the principle of turbulent airflow, please refer to [link / reference]. Figure 16 .

[0064] Traditional heat exchanger tubes are straight tubes, resulting in stable flow. The trajectories of fluid particles show no obvious irregular pulsations, and momentum exchange between adjacent fluid layers occurs only due to molecular thermal motion. Furthermore, the Reynolds number does not exceed the critical value. The flow trajectory is distributed along the Z-axis, with continuously varying velocities forming concentric cylindrical layers, exhibiting a pattern of straight lines and parallel lines. Based on the hierarchical nature and stability of the flow, the airflow state is laminar. See [link to tube flow trajectory diagram] for details. Figure 17 For the principle of turbulent airflow, please refer to [link / reference]. Figure 18 .

[0065] A comparison diagram of the high-temperature heat flow distribution in the heat exchanger tubes of this invention and a traditional hot blast stove is shown below. Figure 19 ,

[0066] Conclusion: The tube-and-tube design of this invention has a higher heat transfer capacity and more uniform heat conduction than traditional heat exchange tubes. Under the condition that the fluid properties and the inner and outer diameters of the heat exchange tubes are the same, turbulence can increase the heat transfer coefficient of the circular tube surface, effectively absorbing heat inside the tube and transferring it to the tube surface, thereby increasing the heat transfer area, significantly improving the heat transfer per unit area, and enhancing the heat exchange efficiency.

[0067] 3. Convective heat transfer analysis The gaseous cloud diagram of flue gas and heat exchange air during combustion in this utility model's hot air furnace is shown in the attached image. Figure 20 and Figure 21 The overall flow is turbulent, with irregular mixing and numerous vortices generated, which detach from the original flow layer (the white mass). See the thermal phase diagram of the air cross-section in heat exchange chamber 9. Figure 22 It can be seen that the mixing of air particles in heat exchange chamber 9 has strong diffusion, and the air flow pattern is disordered, rotating and interlaced, which can quickly transfer heat to the entire pipe and significantly improve heat transfer efficiency.

[0068] See the gaseous cloud diagram of the heat exchange air during combustion in a traditional hot blast stove. Figure 23 The flow is laminar, orderly, and unmixed, with only a small amount of cyclone (white clumps). See the thermal phase diagram of the air cross-section in the heat exchange chamber. Figure 24 It can be seen that the air in the heat exchange chamber is in a laminar flow state, and the air flows smoothly and quietly. The transfer rate of laminar flow is lower than that of turbulent flow.

[0069] The above provides a detailed description of a mobile biomass intelligent hot air furnace provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, based on the idea of ​​this utility model, there will be changes in the specific implementation and application scope. Changes and improvements to this utility model are possible without exceeding the concept and scope specified in the appended claims. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A mobile biomass intelligent hot air furnace, comprising a shell (1), characterized in that: The housing (1) is provided with a combustion chamber (6), the combustion chamber is provided with a combustion cylinder (61), the combustion cylinder (61) is provided with a furnace assembly (7), the furnace assembly (7) is composed of a grate (71), a conical furnace bridge (72), a furnace sleeve (73) and an air inlet pipe (75). The conical furnace bridge (72) is a conical structure with a smaller bottom and a larger top, and is mounted on the air outlet of the furnace sleeve (73). The grate (71) is sealed at the bottom opening of the conical furnace bridge (72) and is slidably detached from the furnace sleeve (73). The grate (71) and the conical furnace bridge (72) are evenly provided with air outlet holes.

2. The mobile biomass intelligent hot air furnace according to claim 1, characterized in that: The furnace sleeve (73) is composed of a square air inlet section (731) and a circular cyclone section (732). The air inlet section (731) is connected to the bottom side of the cyclone section (732). An air outlet is provided above the cyclone section (732). A conical furnace bridge (72) is mounted on the air outlet. The air inlet pipe (75) is arranged laterally on the side of the furnace sleeve (73) and is connected to the middle of the air inlet section (731).

3. A mobile biomass intelligent hot air furnace according to claim 1, characterized in that: The conical furnace bridge (72) is also equipped with an alumina ceramic igniter (74).

4. A mobile biomass intelligent hot air furnace according to claim 1, characterized in that: The combustion cylinder (61) is vertically installed inside the combustion chamber (6). A ventilation channel is left between the outer wall of the combustion cylinder (61) and the combustion chamber (6). The furnace assembly (7) is mounted at the lower center of the combustion cylinder (61). The bottom of the combustion cylinder (61) is the ash chamber (62). A gap is left around the furnace assembly (7) to facilitate the ash and slag falling into the ash chamber (62) after combustion.

5. A mobile biomass intelligent hot air furnace according to claim 4, characterized in that: The shell (1) is also provided with a heat exchange chamber (9) and a fresh air duct (11). The top of the shell (1) is provided with a heating duct (8) and a turbine fan (10). The top of the combustion chamber (61) is connected to the flue gas inlet of the heat exchange chamber (9). The turbine fan (10) is connected to the flue gas outlet of the heat exchange chamber (9). The fresh air duct (11) is connected to the fresh air inlet of the heat exchange chamber (9). The fresh air outlet of the heat exchange chamber (9) is connected to the lower part of the ventilation channel in the combustion chamber (6). The heating duct (8) is connected to the top of the ventilation channel in the combustion chamber (6).

6. A mobile biomass intelligent hot air furnace according to claim 4, characterized in that: The outer wall of the combustion cylinder (61) is also provided with heat exchange plates (66), which are evenly distributed along the outer wall of the combustion cylinder (61).

7. A mobile biomass intelligent hot air furnace according to claim 5, characterized in that: The housing (1) is also provided with an observation window (63), a maintenance door (64) and a slag removal door (65). The observation window (63) is connected to the inside of the combustion cylinder (61) and is directly opposite the vortex combustion part of the furnace assembly (7). The maintenance door (64) is connected to the furnace sleeve (73) of the furnace assembly (7). The slag removal door (65) is connected to the ash chamber (62) at the bottom of the combustion cylinder (61).

8. A mobile biomass intelligent hot air furnace according to claim 1, characterized in that: The shell is equipped with a hopper (5), a feeding assembly (4) and a centrifugal fan (2). The hopper (5) continuously conveys the material to the top of the conical furnace bridge (72) through the feeding assembly (4). The centrifugal fan (2) injects oxygen into the furnace sleeve (73) through the air inlet pipe (75) and forms a vortex airflow above the conical furnace bridge (72), so that the material is suspended and burned in the vortex airflow.

9. A mobile biomass intelligent hot air furnace according to claim 8, characterized in that: The feeding assembly (4) is located at the bottom of the hopper (5) and consists of a motor (41), a chain (42), a sprocket (43), a feeding cylinder (45), a feed cylinder (46), and a discharge cylinder (47). The feeding cylinder (45) is located above the feed cylinder (46), with one end connected to the bottom of the hopper (5) and the other end connected to the upper end of the discharge cylinder (47). The lower end of the discharge cylinder (47) is connected to the middle of the feed cylinder (46). The front end of the feed cylinder (46) extends through the combustion chamber (6) to the top of the conical furnace bridge (72). Both the feeding cylinder (45) and the feed cylinder (46) are equipped with auger spiral blades (44). The motor (41) drives the auger spiral blades (44) to rotate and feed materials through the chain (42) and the sprocket (43).

10. A mobile biomass intelligent hot air furnace according to claim 9, characterized in that: The front end of the feed cylinder (46) is provided with a feeding chute (48) to facilitate the dispersed feeding of materials.

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