A cyclone air cooler for flue gas of a methanol gas fertilizer machine

Abstract

The utility model discloses a kind of methanol gas fertilizer machine flue gas's cyclone air cooler, belong to greenhouse equipment technical field.The device includes cyclone housing, cooling fan, combustor, high-temperature flue pipe and safety monitoring system.Cooling fan is sent into cooling air to cylinder by the inlet passage of tangential angle 15°-25°, forms cyclone cooling passage outside high-temperature flue pipe, realizes the forced convection heat exchange to flue pipe wall;Flue gas is cooled and mixed in upper portion with cyclone air and is fully mixed and cooled down.Innovatively, venturi pressure tube and air pressure switch are used to monitor air pressure in real time, and when the pressure difference is abnormal, the controller immediately cuts off the combustor, forming a safety protection closed loop.The utility model successfully reduces 1200 ℃ high-temperature flue gas to below 50 ℃ by the synergistic effect of optimizing cyclone structure and safety system, solves the problems of complex structure of existing water cooling system, insufficient efficiency of air cooling system and lack of safety monitoring, and has the advantages of high cooling efficiency, compact structure and safety and reliability.

Description

Technical Field

[0001] This utility model belongs to the field of carbon dioxide generators using combustion method in greenhouses, specifically relating to a swirling air cooler for high-temperature flue gas from a methanol fertilizer generator. Background Technology

[0002] The combustion method produces carbon dioxide gas, which is then applied to greenhouse crops to increase yield and improve quality. The carbon dioxide generator for the combustion method has many advantages, including high gas output, controllable application, and pure gas. However, the high-temperature flue gas produced by burning methanol can reach 1200°C. Therefore, the gas temperature must be reduced to below 50°C and kept below 30°C near the crops in the greenhouse. Excessive temperature will damage the crops.

[0003] Currently, water-cooled heat exchange is commonly used to reduce flue gas temperature. However, this method requires components such as water pumps, heat exchangers, and water tanks, resulting in high costs, complex structures, and large volumes. Furthermore, it is prone to scaling and clogging in areas with hard water, making maintenance inconvenient and limiting its widespread application in the agricultural field.

[0004] Chinese patent 202221103817 discloses an instantaneous cooling device for an aerated fertilizer machine, which uses airflow to induce flue gas for cooling. However, due to the short mixing path and insufficient mixing, the cooling effect is limited, making it difficult to achieve a rapid drop from extreme high temperatures to safe temperatures. In addition, existing aerated fertilizer machine cooling devices generally lack effective safety monitoring for cooling system malfunctions such as fan stoppage or duct blockage, posing a risk of equipment burnout or greenhouse fire due to cooling failure. Utility Model Content

[0005] The purpose of this invention is to solve the above-mentioned technical problems and provide a swirling air cooler for methanol fertilizer generator flue gas.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A cyclone air cooler for methanol fertilizer generator flue gas includes a cyclone shell, a cooling fan, a burner, a high-temperature flue pipe, a Venturi pressure measuring tube, a pressure switch, and a controller. The cyclone shell is a cylindrical structure formed by connecting a lower straight section and an upper conical section. The top of the conical section is an exhaust port. The air outlet of the cooling fan is tangentially connected to the bottom of the straight section through the cyclone inlet channel. The burner is located at the center of the bottom of the straight section. The high-temperature flue pipe is coaxial with the straight section and is sleeved outside the burner. A cyclone cooling channel is formed between the high-temperature flue pipe and the straight section. A cooling mixing zone is formed in the space above the high-temperature flue pipe. The Venturi pressure measuring tube is located on the inner wall of the cyclone inlet channel near the cooling fan along the airflow direction. The pressure switch is located on the outer wall of the cyclone inlet channel. The Venturi pressure measuring tube is connected to the pressure switch through a pressure guide pipe. The cooling fan, burner, air pressure switch and controller are electrically connected. The controller is configured to control the burner to stop working when the pressure difference between the inlet and throat of the Venturi pressure measuring tube detected by the air pressure switch is lower than a set threshold.

[0007] Furthermore, the height of the high-temperature flue is 1 / 2 to 2 / 3 of the height of the straight section.

[0008] Furthermore, the angle between the central tangent of the cyclone inlet channel and the inner wall of the straight section is 0°-25°.

[0009] Furthermore, the air inlet of the cooling fan is provided with an air regulating plate for adjusting the air intake.

[0010] Furthermore, the outer wall of the high-temperature flue is provided with several spiral guide vanes for enhancing heat exchange and stabilizing the swirling flow field.

[0011] Furthermore, the inner walls of the straight and conical sections of the hydrocyclone shell are lined with a high-temperature resistant insulation layer.

[0012] 1. High cooling efficiency: This utility model forms a rotating airflow in the swirl cooling channel by tangential air intake, which can form a stable and strong swirling field in the limited equipment space. This not only enhances the convective heat transfer to the outer wall of the high-temperature flue, but also sets the conditions for subsequent turbulent mixing in the cooling mixing zone, thereby achieving efficient cooling of flue gas at 1200℃ to below 50℃ in a short distance. 2. Compact structure and low cost: This utility model adopts air cooling, eliminating the need for complex components such as water pumps and heat exchangers in water cooling systems, thus reducing equipment size and cost, making it suitable for greenhouse applications; 3. High safety: This invention integrates the Venturi pressure measuring tube and the air pressure switch into the swirl air inlet channel, and clarifies the logic of the controller taking action based on the differential pressure threshold. This design directly binds the working status of the cooling air (airflow and air pressure) to the operational safety of the burner, ensuring rapid response and preventing accidents by immediately shutting off the burner in case of fan failure or insufficient air pressure due to duct blockage.

[0013] 4. The spiral guide vanes added to this invention not only improve heat exchange efficiency but also stabilize the swirling flow and reduce energy dissipation. Meanwhile, the high-temperature resistant insulation layer effectively reduces the outer shell temperature, improving the equipment's durability and operational safety under long-term high-temperature environments. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 for Figure 1 Front view structural diagram; Figure 3 This is a schematic diagram of the internal structure of the hydrocyclone of this utility model; Figure 4 This is a schematic diagram of the installation structure of the Venturi pressure gauge of this utility model; In the diagram: 1-Cyclone shell; 1.1-Straight section; 1.2-Cone section; 2-Cooling fan; 3-Air regulating plate; 4-Cyclone inlet channel; 5-Exhaust port; 6-Burner; 7-High temperature flue; 8-Cyclone cooling channel; 9-Cooling mixing zone; 10-Venturi pressure measuring tube; 11-Air pressure switch. Detailed Implementation

[0015] The present invention will be further described below with reference to the embodiments and accompanying drawings. Example 1

[0016] like Figure 1-4 As shown, a cyclone air cooler for methanol fertilizer generator flue gas includes a cyclone shell 1, a cooling fan 2, a burner 6, a high-temperature flue pipe 7, a Venturi pressure measuring tube 10, an air pressure switch 11, and a controller. The cyclone shell 1 is a cylindrical structure formed by connecting a lower straight section 1.1 and an upper conical section 1.2. The top of the conical section 1.2 is an exhaust port 5. The inner walls of the straight section 1.1 and the conical section 1.2 are lined with a high-temperature resistant heat insulation layer. The air inlet of the cooling fan 2 is provided with an air regulating plate 3 for adjusting the air intake. The air outlet is connected tangentially to the bottom of the straight section 1.1 through a cyclone inlet channel 4, and the angle between the central tangent of the cyclone inlet channel 4 and the inner wall of the straight section 1.1 is 0-2°. 5°, the burner 6 is located at the center of the bottom of the straight section 1.1, the high temperature flue 7 is coaxial with the straight section 1.1 and its height is 0.5 times that of the straight section 1.1, and it is sleeved on the outside of the burner 6. Several spiral guide vanes for enhancing heat exchange and stabilizing the swirling field are evenly arranged on the outer wall of the high temperature flue 7. A swirling cooling channel 8 is formed between the high temperature flue 7 and the straight section 1.1, and a cooling mixing zone 9 is formed in the space above the high temperature flue 7. The Venturi pressure measuring tube 10 is set on the inner wall of the swirler air inlet channel 4 near the cooling fan 2 along the airflow direction. The air pressure switch 11 is set on the outer wall of the swirler air inlet channel 4. The Venturi pressure measuring tube 10 is connected to the air pressure switch 11 through the pressure guide tube. The cooling fan 2, burner 6, and air pressure switch 11 are electrically connected to the controller. The controller is configured to control the burner 6 to stop working when the pressure difference between the inlet and throat of the Venturi pressure measuring tube 10 detected by the air pressure switch 11 is lower than a set threshold.

[0017] If the angle between the central tangent of the cyclone inlet channel 4 and the inner wall of the straight section 1.1 is greater than 25°, the energy loss of the cyclone will be too great, and the flow will be turbulent.

[0018] In this embodiment, the ambient temperature air is taken as 20°C, and the cooling fan airflow is 650 m³ / h. 3 The flue gas volume is 16m³. 3 The temperature was 1150℃. After treatment in this embodiment, the flue gas temperature dropped to 43-47℃, which meets the requirements for use in greenhouses. Example 2

[0019] The difference between this example and Example 1 is that the angle between the central tangent of the cyclone inlet channel 4 and the inner wall of the straight section 1.1 is 20°, and the height of the high-temperature flue 7 is 0.62 times the height of the straight section 1.1. CFD fluid dynamics simulation shows that under this parameter combination, a uniform and stable strong swirling flow can be formed in the cyclone cooling channel 8, the cross-sectional flow velocity is maintained at about 25 m / s, and the residence time of the airflow in the cooling mixing zone 9 is extended by about 15%, resulting in more thorough mixing with the high-temperature flue gas. Example 3

[0020] Based on embodiment 1 or 2, several spiral guide vanes with a guide angle of 30° are welded to the outer wall of the high-temperature flue 7. These guide vanes can guide the cooling air to spiral upward close to the outer wall of the high-temperature flue 7, avoiding short circuits or vortex dead zones in the airflow within the channel. According to actual measurements, under the same airflow, this structure can improve the cooling efficiency of the outer tube by about 8%.

[0021] Further explanation of the safety control logic: The differential pressure threshold set by the controller should be near the lower limit of the normal differential pressure range under the rated operating airflow of the cooling fan 2. For example, if the normal differential pressure range is 100-200 Pa, the threshold can be set to 90 Pa. When the air pressure switch 11 detects that the differential pressure is lower than this threshold of 90 Pa, it sends a signal to the controller, and the controller performs a protection action.

[0022] When the carbon dioxide generator is working, burner 6 begins to burn methanol, producing high-temperature flue gas at approximately 1100-1200℃. This flue gas enters the high-temperature flue pipe 7 and exits from the top, simultaneously heating the sidewalls of the high-temperature flue pipe 7. Cooling fan 2 starts, drawing in room-temperature air through the inlet. After the airflow is regulated by the air regulating plate 3, it enters the straight section 1.1 tangentially through the cyclone inlet channel 4, forming a high-speed rotating airflow within the cyclone cooling channel 8. The rotating airflow spirals upwards along the outer wall of the high-temperature flue pipe 7, cooling the sidewalls, and continues to rise to the cooling mixing zone 9, where it mixes violently with the flue gas exiting the high-temperature flue pipe 7. Due to the cyclone effect, the air and flue gas come into full contact, heat is rapidly transferred, and the temperature of the mixed gas is significantly reduced. Finally, it exits from the exhaust port 5, with the temperature dropping below 50℃, further diffused and cooled within the greenhouse space to near the greenhouse temperature.

[0023] Safety Mechanism: When cooling fan 2 is operating, high-speed airflow passes through venturi pressure measuring tube 10, generating negative pressure at the throat. Pressure switch 11 detects the pressure difference between the positive pressure at the inlet of venturi pressure measuring tube 10 and the negative pressure at the throat via a pressure guide tube. Under normal operation, the pressure difference causes pressure switch 11 to activate, outputting a signal to the controller, indicating normal system operation. If cooling fan 2 malfunctions or exhaust port 5 is blocked, abnormal air pressure occurs, pressure switch 11 resets, and the controller, upon receiving the signal, immediately stops burner 6 to prevent high-temperature flue gas from damaging the equipment and ensure system safety.

[0024] This invention not only has a good cooling effect, but also has a simple structure, is safe and reliable, and is suitable for methanol gas fertilizer machines in greenhouses.

Claims

1. A cyclone air cooler for methanol fertilizer generator flue gas, characterized in that: The device includes a hydrocyclone shell (1), a cooling fan (2), a burner (6), a high-temperature flue (7), a Venturi pressure gauge (10), a pressure switch (11), and a controller. The hydrocyclone shell (1) is a cylindrical structure formed by connecting a lower straight section (1.1) and an upper conical section (1.2). The top of the conical section (1.2) is an exhaust port (5). The air outlet of the cooling fan (2) is connected tangentially to the bottom of the straight section (1.1) through the hydrocyclone inlet channel (4). The burner (6) is located at the center of the bottom of the straight section (1.1). The high-temperature flue (7) is coaxial with the straight section (1.1) and is sleeved on the outside of the burner (6). A swirling cooling channel (8) is formed between the high-temperature flue (7) and the straight section (1.1). A cooling mixing zone (9) is formed in the space above the high-temperature flue (7). The Venturi pressure measuring tube (10) is set on the inner wall of the swirler air inlet channel (4) near the cooling fan (2) along the airflow direction. The air pressure switch (11) is set on the outer wall of the swirler air inlet channel (4). The Venturi pressure measuring tube (10) is connected to the air pressure switch (11) through the pressure guide tube. The cooling fan (2), burner (6), and air pressure switch (11) are electrically connected to the controller, which is configured to control the burner (6) to stop working when the pressure difference between the inlet and throat of the Venturi pressure measuring tube (10) detected by the air pressure switch (11) is lower than a set threshold.

2. The swirl air cooler for methanol fertilizer generator flue gas according to claim 1, characterized in that, The height of the high-temperature flue (7) is 1 / 2 to 2 / 3 of the height of the straight section (1.1).

3. The swirl air cooler for methanol fertilizer generator flue gas according to claim 1, characterized in that, The angle between the central tangent of the cyclone inlet channel (4) and the inner wall of the straight section (1.1) is 0°-25°.

4. The swirl air cooler for methanol fertilizer generator flue gas according to claim 1, characterized in that, The cooling fan (2) is provided with an air regulating plate (3) at the air inlet for adjusting the air intake.

5. A cyclone air cooler for methanol fertilizer generator flue gas according to claim 1, characterized in that: The outer wall of the high-temperature flue (7) is provided with several spiral guide vanes for enhancing heat exchange and stabilizing the swirling flow field.

6. A cyclone air cooler for methanol fertilizer generator flue gas according to claim 1, characterized in that: The inner walls of the straight section (1.1) and conical section (1.2) of the hydrocyclone shell (1) are covered with a high-temperature resistant heat insulation layer.

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