A thermal superconductive electric heating grain drying system and method

Abstract

The present application relates to the technical field of grain drying, and particularly relates to a hot superconductive electric heating grain drying system and a method thereof, wherein the hot superconductive electric heating grain drying system comprises a drying tower, a grain flow layer arranged in the inner cavity of the drying tower, a hot air duct arranged below the grain flow layer in a longitudinal direction, and a grain drying bin arranged between the hot air duct and the inner wall of the drying tower, and the grain flows into the grain drying bin through the grain flow layer; a hot superconductive electric heating and heat transfer module comprising a heating body and a hot superconductive vacuum cavity arranged on the inner wall of the hot air duct in a longitudinal direction; the heat emitted by the heating body is transmitted to an evaporation section at the bottom of the hot superconductive vacuum cavity and drives the phase change of a working medium in the hot superconductive vacuum cavity, the hot superconductive vacuum cavity transmits the heat to the air in the hot air duct through phase change heat transfer, forms drying air, and sends the drying air into the grain drying bin; and the thermal efficiency is improved to more than 95%.

Description

Technical Field

[0001] This invention relates to the field of grain drying technology, and in particular to a superconducting electric heating grain drying system and method. Background Technology

[0002] Grain drying is a crucial step in grain storage and processing, directly impacting the quality of stored grain and the efficiency of subsequent processing and utilization. Currently, most grain drying towers on the market employ a drying structure using a combustion heat source and traditional heat exchange ducts. The core heat source is typically a coal-fired or gas-fired hot air furnace. The high-temperature flue gas generated by the furnace transfers heat to cold air through a heat exchanger. The heated hot air is then transported through a vertically installed hot air duct to the inner cavity of the drying tower to contact the grain.

[0003] Traditional drying systems of this type have several technical drawbacks: First, the heat conversion efficiency of combustion heat sources is low, and the high-temperature flue gas suffers significant heat loss during heat exchange and transportation. The hot air in the hot air duct is prone to temperature decay along the path, leading to uneven heating of the grain within the drying tower. The moisture content variation coefficient is typically greater than ±1.8%, resulting in a high rate of grain breakage and severely impacting grain quality. Second, traditional hot air ducts lack dedicated heat transfer structures on their inner walls, relying solely on convection for heat exchange between the hot air and grain. This results in low heat exchange efficiency, requiring increased hot air temperature or extended drying time to meet drying standards, leading to significant energy consumption. First, there is a waste of resources, with high electricity / coal consumption per ton of grain. Second, combustion heat sources generate a large amount of flue gas and dust, posing environmental emission pressures. Furthermore, hot air furnaces and heat exchangers need to be arranged separately, resulting in large equipment footprints, complex fuel delivery and flue gas emission pipelines, and high maintenance costs. Third, some improved drying systems attempt to use electric heating elements to directly heat the air, but these elements are mostly distributed, which can easily cause excessively high local temperatures in the hot air ducts. Moreover, heat is transferred only through conduction and convection, making it impossible to achieve uniform heating and still failing to solve the problem of uneven drying.

[0004] To address the aforementioned issues, a new type of grain drying system is urgently needed that can eliminate the need for traditional combustion-based heat sources and achieve efficient heating through clean electric heating, while balancing drying efficiency, grain quality, and energy utilization. Summary of the Invention

[0005] In this section, as well as in the abstract and title of this application, some simplifications or omissions may be made to avoid obscuring the purpose of this section, the abstract, and the title of this application, and such simplifications or omissions shall not be used to limit the scope of the invention.

[0006] To address the problems of severe heat loss and poor grain quality associated with traditional combustion heat sources in existing technologies, one objective of this invention is to provide a superconducting thermal heating grain drying system. The system includes a drying tower with a grain flow layer within its inner cavity, a hot air duct longitudinally positioned below the grain flow layer, and a grain drying chamber located between the hot air duct and the inner wall of the drying tower. Grain flows into the grain drying chamber through the grain flow layer. A superconducting thermal heating and heat transfer module includes a heating element and a superconducting thermal vacuum chamber longitudinally positioned on the inner wall of the hot air duct. The heat emitted by the heating element is transferred to an evaporation section at the bottom of the superconducting thermal vacuum chamber, driving a phase change in the working fluid within the chamber. The superconducting thermal vacuum chamber transfers heat through this phase change to the air within the hot air duct, forming drying air that is then introduced into the grain drying chamber.

[0007] As a preferred embodiment of the thermal superconducting heating grain drying system of the present invention, the thermal superconducting vacuum chamber is provided in multiple ways, and the multiple thermal superconducting vacuum chambers are arranged in a surrounding array on the inner wall surface of the hot air duct, forming a uniform heating field in the hot air duct.

[0008] As a preferred embodiment of the thermal superconducting heating grain drying system of the present invention, the inner wall surface of the hot air duct is provided with a longitudinal groove, a part of the thermal superconducting vacuum cavity is embedded in the longitudinal groove, and the other part is exposed to the airflow in the hot air duct.

[0009] As a preferred embodiment of the thermal superconducting heating grain drying system of the present invention, the heating element is heated by electric heating, and the material is one of ceramic electric heating material, alloy electric heating material or carbon fiber electric heating material.

[0010] As a preferred embodiment of the thermal superconducting heating grain drying system of the present invention, it further includes: a waste heat recovery device installed at the exhaust port of the drying tower, the waste heat recovery device capturing the waste heat of the exhaust gas and preheating the air to be entered into the hot air inlet; and an induced draft fan installed at the exhaust port, the induced draft fan being used to create negative pressure and exhaust the air in the grain drying chamber.

[0011] As a preferred embodiment of the thermal superconducting heating grain drying system of the present invention, it further includes a control module, which includes a temperature sensor, a humidity sensor, and a controller; the temperature sensor and the humidity sensor are disposed in the grain drying chamber and electrically connected to the controller; the controller is electrically connected to the heating element, and the controller is used to adjust the heating power of the heating element according to the detection signals of the temperature sensor and the humidity sensor.

[0012] As a preferred embodiment of the thermal superconducting heating grain drying system of the present invention, the thermal superconducting vacuum cavity further includes a condensation section, which extends to the hot air inlet of the drying chamber of the drying tower, and the hot air inlet of the drying chamber is used to deliver drying air into the grain drying chamber.

[0013] As a preferred embodiment of the thermal superconducting heating grain drying system of the present invention, the working fluid in the thermal superconducting vacuum cavity is heated and vaporized in the evaporation section, and then transferred to the condensation section for condensation. The condensed working fluid flows back to the evaporation section by gravity, and the heat energy is transferred isothermally from the evaporation section to the condensation section.

[0014] Another objective of this invention is to provide a method for drying grain using superconducting heating, comprising: feeding wet grain into a drying tower, diverting it through a grain flow layer, and then allowing it to fall into a grain drying silo under gravity; generating heat from a heating element, driving a phase change in the working fluid within a superconducting vacuum chamber, converting electrothermal energy into superconducting thermal energy, and initially heating the air at the hot air inlet; the initially heated air entering a hot air duct, undergoing phase change heat transfer through a superconducting vacuum chamber longitudinally positioned on the inner wall of the hot air duct, maintaining a uniform temperature environment within the hot air duct and forming hot air at 80°C to 170°C, which is then delivered to the grain drying silo; a blower creating negative pressure at the exhaust port to expel air from the grain drying silo, while simultaneously using a waste heat recovery device to capture the exhaust heat energy and deliver it to the hot air inlet for preheating; and a control module dynamically adjusting the power of the heating element based on real-time monitored temperature, humidity, and grain moisture parameters until the grain reaches a preset standard.

[0015] In a preferred embodiment of the superconducting heating grain drying method of the present invention, the hot air temperature of the hot air duct is 120℃~170℃, and after isothermal transmission through the superconducting vacuum cavity, the hot air temperature at the hot air inlet of the drying chamber of the drying tower is 110℃~120℃.

[0016] The beneficial effects of this invention are as follows: This invention abandons the traditional combination of combustion-type hot air furnace and heat exchanger in grain drying systems. Through the synergistic cooperation of the heating element and the thermal superconducting vacuum cavity, electrothermal energy is converted into superconducting thermal energy and phase change heat transfer is achieved, replacing the traditional flue gas heat exchange method. This eliminates combustion pollution at its source and achieves clean heating. At the same time, the thermal superconducting vacuum cavity achieves isothermal heat transfer through the phase change of the working fluid, effectively avoiding the temperature decay of the hot air along the way and creating a uniform temperature environment in the hot air duct. Combined with the dynamic power adjustment of the control module, the overall thermal efficiency of the system is increased to over 95%. For a drying tower with a nominal daily processing capacity of 300 tons, it can achieve stable drying of 500 tons of grain in 24 hours, reducing the power consumption per ton of grain to 92.3 kWh / t, and reducing the annual carbon reduction of a single tower by ≥327 tons of CO2, significantly reducing energy consumption. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the thermal superconducting heating grain drying system of the present invention. Figure 1 .

[0019] Figure 2 This is a schematic diagram of the surrounding array arrangement of the thermal superconducting vacuum cavity in the thermal superconducting grain drying system of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of the thermal superconducting heating grain drying system of the present invention. Figure 2 .

[0021] Figure 4 This is a schematic diagram showing the location of the condensation section of the thermal superconducting vacuum cavity in the thermal superconducting grain drying system of the present invention. Detailed Implementation

[0022] To make the objectives, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0025] Example 1

[0026] See Figure 1 This is the first embodiment of the present invention, which provides a superconducting heating grain drying system.

[0027] Specifically, the superconducting heating grain drying system of this embodiment includes a drying tower 100 and a superconducting heating and heat transfer module 200. The drying tower 100 is the main supporting structure for grain drying. The inner cavity of the drying tower 100 is provided with a grain flow layer 101, a hot air duct 102 arranged in the longitudinal direction below the grain flow layer 101, and a grain drying chamber 103 located between the hot air duct 102 and the inner wall of the drying tower 100. The grain flows into the grain drying chamber 103 through the grain flow layer 101. The side wall of the drying tower 100 is provided with a hot air inlet 102b, which is a channel for cold air to enter. The drying tower 100 is also provided with a hot air duct 102 connecting the hot air inlet 102b. The hot air duct 102 extends in the longitudinal direction, which is the extension direction along the height direction of the drying tower 100. It can be set to a vertical state according to the actual site installation requirements, or tilted at a small angle of 0°~30° to any side to improve site adaptability.

[0028] The superconducting heating and heat transfer module 200 is the core heating unit of the system, directly replacing the coal / gas-fired hot air furnace and heat exchanger combination in the traditional drying system. During the replacement, a targeted structural and positional design was carried out to meet the hot air delivery and heat exchange requirements of the drying tower 100. The superconducting heating and heat transfer module 200 includes a heating element 201 and a superconducting vacuum chamber 202. The heating element 201 is located outside the drying tower 100. The heat emitted by the heating element 201 is blown by a fan and enters the hot air duct 102 through the hot air inlet 102b. The superconducting vacuum chamber 202 is fixedly installed longitudinally on the inner wall of the hot air duct 102, and the length direction of the superconducting vacuum chamber 202 is consistent with the airflow direction in the hot air duct 102, ensuring that the hot air can fully contact and exchange heat with the superconducting vacuum chamber 202 when flowing through the hot air duct 102.

[0029] The thermal superconducting vacuum chamber 202 is a sealed vacuum chamber made of aluminum alloy with an axial heat flux density ≥28MW / m². The chamber is filled with a special phase change working fluid (such as alcohols, ketones or mixed working fluids). The bottom of the thermal superconducting vacuum chamber 202 is the evaporation section 202a. The evaporation section 202a is tightly connected to the heating element 201 for heat exchange. The heat exchange connection can be made by contact, welding or thermal adhesive bonding to ensure that the heat generated by the heating element 201 can be efficiently transferred to the evaporation section 202a.

[0030] In this embodiment, when the system is working, the heating element 201 generates heat by energizing it. The heat is transferred to the evaporation section 202a of the thermal superconducting vacuum chamber 202, driving the working fluid in the evaporation section 202a to absorb heat and undergo phase change vaporization. The vaporized working fluid rapidly diffuses within the thermal superconducting vacuum chamber 202, uniformly transferring heat to the entire thermal superconducting vacuum chamber 202. The thermal superconducting vacuum chamber 202 then transfers heat to the air flowing through the hot air duct 102 through phase change heat transfer, achieving rapid heating of the air. The heated air forms drying air and is sent along the hot air duct 102 into the grain drying chamber 103 within the drying tower 100, where it contacts the grain in the drying tower 100 for drying. Furthermore, the hot air duct 102 extends longitudinally to adapt to the working characteristics of the thermal superconducting vacuum chamber 202. If a straight hot air duct 102 and a straight thermal superconducting vacuum chamber 202 were used, the operation of the thermal superconducting vacuum chamber 202 would be hindered.

[0031] This embodiment replaces the traditional combustion-type hot air furnace and heat exchanger with a heating element 201, achieving clean electric heating for grain drying. This eliminates combustion flue gas and dust pollution at the source, meeting environmental emission requirements. The thermal superconducting vacuum chamber 202 is made of aluminum alloy with an axial heat flux density ≥28MW / m². Combined with the rapid heat transfer characteristics of the phase change working fluid, it achieves efficient conversion of electrothermal energy to superconducting thermal energy, with a heat transfer efficiency far exceeding that of traditional heat conduction and convection heat transfer. The hot air duct 102 adopts a longitudinal design and can be arranged vertically or at a small angle. This design greatly improves site adaptability and solves the problem of limited layout in traditional drying systems. The length direction of the thermal superconducting vacuum chamber 202 is consistent with the airflow direction inside the hot air duct 102, ensuring full contact between the hot air and the thermal superconducting vacuum chamber 202, achieving rapid and uniform heating of the air, and effectively avoiding the problem of excessively high local temperatures caused by the dispersed arrangement of traditional electric heating.

[0032] Furthermore, the heating element 201 and the thermal superconducting vacuum chamber 202 do not work independently, but rather work synergistically. The heating element 201, as the core heat-generating module, replaces the traditional combustion heat source with clean electric heating, providing controllable high-temperature heat energy. However, relying solely on electric heating and direct hot air delivery via negative pressure suction still faces problems such as severe temperature attenuation along the hot air path, low thermal efficiency, and poor drying uniformity. This can easily lead to the grain inside the tower being hot at the top and cold at the bottom, a large coefficient of variation in moisture content, and a high rate of grain bursting, making it difficult to achieve high-quality drying. Therefore, the thermal superconducting vacuum chamber 202 is installed, serving as the core heat transfer module, completely replacing traditional convection heat transfer through phase change heat transfer. Its evaporation section 202a absorbs heat, and low-loss isothermal transmission is achieved through the phase change of the working fluid, minimizing temperature decay. The two work together, with the heating element 201 responsible for generating heat and the thermal superconducting vacuum cavity 202 responsible for heat transfer, increasing the overall thermal energy utilization rate of the system to over 95%. This not only solves the energy consumption problem of traditional drying but also improves grain quality and energy efficiency.

[0033] Example 2

[0034] See Figures 1-4 This is the second embodiment of the present invention. This embodiment details the structure of the superconducting heating grain drying system in detail.

[0035] Specifically, multiple thermal superconducting vacuum cavities 202 are provided, arranged in a surrounding array on the inner wall of the hot air duct 102. The arrangement can be either evenly spaced along the circumference of the hot air duct 102, or layered along the longitudinal direction of the hot air duct 102, with adjacent layers of thermal superconducting vacuum cavities 202 staggered. The heat exchange surfaces of these multiple thermal superconducting vacuum cavities 202 collectively form a uniform heating field within the hot air duct 102, ensuring that air at different locations within the hot air duct 102 is uniformly heated. This surrounding array of multiple thermal superconducting vacuum cavities forms a uniform heating field, enabling 360° uniform heating of the air within the hot air duct 102 without dead angles. This effectively avoids localized temperature differences within the hot air duct 102, ensuring uniform temperature of the drying air entering the drying tower 100, and controlling the grain moisture variation coefficient within ±0.5%.

[0036] Preferably, the inner wall of the hot air duct 102 is provided with a longitudinal groove 102a adapted to the thermal superconducting vacuum cavity 202. The longitudinal groove 102a extends longitudinally along the hot air duct 102. A portion of the thermal superconducting vacuum cavity 202 is embedded in the longitudinal groove 102a and fixed by bolts or snap-fit ​​structures. Another portion of the thermal superconducting vacuum cavity 202 is exposed to the airflow in the hot air duct 102, and the exposed area is not less than 2 / 3 of the total heat exchange area of ​​the thermal superconducting vacuum cavity 202. The longitudinal groove 102a ensures the stable installation of the thermal superconducting vacuum cavity 202, preventing the thermal superconducting vacuum cavity 202 from shaking or shifting when the hot air flows at high speed. At the same time, the structure of the thermal superconducting vacuum cavity 202 being partially embedded and partially exposed reduces the heat conduction loss between the thermal superconducting vacuum cavity 202 and the inner wall of the hot air duct 102, while ensuring sufficient contact and heat exchange with the hot air, further improving the heat exchange efficiency.

[0037] Furthermore, the longitudinal arrangement is the core design logic. The thermal superconducting vacuum chamber 202 extends longitudinally along the hot air duct 102 and its axis is parallel to the airflow direction. This extension ensures sufficient heat exchange area while avoiding obstruction of airflow by the lateral arrangement, minimizing wind resistance and pressure loss, and ensuring smooth flow of drying air within the hot air duct 102. The embedded design enables modular assembly while allowing the thermal superconducting vacuum chamber to partially embed into the longitudinal groove 102a on the inner wall of the hot air duct 102. This effectively avoids dust entrainment by the high-speed airflow. The erosion and wear of the cavities extend the service life of the equipment. Furthermore, the contact between the thermally superconducting vacuum cavity 202 and the inner wall of the hot air duct 102 facilitates auxiliary heat conduction, further improving thermal energy utilization. The surrounding array arrangement solves the problem that a single cavity cannot cover the entire cross-section of the hot air duct 102. Multiple thermally superconducting vacuum cavities 202 are arranged at equal intervals along the circumference of the hot air duct 102, constructing an isothermal heating sleeve on the inner wall of the hot air duct 102. This ensures that every wisp of drying air entering the drying tower 100 is uniformly heated, eliminating temperature gradients across the duct cross-section. The synergistic effect of these three elements achieves both efficient heat exchange and low-resistance flow, while also creating a uniformly heated environment throughout the hot air duct 102, providing a foundation for uniform and efficient grain drying.

[0038] Preferably, the heating element 201 is heated electrically, and its material is selected from ceramic heating materials, alloy heating materials, or carbon fiber heating materials. Among these, ceramic heating materials can be PTC ceramics or silicon molybdenum rods, which have strong high-temperature resistance, precise temperature control, and are suitable for high-temperature drying requirements. Alloy heating materials can be nickel-chromium alloys or iron-chromium-aluminum alloys, which are lower in cost and suitable for medium- and low-temperature drying requirements. Carbon fiber heating materials provide uniform heating and low thermal inertia, making them suitable for drying requirements requiring rapid temperature rise. The heating element 201 uses electric heating, and with the selection of various heating materials, it can be flexibly adapted to different grain types such as rice, wheat, and corn, and drying requirements such as high-temperature rapid drying and low-temperature slow drying, improving the system's versatility. Furthermore, electric heating eliminates fuel transportation and flue gas emissions, making equipment maintenance convenient.

[0039] Preferably, an exhaust port 104 is provided on the side wall corresponding to the grain drying chamber 103 of the drying tower 100. A waste heat recovery device 300 and an induced draft fan 400 are fixedly installed at the exhaust port 104. The waste heat recovery device 300 is a tubular heat exchange structure, which is existing technology and will not be described in detail here. Its heat exchange end extends into the exhaust port 104, the air inlet end is connected to the outside cold air, and the air outlet end is connected to the hot air inlet 102b of the drying tower 100 through a pipeline. It can capture the waste heat in the exhaust gas discharged from the drying tower 100 and return it to the hot air inlet 102b to preheat the cold air to be entered into the hot air inlet 102b. The induced draft fan 400 and the waste heat recovery device 300 are arranged side by side to form a continuous negative pressure at the exhaust port 104, ensuring that the drying air is fully in contact with the grain before being discharged from the exhaust port 104. The waste heat recovery device 300 can capture the waste heat in the exhaust gas and preheat the cold air entering the hot air inlet 102b, so that the cold air has a basic temperature before entering the hot air duct 102, which greatly reduces the heating load of the superconducting heating and heat transfer module 200 and improves the overall thermal efficiency of the system to over 95%. The negative pressure generated by the induced draft fan 400 drives the drying air flow, ensuring the contact time and contact area between the drying air and the grain, improving the drying efficiency, and at the same time preventing the drying air from flowing back in the inner cavity of the drying tower 100, preventing the grain from becoming damp locally.

[0040] Furthermore, a control module 500 is also included. The control module 500 includes a temperature sensor 501, a humidity sensor 502, and a controller 503. Multiple temperature sensors 501 and humidity sensors 502 are evenly arranged at different heights inside the drying tower 100 to detect the temperature inside the drying tower 100 and the moisture content of the grain in real time. Both temperature sensors 501 and humidity sensors 502 are electrically connected to the controller 503 via wires to transmit the detection signals to the controller 503. The controller 503 is a PLC controller, which is existing technology and will not be described in detail here. Its signal output terminal is electrically connected to the heating element 201 via wires. It can automatically adjust the heating power of the heating element 201 according to the detection signals of the temperature sensors 501 and humidity sensors 502 to achieve temperature and drying progress control. Multiple temperature sensors 501 and humidity sensors 502 enable real-time, all-around monitoring of the temperature, humidity, and grain moisture content within the drying tower 100. The controller 503 dynamically adjusts the heating power of the heating element 201 based on the detection signals to prevent overheating and grain cracking due to excessive heating power or insufficient drying due to insufficient heating power, thus ensuring the quality of grain drying and keeping the grain cracking rate ≤2.5%. At the same time, precise power adjustment can further reduce energy consumption and achieve energy-saving drying.

[0041] Preferably, the thermal superconducting vacuum cavity 202 further includes a condensation section 202b, which is the end of the thermal superconducting vacuum cavity 202 away from the evaporation section 202a. The condensation section 202b extends longitudinally upward along the hot air duct 102 until it reaches the hot air inlet 105 of the drying chamber of the drying tower 100. The hot air inlet 105 is the connection end between the hot air duct 102 and the grain drying chamber 103 of the drying tower 100, and is the position where the drying air enters the grain drying chamber 103. The condensation section 202b is extended to the hot air inlet 105 of the drying chamber, so that the heat transfer process of the thermal superconducting vacuum cavity 202 covers the entire transport path of the hot air in the hot air duct 102. This ensures that the hot air is always at a uniform temperature before reaching the hot air inlet 105 of the drying chamber, effectively avoiding the temperature decay of the hot air along the way. This ensures that the hot air at 120℃~170℃ in the hot air duct 102 can still be stably maintained at 110℃~120℃ at the hot air inlet 105 of the drying chamber after transmission.

[0042] Furthermore, after the working fluid in the thermal superconducting vacuum cavity 202 is heated and vaporized in the evaporation section 202a, it is rapidly transferred to the condensation section 202b under the action of the internal pressure difference. The condensation section 202b comes into contact with the low-temperature hot air, causing the vaporized working fluid to release heat and condense into a liquid state. The condensed liquid working fluid flows back to the evaporation section 202a along the inner wall of the thermal superconducting vacuum cavity 202 by its own gravity, completing the phase change cycle of the working fluid. In the entire cycle, heat energy is transferred from the evaporation section 202a to the condensation section 202b with low loss at an isothermal rate. The working fluid inside the thermal superconducting vacuum chamber 202 achieves isothermal, low-loss, and rapid heat transfer through a phase change cycle of vaporization, transmission, condensation, and reflux. The heat transfer efficiency is hundreds of times that of traditional metal heat conduction, and the entire process does not require additional power equipment, belonging to a pump-free self-circulation, further reducing system energy consumption. The continuous phase change cycle of the working fluid ensures that the heat exchange surface of the thermal superconducting vacuum chamber 202 always maintains a uniform temperature, providing a guarantee for uniform heating of hot air.

[0043] Example 3

[0044] See Figures 1-4 This is the third embodiment of the present invention, which provides a method for drying grain using a superconducting thermal heating system. This method is based on the aforementioned superconducting thermal heating grain drying system and specifically includes the following steps: Feeding and drying: The wet grain to be dried is conveyed to the top feed inlet of the drying tower 100 by the elevator. The wet grain enters the drying tower 100 through the feed inlet. After being evenly distributed by the grain distributor at the grain flow layer 101 of the drying tower 100, it falls into the grain drying silo 103 under its own gravity. Thermal energy conversion and preliminary heating: The heating element 201 of the thermal superconducting heating and heat transfer module 200 is activated. After the heating element 201 is powered on, it generates heat. The heat is quickly transferred to the evaporation section 202a of the thermal superconducting vacuum chamber 202, driving the phase change working fluid in the evaporation section 202a to rapidly vaporize within 5~10s, efficiently converting electrothermal energy into superconducting thermal energy. The vaporized working fluid diffuses in the thermal superconducting vacuum chamber 202, providing preliminary heating to the cold air entering at the hot air inlet 102b, raising the temperature of the cold air to 40℃~60℃. Hot air is generated by uniform heating: The preheated air enters the hot air duct 102 under the drive of the fan. The air flows upward along the hot air duct 102 and achieves secondary uniform heating of the air through the phase change heat transfer of the thermal superconducting vacuum cavity 202 set in the inner wall of the hot air duct 102. The heat exchange temperature of the thermal superconducting vacuum cavity 202 is controlled at 150℃~200℃ to ensure that high temperature hot air of 80℃~170℃ is formed in the hot air duct 102, and the temperature difference at different positions in the hot air duct 102 is ≤±2℃. Negative pressure drying and waste heat recovery: The drying air and wet grain undergo sufficient heat and mass exchange, absorbing the moisture in the wet grain. The induced draft fan 400 forms a negative pressure of -50Pa to -100Pa at the exhaust port 104, driving the air in the hot air duct 102 to be discharged. That is, the exhaust gas after heat exchange is discharged from the exhaust port 104. The waste heat recovery device 300 captures the waste heat in the exhaust gas in real time, recovers 30% to 50% of the heat in the exhaust gas and transports it to the hot air inlet 102b to preheat the incoming cold air. The temperature of the preheated cold air is 20℃ to 30℃ higher than the ambient temperature. Precise temperature control drying: Throughout the drying process, multiple temperature sensors 501 and humidity sensors 502 arranged inside the drying tower 100 detect the temperature inside the drying tower 100 in real time (detection accuracy ±0.5℃) and the moisture content of the grain (detection accuracy ±0.1%) at a frequency of 10 seconds / time, and transmit the detection signals to the controller 503; the controller 503 has a built-in standard parameter library for grain drying, and automatically adjusts the heating power of the heating element 201 of the superconducting heating and heat transfer module 200 according to the real-time monitored temperature, humidity and grain moisture parameters. The power adjustment range is 20kW~200kW, until the moisture content of the grain reaches the preset drying standard: such as the safe storage moisture content of grain is 13%~14%, and the dried grain is discharged from the bottom outlet of the drying tower 100.

[0045] This method achieves efficient conversion of electrothermal energy to superconducting thermal energy through the superconducting heating and heat transfer module 200. Combined with uniform heating within the hot air duct 102, it enables uniform drying of grain, solving the problems of uneven heating and poor quality in traditional drying methods. The negative pressure drive of the induced draft fan 400 ensures unidirectional flow of hot air, guaranteeing full contact between the hot air and the grain, thus improving drying efficiency. For the drying tower 100 with a nominal daily processing capacity of 300 tons, it can achieve stable drying of 500 tons of grain in 24 hours. The waste heat recovery step of the waste heat recovery device 300 effectively reduces the heating load of the superconducting heating and heat transfer module 200, reducing the power consumption per ton of grain to 92.3 kWh / t, significantly reducing energy consumption. The precise temperature control step of the control module 500 enables automated adjustment of the drying process without manual intervention, improving the stability and controllability of the drying process, while preventing overheating and cracking of the grain, ensuring drying quality.

[0046] Furthermore, in the above drying method, according to the drying requirements of the grain, the hot air temperature in the hot air duct 102 is precisely controlled at 120℃~170℃. This temperature range is suitable for the high-temperature and rapid drying requirements of mainstream grains such as rice, wheat, and corn. After low-loss isothermal transmission through the thermal superconducting vacuum cavity 202, the hot air temperature at the hot air inlet 105 of the drying chamber of the drying tower 100 is stabilized at 110℃~120℃. This temperature is the optimal heat exchange temperature for grain drying, which not only ensures drying efficiency but also effectively avoids quality problems such as cracking and splitting of the grain caused by high-temperature heat exchange. The hot air temperature in the hot air duct 102 is controlled at 120℃~170℃ to achieve high-temperature and rapid drying of grain, significantly shortening the drying time. The hot air temperature at the hot air inlet 105 of the drying chamber is stabilized in the optimal heat exchange range of 110℃~120℃, ensuring drying efficiency while minimizing the grain breakage rate to ≤2.5%, thus improving the storage quality and commercial value of the dried grain. At the same time, precise temperature control can avoid energy waste caused by excessive temperature, further improving the energy efficiency of the system.

[0047] To facilitate understanding of the technical solution of this invention, its working principle is explained in detail below: The superconducting heating and heat transfer module 200 replaces the traditional combustion heat source, achieving efficient heating through clean electric heating. The heat generated by the heating element 201 drives the working fluid in the superconducting vacuum chamber 202 to undergo a phase change. Through pump-free self-circulation of vaporization, transmission, condensation, and reflux, isothermal and low-loss heat energy transfer is achieved. The superconducting vacuum chamber 202 is arranged longitudinally on the inner wall of the hot air duct 102 and arranged in a surrounding array, forming a uniform heating field in the hot air duct 102 to uniformly heat the cold air. The hot air duct 102 can be arranged vertically or at a small angle to improve site adaptability. The waste heat recovery device 300 captures the waste heat of the exhaust gas to preheat the cold air and reduce the heating load. The control module 500 dynamically adjusts the heating power according to the real-time monitored parameters to achieve precise temperature control and drying.

[0048] The entire system achieves an integrated drying process of clean heating, uniform temperature transmission, negative pressure drying, waste heat recovery, and precise temperature control. It solves the problems of low thermal efficiency, uneven heating of grain, poor environmental performance, and low site adaptability of traditional grain drying systems. While improving drying efficiency and grain quality, it significantly reduces energy consumption and carbon emissions. It is environmentally friendly, economical, and practical, and is suitable for the renovation and construction of various grain drying towers.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A superconducting electric heating grain drying system, characterized in that, include: The drying tower (100) has a grain flow layer (101) in its inner cavity, a hot air duct (102) arranged in the longitudinal direction below the grain flow layer (101), and a grain drying chamber (103) located between the hot air duct (102) and the inner wall of the drying tower (100). Grain flows into the grain drying chamber (103) through the grain flow layer (101). The thermal superconducting heating and heat transfer module (200) includes a heating element (201) and a thermal superconducting vacuum cavity (202) longitudinally disposed on the inner wall of the hot air duct (102). The heat emitted by the heating element (201) is transferred to the evaporation section (202a) at the bottom of the thermal superconducting vacuum cavity (202) and drives the working fluid in the thermal superconducting vacuum cavity (202) to undergo a phase change. The thermal superconducting vacuum cavity (202) transfers heat to the air in the hot air duct (102) through phase change heat transfer, forming drying air and sending it into the grain drying chamber (103).

2. The superconducting electric heating grain drying system as described in claim 1, characterized in that: Multiple thermal superconducting vacuum cavities (202) are provided, and the multiple thermal superconducting vacuum cavities (202) are arranged in a surrounding array on the inner wall surface of the hot air duct (102), forming a uniform heating field in the hot air duct (102).

3. The superconducting heating grain drying system as described in claim 2, characterized in that: The inner wall of the hot air duct (102) is provided with a longitudinal groove (102a). A part of the thermal superconducting vacuum cavity (202) is embedded in the longitudinal groove (102a), and the other part is exposed to the airflow in the hot air duct (102).

4. The superconducting electric heating grain drying system according to any one of claims 1 to 3, characterized in that: The heating element (201) is heated by electric heating, and the material is one of ceramic electric heating material, alloy electric heating material or carbon fiber electric heating material.

5. The thermal superconducting heating grain drying system according to any one of claims 1 to 3, characterized in that: It also includes a waste heat recovery device (300) installed at the exhaust port (104) of the drying tower (100), the waste heat recovery device (300) capturing the waste heat of the exhaust gas and preheating the air to be entered into the hot air inlet (102b); An exhaust fan (400) is provided at the exhaust port (104), the exhaust fan (400) is used to create negative pressure and exhaust the air in the grain drying chamber (103).

6. The thermal superconducting heating grain drying system according to any one of claims 1 to 3, characterized in that: It also includes a control module (500), which includes a temperature sensor (501), a humidity sensor (502), and a controller (503); The temperature sensor (501) and the humidity sensor (502) are installed inside the grain drying chamber (103) and are electrically connected to the controller (503); The controller (503) is electrically connected to the heating element (201), and the controller (503) is used to adjust the heating power of the heating element (201) according to the detection signals of the temperature sensor (501) and the humidity sensor (502).

7. The superconducting heating grain drying system according to any one of claims 1 to 3, characterized in that: The thermal superconducting vacuum cavity (202) also includes a condensation section (202b), which extends to the drying chamber hot air inlet (105) of the drying tower (100), and the drying chamber hot air inlet (105) is used to deliver drying air into the grain drying chamber (103).

8. The superconducting heating grain drying system as described in claim 7, characterized in that: The working fluid in the thermal superconducting vacuum cavity (202) is heated and vaporized in the evaporation section (202a), and then transferred to the condensation section (202b) and condensed. The condensed working fluid flows back to the evaporation section (202a) by gravity, and the thermal energy is transferred isothermally from the evaporation section (202a) to the condensation section (202b).

9. A method for drying grain using thermal superconducting heating, characterized in that: include, Wet grain is fed into the drying tower (100), and after being diverted by the grain flow layer (101), it falls into the grain drying silo (103) under the action of gravity. The heating element (201) generates heat, which drives the working fluid in the thermal superconducting vacuum cavity (202) to undergo a phase change, converting electrothermal energy into superconducting thermal energy, and initially heating the air in the hot air inlet (102b); The preheated air enters the hot air duct (102), and through the phase change heat transfer of the thermal superconducting vacuum cavity (202) arranged longitudinally on the inner wall of the hot air duct (102), the uniform temperature environment in the hot air duct (102) is maintained and hot air of 80°C~170°C is formed and delivered to the grain drying chamber (103). The induced draft fan (400) creates a negative pressure at the exhaust port (104) to discharge the air in the grain drying chamber (103). At the same time, the waste heat recovery device (300) captures the heat energy of the exhaust gas and sends it to the hot air inlet (102b) for preheating. The control module (500) dynamically adjusts the power of the heating element (201) based on the real-time monitored temperature, humidity and grain moisture parameters until the grain reaches the preset standard.

10. The method for drying grain using thermal superconducting heating as described in claim 9, characterized in that: The hot air temperature of the hot air duct (102) is 120℃~170℃. After isothermal transmission through the thermal superconducting vacuum cavity (202), the hot air temperature at the hot air inlet (105) of the drying chamber of the drying tower (100) is 110℃~120℃.

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