A biomass-based waste resource recycling and drying system and method

Abstract

This invention relates to the field of biomass treatment technology, and particularly to a waste resource recycling and drying system and method based on biomass combined heat and power (CHP). The waste resource recycling and drying system includes a combustion furnace, a steam generator, a pressure-stabilized air supply unit, and a biomass drying unit connected in sequence by pipes. The biomass drying unit includes a body with a high-temperature drying zone and a low-temperature drying zone arranged from top to bottom. Both the high-temperature and low-temperature drying zones are connected to the pressure-stabilized air supply unit. The high-temperature drying zone is connected to an exhaust device, and a heat exchange device is provided between the low-temperature drying zone and the exhaust device. This invention forms an integrated system of CHP and drying functions through the combustion furnace, steam generator, pressure-stabilized air supply unit, and biomass drying unit, ensuring stable and reliable drying quality of the output material. This constructs a complete closed loop from waste to energy conversion to energy feedback for waste treatment, achieving reduced energy consumption and improved energy efficiency.

Description

Technical Field

[0001] This invention relates to the field of biomass treatment technology, and in particular to a waste resource recycling and drying system and method based on biomass combined heat and power. Background Technology

[0002] In the field of livestock and poultry waste resource utilization, drying high-moisture materials such as chicken manure is a crucial step in converting them into organic fertilizer or biomass fuel. Fresh chicken manure has an extremely high moisture content, typically requiring reduction from over 75% to 15%-20% or even lower to meet the requirements of storage, transportation, and subsequent processing. Hot air drying is widely used due to its large processing capacity and high efficiency. However, traditional coal-fired boilers directly generate high-temperature heat to heat the entire drying process. This not only leads to overheating and quality damage in the later stages of drying but also results in significant sensible heat loss during discharge, leading to serious issues of underutilization of high-quality materials and energy level mismatch. Furthermore, open systems are highly susceptible to external environmental temperature and humidity fluctuations, resulting in large variations in the moisture content of the discharged material. While heat pump technology offers high energy efficiency, its initial investment is high, and it is heavily reliant on the external power grid, posing significant costs for power distribution system upgrades and operating electricity consumption in farms with insufficient power supply. Furthermore, existing drying equipment suffers from simplistic airflow organization designs, often resulting in uneven temperature distribution and drying dead zones within the system, making it difficult to consistently achieve biosafety sterilization standards above 75°C. The lack of effective control mechanisms in the later stages of drying leads to the direct emission of high-temperature, high-humidity exhaust gas from the drying zone, without the recovery of its substantial waste heat. This results in low overall system thermal efficiency and significant energy waste. Therefore, it is essential to develop a structurally optimized drying system capable of cascaded utilization of thermal energy and efficient recovery of waste heat from exhaust gas. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a waste resource based on biomass combined heat and power. The invention relates to a closed-loop drying system and method to address the technical problems of high energy consumption, heavy carbon emissions from traditional boilers, and overheating damage to dried materials in existing high-moisture organic waste drying systems. It achieves the technical effects of fully closed-loop energy, zero external heat energy consumption, and highly uniform airflow organization.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On one hand, the present invention provides a waste resource recycling and drying system based on biomass cogeneration, which includes: a combustion furnace, a steam generator, a pressure-stabilizing air supply unit and a biomass drying unit connected in sequence by pipes; the biomass drying unit includes a body, in which a high-temperature drying zone and a low-temperature drying zone are provided from top to bottom, and both the high-temperature drying zone and the low-temperature drying zone are connected to the pressure-stabilizing air supply unit, the high-temperature drying zone is connected to an exhaust device, and a heat exchange device is provided between the low-temperature drying zone and the exhaust device.

[0005] Furthermore, the pressure-stabilizing air supply unit includes a high-temperature air supply static pressure box, a low-temperature air supply static pressure box, a first indirect heat exchanger, and a main fan. The high-temperature air supply static pressure box is connected to the high-temperature drying zone, the low-temperature air supply static pressure box is connected to the low-temperature drying zone, the low-temperature fluid outlet of the first indirect heat exchanger is connected to the high-temperature air supply static pressure box through the main fan, the high-temperature fluid inlet of the first indirect heat exchanger is connected to the steam generator, and the low-temperature air supply static pressure box is connected to the heat exchange device.

[0006] In one embodiment, the high-temperature drying zone is provided with a first horizontal partition, which divides the high-temperature drying zone into an upper drying chamber and a lower drying chamber, and the lower drying chamber is separated from the low-temperature drying zone by a second horizontal partition.

[0007] In one embodiment, at least one conveyor belt is installed in both the high-temperature drying zone and the low-temperature drying zone. The top of the machine body is provided with a feed inlet, and the bottom of the machine body is provided with a discharge outlet. A first discharge outlet is provided on the first horizontal partition, and a second discharge outlet is provided on the second horizontal partition. The material flows through the feed inlet, the conveyor belt, the first discharge outlet, the second discharge outlet, and the discharge outlet to form an S-shaped material path.

[0008] In one embodiment, the exhaust device includes an exhaust static pressure box and an exhaust fan connected by pipes. The exhaust static pressure box is connected to the high-temperature drying zone, and the exhaust fan is connected to the high-temperature pipeline inlet of the heat exchange device.

[0009] Furthermore, the heat exchange device includes a second wall-mounted heat exchanger and a low-temperature fan connected by a pipeline. The air inlet of the low-temperature fan is connected to the low-temperature air outlet of the second wall-mounted heat exchanger, and the air outlet of the low-temperature fan is connected to the low-temperature air supply static pressure box. The high-temperature flue gas inlet pipeline of the second wall-mounted heat exchanger is connected to the exhaust fan.

[0010] In one embodiment, there are two high-temperature air supply static pressure boxes, which are installed on the machine body. One high-temperature air supply static pressure box is located near the air inlet device and is connected to both the upper and lower drying chambers. The other high-temperature air supply static pressure box is located near the exhaust device and is connected to the lower drying chamber.

[0011] In one embodiment, the low-temperature air supply static pressure box and the exhaust static pressure box are both one unit, which are installed on the machine body. The exhaust static pressure box is located near the exhaust device and is connected to the upper drying chamber.

[0012] In one embodiment, the device further includes a PLC controller, a moisture sensor, a temperature sensor, and a pressure sensor disposed in the machine body, wherein the moisture sensor, temperature sensor, pressure sensor, pressure stabilizing air supply unit, exhaust device, and heat exchange device are all electrically connected to the PLC controller.

[0013] Secondly, the present invention also provides a biomass drying method based on a biomass cogeneration waste resource recycling drying system, which includes the following steps: S1. Waste biomass fuel is fed into a combustion furnace for combustion. The high-temperature steam generated drives a steam generator to generate electricity. The exhaust gas or waste heat from the steam generator is fed into the first inter-wall heat exchanger, which heats the cold air flowing through the first inter-wall heat exchanger into high-temperature dry hot air at 80℃-110℃. S2. After the high-temperature dry hot air is sent into the high-temperature air supply static pressure box at a certain pressure and flow rate, it is transformed into a stable and uniform airflow and sent into the high-temperature drying zone to contact the fresh high-humidity biological material. The biological material that has completed the initial dehydration is transported to the low-temperature drying zone. The high-temperature and high-humidity exhaust gas that has absorbed moisture is discharged from the high-temperature drying zone and then introduced into the second wall-mounted heat exchanger, so that the cold air flowing through the second wall-mounted heat exchanger is heated into low-temperature dry hot air at 45℃-65℃. S3. Low-temperature dry hot air is sent into the low-temperature air supply static pressure box at a certain pressure and flow rate. After being converted into a stable and uniform airflow, it is sent into the low-temperature drying zone to contact the biological material that has been initially dehydrated. The biological material is discharged after being deeply dried, while the low-temperature exhaust gas that has absorbed moisture penetrates the material layer, flows through the high-temperature drying zone and is discharged. S4. Based on the detected moisture content of the discharged material, the PLC controller dynamically adjusts the speed of the main blower, the feed rate of the combustion furnace, and the load of the steam generator to regulate the hot air temperature and air volume, ensuring the drying quality of the discharged material.

[0014] Beneficial Effects: The waste resource recycling and drying system based on biomass cogeneration provided by this invention integrates cogeneration and drying functions through a combustion furnace, steam generator, pressure-stabilizing air supply unit, and biomass drying unit. The energy generated by combustion in the furnace drives the steam turbine unit to generate electricity, achieving self-sufficiency in electricity for the farm. Subsequently, the high-temperature exhaust gas or waste heat from the unit is converted into high-quality dry hot air through a first indirect heat exchanger. The tiered setting of high-temperature and low-temperature drying zones enables the cascade utilization of thermal energy, significantly improving the overall thermal efficiency of the system and reducing energy consumption. By real-time monitoring of material moisture content and dynamic adjustment of fan speed, combustion furnace feed rate, and generator load, the drying quality of the discharged material is ensured to be stable and reliable. This constructs a complete closed loop from waste to energy conversion to energy feedback for waste treatment, achieving reduced energy consumption and improved energy efficiency, and possessing significant industrial application value. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the machine body in this invention; Figure 4 for Figure 3 The left view; Figure 5 for Figure 3 The right view. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship between the components in a specific posture (as shown in the attached figures). If the specific posture changes, the directional indication will also change accordingly. Furthermore, the descriptions using terms such as "first" and "second" in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention. In this invention, terms such as "installation," "connection," "coupling," and "fixing" should be interpreted broadly. Specifically, connection can be a fixed connection, a detachable connection, or even a structurally integral molding; it can refer to physical mechanical contact or the conduction of electrical signals; furthermore, connection includes both direct connection and indirect connection achieved through an intermediate medium. Those skilled in the art can determine the exact meaning of the above terms in this application based on the specific context and technical logic.

[0018] Figure 1 A schematic diagram of the overall structure of one embodiment of the present invention is shown. Figure 1As shown, an embodiment of the present invention provides a waste resource recycling and drying system based on biomass combined heat and power (CHP). The system includes a combustion furnace 100, a steam generator 200, a pressure-stabilizing air supply unit 300, and a biomass drying unit 400 connected in sequence by pipes. This structure forms a complete closed-loop circuit from energy production to energy utilization. The combustion furnace 100 is responsible for converting waste biomass fuel (such as dried chicken manure and straw) into high-temperature heat energy, and the generated high-temperature, high-pressure steam is used as a power source and transported to the steam generator 200. The steam generator 200 uses the steam power to generate electricity, achieving self-sufficiency in electricity and effectively solving the problem of high costs for expanding power capacity in remote farms. After performing work, the steam generator 200 discharges waste gas or exhaust steam with reduced temperature and pressure. This fluid, still containing significant heat energy, is not directly discharged but is introduced into the pressure-stabilizing air supply unit 300 as a drying heat source for waste heat utilization. The pressure-stabilizing air supply unit 300 receives waste heat from the steam generator 200 and draws in clean, cold outside air. Through a partitioned heat exchanger, the cold air is heated into clean, high-temperature, dry, hot air. This process achieves combined heat and power (CHP): electricity powers the system itself and the plant area, while waste heat is used for drying, resulting in a significant leap in the overall thermal efficiency of biomass energy. The biomass drying unit 400 is the execution end of the entire system for material drying. It receives dry, hot air from the pressure-stabilizing air supply unit 300 and dries the material in stages. Through this energy cascade utilization architecture, waste heat that was originally directly emitted is "squeezed" to extract drying value. The system requires almost no additional fossil fuels during operation, achieving a near-zero carbon emission circular economy model.

[0019] like Figure 1 and Figure 2As shown, the biomass drying unit 400 specifically includes a body 410, which serves as a closed container for the drying process. Its internal cavity is spatially divided from top to bottom into a high-temperature drying zone 420 and a low-temperature drying zone 430. Both the high-temperature drying zone 420 and the low-temperature drying zone 430 are connected to the pressure-stabilized air supply unit 300 via air paths to receive their respective drying media. This zoned design is key to achieving both superior material quality and energy efficiency. Specifically, high-moisture materials (such as fresh chicken manure with a moisture content of over 75%) first enter the high-temperature drying zone 420. In this area, high-temperature dry hot air (typically 80℃-110℃) provided by the pressure-stabilized air supply unit 300 rapidly removes a large amount of free moisture from the material surface through strong convection, achieving rapid dehydration. This stage is high-intensity and high-efficiency. When the moisture content of the material drops to an intermediate value (such as 40%-50%), the material is sent to the low-temperature drying zone 430. If high-temperature hot air is continued to be used, the temperature will rise rapidly as the moisture content of the material decreases, which can easily lead to overheating and coking, decomposition of organic matter, and even the risk of combustion. Simultaneously, the material exiting the furnace will carry a large amount of sensible heat, resulting in energy waste. At this point, the low-temperature drying zone 430 receives medium-temperature hot air (typically 45℃-65℃) for deep drying. The temperature difference between the low-temperature hot air and the material is smaller, and heat transfer is more gradual. This effectively transfers the bound water inside the material to the surface and vaporizes it, ensuring that the final moisture content meets the standard while protecting the material's nutrients from high-temperature damage. Furthermore, the temperature of the discharged material is lower, resulting in less sensible heat loss. The exhaust end of the high-temperature drying zone 420 is connected to an exhaust device 500 to orderly discharge the high-temperature, high-humidity exhaust gas after moisture absorption. To prevent the residual heat contained in this exhaust gas from being directly emitted, a heat exchange device 600 is installed between the low-temperature drying zone 430 and the exhaust device 500. The heat exchanger 600 is the central hub for heat recovery. It transfers the heat from the high-temperature, high-humidity exhaust gas discharged from the exhaust system 500 to the clean, cold air that is about to enter the low-temperature drying zone 430, preheating the cold air into low-temperature dry hot air. This completes the cascade and recycling of heat energy: the high-temperature waste heat is used to preheat the low-temperature air, realizing the staged extraction of heat energy, greatly improving the overall thermal efficiency of the system, and reducing the unit energy consumption of the drying process.

[0020] In this embodiment, the pressure-stabilizing air supply unit 300 serves as the hub for system heat energy conversion and airflow distribution, and includes a high-temperature air supply static pressure box 310, a low-temperature air supply static pressure box 320, a first partition wall heat exchanger 330, and a main fan 340. The first partition wall heat exchanger 330 has independent high-temperature fluid channels and low-temperature fluid channels. The high-temperature fluid inlet of the first partition wall heat exchanger 330 is connected to the exhaust port of the steam generator 200 via a pipe, used to receive still-high-temperature waste gas or exhaust steam. The low-temperature fluid inlet of the first partition wall heat exchanger 330 is connected to the outside atmosphere, used to draw in clean, cold air. The high-temperature fluid discharged from the steam generator 200 flows through the high-temperature fluid channels, transferring its heat through the partition wall to the cold air in the low-temperature fluid channels, thereby heating the cold air, lowering its own temperature, and discharging it from the high-temperature fluid outlet. The low-temperature fluid outlet of the first partition wall heat exchanger 330 is connected to the high-temperature air supply static pressure box 310 via the main fan 340. The main fan 340 is one of the main power sources in the system. Its inlet is connected to the first indirect heat exchanger 330, and its outlet is connected to the high-temperature air supply plenum 310. The main fan 340 draws pre-heated, high-temperature dry air from the heat exchanger and delivers it to the high-temperature air supply plenum 310 at a certain pressure and flow rate. The main fan 340 is preferably a variable frequency fan to dynamically adjust the airflow according to the load. The high-temperature air supply plenum 310 is an expanded, sealed cavity with an internal volume much larger than the inlet and outlet ducts. The outlet of the high-temperature air supply plenum 310 is connected to the high-temperature drying zone 420. When the unstable, pulsating airflow enters the high-temperature air supply static pressure box 310, the sudden increase in volume leads to a decrease in flow velocity and dynamic pressure, while the static pressure increases. This causes the static pressure at points near the air outlet within the box to become uniform, ultimately transforming into a stable and uniform stratified airflow. This airflow penetrates the material layer vertically at approximately equal speeds, fundamentally eliminating drying dead zones caused by uneven air distribution and ensuring uniform heating of all materials within the high-temperature drying zone 420. The low-temperature air supply static pressure box 320 is connected to the heat exchange device 600, and its principle and function are similar to those of the high-temperature air supply static pressure box 310. It is used to homogenize the low-temperature hot air preheated by the heat exchange device 600 before sending it into the low-temperature drying zone 430. By configuring independent air supply static pressure boxes, the air supply pressure and flow field of the high-temperature and low-temperature zones do not interfere with each other, ensuring the stability and reliability of their respective drying processes.

[0021] To further refine the drying process and optimize heat utilization, the structure of the casing 410 is designed in greater detail. In this embodiment, Figure 3The detailed internal structure of the machine body 410 is shown. A first horizontal partition 421 is provided in the high-temperature drying zone 420. This first horizontal partition 421 vertically divides the originally single high-temperature drying zone 420 into two independent working chambers: an upper drying chamber 422 located at the top and a lower drying chamber 423 located at the bottom. Simultaneously, the lower drying chamber 423 is separated from the lower low-temperature drying zone 430 by a second horizontal partition 431. This structure physically extends the entire drying path and subdivides the high-temperature drying process into two consecutive sub-stages. Under the influence of gravity, the material falls from the upper drying chamber 422 into the lower drying chamber 423, continuing to undergo high-temperature drying. This extends the effective residence time of the material in the high-temperature zone, allowing for more complete absorption of high-temperature heat energy and improving heat utilization efficiency. Furthermore, since the state of the hot air in the upper and lower drying chambers can be different (for example, the upper chamber has newly introduced hot air at the highest temperature, while the lower chamber has a slightly lower temperature), this design also provides a structural basis for implementing more refined "high temperature-secondary high temperature" stepped drying in the high temperature zone, making the drying curve smoother and effectively preventing premature crusting and hardening of the material surface.

[0022] To reliably achieve automatic and continuous material transfer between the various chambers, at least one conveyor belt 440 is installed in both the high-temperature drying zone 420 and the low-temperature drying zone 430. The conveyor belt 440 is a continuous moving platform that supports and transports materials; it can be a mesh belt or a chain conveyor. Mesh belts have a high opening ratio, allowing hot air to penetrate upwards from the bottom of the material layer, forming through-flow drying, resulting in higher efficiency. A feed inlet 411 for receiving wet material to be dried is provided at the top of the machine body 410. A discharge outlet 412 for discharging finished dry material is provided at the bottom of the machine body 410. To ensure a smooth transition of material from the upper conveyor belt to the lower conveyor belt, a first discharge port 424 is provided on the first horizontal partition 421. The first discharge port 424 is the channel for material to fall from the upper drying chamber 422 into the lower drying chamber 423, dropping from the end of the upper conveyor belt. A second discharge port 432 is provided on the second horizontal partition 431, serving as a channel for materials to fall from the lower drying chamber 423 into the lowest low-temperature drying zone 430, forming a long, winding material path in an "S" or "Z" shape within the entire machine body 410. When a conveyor belt 440 is installed in the high-temperature drying zone 420 and the low-temperature drying zone 430, the feed port 411, the first discharge port 424, the second discharge port 432, and the discharge port 412 are designed to be staggered at both ends of the conveyor belt 440. Specifically, if the feed port 411 is located at the top left end of the machine body 410, the conveyor belt 440 in the upper drying chamber 422 receives the material and runs from left to right. The material will fall from the right end into the first discharge port 424 and onto the left end of the conveyor belt 440 in the lower drying chamber 423. At this time, the conveyor belt 440 of the lower drying chamber 423 will run from left to right, and the material will eventually fall onto the conveyor belt 440 of the low-temperature drying zone 430 through the second discharge port 432 at its right end. This alternating staggered arrangement greatly extends the drying journey of the material within the limited equipment space, ensuring that the material stays in the machine for a sufficient time and makes full contact with the hot air, eliminating the "short circuit" phenomenon in the drying process, and is an indispensable structural guarantee for achieving high uniformity drying.

[0023] Regarding the orderly emission of exhaust gases, such as Figure 1-3As shown, the exhaust system 500 includes an exhaust plenum 510 and an exhaust fan 520 connected by pipes. The exhaust plenum 510 is installed on the side wall of the machine body 410 and communicates with the high-temperature drying zone 420, specifically with the exhaust area of ​​the upper drying chamber 422 near the air outlet. The function of the exhaust plenum 510 is to collect the high-temperature and high-humidity exhaust gas flowing from various parts of the high-temperature drying zone 420, balance the collection pressure, and ensure smooth exhaust. The air inlet of the exhaust fan 520 is connected to the outlet of the exhaust plenum 510, and its air outlet is connected to the inlet of the high-temperature pipeline of the heat exchange device 600. The exhaust fan 520 is driven by a motor, and when it runs, it generates negative pressure in the exhaust plenum 510, thereby drawing in and pressurizing the exhaust gas distributed in various places before sending it out. The exhaust fan 520 also preferably adopts a variable frequency speed control fan. By adjusting its speed, it can work in coordination with the main fan 340 on the air inlet side to precisely control the pressure state inside the machine body 410, such as maintaining a slight positive pressure (e.g., 20-50Pa), to prevent cold and humid air from the outside environment from flowing back into the machine body through gaps that are not completely sealed (e.g., inlet and outlet ports), thus avoiding secondary humidification of the already dried materials.

[0024] The heat exchange device 600 is specifically the core actuator for heat recovery. In this embodiment, the heat exchange device 600 includes a second wall-mounted heat exchanger 610 and a low-temperature fan 620 connected by pipes. The second wall-mounted heat exchanger 610 also has a high-temperature flue gas passage and a low-temperature air passage that are not in direct contact. The high-temperature flue gas inlet of the second wall-mounted heat exchanger 610 is connected to the outlet of the exhaust fan 520 through a pipe to receive high-temperature and high-humidity exhaust gas from the exhaust device 500. The inlet of the low-temperature fan 620 is connected to the low-temperature air outlet of the second wall-mounted heat exchanger 610, and its outlet is connected to the low-temperature air supply static pressure box 320. Its working process is as follows: the exhaust fan 520 sends high-temperature exhaust gas with a temperature of 55-70℃ and a relative humidity close to saturation into the high-temperature side of the second wall-mounted heat exchanger 610; on the other hand, the suction of the low-temperature fan 620 introduces fresh, clean, cold air from the outside into the low-temperature side of the second wall-mounted heat exchanger 610. Within the second partition wall heat exchanger 610, heat from the high-temperature exhaust gas is transferred to the low-temperature fresh air through the partition wall (such as metal heat transfer plates or tube bundles). The exhaust gas cools due to heat release, and some of the water vapor it carries condenses into liquid water, releasing a large amount of latent heat, further heating the fresh air. Finally, the exhaust gas, with its temperature reduced to near ambient temperature, is discharged into the atmosphere; while the fresh air is heated to a medium temperature of 45℃-65℃, becoming low-temperature dry hot air. The low-temperature fan 620 then compresses this low-temperature dry hot air and sends it into the low-temperature air supply static pressure box 320, finally smoothly entering the low-temperature drying zone 430. It is evident that the heat exchange device 600 efficiently recovers the sensible heat and some latent heat from the exhaust gas, which is almost "zero-cost" energy. This significantly reduces the system's heat demand on the first partition wall heat exchanger 330 (the main heat source), achieving the dual goals of energy saving and emission reduction. The second wall-mounted heat exchanger 610 can be a plate type, shell and tube type, or heat pipe type, but a type that is more adaptable to dust and condensate is preferred to deal with the small amount of dust that may be carried in the exhaust gas.

[0025] To achieve better airflow distribution and temperature field uniformity, the layout of the static pressure chamber has been specifically optimized in this embodiment. For example... Figure 2 , Figure 4 and Figure 5As shown, two high-temperature air-supply static pressure chambers 310 are configured. Both high-temperature air-supply static pressure chambers 310 are installed on the same side wall of the machine body 410. One of the high-temperature air-supply static pressure chambers 310, referred to as the first high-temperature air-supply static pressure chamber 311, is located near the air inlet device (i.e., the direction of the airflow from the main fan 340). The air outlet of the first high-temperature air-supply static pressure chamber 311 is connected to the upper drying chamber 422 and the lower drying chamber 423 simultaneously through several air outlets (such as slots or evenly distributed round holes) opened on the wall panel of the machine body 410. This means that the freshest and hottest dry air provided by the main fan 340 can be supplied to the beginning of both the upper and lower high-temperature drying chambers simultaneously, providing a strong drying driving force for these two chambers and ensuring that the material can be rapidly heated and its surface moisture rapidly removed in the initial stage of entering the high-temperature zone. The second high-temperature air supply static pressure box 312 is located near the exhaust device 500, specifically at the rear of the machine body 410. The air outlet of the second high-temperature air supply static pressure box 312 is only connected to the end of the lower drying chamber 423. Specifically, it provides supplementary heating to the "medium-temperature" airflow that has decreased in temperature and increased in humidity as it flows through the lower drying chamber 423 to the rear. A fresh, pure, high-temperature hot air stream is injected into the material at the outlet of the lower drying chamber 423 through the second high-temperature air supply static pressure box 312. This air mixes thoroughly with the degraded moisture-carrying airflow within the chamber, causing the material at the end of the lower drying chamber 423 to undergo a final "high-temperature shock," raising the core temperature of the material to over 75°C and maintaining it for several minutes. This ensures that the biosafety sterilization standard for killing pathogens is met, fully utilizing the potential of the high-temperature heat source within the high-temperature zone. This avoids the problem of insufficient drying in the rear due to reliance solely on front-end air supply, achieving a more balanced temperature distribution and a more thorough drying effect throughout the high-temperature zone.

[0026] To match the optimized layout described above, both the low-temperature supply air static pressure box 320 and the exhaust air static pressure box 510 are configured as a single unit in this embodiment. The low-temperature supply air static pressure box 320 is installed on the side wall of the body 410, below the high-temperature supply air static pressure box 310. It evenly distributes preheated clean low-temperature hot air from the heat exchange device 600 throughout the entire low-temperature drying zone 430. Since the volume of the low-temperature drying zone 430 is relatively compact and the required air temperature is uniform, using a single low-temperature supply air static pressure box 320 for air supply can fully meet the uniformity requirements, and the structure is more streamlined and reliable. Similarly, the exhaust air static pressure box 510 is also configured as a single unit, installed on the body 410 and located near the exhaust fan 520. It is specifically connected to the end exhaust area of ​​the upper drying chamber 422. Specifically, during the high-temperature drying process, the upper drying chamber 422 receives the most direct heat, and the high-temperature and high-humidity exhaust gas generated here has the highest temperature. It is prioritized to be directly captured and sent to the heat exchange device 600, which can ensure the highest quality of the recovered heat source, thereby maximizing the waste heat recovery efficiency of the second wall-mounted heat exchanger 610, ensuring that the hot air temperature required by the low-temperature drying zone 430 is stable in a reasonable high range, and reducing the complexity and manufacturing cost of the system while ensuring performance.

[0027] To achieve intelligent and precise control, this system also includes a PLC controller 700 and various sensors distributed throughout the machine body 410, including at least moisture sensors, temperature sensors, and pressure sensors. Moisture sensors are typically installed near the feed inlet 411 and discharge outlet 412 of the machine body 410 to detect the real-time moisture content of the incoming and outgoing materials, providing a direct basis for judging the drying effect. Multiple temperature sensors are arranged in layers in the high-temperature drying zone 420 (upper drying chamber 422 and lower drying chamber 423), the low-temperature drying zone 430, and key air ducts (such as the outlet of the high-temperature air supply static pressure box 310 and the air outlet of the heat exchanger 600), to monitor the temperature of each hot air stream and material layer in real time. Pressure sensors are typically installed inside the machine body 410 and in the exhaust static pressure box 510, etc., to monitor the slight pressure difference between each drying zone and the external atmosphere. For those skilled in the art, arranging the moisture, temperature, and pressure sensors within the machine body according to actual needs is also a conventional technique in this field. Moisture sensor, temperature sensor, pressure sensor, pressure-stabilized air supply unit 300, exhaust device 500, and heat exchange device 600 are all electrically connected to the input / output module of PLC controller 700 via signal cables. PLC controller 700 serves as the control center, and it has pre-stored optimized drying process curves and PID control algorithms. PLC controller 700 reads data from each sensor in real time, performs calculations and makes decisions based on program logic, and then outputs adjustment commands to each actuator. For example, when the moisture sensor at the discharge port 412 detects that the material moisture content is higher than the target value (e.g., the target value is set to 12-15%), the PLC controller 700 will issue a command to increase the frequency of the main blower 340 (e.g., increase the main blower speed by 5-30%) to increase the total air supply; it can also simultaneously and appropriately increase the feeding speed of the combustion furnace 100 (e.g., increase the feeding motor speed by 5-30%) or decrease the grate running speed (e.g., decrease the grate speed by 5-10%) to improve steam quality, thereby increasing the outlet air temperature of the first indirect heat exchanger 330; it can also instruct the exhaust fan 520 to slightly reduce its speed (e.g., decrease the exhaust fan speed by 5-20%) to prolong the residence time of the high-temperature hot air in the machine body. Conversely, if the discharge moisture content is too low or the material is detected to be overheating, the opposite adjustment will be made to reduce the hot air supply. At the same time, the pressure sensor constantly monitors the slight positive pressure state of the machine body. Once the pressure difference deviates from the set value, the PLC controller 700 will fine-tune the speed of the exhaust fan 520 to restore balance. This fully closed-loop variable frequency control system, guided by the quality of the final output and linking the front-end energy supply and the back-end ventilation function, enables the system to adapt to fluctuations in material quality and changes in ambient temperature and humidity, always operating at the optimal energy efficiency point and ensuring long-term stability and high consistency of the output drying quality. The specific models and power of components such as exhaust fans, moisture sensors, temperature sensors, and pressure sensors can be selected according to the actual production scale and processing volume.

[0028] Based on the aforementioned system, the present invention also provides a biomass drying method for a waste resource recycling and drying system based on biomass combined heat and power. The steps of this method are described in detail below.

[0029] Step S1, namely the system startup and high-temperature hot air generation stage. First, shaped biomass fuel made from livestock and poultry manure (such as chicken manure), straw, etc., is fed into the combustion furnace 100 for combustion via an automatic conveying device. The combustion furnace 100 can be a fluidized bed furnace or a fixed bed furnace, which generates high-temperature flue gas at 800°C to 1000°C or higher in its combustion chamber. This high-temperature flue gas flows through the boiler heat exchange surface, transferring heat to the boiler water and generating high-temperature, high-pressure steam. This high-temperature steam enters the steam generator 200 through pipelines, driving the turbine to rotate, which in turn drives the generator to generate electricity. The generated electricity is first used to supply the system's own electrical equipment, such as various types of fans, water pumps, conveyor belts, PLC controller 700, etc., and excess electricity can be used by other equipment in the power plant or connected to the grid. The working fluid discharged by the steam generator 200 after completing its work, i.e., exhaust steam or cooled waste gas, still has a temperature of over 120°C. This part of the fluid is guided into the high-temperature fluid channel of the first indirect heat exchanger 330. Simultaneously, clean, cold air from the outside flows into the low-temperature fluid channel of the first partition heat exchanger 330 on the other side. The two fluids exchange heat without contact on either side of the partition. The cold air is continuously and stably heated, with its temperature precisely controlled between 80℃ and 110℃, such as 85℃, 95℃, or 105℃. This temperature can be adjusted based on the initial moisture content of the material by regulating the flow rates of the hot and cold fluids, thus producing clean, high-temperature dry hot air. This step not only achieves self-sufficiency in power generation but also completes the task of converting high-grade thermal energy into a clean, usable drying heat source.

[0030] Step S2 is the initial stage of high-temperature dehydration of the material and waste heat recovery from the exhaust gas. The high-temperature dry hot air generated in step S1 is pressurized by the main fan 340 and sent into the high-temperature air supply static pressure box 310 (including the first high-temperature air supply static pressure box 311 and the second high-temperature air supply static pressure box 312) at a preset wind speed of 3-15 m / s. After the airflow expands and becomes uniform in the static pressure box, it is transformed into a laminar flow with stable static pressure and highly uniform cross-sectional wind speed. It is then smoothly sent into each chamber of the high-temperature drying zone 420 (upper drying chamber 422 and lower drying chamber 423) through the air outlet 413 on the machine wall. At the same time, fresh, high-humidity biological materials (such as chicken manure with a moisture content of 75%-85%) enter from the feed inlet 411 and are spread on the conveyor belt 440 of the upper drying chamber 422. The uniform high-temperature hot air vertically penetrates the slowly moving material layer, causing intense heat and mass transfer with the material. The surface moisture of the material is rapidly vaporized and carried away by the wind. After initial dehydration in the upper drying chamber 422, the material falls into the lower drying chamber 423 through the first discharge port 424 to continue high-temperature drying. Finally, in the high-temperature drying zone 420, the moisture content of the material can be reduced to approximately 40%-50%, completing the main dehydration task. The humid hot air that has absorbed moisture becomes high-temperature, high-humidity exhaust gas, which is collected by the exhaust static pressure box 510 from the upper drying chamber 422. The exhaust fan 520 extracts this 65℃-75℃ high-temperature, high-humidity exhaust gas and forces it into the high-temperature pipeline of the second partition wall heat exchanger 610. Similarly, cold air from the outside enters the low-temperature pipeline of the second partition wall heat exchanger 610 from the other side. Through efficient heat exchange via the partition wall, the exhaust gas releases heat, and its temperature drops sharply; the cold air absorbs heat and is heated into clean, warm air at 45℃-65℃, i.e., low-temperature dry hot air. This step not only achieves rapid material reduction but also initiates a closed loop for waste heat recovery.

[0031] Step S3 is the low-temperature deep drying and closed-loop airflow stage of the material. The low-temperature dry hot air generated in step S2 is drawn in and compressed by the low-temperature fan 620 and sent into the low-temperature air supply static pressure box 320 at a certain pressure and flow rate. Under the uniform flow effect of the static pressure box, it is transformed into a stable and uniform airflow, which is sent into the low-temperature drying zone 430 through the air outlet 413 on the machine wall. At this time, the preliminarily dehydrated biological material has fallen from the lower drying chamber 423 into the conveyor belt 440 of the low-temperature drying zone 430 through the second discharge port 432. The low-temperature dry hot air with moderate temperature and extremely low humidity gently sweeps over the surface of the material, and through the low vapor pressure difference, slowly and continuously "extracts" the bound water inside the material, so that the moisture content of the material is finally reduced to the target value of 15% or lower, and then discharged from the discharge port 412 as a qualified dried product. This stage avoids the thermal degradation of the material and can recover some of the sensible heat carried by the discharged material. The humidified waste gas has now become a "medium-low temperature" high-humidity gas. However, since its temperature may still be higher than the temperature of the fresh air entering the high-temperature drying zone 420, or if the pressure field allows, this gas continues to penetrate the material layer and flow upward under the negative pressure guidance of this system. It then enters the latter part of the high-temperature drying zone 420 as a supplementary airflow to participate in the next round of drying and exhaust processes. Finally, it is drawn away by the exhaust device 500 along with the high-temperature waste gas and enters the heat exchange device 600. In this way, a complete airflow circulation path is formed inside the machine body 410, flowing from the high-temperature zone to the low-temperature zone and then to waste heat recovery, further realizing the ultimate recovery and utilization of the meager residual heat.

[0032] Step S4 is the intelligent feedback and dynamic balance adjustment stage of the system. During the continuous operation of the drying system, a moisture sensor located near the discharge port 412 scans in real time in a non-contact manner or measures in a contact manner the moisture content of the dry material to be output. This moisture content data is transmitted to the PLC controller 700 in real time. The PLC controller 700 compares this value with a preset drying quality standard (e.g., 15%). If the detected value is consistently higher than the set upper limit, it indicates insufficient drying intensity. The PLC controller 700 will execute a set of compound adjustment actions: First, it will increase the input frequency of the main blower 340, increasing its rotation speed, thereby increasing the volumetric flow rate of the high-temperature hot air fed into the system and accelerating moisture evaporation; at the same time, it will increase the frequency of the screw feeder of the combustion furnace 100, increasing the amount of biomass fuel fed into the furnace, and correspondingly increase the opening of the steam inlet regulating valve of the steam generator 200 (if the generator is connected to an excitation regulating system, the load will change accordingly) to generate more and higher-temperature steam, thereby generating more heat at the first wall-mounted heat exchanger 330 to cope with the increased drying load. If the moisture content of the discharged material is too low, the above operation is reversed to reduce the rotation speed, fuel, and hot air usage, thus avoiding energy waste. For hot air temperature control, the PLC controller 700 adjusts the opening of the bypass valve flowing through the cold side of the first indirect heat exchanger 330 or directly adjusts the rotation speed of the main fan 340. The entire system, through this "on-demand allocation" dynamic balance logic, forms an intelligent energy management closed loop. It ensures that regardless of fluctuations in raw material moisture content or changes in environmental conditions, the system can always stably control the drying quality of the discharged material within the preset process window in the most economical way.

[0033] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Those skilled in the art, under the guidance of the present invention, can make various similar representations without departing from the spirit and claims of the present invention, and such modifications all fall within the protection scope of the present invention.

Claims

1. A waste resource recycling drying system based on biomass combined heat and power, comprising a combustion furnace (100), a steam generator (200), a constant pressure air supply unit (300) and a biomass drying unit (400) connected in sequence by pipelines; The biomass drying unit (400) comprises a machine body (410), wherein a high-temperature drying zone (420) and a low-temperature drying zone (430) are arranged from top to bottom in the machine body (410), the high-temperature drying zone (420) and the low-temperature drying zone (430) are both in communication with the constant pressure air supply unit (300), the high-temperature drying zone (420) is connected with an exhaust device (500), and a heat exchange device (600) is arranged between the low-temperature drying zone (430) and the exhaust device (500).

2. The biomass-based combined heat and power waste resource recycling drying system according to claim 1, characterized in that: The constant pressure air supply unit (300) comprises a high-temperature air supply static pressure tank (310), a low-temperature air supply static pressure tank (320), a first partition wall type heat exchanger (330) and a main fan (340), the high-temperature air supply static pressure tank (310) is in communication with the high-temperature drying zone (420), the low-temperature air supply static pressure tank (320) is in communication with the low-temperature drying zone (430), a low-temperature fluid outlet of the first partition wall type heat exchanger (330) is in communication with the high-temperature air supply static pressure tank (310) through the main fan (340), a high-temperature fluid inlet of the first partition wall type heat exchanger (330) is in communication with the steam generator (200), and the low-temperature air supply static pressure tank (320) is in communication with the heat exchange device (600).

3. The biomass-based combined heat and power waste resource recycling drying system according to claim 1, characterized in that: A first horizontal partition plate (421) is arranged in the high-temperature drying zone (420), the first horizontal partition plate (421) divides the high-temperature drying zone (420) into an upper drying room (422) and a lower drying room (423), and the lower drying room (423) is divided from the low-temperature drying zone (430) by a second horizontal partition plate (431).

4. The biomass-based combined heat and power waste resource recycling drying system according to claim 1 or 2, characterized in that: At least one conveying belt (440) is installed in each of the high-temperature drying zone (420) and the low-temperature drying zone (430), a feeding port (411) is arranged at the top of the machine body (410), a discharging port (412) is arranged at the bottom of the machine body (410), a first discharging port (424) is arranged on the first horizontal partition plate (421), and a second discharging port (432) is arranged on the second horizontal partition plate (431), and the material flows through the feeding port (411), the conveying belt (440), the first discharging port (424) and the second discharging port (432) to form an S-shaped material path.

5. The biomass-based combined heat and power waste resource recycling drying system according to claim 1 or 2, characterized in that: The exhaust device (500) comprises an exhaust static pressure tank (510) and an exhaust fan (520) connected by a pipeline, the exhaust static pressure tank (510) is in communication with the high-temperature drying zone (420), and the exhaust fan (520) is in communication with a high-temperature pipeline inlet of the heat exchange device (600).

6. The waste recycling and drying system based on biomass combined heat and power according to claim 5, wherein: The heat exchange device (600) includes a second wall-mounted heat exchanger (610) and a low-temperature fan (620) connected by a pipe. The air inlet of the low-temperature fan (620) is connected to the low-temperature air outlet of the second wall-mounted heat exchanger (610), and the air outlet of the low-temperature fan (620) is connected to the low-temperature air supply static pressure box (320). The high-temperature flue gas inlet pipe of the second wall-mounted heat exchanger (610) is connected to the exhaust fan (520).

7. The waste recycling and drying system based on biomass combined heat and power according to claim 2, wherein: There are two high-temperature air supply static pressure boxes (310). The two high-temperature air supply static pressure boxes (310) are installed on the body (410). One high-temperature air supply static pressure box (310) is set close to the pressure stabilizing air supply unit (300) and is connected to both the upper drying chamber (422) and the lower drying chamber (423). The other high-temperature air supply static pressure box (310) is set close to the exhaust device (500) and is connected to the lower drying chamber (423). 8.The waste resource recycling and drying system based on biomass combined heat and power according to claim 5, wherein: The low-temperature air supply static pressure box (320) and the exhaust static pressure box (510) are both one. The low-temperature air supply static pressure box (320) and the exhaust static pressure box (510) are installed on the machine body (410). The exhaust static pressure box (510) is located close to the exhaust device (500) and is connected to the upper drying room (422).

9. The biomass-based combined heat and power waste resource recycling drying system according to claim 1, characterized in that: It also includes a PLC controller (700), a moisture sensor, a temperature sensor and a pressure sensor installed in the body (410), and the moisture sensor, temperature sensor and pressure sensor, pressure stabilizing air supply unit (300), exhaust device (500) and heat exchange device (600) are all electrically connected to the PLC controller (700).

10. A method of drying biomass using the waste recycling and drying system according to any one of claims 1 to 9, characterized in that, include: S1. Waste biomass fuel is fed into a combustion furnace (100) for combustion. The generated high-temperature steam drives a steam generator (200) to generate electricity. The high-temperature exhaust gas or waste heat from the steam generator (200) is fed into the first wall-mounted heat exchanger (330), so that the cold air flowing through the first wall-mounted heat exchanger (330) is heated into high-temperature dry hot air at 80℃-110℃. S2. After the high-temperature dry hot air is sent into the high-temperature air supply static pressure box (310) at a certain pressure and flow rate, it is transformed into a stable and uniform airflow and sent into the high-temperature drying zone (420) to contact the fresh high-humidity biological material. The biological material that has completed the initial dehydration is transported to the low-temperature drying zone (430). The high-temperature and high-humidity exhaust gas after absorbing moisture is discharged from the high-temperature drying zone (420) and then introduced into the second wall-mounted heat exchanger (610), so that the cold air flowing through the second wall-mounted heat exchanger (610) is heated into low-temperature dry hot air at 45℃-65℃. S3. Low-temperature dry hot air is sent into the low-temperature air supply static pressure box (320) at a certain pressure and flow rate. After being converted into a stable and uniform airflow, it is sent into the low-temperature drying zone (430) to contact the biological material that has been initially dehydrated. The biological material is discharged after being deeply dried, while the low-temperature exhaust gas that has absorbed moisture penetrates the material layer, flows through the high-temperature drying zone (420), and is discharged. S4. Based on the detected moisture content of the discharged material, the PLC controller (700) dynamically adjusts the main blower. The rotational speed of (340), the feed rate of the combustion furnace (100), and the load of the steam generator (200) are adjusted to regulate the rotational speed of (340). Control the temperature and volume of hot air to ensure the drying quality of the discharged material.

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