Grain cross-flow drying system and method utilizing waste heat of data center

Abstract

The invention relates to the technical field of data center energy saving and agricultural product processing, and discloses a grain cross-flow drying system and method utilizing waste heat of a data center, and the grain cross-flow drying system comprises a heat energy production subsystem, a pneumatic decoupling buffer subsystem, a grain drying execution subsystem and a central control subsystem. The heat energy production subsystem comprises a server cabinet for generating calculation heat; the pneumatic decoupling buffer subsystem is connected between a heat source and a drying end, a micro-negative pressure environment is maintained through a pressure stabilizing cavity and a variable-frequency booster fan, and decoupling balance of pneumatic pressure is achieved. And the central control subsystem reversely calculates and adjusts the calculation load rate of the server based on the drying requirement fed back by the grain drying execution subsystem, and dynamically adjusts pneumatic operation parameters at the same time. Through pneumatic isolation of a physical level and reverse scheduling of computing power and heat energy of a logic level, the problems of impedance matching and safe interconnection of precise computing equipment and an agricultural drying environment are solved, and efficient on-demand utilization of waste heat of a data center is achieved.

Description

Technical Field

[0001] This invention relates to the fields of data center energy conservation and agricultural product processing technology, specifically to a grain through-flow drying system and method that utilizes waste heat from data centers. Background Technology

[0002] With the rapid development of information technology, data centers, as computing infrastructure, are experiencing continuous growth in both construction scale and energy consumption. Electricity costs constitute a significant proportion of data center operating costs, with the vast majority of this energy ultimately being converted into low-grade heat and released into the atmosphere through cooling systems. This not only results in enormous energy waste but also exacerbates the urban heat island effect. Meanwhile, in agriculture, post-harvest grain drying is a crucial step in ensuring food security. While traditional coal-fired, oil-fired, or electric heating drying methods are mature, they suffer from high energy consumption, significant pollution, and high operating costs. Therefore, exploring the application of waste heat from data centers in agricultural drying is of great significance for promoting energy conservation, emission reduction, and cost reduction and efficiency improvement in agriculture.

[0003] However, attempts to directly apply data center waste heat to grain drying face numerous intractable technical contradictions. Most current waste heat recovery technologies operate on a passive model, meaning heat output depends entirely on the data center's current workload, lacking coordination with actual backend heat demand. Because server computing tasks are typically random and fluctuating, hot air temperature and flow rates are highly unstable. During peak heat demand periods for grain drying, servers operate at low loads due to fewer computing tasks, resulting in insufficient heat supply, affecting drying efficiency, and even causing grain mold. Conversely, when servers are running at full capacity, low backend drying demand leads to ineffective heat release. This spatiotemporal mismatch between heat supply and demand severely restricts the effectiveness of waste heat utilization and the stability of drying operations.

[0004] Furthermore, data centers and grain drying environments are inherently incompatible in terms of physical environment and aerodynamic characteristics. IT equipment in data centers is highly precise electronic equipment with extremely high requirements for the cleanliness, temperature, and airflow pressure of the operating environment; its cooling fans are typically designed for low back pressure conditions. Grain drying towers, on the other hand, are high-resistance devices, and their airflow resistance fluctuates dynamically and drastically as grain moisture evaporates, shrinks in volume, and changes in grain porosity. If the two are simply physically connected by pipes, the resistance fluctuations at the drying tower end will directly feed back to the server exhaust vents, easily disrupting the internal heat dissipation flow field of the server, leading to chip overheating, frequency reduction, or even system crashes. Even more seriously, agricultural drying sites are filled with dust, chaff, and high-humidity exhaust gases. If equipment stops or airflow reverses, these pollutants can easily flow back into the server racks, causing circuit board corrosion or short circuits, resulting in irreversible damage to valuable data assets.

[0005] Therefore, there is an urgent need to develop a system and method that can actively coordinate computing load and thermal energy demand, and achieve efficient grain drying while ensuring the aerodynamic stability of precision equipment in data centers and environmental safety. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a grain through-flow drying system and method that utilizes waste heat from data centers. This solves the problems of spatiotemporal mismatch between computing power heat generation and drying heat demand in existing data center waste heat recovery technologies, as well as aerodynamic impedance mismatch and operational safety risks caused by direct coupling between precision computing equipment and the agricultural drying environment.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] The first aspect of the present invention provides a grain through-flow drying system that utilizes waste heat from a data center, including a thermal energy production subsystem, a pneumatic decoupling buffer subsystem, a grain drying execution subsystem, and a central control subsystem.

[0009] The thermal energy production subsystem provides the hot airflow required for drying and includes several server rack units that generate computational heat and a main heat collection duct for collecting the hot airflow. The pneumatic decoupling buffer subsystem, located downstream of the thermal energy production subsystem, is physically connected to the main heat collection duct and is used to balance airflow pressure and eliminate airflow pulsations. The grain drying execution subsystem, located downstream of the pneumatic decoupling buffer subsystem, has its air inlet connected to the output of the pneumatic decoupling buffer subsystem. It is used to contain the grain and guide the hot airflow through the grain layer for heat and mass exchange.

[0010] The central control subsystem establishes communication connections with the thermal energy production subsystem, the pneumatic decoupling buffer subsystem, and the grain drying execution subsystem. The central control subsystem is configured to calculate and adjust the server load rate of the thermal energy production subsystem based on drying demand data fed back from the grain drying execution subsystem. Simultaneously, it maintains a pneumatic pressure decoupling balance between the thermal energy production subsystem and the grain drying execution subsystem by adjusting the operating parameters of the pneumatic decoupling buffer subsystem.

[0011] Through the above configuration, this system changes the traditional passive utilization of waste heat and realizes on-demand heat generation. At the same time, the pneumatic decoupling buffer subsystem, as an intermediate layer, effectively isolates the impact of flow resistance fluctuations in the back-end agricultural drying scenario on the front-end precision server heat dissipation system.

[0012] In a preferred embodiment, each server rack unit in the thermal energy production subsystem is equipped with an anti-backflow check valve assembly at its back panel exhaust vent. This anti-backflow check valve assembly is configured with a mechanical automatic opening and closing structure, operating on the principle of pressure difference: it opens when the internal exhaust pressure of the server rack unit is greater than the external main heat collection duct pressure; it automatically closes when the internal pressure is less than the external pressure or when a system shutdown occurs. This structure forms a physical barrier, preventing external airflow carrying dust from flowing back into the server rack unit, thus ensuring the safety of the computing equipment.

[0013] In a preferred embodiment, the pneumatic decoupling buffer subsystem includes a pressure-stabilizing chamber, an electrically adjustable mixing valve, and a variable frequency booster fan. The pressure-stabilizing chamber is an expanded chamber with a predetermined expansion volume, used to reduce airflow velocity and mix airflow. The electrically adjustable mixing valve is installed at the air inlet on the side wall of the pressure-stabilizing chamber to introduce ambient cold air to regulate the mixed air temperature. The variable frequency booster fan is installed at the outlet end of the pressure-stabilizing chamber to provide the static pressure required to overcome grain layer resistance for the grain drying execution subsystem. A chamber pressure sensor is also installed inside the pressure-stabilizing chamber to monitor the static pressure within the chamber.

[0014] Furthermore, to achieve precise pneumatic control, the central control subsystem includes pre-set pneumatic balance control logic. This logic is configured to receive real-time static pressure data collected by the chamber pressure sensor and, based on the deviation between this data and the preset micro-negative pressure target value, adjust the operating frequency of the variable frequency booster fan using a PID algorithm. Through this adjustment, the air pressure in the pressure stabilizing chamber is always maintained at a micro-negative pressure state below atmospheric pressure, thereby ensuring that the back pressure of the server rack unit's exhaust vent remains stable and is not affected by resistance fluctuations caused by changes in grain layer thickness or porosity within the grain drying execution subsystem.

[0015] In a preferred embodiment, the grain drying execution subsystem includes a vertically arranged drying tower, stratified air supply ducts disposed within the drying tower, and electrically operated airflow regulating valves installed on each branch pipe of the stratified air supply ducts. The drying tower contains channels for grain movement, and grain moisture content sensors and grain temperature sensors are installed on the side walls or inside the channels. The central control subsystem is configured to independently adjust the opening of the electrically operated airflow regulating valves for the corresponding layers based on the stratified detection data from the grain temperature sensors, thereby controlling the local airflow and preventing localized overheating or uneven drying.

[0016] In a preferred embodiment, to achieve coupled control of computing power and thermal energy, the central control subsystem is pre-configured with a drying heat demand calculation model and a server heat generation and computing power coupling model. The central control subsystem executes the following control strategy: First, using the drying heat demand calculation model, it calculates the total required heat power based on the initial moisture content detected by the grain moisture content sensor, the set target moisture content, and the grain mass flow rate; then, using the server heat generation and computing power coupling model, it calculates the target computing load rate required by the server rack unit based on the total heat power; finally, it sends a computing power scheduling command containing the target computing load rate to the task scheduling interface of the thermal energy production subsystem.

[0017] Furthermore, the computing power scheduling command is configured to trigger the data center task scheduling system to perform the following operations: when the target computing load rate is higher than the current actual load rate, non-real-time batch processing computing tasks are retrieved and distributed to server rack units to increase the power consumption of computing nodes and thus increase heat output; when the target computing load rate is lower than the current actual load rate, or when the server rack unit is fully loaded and the heat generated still exceeds the required total heat power, the current load is maintained and a command to open the electric regulating mixing valve is sent to the pneumatic decoupling buffer subsystem to introduce cold air for temperature control.

[0018] In a preferred embodiment, to cope with extreme operating conditions, an emergency pressure relief valve assembly is also provided at the top of the pressure stabilizing chamber. This assembly is configured to automatically open when the static pressure in the pressure stabilizing chamber exceeds a preset safe back pressure threshold, directly discharging the hot airflow to the atmosphere, forming a bypass pressure relief channel. The central control subsystem is configured to control the variable frequency booster fan to stop operating and trigger the emergency pressure relief valve assembly to open when an abnormal increase in pressure is detected in the pressure stabilizing chamber, thereby preventing the server rack unit from overheating due to obstructed heat dissipation when the grain drying execution subsystem is blocked (such as tower blockage).

[0019] In a preferred embodiment, the central control subsystem is also equipped with shutdown purging logic. Upon receiving a shutdown command, the system maintains the variable frequency booster fan running at low speed and controls the electric regulating mixing valve to be fully open, introducing ambient cold air to replace the high humidity and heat air in the pressure stabilizing chamber and pipeline, until the monitored temperature drops to a preset safety value, at which point the power is cut off, thereby preventing moisture condensation and corrosion of the equipment after shutdown.

[0020] A second aspect of the present invention provides a method for through-flow drying of grains using waste heat from a data center. This method, applied to the aforementioned system, includes the following steps:

[0021] System initialization steps: Start the pneumatic decoupling buffer subsystem to establish a micro-negative pressure environment in the buffer area between the thermal energy production subsystem and the grain drying execution subsystem to ensure smooth exhaust from the server;

[0022] Parameter acquisition and calculation steps: Collect the initial moisture content and temperature of the grain entering the grain drying execution subsystem, and use the drying heat demand calculation model to calculate the heat flux required to maintain the set drying rate.

[0023] Computing power scheduling and thermal energy matching steps: Using the server heat generation and computing power coupling model, the heat flux is converted into the server's target computing load rate, and computing power scheduling instructions are sent to the thermal energy production subsystem to adjust the server's power consumption, so as to achieve production based on demand;

[0024] Pneumatic closed-loop control steps: Real-time monitoring of the static pressure value of the buffer zone, adjustment of the airflow pressurization amplitude through PID algorithm, compensation for dynamic flow resistance changes in the grain drying execution subsystem, maintenance of a slightly negative pressure environment, and realization of pneumatic decoupling;

[0025] Temperature and humidity control and execution steps: When the server exhaust temperature is higher than the grain tolerance temperature, adjust the cold air mixing ratio and control the air inlet temperature, and send the conditioned hot air into the grain drying execution subsystem to dry the grain through flow.

[0026] This invention provides a grain through-flow drying system and method utilizing waste heat from data centers. It offers the following advantages:

[0027] 1. This invention establishes a reverse control link from grain drying demand to server computing load by coupling a drying heat demand calculation model built into the central control subsystem with a server heat generation coupling model. The system can calculate and schedule non-real-time batch processing tasks in the data center based on the current moisture content and drying rate requirements of the grain, actively adjusting server power consumption to generate the target heat. This design overcomes the shortcomings of traditional waste heat recovery systems, which are passively adaptive and suffer from supply-demand mismatch, transforming data center waste heat into resources that can be allocated on demand, thus improving the system's overall energy efficiency ratio.

[0028] 2. This invention establishes and maintains a slight negative pressure balance zone between the heat source and the load by setting up a pneumatic decoupling buffer subsystem and using PID control logic to adjust the variable frequency booster fan in real time. Combined with the mechanical anti-backflow one-way valve assembly on the server backplane, this forms multiple physical isolation barriers. This feature effectively shields the operating point of the front-end server cooling fan from the flow resistance fluctuations caused by changes in grain layer thickness or porosity in the back-end drying tower, while simultaneously eliminating the risk of dust and hot, humid exhaust gases flowing back into the precision computing equipment in agricultural settings.

[0029] 3. This invention employs a combination of layered air ducts and independent electric airflow regulating valves in the grain drying execution subsystem. Combined with real-time feedback from grain temperature and moisture content sensors, it achieves independent control of local airflow and enthalpy at different drying stages. Coupled with the temperature clamping logic of the mixing valve, the system can dynamically adjust drying process parameters based on the grain's tolerance characteristics at different stages such as preheating, constant-rate drying, and deceleration drying. This effectively avoids problems such as grain cracking, scorching, or uneven drying caused by localized overheating, ensuring the quality of the finished grain. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall system structure and airflow path of the present invention;

[0031] Figure 2 This is a block diagram illustrating the control logic architecture and signal interaction of the present invention.

[0032] Figure 3 This is a flowchart of the dual closed-loop dynamic drying method of the present invention. Detailed Implementation

[0033] The technical solutions in 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] See attached document Figure 1 The present invention provides a grain through-flow drying system that utilizes waste heat from a data center. The system includes: a heat energy production subsystem, a pneumatic decoupling buffer subsystem, a grain drying execution subsystem, and a central control subsystem.

[0035] The thermal energy production subsystem is physically connected to the input of the pneumatic decoupling buffer subsystem via a sealed duct. The output of the pneumatic decoupling buffer subsystem is connected to the air inlet of the grain drying execution subsystem. The central control subsystem establishes electrical and data communication connections with the thermal energy production subsystem, the pneumatic decoupling buffer subsystem, and the grain drying execution subsystem, respectively.

[0036] The thermal energy production subsystem generates dry air with a specific enthalpy. This subsystem comprises several server rack units, each housing high-density computing nodes. At the rear panel exhaust vent of each server rack unit, an anti-backflow check valve assembly is installed. This assembly is configured to allow airflow only from inside the server rack unit to the external duct, blocking reverse airflow. The exhaust vents from multiple server rack units converge into a central heat exchange duct.

[0037] A pneumatic decoupling buffer subsystem is positioned between the thermal energy production subsystem and the grain drying execution subsystem to balance the server exhaust back pressure and the grain layer resistance. The pneumatic decoupling buffer subsystem includes a sealed pressure-stabilizing chamber. A cooling air inlet is located on the side wall of the pressure-stabilizing chamber, and an electrically adjustable mixing valve is installed at this inlet. A variable frequency booster fan is installed at the outlet of the pressure-stabilizing chamber. A first temperature sensor and a chamber pressure sensor are located inside the pressure-stabilizing chamber.

[0038] The grain drying execution subsystem is configured to receive conditioned hot air and dehydrate the grain. The grain drying execution subsystem includes a vertically arranged drying tower. Inside the drying tower, a grain channel is defined for the grain to move downwards under gravity. A tiered air supply duct is located on one side of the drying tower, and this tiered air supply duct is connected to the grain channel via several inlet branch pipes. Each inlet branch pipe is equipped with an electrically operated airflow regulating valve. Grain moisture content sensors and grain temperature sensors are arranged at different height levels within the grain channel.

[0039] The central control subsystem includes a data processing unit, a storage unit, and input / output interfaces. It communicates with the server rack unit's task scheduling interface to read the server's current computing load and send load scheduling commands. The central control subsystem receives detection signals from the first temperature sensor, the cavity pressure sensor, the grain moisture content sensor, and the grain temperature sensor, and outputs control signals to the electrically adjustable mixing valve, the variable frequency booster fan, and the electrically adjustable airflow valve.

[0040] The central control subsystem has a pre-set model for calculating drying heat demand. This model is based on the initial moisture content of the grain detected by the grain moisture sensor. The set target moisture content at the outlet and the mass flow rate of grain through the drying tower The calculation system requires the thermal power to maintain the current drying process. The calculation formula is as follows:

[0041] ;

[0042] In the formula, The specific heat capacity of grains, To set the optimal intake air temperature, The initial temperature at which the grain enters the drying tower. This is the latent heat of vaporization of water. Of the parameters mentioned above... and Stored in the database of the central control subsystem.

[0043] The central control subsystem also includes a pre-defined model coupling server heat generation and computing power. This model describes the total heat output generated by the server rack unit. Its average computed load rate The relationship between them:

[0044] ;

[0045] In the formula, This refers to the number of nodes within the running server rack unit. This represents the idle standby power consumption of a single server node. This represents the full-load power consumption of a single server node. This is the effective utilization coefficient of the heat recovery system.

[0046] The central control subsystem is based on thermal equilibrium conditions. Calculate the target compute load rate :

[0047] ;

[0048] The central control subsystem will calculate the The task scheduling interface, which converts the data into scheduling commands, sends them to the server rack unit. By increasing or decreasing the amount of non-real-time computing tasks, the actual heat generation power of the server rack unit is made closer to the target value. .

[0049] When the server rack unit is fully loaded and the exhaust temperature detected by the first temperature sensor is... Temperatures exceeding the maximum allowable temperature for grains At this time, the central control subsystem initiates the air-mixing cooling logic. The central control subsystem adjusts the opening of the electrically controlled air-mixing valve to introduce ambient cold air. The required cold air mass flow rate... Determined by the following formula:

[0050] ;

[0051] In the formula, The mass flow rate of hot air from the thermal energy production subsystem. The ambient air temperature.

[0052] The central control subsystem also performs aerodynamic balance control. It reads the values ​​from the chamber pressure sensors in real time and adjusts the rotational speed of the variable frequency booster fan. The control objective is to maintain the static pressure within the pressure-stabilizing chamber within a preset slightly negative pressure range, lower than the back pressure at the server rack unit exhaust vents, to ensure smooth hot air entry into the pressure-stabilizing chamber without backflow. Simultaneously, the total pressure provided by the variable frequency booster fan must be greater than the grain resistance within the grain channel, a resistance value calculated based on the Ergun equation and the geometry of the grain channel.

[0053] See attached document Figure 2In this embodiment, the thermal energy production subsystem, the pneumatic decoupling buffer subsystem, and the grain drying execution subsystem are physically connected sequentially along the airflow transmission direction to form a closed thermal circulation loop.

[0054] The thermal energy production subsystem comprises arrayed server rack units. Each server rack unit features a back-panel enclosed design, with its rear exhaust area defined as the hot air output chamber. At the interface between this hot air output chamber and the external main heat collection duct, an anti-backflow check valve assembly is installed. This anti-backflow check valve assembly specifically employs a gravity-driven self-closing louver structure or a spring-return check valve structure. When the cooling fans inside the server rack unit stop operating or the external air pressure exceeds the internal air pressure, the blades of the anti-backflow check valve assembly automatically close under gravity or spring force, forming a physical barrier to prevent dusty external air from flowing back into the precision circuitry area inside the server rack unit. The thermal energy production subsystem also includes a main heat collection duct, which is made of double-layered insulated metal plates and collects the hot air exhaust from all server rack units via a flange interface. A primary filter mesh, configured as a high-temperature resistant metal wire mesh or glass fiber filter, is installed at the end of the main heat collection duct to intercept large particulate impurities.

[0055] The pneumatic decoupling buffer subsystem is physically located between the end of the main heat collection duct of the thermal energy production subsystem and the air inlet of the grain drying execution subsystem. The main structure of the pneumatic decoupling buffer subsystem is a pressure-stabilizing chamber, a metal box with a predetermined expansion volume. Its cross-sectional area is larger than that of the main heat collection duct, causing the high-speed inflow of hot air to expand, reducing its velocity and inducing turbulent mixing, thus eliminating airflow pulsation. A cold air inlet is provided on the side wall of the pressure-stabilizing chamber, and an electrically adjustable mixing valve is installed at this inlet. The electrically adjustable mixing valve adopts a multi-leaf opposing type regulating valve structure, with the blades rotated by an actuator to linearly adjust the intake area of ​​external cold air. A first temperature sensor is suspended in the central region of the pressure-stabilizing chamber, with its probe located at the center of the mixed flow field of hot and cold air. A chamber pressure sensor is connected to a static pressure orifice on the wall of the pressure-stabilizing chamber via a pressure guide pipe to monitor the static pressure value within the chamber relative to the atmospheric environment. The power source for the pneumatic decoupling buffer subsystem is a variable frequency booster fan installed at the air outlet of the pressure stabilizing chamber. The fan adopts a backward-curved centrifugal fan structure to provide high static pressure output. The air inlet of the fan is directly connected to the pressure stabilizing chamber, and the air outlet is connected to the grain drying execution subsystem through a flexible connection component.

[0056] The grain drying subsystem includes a vertically arranged drying tower. The drying tower is divided into a preheating section, a drying section, and a tempering section from top to bottom. Inside the drying tower are two concentric layers of mesh cylinders or parallel porous sieves, defining an annular or columnar grain channel between the two sieve layers. Grain enters from the distributor at the top of the tower, fills the grain channel under gravity, and flows slowly downwards. A stratified air duct is located at the center or one side of the drying tower. This duct employs a variable cross-section conical design, meaning the flow cross-sectional area gradually decreases along the airflow direction to compensate for pressure loss along the flow path and ensure uniform static pressure distribution at the air outlets at all height levels.

[0057] The stratified air supply duct connects to the air inlet sides of the preheating, drying, and tempering sections via several independent air inlet branches. Each air inlet branch is equipped with an electric airflow regulating valve to independently control the hot air flow entering each drying stage. The hot airflow exits from the stratified air supply duct, passes laterally through the grain layer in the grain channel, exchanges heat and mass with the grain, and then exits from the exhaust port on the outside of the drying tower. The grain moisture content sensor uses a capacitive or microwave online moisture detector, with its probe embedded in the side wall of the grain channel, directly contacting the flowing grain. The grain temperature sensor uses a PT100 resistance temperature detector probe, deeply inserted into the grain layer to detect the core temperature of the grain. A grain discharge mechanism is located at the bottom of the drying tower, including a variable frequency motor-driven impeller airlock or an electromagnetic vibrating discharge plate, used to control the downward speed of the grain, thereby adjusting the heat retention time of the grain within the tower.

[0058] Through the aforementioned hardware connections, the thermal energy production subsystem, acting as the heat source, forms the first-level fluid loop with the pneumatic decoupling buffer subsystem, while the variable frequency booster fan and the grain drying execution subsystem form the second-level fluid loop. The pneumatic decoupling buffer subsystem, acting as an intermediate pressure balancing node, physically isolates the back pressure fluctuations on the server exhaust side from the high flow resistance characteristics on the grain layer side of the drying tower, thus achieving decoupling of the heat source and load in terms of aerodynamic characteristics.

[0059] In this embodiment, the central control subsystem not only serves as the driving source for the electrical actuators, but also as the core of logic operations connecting the physical thermodynamic environment and the digital computing environment.

[0060] The central control subsystem is configured at the hardware level as an industrial-grade programmable logic controller (PLC) or edge computing gateway. This subsystem acquires real-time data from the first temperature sensor, cavity pressure sensor, grain moisture content sensor, and grain temperature sensor via analog input modules (AI) using standard signal formats of 4-20mA or 0-10V. It establishes bidirectional communication with the frequency converter of the variable frequency booster fan, the servo actuator of the electrically adjustable mixing valve, and the electrically adjustable airflow control valve through digital communication interfaces (such as Modbus TCP or EtherCAT protocols). Crucially, the central control subsystem establishes a cross-system logical connection with the task scheduling server of the thermal energy production subsystem via an encrypted API interface or SNMP protocol.

[0061] The central control subsystem operates a multivariable coupled control algorithm, which is divided into three parallel and interconnected logic control loops:

[0062] First control loop: Computational thermal energy feedforward control based on grain drying dynamics

[0063] This loop aims to solve the problem of matching heat source supply with load demand. The central control subsystem first performs the drying heat demand calculation. The system uses a preset grain drying process curve (i.e., the target moisture reduction rate corresponding to different drying stages) combined with real-time feedback from grain moisture content sensors. The rate of change is used to calculate the heat flux required by the system within the current time step using the aforementioned dry heat demand model. .

[0064] Subsequently, the system performs a computing power scheduling inversion operation. The central control subsystem retrieves the server energy consumption characteristic curves (i.e., the power consumption of a single server) from its internal storage. With load rate (the functional relationship), the required heat flux Mapped to the overall target calculated load factor required by the thermal energy production subsystem .

[0065] If the calculation yields If the load rate exceeds the actual baseline load rate of the current server cluster, the central control subsystem generates a computing power increase request instruction. This instruction contains specific load increment parameters and is sent to the data center scheduling system. In response to this instruction, the data center scheduling system retrieves pending non-real-time fault-tolerant computing tasks (including but not limited to offline rendering tasks, blockchain hash calculations, or large-scale data cleaning tasks) from the task queue and distributes them to the server nodes on the heat dissipation island, thereby actively increasing Joule heat generation by increasing the transistor switching frequency of the CPU / GPU. If the calculated... Exceeding the physical full load limit of the server cluster (i.e. The central control subsystem then issues a flow reduction command, decreasing the grain flow rate by adjusting the grain discharge mechanism at the bottom of the drying tower. In order to maintain thermal balance.

[0066] Second control loop: Pressure-flow cascade control based on pneumatic decoupling

[0067] This loop is designed to ensure the stability and safety of fluid transmission. The central control subsystem uses a PID control algorithm to perform closed-loop control of the pressure in the pressure stabilizing chamber. The target static pressure value for the pressure stabilizing chamber is set. A slightly negative pressure setting (e.g., -5Pa to -20Pa, relative to atmospheric pressure) is used to offset the friction resistance of the main heat exchange duct, ensuring that the server rack unit's exhaust vents are always in a smooth exhaust state. The cavity pressure sensor acts as a feedback element, and its measured value is... The deviation is input to the PID controller. The output signal of the PID controller adjusts the operating frequency of the variable frequency booster fan. When the thickness of the grain layer in the drying tower increases or the porosity decreases, leading to increased flow resistance, the variable frequency booster fan automatically increases its speed to overcome the resistance while maintaining stable pressure in the pressure stabilizing chamber. This logic ensures that the back pressure on the server exhaust side is not affected by fluctuations in the downstream drying load, achieving decoupling of aerodynamic characteristics.

[0068] Third control loop: Temperature and humidity correction control based on safety threshold

[0069] This loop serves as a protection and fine-tuning mechanism for the system. When the thermal energy production subsystem is operating under high load, and the first temperature sensor detects the pre-mixing hot air temperature... When the temperature exceeds the grain’s current tolerance threshold (e.g., seed grain is limited to 43°C), the central control subsystem intervenes with temperature control logic.

[0070] The system calculates how to reduce the high-temperature hot air to a safe set temperature based on the thermodynamic mixing equation. The required proportion of cold air is determined. A control signal drives the electrically adjustable mixing valve to open to the corresponding angle. Simultaneously, to prevent fluctuations in total airflow caused by the introduction of cold air, which could affect the chamber pressure, the central control subsystem uses a feedforward compensation mechanism to pre-adjust the speed of the variable frequency booster fan. This compensates for changes in intake resistance caused by variations in the mixing valve opening, ensuring a constant airflow into the grain drying execution subsystem. Furthermore, the electrically adjustable airflow valves on each layer of the air duct adjust independently based on feedback from the grain temperature sensors for each layer. If the grain temperature in a certain layer is too high, the corresponding valve opening decreases, achieving localized overheat protection.

[0071] See attached document Figure 3 The method in this embodiment is not limited to simple on / off control, but rather involves a dynamic adjustment process that combines thermodynamics and computational science across domains. This process is executed by a central control subsystem and specifically includes the following steps:

[0072] Step S100: System initialization and pneumatic negative pressure establishment

[0073] Before initiating the grain drying process, the central control subsystem first performs a self-test to confirm the online status of all sensors and the absence of fault feedback from the actuators. Subsequently, the system enters a pre-start state. In this state, the central control subsystem controls the variable frequency booster fan to start at a preset low-frequency speed, while simultaneously keeping the electric airflow regulating valve slightly open. The purpose of this step is to establish an initial negative pressure environment (relative to atmospheric pressure) within the pressure-stabilizing chamber of the pneumatic decoupling buffer subsystem. The central control subsystem reads data from the chamber pressure sensor; when the detected static pressure within the chamber reaches a preset negative pressure threshold (e.g., -10 Pa), it confirms that the pneumatic decoupling state has been established, and the system enters a standby ready mode. This sequence ensures that the heat exhaust from the server rack unit can be smoothly drawn in during subsequent heat load loading, preventing server overheating due to back-end resistance.

[0074] Step S200: Grain loading and drying parameter inversion

[0075] The grain to be dried is loaded into the drying tower from the top via an elevator until the preheating section, drying section, and tempering section are filled. Grain moisture content sensors and grain temperature sensors then collect the initial state data of the grain. and The operator or upper management system inputs the grain type and target moisture content at the outlet. The central control subsystem calls upon the grain desorption isotherm model in its internal database to determine the maximum permissible critical wind temperature for this batch of grain. The system calculates the instantaneous heat flux required to maintain the rated dehydration rate under the current operating conditions, based on the aforementioned drying heat demand calculation model and the above physical parameters, including the maximum temperature gradient. .

[0076] Step S300: Reverse scheduling and matching of computing power and thermal energy

[0077] This step is the core of this method; the system transforms the heat demand of the physical world into the computing power demand of the digital world. The central control subsystem then calculates... Using the aforementioned server heat generation and computing power coupling model, the target computing load rate required by the server cluster can be calculated in reverse. .

[0078] like If the current server load exceeds the actual baseline load, the system generates a computing power injection instruction. This instruction carries the required increase in power consumption and is sent to the data center task scheduling interface. The scheduling interface then retrieves pending batch processing tasks or high-throughput computing tasks and injects them into the computing nodes of the thermal energy production subsystem, causing the CPU / GPU load rate to climb to [a certain level]. .

[0079] like If the load is below the current baseline (e.g., during the off-season or when grains are about to be dried), the system will not attempt to calculate the load, but will instead mark the state of excess heat and switch to the subsequent air mixing regulation logic.

[0080] Step S400: Dynamic compensation of aerodynamic resistance

[0081] As hot air continuously flows from the heat production subsystem into the pressure stabilizing chamber, the central control subsystem performs real-time closed-loop pressure control. Due to changes in porosity caused by grain volume shrinkage during drying, or changes in grain layer looseness caused by the operation of the grain discharge mechanism, the flow resistance of the drying tower fluctuates dynamically.

[0082] The system continuously monitors the feedback values ​​from the chamber pressure sensor. When the absolute value of the negative pressure decreases (approaching zero or positive pressure), it indicates an increase in the resistance of the grain layer at the rear end or a surge in the airflow at the front end. The control system immediately increases the drive frequency of the variable frequency booster fan to increase the fan's total pressure output; conversely, it decreases the frequency. This step consistently maintains the pressure-stabilizing chamber at a slight negative pressure equilibrium point, isolating the drying tower resistance changes from interference with the server's cooling fan operating point from a fluid dynamics perspective.

[0083] Step S500: Heat and Mass Exchange and Precise Temperature and Humidity Control

[0084] The pressurized hot air enters the stratified air supply duct. During this stage, the system executes dual temperature control logic:

[0085] Source coarse adjustment (based on mixed air): If the exhaust temperature of the server under full load is... Still higher than the grain allowance Alternatively, in a state of excess heat, the central control subsystem calculates and adjusts the opening of the electrically controlled mixing valve based on the aforementioned air mixing model, introducing ambient cold air to precisely clamp the mixing temperature at the set value. .

[0086] Local fine-tuning (based on layering): Hot air passes through the grain layer. The system monitors the values ​​of the grain temperature sensors in each layer. If the grain temperature in a certain layer (such as the bottom drying section) rises too quickly and approaches the heat damage threshold, the system individually reduces the opening of the electric airflow regulating valve corresponding to that layer to reduce enthalpy input and achieve local overheat protection.

[0087] Step S600: Determination of drying endpoint and grain discharge cycle

[0088] As drying progresses, a grain moisture sensor monitors the changes in value in real time. When the moisture content of the grain at the bottom reaches... At this time, the central control subsystem activates the grain discharge mechanism at the bottom to discharge the dried and qualified grains, while wet grains are simultaneously added at the top to maintain dynamic continuous drying.

[0089] During continuous operation, if the system receives an emergency power cut-off or maintenance shutdown signal from the data center, or if a sudden power outage occurs, the anti-backflow check valve component will automatically close due to the loss of airflow thrust, physically cutting off the hot air channel and preventing dust and humid exhaust gas in the drying tower from flowing back into the server rack.

[0090] Step S700: Waste Heat Recovery and Discharge

[0091] In cold environments, if the exhaust gas temperature after heat exchange through the grain layer is still higher than the ambient temperature and the relative humidity is not saturated (i.e., it still has moisture absorption capacity), the system controls the opening of the air valve on the exhaust gas return duct, drawing some of the exhaust gas back to the intake side of the variable frequency booster fan to mix with fresh hot air. The system monitors the dew point temperature of the mixed airflow through a humidity sensor to ensure that condensation does not occur before the mixed air comes into contact with the grain, thereby utilizing heat energy in stages.

[0092] See attached document Figure 1 -Appendix Figure 3 To ensure the safety of the coupling between the server rack unit, which is a high-value asset, and flammable biomass (grain), this embodiment is configured with a multi-level circuit breaker mechanism that combines physical passive protection with logical active intervention.

[0093] Level 1 protection: Pneumatic backflow and physical dust isolation mechanism

[0094] This mechanism primarily addresses situations where sudden power outages, mechanical failures of the variable frequency booster fan, or voltage fluctuations in the power grid cause pressure imbalances at the downstream end. During normal operation, the pressure stabilizing chamber maintains a slight negative pressure (e.g., -10 Pa). If the variable frequency booster fan unexpectedly stops, airflow inertia or thermal buoyancy within the drying tower will cause an instantaneous positive pressure backflow.

[0095] Under these conditions, the anti-backflow check valve assembly installed at the back of the server rack unit functions as a physical shut-off. The valve blades of this assembly are designed with an eccentric gravitational moment; when the server exhaust dynamic pressure is lost (e.g., the server is also powered off) or the external back pressure exceeds the exhaust dynamic pressure, the valve blades instantly fall back and adhere to the valve seat under gravity. The valve seat contact surface is embedded with a high-temperature resistant silicone sealing strip, forming an airtight closure. This action is purely mechanical and does not rely on electricity, thus physically cutting off the possibility of airflow containing grain dust and high-humidity exhaust gases reversing and entering the precision computing equipment.

[0096] Second-level protection: Bypass pressure relief mechanism for impedance mismatch on the heat source side

[0097] This mechanism is designed to address extreme conditions where blockages occur in the drying tower (such as grain arching or screen blockage), leading to a sharp increase in flow resistance and threatening the server's heat dissipation safety.

[0098] The pressure-stabilizing chamber of the pneumatic decoupling buffer subsystem also has an independently installed emergency pressure relief valve assembly at its top. This assembly includes a normally closed gravity-weighted cover or a flap engaged by an independent electromagnet. The central control subsystem continuously monitors the values ​​of the chamber pressure sensors at millisecond intervals.

[0099] When a sharp increase in static pressure within the voltage stabilization chamber is detected and exceeds the preset server back pressure safety threshold (this threshold is set as the stall pressure of the server fan's PQ curve, for example, 50 Pa), the central control subsystem determines that there is a back-end blockage. At this point, the system immediately triggers the thermal bypass mode.

[0100] The central control subsystem cuts off the power supply to the variable frequency booster fan to prevent surge.

[0101] Simultaneously, the emergency pressure relief valve assembly is fully opened, or if it is a mechanical pressure relief valve, it will automatically open under the push of internal pressure.

[0102] At this point, the high-temperature airflow bypasses the grain drying subsystem and is directly discharged to the atmosphere through the emergency pressure relief valve assembly. This logic ensures that the data center's heat dissipation path remains unobstructed with low impedance in the event of any mechanical failure at the agricultural end, guaranteeing the continuity of computing power services.

[0103] Level 3 Protection: Grain Heat Damage and Fire Prevention Mechanisms

[0104] This mechanism prevents uncontrolled air temperature due to sudden increases in computing power or malfunctions in the mixing valve. The central control subsystem has two temperature warning levels:

[0105] Level 1 Alert (Temperature Control Intervention): When the first temperature sensor detects a value... Exceeding the set value When the temperature exceeds the target value by 5°C, the system will force the electric regulating mixing valve to open to 100%, introduce the maximum amount of cold air, and temporarily ignore the pressure balance logic.

[0106] Level 2 Alert (Heat Source Cut-off): When the temperature continues to rise and reaches... When the temperature reaches the critical point for grain scorching (e.g., 60℃-70℃), the system determines there is a fire risk. The central control subsystem immediately sends a highest-priority emergency frequency reduction command to the data center, forcibly reducing the CPU voltage and frequency to lower the exhaust temperature by reducing Joule heating at the source. Simultaneously, all electrically operated airflow regulating valves on the stratified air ducts are closed to isolate oxygen supply and prevent potential smoldering.

[0107] Level 4 protection: Anti-condensation shutdown and purging mechanism

[0108] This mechanism is designed to prevent the humid, hot air remaining in the pipes and cabinets from condensing into liquid water upon contact with cold walls after system shutdown, thus preventing corrosion of electronic components.

[0109] When the system receives a shutdown command, the central control subsystem does not immediately cut off the power supply, but instead executes a shutdown purging procedure. The specific timing is as follows:

[0110] Send a command to the server to relieve the computing load and restore it to a low-power standby state, thereby reducing heat output;

[0111] Open the electric regulating mixing valve fully to introduce dry, cool ambient air.

[0112] Control the variable frequency booster fan to continue running at 50% of its rated speed for a predetermined time (e.g., 10-15 minutes).

[0113] The process uses unsaturated cold air to replace the hot and humid air in the pressure stabilizing chamber and the main heat collection duct until the value detected by the first temperature sensor is close to the ambient temperature and the reading of the humidity sensor drops below the safe dew point. Only then does the system completely cut off the power to each actuator and complete the safe shutdown.

Claims

1. A grain through-flow drying system utilizing waste heat from a data center, characterized in that, include: The thermal energy production subsystem is used to provide the hot airflow carrying the waste heat of the data center required for drying. It includes several server rack units that generate computing heat and a main heat collection duct for collecting the hot airflow. A pneumatic decoupling buffer subsystem is located downstream of the thermal energy production subsystem to balance airflow pressure and eliminate airflow pulsation. The input end of the pneumatic decoupling buffer subsystem is physically connected to the main heat collection duct. The grain drying execution subsystem is located downstream of the pneumatic decoupling buffer subsystem. It is used to contain grain and guide hot airflow through the grain layer for heat and mass exchange. The air inlet of the grain drying execution subsystem is connected to the output of the pneumatic decoupling buffer subsystem. The central control subsystem establishes communication connections with the thermal energy production subsystem, the pneumatic decoupling buffer subsystem, and the grain drying execution subsystem, respectively. The central control subsystem is configured to calculate and adjust the server load rate of the thermal energy production subsystem based on the drying demand data fed back by the grain drying execution subsystem. At the same time, it maintains the decoupling balance of pneumatic pressure between the thermal energy production subsystem and the grain drying execution subsystem by adjusting the operating parameters of the pneumatic decoupling buffer subsystem.

2. The grain flow drying system utilizing waste heat from a data center according to claim 1, characterized in that, Each server rack unit in the thermal energy production subsystem is equipped with a backflow prevention check valve assembly at its back panel exhaust vent. The anti-backflow one-way valve assembly is configured with a mechanical automatic opening and closing structure. It opens when the exhaust pressure inside the server rack unit is greater than the pressure of the external main heat collection duct, and automatically closes when the exhaust pressure inside the server rack unit is less than the pressure of the external main heat collection duct or when a shutdown occurs, thereby forming a physical barrier to prevent external airflow carrying dust from flowing back into the server rack unit.

3. The grain through-flow drying system utilizing waste heat from a data center according to claim 1, characterized in that, The pneumatic decoupling buffer subsystem includes a pressure stabilizing chamber, an electrically adjustable mixing valve, and a variable frequency booster fan. The pressure-stabilizing chamber is an expanded box with a predetermined expansion volume, used to reduce the airflow velocity and mix the airflow. The electrically adjustable mixing valve is installed at the air inlet on the side wall of the pressure stabilizing chamber and is used to introduce ambient cold air to regulate the temperature of the mixed air. The variable frequency booster fan is installed at the outlet end of the pressure stabilizing chamber to provide the static pressure required to overcome the resistance of the grain layer for the grain drying execution subsystem. The pressure stabilizing chamber is also equipped with a chamber pressure sensor for monitoring the static pressure inside the chamber.

4. The grain flow drying system utilizing waste heat from a data center according to claim 3, characterized in that, The central control subsystem is pre-configured with aerodynamic balance control logic. The pneumatic balance control logic is configured to: receive real-time static pressure data collected by the cavity pressure sensor, and adjust the operating frequency of the variable frequency booster fan according to the deviation between the real-time static pressure data and the preset micro negative pressure target value through a PID algorithm; Through the aforementioned adjustment, the air pressure in the pressure stabilizing chamber is always maintained at a slightly negative pressure state below atmospheric pressure, thereby ensuring that the back pressure of the exhaust vent of the server rack unit is not affected by the fluctuation of grain layer resistance within the grain drying execution subsystem.

5. The grain flow drying system utilizing waste heat from a data center according to claim 1, characterized in that, The grain drying execution subsystem includes a vertically arranged drying tower, a stratified air supply duct installed inside the drying tower, and an electric air volume regulating valve installed on each branch pipe of the stratified air supply duct. The drying tower body is defined by a channel for grain movement, and the side wall or interior of the channel is equipped with a grain moisture content sensor and a grain temperature sensor. The central control subsystem is configured to independently adjust the opening of the electric air volume regulating valve at the corresponding level based on the stratified detection data of the grain temperature sensor, thereby controlling the local air volume.

6. The grain flow drying system utilizing waste heat from a data center according to claim 5, characterized in that, The central control subsystem is pre-configured with a drying heat demand calculation model and a server heat generation and computing power coupling model. The central control subsystem is configured to: firstly, using the drying heat demand calculation model, calculate the total heat power required based on the initial moisture content detected by the grain moisture content sensor, the set target moisture content, and the grain mass flow rate; Then, using the server heat generation and computing power coupling model, the target computing load rate required by the server rack unit is calculated in reverse based on the total heat power. Finally, a computing power scheduling instruction containing the target computing load rate is sent to the task scheduling interface of the thermal energy production subsystem.

7. The grain flow drying system utilizing waste heat from a data center according to claim 3, characterized in that, An emergency pressure relief valve assembly is also installed at the top of the pressure stabilizing chamber; The emergency pressure relief valve assembly is configured to automatically open when the static pressure in the pressure stabilizing chamber exceeds a preset safety back pressure threshold, thereby directly discharging the hot airflow to the atmospheric environment and forming a bypass pressure relief channel. The central control subsystem is also configured to control the variable frequency booster fan to stop running and trigger the emergency pressure relief valve assembly to open when the pressure in the pressure stabilizing chamber is detected to rise abnormally, thereby preventing the server rack unit from overheating when the grain drying execution subsystem is blocked.

8. The grain flow drying system utilizing waste heat from a data center according to claim 6, characterized in that, The computing power scheduling command sent by the central control subsystem is configured to trigger the data center task scheduling system to perform the following operations: When the target computing load rate is higher than the current actual load rate, non-real-time batch processing computing tasks are retrieved and distributed to the server rack unit to increase the power consumption of the computing nodes and thus increase heat generation. When the target computing load rate is lower than the current actual load rate, or when the server rack unit is fully loaded and the heat generated still exceeds the required total heat power, maintain the current load and send a command to the pneumatic decoupling buffer subsystem to open the electric regulating mixing valve.

9. The grain flow drying system utilizing waste heat from a data center according to claim 3, characterized in that, The central control subsystem is also equipped with shutdown purging logic; The shutdown purging logic is configured as follows: upon receiving a shutdown command, the variable frequency booster fan is kept running at low speed and the electric regulating mixing valve is fully opened to introduce ambient cold air to replace the high humidity and heat air in the pressure stabilizing chamber and pipeline, until the monitored temperature drops to a preset safety value and then the power is cut off.

10. A grain through-flow drying method utilizing waste heat from a data center, characterized in that, The grain flow drying system utilizing waste heat from data centers, as described in any one of claims 1-9, comprises the following steps: System initialization steps: Start the pneumatic decoupling buffer subsystem to establish a micro-negative pressure environment in the buffer zone between the thermal energy production subsystem and the grain drying execution subsystem; Parameter acquisition and calculation steps: Collect the initial moisture content and temperature of the grain entering the grain drying execution subsystem, and use the drying heat demand calculation model to calculate the heat flux required to maintain the set drying rate; Computing power scheduling and thermal energy matching steps: Using the server heat generation and computing power coupling model, the heat flux is converted into the server's target computing load rate, and a computing power scheduling command is sent to the thermal energy production subsystem to adjust the server's power consumption; Pneumatic closed-loop control steps: Real-time monitoring of the static pressure value of the buffer area, adjustment of the airflow pressurization amplitude through PID algorithm, and compensation for dynamic flow resistance changes in the grain drying execution subsystem to maintain the micro-negative pressure environment; Temperature and humidity control and execution steps: When the server exhaust temperature is higher than the grain tolerance temperature, adjust the cold air mixing ratio and control the air inlet temperature, and send the conditioned hot air into the grain drying execution subsystem to dry the grain through flow.

Images