A method for intelligent heat energy dynamic recovery for liquid organic fertilizer production

Abstract

The application discloses a kind of for the intelligent heat energy dynamic recovery method of liquid organic fertilizer production, it is related to the recovery and utilization technology of energy in agricultural production field.The method extracts heat from ambient air by air source heat pump system, which is converted into hot water with a temperature of 30℃ to 85℃, and the fermentation broth in multiple fermentation barrels is precisely heat exchanged by corrosion-resistant coil heat exchanger.Using PLC control system with high-precision temperature sensor, real-time monitoring of liquid temperature in each fermentation barrel, fuzzy-PID algorithm is used to dynamically adjust hot water flow, realize the temperature difference control between fermentation barrels within ±1℃, form the dynamic balance of heat energy.The system is provided with closed-loop hot water recovery device, and the cooled hot water is heated again for recycling, which significantly improves the energy utilization efficiency, and the comprehensive energy-saving rate reaches more than 60%.The method has the advantages of energy saving, precise temperature control, high automation, good equipment stability and green environmental protection, and is suitable for large-scale continuous production of liquid organic fertilizer.

Description

Technical Field

[0001] This invention relates to energy recovery and optimized utilization technology in the production of liquid organic fertilizers in agricultural production processes, particularly through intelligent heat recovery methods to improve energy utilization efficiency in the liquid organic fertilizer production process. This invention combines air source heat pump technology with a heat recovery system, belonging to the field of green agricultural equipment, and has significant advantages, especially in renewable energy and energy conservation and emission reduction in agricultural production processes. Background Technology

[0002] In the production of liquid organic fertilizer, the fermentation raw materials need to be maintained within a stable temperature range to ensure the activity of microorganisms and promote effective fermentation. Currently, liquid organic fertilizer production mainly uses electric heating or boiler heating technology. These traditional heating methods have the following problems: high energy consumption, low thermal efficiency, and poor temperature control accuracy. In addition, temperature differences between multiple fermentation tanks lead to heat energy waste, which in turn affects the fermentation effect and the quality of organic fertilizer, resulting in poor production efficiency and product consistency.

[0003] Air source heat pumps are increasingly being used in agriculture due to their high energy efficiency and low carbon emissions. However, there is currently no method that can achieve dynamic heat balance among multiple fermentation units, intelligently regulate temperature differences, and recycle excess heat. Therefore, there is an urgent need for an intelligent dynamic heat recovery method based on air source heat pumps to solve problems such as large temperature differences between multiple fermentation units, energy waste, and low system operating efficiency. Summary of the Invention

[0004] This invention provides an intelligent dynamic heat recovery method for liquid organic fertilizer production, applicable to the liquid organic fertilizer production process. It combines air-source heat pump technology with a coil heat exchange system, effectively solving problems such as low heat utilization efficiency and serious energy waste in existing production processes. Through optimized heat recovery and dynamic adjustment mechanisms, this invention significantly improves energy utilization efficiency while reducing production costs and carbon emissions. The method specifically includes the following technical solutions:

[0005] Air source heat supply: This invention uses an air source heat pump system to extract low-grade heat from the ambient air and convert it into hot water with a temperature range of 30℃ to 85℃. Through an intelligent control system, the system can monitor the temperature changes of the fermentation tank in real time, automatically adjust the operating power and output flow of the heat pump, ensure temperature stability during the fermentation process, and maximize energy utilization efficiency.

[0006] Coil heat exchange technology: This invention employs a highly corrosion-resistant coil heat exchange device to improve heat exchange efficiency and system durability. The coil is made of 316L stainless steel with a preferred wall thickness of 3mm, effectively resisting acid and alkali corrosion from the liquid during fermentation. It also reduces internal heat exchange resistance, improving heat transfer rate and stability. During heat exchange, hot water is pumped via a variable frequency circulating water pump through insulated circulation pipes to the coil device in at least two fermentation tanks, where it exchanges heat with the fermentation liquid within the tanks. This achieves precise temperature control, ensuring that the liquid in each fermentation tank reaches and maintains the optimal fermentation temperature uniformly and stably, thereby guaranteeing microbial activity and fermentation quality.

[0007] Intelligent Temperature Control System and Dynamic Thermal Energy Balance: This invention employs a PLC control system as the core control device. High-sensitivity temperature sensors precisely positioned within each fermentation tank collect liquid temperature data in real time, transmitting the data to the PLC control unit for analysis and processing. The PLC control system uses a fuzzy-PID algorithm to precisely adjust the flow control valves of each hot water supply pipeline based on the deviation between the real-time temperature data and the preset target temperature, thereby dynamically optimizing the hot water supply to each fermentation tank. When the temperature of a fermentation tank is detected to be lower than the preset target value, the system automatically increases the hot water flow to that tank while simultaneously reducing the hot water supply to other tanks that have reached the target temperature, ensuring that the temperature fluctuation range of all fermentation tanks is controlled within ±1℃, achieving real-time dynamic thermal energy balance for the entire system. This refined intelligent control mode ensures temperature stability and consistency during the microbial fermentation process, significantly improving fermentation quality and production efficiency.

[0008] Hot water recovery and recycling: This invention incorporates a hot water return pipe that guides cooled hot water back to the air-source heat pump for reheating. This recovery mechanism, through intelligent adjustment, avoids hot water waste and forms a highly efficient energy closed loop. The recycled hot water and the heat pump's coefficient of performance (COP) can reach over 3.0, thus significantly improving the utilization rate of thermal energy.

[0009] Fault and safety protection mechanisms: This invention is equipped with high temperature alarm, water pump overload protection, liquid level monitoring and backup hot water switching functions to ensure that the system can automatically shut down or bypass cooling in the event of a fault, avoiding irreversible damage to the system.

[0010] This invention solves the problems of high energy consumption and heat waste in liquid organic fertilizer production by combining an air-source heat pump with a coil heat transfer system. Its beneficial effects are as follows:

[0011] Energy saving and consumption reduction: This invention adopts air source heat pump technology with a coefficient of performance (COP) as high as 3.2. Under the same energy input conditions, it significantly improves energy conversion efficiency, thereby greatly reducing energy consumption. Through real-time adjustment of the intelligent control system, the hot water flow and temperature are precisely controlled, avoiding heat energy waste. In particular, the closed-loop design of the heat recovery system effectively reduces hot water loss. By returning cooling return water to the heat pump for heating, the system maximizes the recovery and utilization of heat generated during fermentation, ensuring efficient heat energy utilization and greatly reducing the overall energy consumption of the system.

[0012] The temperature control system of this invention, based on a PLC control unit and a high-precision temperature sensor, can monitor and precisely adjust the temperature of the liquid in each fermentation tank in real time, ensuring an error of no more than ±1℃. By intelligently adjusting the hot water flow and temperature, it maintains temperature stability in each fermentation tank, ensuring that microorganisms reproduce efficiently under optimal temperature conditions, thereby improving fermentation efficiency and the production quality of liquid organic fertilizer. The system's dynamic balancing mechanism effectively solves the problem of excessive temperature differences between fermentation tanks, further optimizing the production process.

[0013] The control system of this invention integrates multiple advanced intelligent technologies, enabling it to automatically adjust heat source output, hot water flow, and temperature control system based on real-time ambient temperature and production needs. Through automated control and adjustment, the necessity of manual intervention is greatly reduced, lowering the risk of operational errors and ensuring the system's efficient and stable operation. The system's adaptive adjustment reduces fluctuations caused by human operation, improving the stability and production efficiency of the entire fermentation process.

[0014] Environmentally Friendly and Green Sustainable Development: The air-source heat pump system used in this invention has significant environmental advantages. The system operates without pollution or emissions, meeting modern environmental protection requirements. By significantly reducing energy consumption and carbon emissions associated with traditional heating methods, it promotes the green transformation of agricultural production processes. Furthermore, the low-carbon and high-efficiency characteristics of air-source heat pumps further enhance the sustainability of the entire production process, contributing to the green development of agriculture.

[0015] Long-term stable operation: The system employs a highly corrosion-resistant 316L stainless steel coil heat exchanger and a heat pump system, enabling long-term stable operation in harsh fermentation environments and extending equipment lifespan. The corrosion resistance of the heat exchanger ensures the system's stability under long-term high-temperature and high-humidity conditions, while the high efficiency and low maintenance costs of the heat pump system further reduce operating costs. This makes the invention particularly suitable for large-scale, long-term agricultural production environments, guaranteeing the equipment's economic viability and long-term benefits. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the intelligent dynamic heat energy recovery system of the present invention. Detailed Implementation

[0017] Example 1: Standard Liquid Organic Fertilizer Production System

[0018] In this embodiment, the system includes an air source heat pump, a PLC control system, four fermentation tanks, a coil heat exchanger, a temperature control sensor, and hot water circulation pipes. The system operation process is as follows:

[0019] Equipment Start-up and Temperature Control: Upon system startup, the PLC controller sets the hot water temperature (e.g., 40℃) according to production requirements, activates the air source heat pump, and converts low-grade heat from the ambient air into hot water. The hot water is then transported to the coil heat exchanger via a variable frequency pump, where it efficiently exchanges heat with the liquid in each fermentation tank, ensuring that the liquid temperature remains within the set range, thus providing the optimal fermentation environment for microorganisms.

[0020] Temperature control and heat regulation: The temperature in each fermentation tank is monitored in real time by a temperature sensor, and the data is transmitted to the PLC control system. Based on the temperature deviation, the PLC control system automatically adjusts the hot water flow, increasing the hot water supply to fermentation tanks with lower temperatures and decreasing the hot water supply to fermentation tanks with higher temperatures, thereby ensuring that the temperature difference between all fermentation tanks is controlled within ±1℃, ensuring dynamic balance of heat energy.

[0021] Hot water recovery and reuse: During fermentation, the cooled hot water after heat exchange is guided back to the air source heat pump through a return pipe. The hot water is monitored by temperature and level sensors during the return process to ensure a stable supply and heat recovery. The hot water is then reheated and supplied back to the fermentation tank, achieving efficient heat recovery and reuse.

[0022] Energy saving effect: Data analysis after 24 hours of continuous operation shows that compared with traditional electric heating methods, the method of this invention can achieve approximately 60% energy saving, and the temperature fluctuation inside the fermentation tank is controlled within ±1℃, effectively ensuring the stability of the fermentation process and product quality.

[0023] Example 2: Multi-barrel Intelligent Temperature Control System

[0024] This embodiment uses four fermentation tanks, each equipped with an independent temperature control system. Temperature data is transmitted wirelessly to a central PLC control system, which then performs intelligent analysis and adjustment. The specific operation process is as follows:

[0025] Temperature data acquisition and analysis: The temperature inside each fermentation tank is collected in real time by a high-precision temperature sensor and uploaded to the PLC control system via wireless signal. The PLC control system analyzes the temperature change data of each tank and calculates the required hot water flow rate for each fermentation tank.

[0026] Hot water distribution and dynamic recycling: The temperature control system adjusts the hot water flow rate based on real-time temperature data to ensure that the temperature of each fermentation tank remains within the set range, avoiding excessive temperature differences between tanks. The hot water returns to the heat pump through a return pipe for reheating and circulation, improving the efficiency of heat energy utilization.

[0027] Energy saving and efficiency improvement: Through precise hot water flow regulation and temperature control management, the system saves about 60% of energy consumption. It also reduces human error and energy waste during system operation through intelligent management, thereby reducing operating costs and improving overall production efficiency.

[0028] In summary, this invention provides an intelligent dynamic heat energy recovery method that combines air source heat pump technology and a coil heat exchange system. This method not only achieves efficient heat energy recovery and utilization during liquid organic fertilizer production but also significantly improves energy utilization, reduces carbon emissions, and enhances production efficiency through an intelligent temperature control system and dynamic heat regulation mechanism. This method offers advantages such as energy saving, environmental protection, and precise temperature control, making it particularly suitable for large-scale continuous liquid fermentation production lines in modern agriculture and possessing broad market potential.

[0029] The above embodiments are used to illustrate the present invention, but do not limit the scope of the invention. Those skilled in the art, based on the teachings disclosed in this invention, can make various modifications or equivalent substitutions, all of which should fall within the protection scope of the claims of this invention.

Claims

1. A method for intelligent dynamic heat recovery in liquid organic fertilizer production, characterized in that, Specifically, the following steps are included: (1) Air source heat extraction: The air source heat pump system extracts low-grade heat from the ambient air to produce hot water at a temperature of 30℃~85℃; (2) Coil heat exchange: The hot water is transported by a variable frequency circulating water pump through an insulated circulating pipe to the coil heat exchangers installed in at least two fermentation tanks, where it exchanges heat with the fermentation liquid in the fermentation tanks in a wall-to-wall manner; (3) Real-time temperature monitoring: A high-precision temperature sensor is installed in each fermentation tank to monitor and collect the temperature data of the fermentation liquid in real time and upload it to the PLC control unit; (4) Dynamic heat regulation and balance: The PLC control unit adopts a fuzzy-PI The D algorithm automatically and accurately adjusts the opening of the hot water flow control valve based on the deviation between the real-time temperature data and the set target temperature, so as to realize the real-time dynamic distribution of hot water flow and keep the temperature difference between each fermentation tank within ±1℃; (5) Hot water recycling and reuse: The cooling return water after the fermentation tank heat exchange is returned to the air source heat pump for reheating through the return pipe, so as to realize the closed-loop recovery and efficient recycling of heat energy; (6) Fault safety protection: The system is equipped with high temperature alarm, water pump overload protection, liquid level monitoring and backup hot water switching functions. When an abnormal situation occurs, the safety protection measures are automatically implemented.

2. The method according to claim 1, characterized in that, The coil heat exchanger is made of 316L stainless steel, and the coil wall thickness is preferably 3mm to enhance corrosion resistance, reduce heat exchange resistance and improve heat exchange efficiency.

3. The method according to claim 1, characterized in that, The air source heat pump has a COP ≥ 3.2 under rated ambient temperatures of 7℃ / 6℃ (dry / wet bulb) and the outlet water temperature fluctuation is controlled within ±1℃.

4. The method according to claim 1, characterized in that, A flow meter and an electromagnetic regulating valve are installed on the hot water circulation pipeline. The PLC control system adopts a temperature-flow dual closed-loop control strategy to ensure accurate flow regulation and dynamic distribution of hot water.

5. The method according to claim 1, characterized in that, The hot water recovery system includes a hot water return pipe, a 50μm fine filter, and a buffer insulation tank. After impurities are removed by the filter, the returned water enters the insulation tank and then returns to the air source heat pump for reheating and circulation.

6. The method according to claim 1, characterized in that, Each fermentation tank has a working volume of 3m³ to 30m³, and a target fermentation temperature range of 30℃ to 85℃.

7. The method according to claim 1, characterized in that, When the temperature inside any fermentation tank exceeds the set safe temperature of 45°C, the PLC control system immediately reduces the operating frequency of the air source heat pump to below 50% and starts the bypass cooling cycle until the temperature returns to the safe range.

8. The method according to claim 1, characterized in that, A calorimeter is installed on the hot water circulation pipeline and connected to a cloud data management platform via a communication module to record and upload heat recovery data per unit time in real time for system energy efficiency analysis and preventive maintenance.

9. The method according to claim 1, characterized in that, The temperature sensor has a data acquisition cycle of less than or equal to 3 seconds, and the data is transmitted to the PLC control system wirelessly or via wired means. The PLC's control response time is less than or equal to 2 seconds.

10. The method according to claim 1, characterized in that, This liquid fermentation production line is suitable for various organic raw materials such as livestock and poultry manure, straw, and kitchen waste. After continuous operation for more than 30 days, the overall energy saving rate of the system reaches more than 60%.

Images