Fertilizer and heat co-production system for rural heating

Abstract

The utility model discloses a fertilizer and heat co-production system for rural heating. The fertilizer and heat co-production system comprises an ultrahigh-temperature compost fermentation system, a heat exchange system, an intelligent regulation and control system and a rural energy network system, the ultrahigh-temperature compost fermentation system is used for transmitting a large amount of heat generated by fermentation to the heat exchange system; the heat exchange system is used for recovering heat energy generated by the ultrahigh-temperature compost fermentation system and transmitting the heat energy to the rural energy network system; the intelligent regulation and control system is respectively connected with the ultra-high-temperature compost fermentation system and the heat exchange system, and is used for monitoring and controlling the fermentation condition of the ultra-high-temperature compost fermentation system in real time, and regulating the heat energy transmitted to the rural energy network system by the heat exchange system according to the fermentation condition of the ultra-high-temperature compost fermentation system. According to the utility model, not only can organic wastes be quickly converted into stable organic fertilizers, but also a large amount of heat can be generated, and a brand-new technical path is provided for solving the problems of rural heating, hot water and the like.

Description

Technical Field

[0001] This utility model relates to the field of rural renewable energy development and utilization technology, and more specifically to a fertilizer and heat cogeneration system for rural heating. Background Technology

[0002] Traditional rural heating methods mainly rely on coal, firewood, or electricity, but these methods present significant environmental and economic problems. Coal and firewood heating produce large amounts of smoke and greenhouse gases, exacerbating air pollution and harming the ecological environment. Furthermore, while electric heating is cleaner, its high operating costs in remote rural areas hinder its widespread adoption. With the introduction of the "dual carbon target," coal-fired heating is gradually being phased out, and rural heating methods urgently need a clean transformation. However, some rural areas lack centralized heating facilities, and the problem of insufficient heating resources in winter remains prominent. Therefore, against the backdrop of rural energy transition and the resource utilization of agricultural waste, developing an economical and environmentally friendly renewable energy heating technology has become an important direction for current research and practice. Agricultural production generates a large amount of organic solid waste annually, including livestock manure and crop straw. Improper disposal of this waste can lead to serious environmental problems, such as manure leakage polluting water sources and straw accumulation and burning polluting the air. Because these wastes contain abundant organic matter and nutrients, direct disposal would lead to resource waste. Therefore, developing a recyclable and efficient waste treatment and utilization model is crucial. Although traditional composting technology can convert waste into organic fertilizer, its processing cycle is long and its efficiency is low. Furthermore, the heat generated during fermentation is minimal and not effectively utilized, resulting in energy waste.

[0003] Therefore, a combined fertilizer and heat production system for rural heating was designed, which can not only quickly convert organic waste into stable organic fertilizer, but also generate a large amount of heat, providing a brand-new technical approach to solving problems such as rural heating and hot water. Utility Model Content

[0004] In view of this, the present invention provides a fertilizer-heat co-production system for rural heating, which can promote the development of circular economy and ecological agriculture. The direct return of compost products to the field helps to improve soil fertility, thereby realizing resource recycling and promoting sustainable agricultural development.

[0005] To achieve the above objectives, this utility model adopts the following technical solution: a rural heating and fertilizer co-production system, comprising: an ultra-high temperature composting fermentation system, a heat exchange system, an intelligent control system, and a rural energy network system;

[0006] The ultra-high temperature composting fermentation system is used to transfer the large amount of heat generated during fermentation to the heat exchange system.

[0007] The heat exchange system is used to recover the heat energy generated by the ultra-high temperature composting fermentation system and transmit it to the rural energy network system.

[0008] The intelligent control system is connected to the ultra-high temperature composting fermentation system and the heat exchange system respectively, and is used to monitor and control the fermentation status of the ultra-high temperature composting fermentation system in real time, and to adjust the heat energy transmitted from the heat exchange system to the rural energy network system according to the fermentation status of the ultra-high temperature composting fermentation system.

[0009] Preferably, the ultra-high temperature composting fermentation system includes: a fermentation chamber, a fermentation pile, a top box, a blower, and ventilation pipes;

[0010] The fermentation chamber is used to contain the fermentation pile and maintain thermal insulation and sealing.

[0011] The fermentation pile is provided with a support member on the outside, which separates a ventilation space on one side of the fermentation pile and a top box on the other side; the top box is located above the fermentation pile and is connected to the heat exchange system, and the ventilation pipe is located in the ventilation space and is connected to the blower.

[0012] Preferably, the heat exchange system includes: a heat exchanger, external pipelines of the first fermentation chamber, external pipelines of the second fermentation chamber, internal pipelines, and site heating pipelines;

[0013] The heat exchanger is connected to the external pipelines of the first fermentation chamber, the external pipelines of the second fermentation chamber, and the site heating pipeline. The internal pipeline is arranged inside the fermentation chamber, with one end connected to the external pipeline of the first fermentation chamber and the other end connected to the external pipeline of the second fermentation chamber, forming a closed loop with the heat exchanger. The site heating pipeline is used to connect to the rural energy network system.

[0014] Preferably, the internal pipeline is equipped with a return water internal pipeline with nozzles for replenishing water to the fermentation pile.

[0015] Preferably, the intelligent control system includes a sensor group, a main control unit, a return water control valve, and a blower control valve;

[0016] The sensor group, including a temperature sensor, a humidity sensor, and an oxygen sensor, is installed inside the fermentation pile to detect the temperature, humidity, and oxygen concentration inside the fermentation pile in real time and transmit the data to the main control unit. The main control unit controls the switching frequency of the blower control valve and the return water control valve based on the received data. The blower control valve and the return water control valve are used to control the blower and the internal pipeline of the return water, respectively, to regulate the oxygen content and humidity inside the fermentation pile.

[0017] As can be seen from the above technical solution, compared with the prior art, this utility model discloses a combined fertilizer and heat production system for rural heating. It can monitor the internal temperature, humidity, and oxygen dynamics of the compost in real time, and control the blower and return water pipeline switches according to the parameters to realize the control of the composting process, ensuring the production of high-quality organic fertilizer and the efficient utilization of the calorific value of the compost. It also provides an integrated water and air heat exchange method, which can select the heating medium according to the needs of the site. For example, the heating medium for livestock farms and residences is water. The water medium is connected to the heat exchanger and heated through the internal pipeline and top box of the fermentation pile. Then, it returns to the heat exchanger through the external pipeline of the second fermentation chamber to realize the supply of heat to the rural energy network. If the heating medium for greenhouses is air, it can provide the temperature and gaseous fertilizer (CO2, NH3) generated by compost for vegetable planting. Air is blown into the fermentation pile through the blower and ventilation pipe. The air is blown out from the interface between the internal pipeline of the fermentation pile and the external pipeline of the fermentation chamber. After being heated inside the pile, the hot air is connected to the farm energy network system through the heat exchanger. This invention also establishes a three-chain coupling model of "heating-production-ecology": ① On the residential side, it provides a clean heat source for residences, greenhouses, and farms, reducing winter heating costs by 80%; ② On the production side, it produces high-quality organic fertilizer (humic acid content ≥35%) and ensures greenhouse production; ③ On the ecological side, it can dispose of tens of thousands of tons / hectare of agricultural and livestock waste annually. The establishment of this system promotes a closed-loop cycle of "waste-heat energy-fertilizer," possessing both economic and ecological sustainability advantages. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 The system structure block diagram provided by this utility model;

[0020] Figure 2 The system flowchart provided for this utility model;

[0021] Figure 3 A graph showing the temperature changes of the fermentation pile and the residential building, provided for this utility model.

[0022] Figure 4 The graph shows the changes in total nitrogen, total phosphorus, and total potassium content at the beginning and end of composting, as provided by this utility model.

[0023] Figure 5 A graph showing the change in humic acid (HS) content at the beginning and end of composting, provided by this utility model;

[0024] Figure 6 A graph showing the change in organic matter content during the composting process provided by this utility model. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] See Figures 1-2 As shown in the figure, this utility model embodiment discloses a fertilizer and heat cogeneration system for rural heating, including: an ultra-high temperature composting fermentation system, a heat exchange system, an intelligent control system, and a rural energy network system;

[0027] The ultra-high temperature composting fermentation system is used to transfer the large amount of heat generated during fermentation to the heat exchange system.

[0028] The heat exchange system is used to recover the heat energy generated by the ultra-high temperature composting fermentation system and transmit it to the rural energy network system.

[0029] The intelligent control system is connected to the ultra-high temperature composting fermentation system and the heat exchange system respectively, and is used to monitor and control the fermentation status of the ultra-high temperature composting fermentation system in real time, and to adjust the heat energy transmitted from the heat exchange system to the rural energy network system according to the fermentation status of the ultra-high temperature composting fermentation system.

[0030] Specifically, the ultra-high temperature composting fermentation system includes: a fermentation chamber, a fermentation pile, a top box, a blower, and ventilation pipes;

[0031] The fermentation chamber is used to contain the fermentation pile and maintain thermal insulation and sealing.

[0032] The fermentation pile is provided with a support member on the outside, which separates a ventilation space on one side of the fermentation pile and a top box on the other side; the top box is located above the fermentation pile and is connected to the heat exchange system, and the ventilation pipe is located in the ventilation space and is connected to the blower.

[0033] In a specific embodiment of this utility model, the fermentation chamber is required to have good heat insulation and sealing, and the lower part has a support component to separate the ventilation space; the fermentation pile is mainly composed of organic solid waste and thermophilic bacteria, and the bacteria content needs to be controlled at 1-2%, C / N ratio at 25-30:1, and moisture content at 40-60%; the top box is required to be in close contact with the fermentation pile, with an interface on the side to connect to the external pipelines of the first fermentation chamber and the external pipelines of the second fermentation chamber, and air holes at the bottom; the blower is used to blow air into the fermentation chamber to ensure the oxygen demand for microbial growth, and is required to have a power greater than 3kw and a blower flow rate greater than 1000m3 / h; the ventilation pipe is made of PVC, PPR, etc., with a diameter greater than 90mm, and the channels are randomly distributed on the ventilation pipe wall, and the pressure resistance needs to be greater than 6kg.

[0034] Specifically, the heat exchange system includes: a heat exchanger, external piping for the first fermentation chamber, external piping for the second fermentation chamber, internal piping, and heating piping for the site;

[0035] The heat exchanger is connected to the external pipeline of the fermentation chamber and the site heating pipeline respectively. The internal pipeline is arranged inside the fermentation chamber, with one end connected to the external pipeline of the first fermentation chamber and the other end connected to the external pipeline of the second fermentation chamber, forming a closed loop with the heat exchanger. The site heating pipeline is used to connect to the rural energy network system.

[0036] Specifically, the internal pipeline is equipped with a return water pipeline with nozzles for replenishing water to the fermentation pile.

[0037] Furthermore, the internal return water pipeline is a water pipe with a nozzle, which is connected to the external pipeline (outlet pipeline) of the second fermentation chamber and then back to the fermentation pile. It is controlled by the return water control valve to replenish water to the fermentation pile and control the humidity inside the pile.

[0038] In a specific embodiment of this utility model, the heat exchanger is required to meet the multi-channel heat exchange needs of both air and water media. It needs to be connected to the external pipelines of the first fermentation chamber, the external pipelines of the second fermentation chamber, and the heating pipelines of residences, greenhouses, and farms. The external pipeline of the second fermentation chamber needs to be connected to the heat exchanger and also to the internal pipelines to form a closed loop, and is required to have an on / off valve. The internal pipelines can be arranged along the inner wall of the fermentation chamber or in layers in the reactor. They need to be connected to the external pipelines and also to the heat exchanger to form a closed loop. A section of return water internal pipeline with nozzles needs to be arranged and connected to the outlet water pipeline through a control switch. The heating pipelines of the locations need to be connected to the heat exchanger. The heating medium is selected according to the needs of the location. For example, the heating medium for farms and residences is water, and the heating medium for greenhouses is air.

[0039] Specifically, the intelligent control system includes a sensor group, a main control unit, a return water control valve, and a blower control valve;

[0040] The sensor group, including a temperature sensor, a humidity sensor, and an oxygen sensor, is installed inside the fermentation pile to detect the temperature, humidity, and oxygen concentration inside the fermentation pile in real time and transmit the data to the main control unit. The main control unit controls the switching frequency of the blower control valve and the return water control valve based on the received data. The blower control valve and the return water control valve are used to control the blower and the internal pipeline of the return water, respectively, to regulate the oxygen content and humidity inside the fermentation pile.

[0041] In a specific embodiment of this utility model, composting heat energy is innovatively integrated into the rural energy network, forming a three-chain coupling model of "heating-production-ecology": ① On the residential side, it provides a clean heat source for residences, greenhouses, and farms, reducing winter heating costs by 80%; ② On the production side, it produces high-quality organic fertilizer (humic acid content ≥35%) and ensures greenhouse production; ③ On the ecological side, it can dispose of tens of thousands of tons / hectare of agricultural and livestock waste annually. The establishment of this technical system promotes a closed-loop cycle of "waste-heat energy-fertilizer," possessing both economic and ecological sustainability advantages.

[0042] Further, see Figure 3 As shown, the temperature of the fermentation pile reached 55.2℃ on day 13, which could raise the residential temperature to 16.9℃. The entire pile maintained a high temperature for 45 days, reaching a maximum temperature of 111.6℃. The highest temperature at the outlet was 55.2℃. During this process, the heat generated by the fermentation pile was effectively transferred to the residential building (120 square meters), causing the residential temperature to gradually rise and remain above 20℃ for a long time, reaching a maximum of 32℃. As the temperature of the fermentation pile decreased, the residential temperature also gradually decreased. The outdoor temperature remained low, reaching a minimum of -24℃, but the residential temperature remained comfortable, fully demonstrating the heat conduction effect of the fermentation pile. The experimental results show that the heat from the fermentation pile can provide stable heating support for residences in the low-temperature environment of Northeast China during winter; and improve the nutrient content of organic fertilizer.

[0043] Further, see Figure 4As shown in the figure, the TN content decreases significantly during composting. This is because microorganisms use nitrogen as a nutrient source, absorbing some nitrogen for growth and reproduction, thus reducing its concentration. Furthermore, as the composting temperature increases, the rate of microbial decomposition of organic matter accelerates, and some nitrogen is converted into ammonia gas and volatilized, further reducing the TN content. Nevertheless, the TN content at the end of composting still meets the standards for fertilizer return to the soil. Meanwhile, the TP and TK contents gradually increase during composting. During the high-temperature stage, the intensity of microbial decomposition of organic matter increases, leading to an increase in the relative concentrations of TP and TK; in the later stage of composting (cooling stage), the TP and TK contents tend to stabilize. This increase is mainly attributed to the continuous decomposition of organic matter and the reduction in the total mass of the compost pile, thus concentrating the relative contents of TP and TK. Although microbial growth requires a certain amount of phosphorus and potassium in the early stages of composting, causing a temporary decrease in TP and TK contents, the TP and TK contents significantly increase at the end of composting, still ensuring sufficient nutrients in the fertilizer.

[0044] TN was determined using the Kjeldahl method. TP was determined using the ammonium vanadate-molybdate colorimetric method. TK was determined using flame spectrophotometry. All of the above methods are existing technologies.

[0045] Further, see Figure 5 As shown in the figure, the humic acid (HS) content changed significantly during composting. In the early stage (high temperature stage), due to the decomposition of unstable organic matter, the accumulation rate of HS was relatively slow. When the compost entered the cooling and maturation stage, microbial activity gradually stabilized, the transformation of organic matter accelerated, and the HS content increased significantly. At the end of composting, the HS content reached 75.2 g / kg, indicating a high degree of humification, consistent with the pattern of organic matter transforming into a stable state.

[0046] Further, see Figure 6 As shown in the figure, the organic matter (OM) content decreased significantly during composting. In the early stages of composting, the activity of thermophilic microorganisms increased rapidly with the rapid rise in temperature, promoting the rapid decomposition of organic matter. The high-temperature stage was the period of most intense organic matter consumption. After entering the cooling stage, the activity of microorganisms gradually weakened, the decomposition rate of organic matter slowed down, and the remaining organic matter tended to stabilize after further transformation during the cooling and maturation stages. At the end of composting, the organic matter content was 620 g / kg, which meets the requirement of the national standard NY / T 525-2021 for organic matter content (≥300 g / kg).

[0047] The specific working process of this utility model is as follows: Organic solid waste is mixed with thermophilic bacteria to form a fermentation pile. A blower supplies oxygen through ventilation pipes, and the pile temperature rises to 60-80℃. A box on top collects heat and gas. In the heat exchange system, internal pipes absorb heat from the pile, which is then used to heat residences and farms via water-medium pipes through a heat exchanger. Air-medium pipes supply heat to greenhouses and deliver CO2 and NH3-containing gaseous fertilizer. Sensors in the intelligent control system monitor the temperature, oxygen, and humidity of the fermentation pile in real time. The main control unit dynamically adjusts the system: when oxygen is insufficient, the blower is activated to supplement oxygen; when humidity is low, the valve is opened to add water; and when the temperature is too high, the ventilation volume is adjusted. The entire system forms a cycle, converting agricultural waste into organic fertilizer and heat energy for agricultural production and domestic heating. Intelligent control ensures efficient and stable fermentation, achieving synergy between the production end (organic fertilizer), the living end (heating), and the ecological end (waste disposal), thus achieving resource recycling and low-carbon goals.

[0048] When the sensor array detects that the oxygen content is below a preset value 'a', the main control unit controls the blower control valve to turn on the blower; when the oxygen content is above a preset value 'b', the main control unit controls the blower control valve to turn off the blower; when the moisture content is below a preset value 'c', the main control unit controls the return water control valve to turn on the return water; when the moisture content is above a preset value 'd', the main control unit controls the return water control valve to turn off the return water. The functions of the main control unit are implemented based on existing technology.

[0049] In a specific embodiment of this utility model, temperature sensors, oxygen sensors, and humidity sensors are connected to the main control unit, as well as the return water control valve and the blower control valve, via Internet of Things (IoT) technology to enable real-time monitoring and control of the reactor core temperature, oxygen content, and moisture content. Specifically, oxygen control is achieved by the main control unit adjusting the switching frequency of the blower control valve based on oxygen sensor data. The blower is activated when the oxygen content is below 15% (preset value a) and deactivated when it is above 20% (preset value b). Humidity control is achieved by the main control unit adjusting the switching frequency of the return water control valve based on humidity sensor data. The return water control valve is activated when the moisture content is below 40% (preset value c) and deactivated when it is above 60% (preset value d). This control of oxygen and humidity ensures the efficient degradation activity of thermophilic bacteria.

[0050] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A combined fertilizer and heat production system for rural heating, characterized in that, include: Ultra-high temperature composting fermentation system, heat exchange system, intelligent control system and rural energy network system; The ultra-high temperature composting fermentation system is used to transfer the large amount of heat generated during fermentation to the heat exchange system. The heat exchange system is used to recover the heat energy generated by the ultra-high temperature composting fermentation system and transmit it to the rural energy network system. The intelligent control system is connected to the ultra-high temperature composting fermentation system and the heat exchange system respectively, and is used to monitor and control the fermentation status of the ultra-high temperature composting fermentation system in real time, and to adjust the heat energy transmitted from the heat exchange system to the rural energy network system according to the fermentation status of the ultra-high temperature composting fermentation system.

2. The combined fertilizer and heat production system for rural heating according to claim 1, characterized in that, The ultra-high temperature composting fermentation system includes: a fermentation chamber, a fermentation pile, a top box, a blower, and ventilation pipes; The fermentation chamber is used to contain the fermentation pile and maintain thermal insulation and sealing. The fermentation pile is provided with a support structure on the outside, which separates a ventilation space on one side of the fermentation pile and a top box on the other side. The top box is positioned above the fermentation pile and connected to the heat exchange system, while the ventilation pipe is positioned in the ventilation space and connected to the blower.

3. A combined fertilizer and heat production system for rural heating according to claim 2, characterized in that, The heat exchange system includes: a heat exchanger, external piping for the first fermentation chamber, external piping for the second fermentation chamber, internal piping, and heating piping for the site; The heat exchanger is connected to the external pipelines of the first fermentation chamber, the external pipelines of the second fermentation chamber, and the site heating pipeline. The internal pipeline is arranged inside the fermentation chamber, with one end connected to the external pipeline of the first fermentation chamber and the other end connected to the external pipeline of the second fermentation chamber, forming a closed loop with the heat exchanger. The site heating pipeline is used to connect to the rural energy network system.

4. A combined fertilizer and heat production system for rural heating according to claim 3, characterized in that, The internal pipeline is equipped with a return water pipeline with nozzles for replenishing water to the fermentation pile.

5. A combined fertilizer and heat production system for rural heating according to claim 3, characterized in that, The intelligent control system includes a sensor group, a main control unit, a return water control valve, and a blower control valve; The sensor group, including a temperature sensor, a humidity sensor, and an oxygen sensor, is installed inside the fermentation pile to detect the temperature, humidity, and oxygen concentration inside the fermentation pile in real time and transmit the data to the main control unit. The main control unit controls the switching frequency of the blower control valve and the return water control valve based on the received data. The blower control valve and the return water control valve are used to control the blower and the internal pipeline of the return water, respectively, to regulate the oxygen content and humidity inside the fermentation pile.

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