Biochar heat exchange system for increasing temperature of greenhouse

Abstract

The invention discloses a biochar heat exchange system for greenhouse warming, which comprises a pair of biochar preparation devices arranged on the head and tail sides of the outside of a greenhouse; the heat exchange devices are arranged on the head side and the tail side of the exterior of the greenhouse, one heat exchange device is communicated with one charcoal preparation device on the side through a set of hot gas mixing pipelines and a set of cold gas mixing pipelines, the heat exchange devices are communicated through a set of upstream air pipelines and a set of downstream air pipelines, and the two sets of hot gas mixing pipelines and the two sets of cold gas mixing pipelines are arranged on the exterior of the greenhouse; and a group of ascending air pipelines and descending air pipelines penetrate through the interior of the greenhouse. Heat energy in the biochar preparation process can be used for increasing the temperature of the greenhouse, the energy utilization efficiency is improved, and the temperature increasing cost of the greenhouse is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of greenhouse environment control. More specifically, the present invention relates to a biochar heat exchange system for greenhouse warming. Background Art

[0002] In agricultural production, greenhouse cultivation is an important production method, which can create a suitable growth environment for crops, extend the growth cycle of crops, and improve the yield and quality of crops. However, the temperature control of the greenhouse environment has always been a key and challenging problem. In cold seasons or regions with low temperatures, a large amount of energy is required to warm the greenhouse to maintain a suitable temperature inside. Traditional greenhouse warming methods mainly include heating methods such as coal, oil, and gas, and these methods have many problems. First, the energy utilization efficiency is low, and a large amount of heat is wasted during transmission and use, resulting in high energy costs and increasing the production costs of farmers. Second, the combustion of these traditional energy sources will produce a large amount of pollutants, such as carbon dioxide, sulfur dioxide, nitrogen oxides, etc., causing serious pollution to the environment and not meeting the requirements of sustainable development. In addition, although some electric heating methods are relatively clean, the electricity cost is high, and in some regions with unstable power supply, power outages and other problems may also occur, affecting the normal production of the greenhouse. There are also some methods of using solar energy for warming, which are greatly affected by weather and seasons. In cloudy days or in winter with short sunshine hours, the warming effect is often not ideal.

[0003] In terms of biochar preparation, current technologies mainly focus on the production of biochar, and the large amount of heat energy generated during the biochar preparation process has not been fully and effectively utilized. This heat energy is usually discharged into the environment in the form of high-temperature waste gas, not only causing waste of energy, but also possibly generating heat pollution to the surrounding environment. How to combine the heat energy in the biochar preparation process with the greenhouse warming demand and develop an efficient, environmentally friendly, and economical greenhouse warming system is the problem that this application endeavors to solve. In previous attempts, due to difficulties in aspects such as the matching between the biochar preparation device and the greenhouse environment, heat exchange efficiency, and system stability, it has been difficult to achieve ideal warming effects and energy utilization efficiencies. Summary of the Invention

[0004] The present invention provides a biochar heat exchange system for greenhouse warming, which can utilize the heat energy generated during the biochar preparation process to warm the greenhouse, improve energy utilization efficiency, and reduce the cost of greenhouse warming.

[0005] To achieve these and other advantages in accordance with the present invention, there is provided a biochar heat exchange system for greenhouse warming, comprising: A pair of biochar preparation devices (1), which are arranged on both the head and tail sides outside the greenhouse (7); A pair of heat exchange devices (2) are arranged on both the head and tail sides outside the greenhouse (7). One heat exchange device (2) is connected to a biochar production device (1) on this side through a group of hot mixing gas pipelines (3) and cold mixing gas pipelines (4). The pair of heat exchange devices (2) are connected through a group of upward air pipelines (5) and downward air pipelines (6). The two groups of hot mixing gas pipelines (3) and cold mixing gas pipelines (4) are arranged outside the greenhouse (7), and a group of upward air pipelines (5) and downward air pipelines (6) pass through the inside of the greenhouse (7); Among them, the hot mixing gas of the biochar production device (1) enters the heat exchange device (2) through the hot mixing gas pipeline (3), is cooled after heat exchange, and then flows back to the biochar production device (1) through the cold mixing gas pipeline (4) for purification and recovery. The cold air passing through the greenhouse (7) enters one heat exchange device (2) through the upward air pipeline (5) or downward air pipeline (6), is heated after heat exchange, and then passes through the greenhouse (7) again through the downward air pipeline (6) or upward air pipeline (5) and enters the other heat exchange device (2).

[0006] Preferably, the heat exchange device (2) includes: A double heat storage chamber, which includes a first heat storage chamber (21) and a second heat storage chamber (25), and ceramic heat storage bodies are filled inside the first heat storage chamber (21) and the second heat storage chamber (25); A valve assembly, which includes a first valve assembly and a second valve assembly. The switching valve controls the flow direction of the air flow to realize the switching of the cycle of heating the first heat storage chamber (21) with hot mixing gas while cooling the second heat storage chamber (25) with cold air, and cooling the first heat storage chamber (21) with cold air while heating the second heat storage chamber (25) with hot mixing gas.

[0007] Preferably, the first heat storage chamber (21) has a first ventilation opening (211) and a second ventilation opening (212); The second heat storage chamber (25) has a third ventilation opening (251) and a fourth ventilation opening (252); The first valve assembly includes a first inner chamber (22) and a first outer chamber (23) arranged coaxially. A first valve rod (24) is provided inside the first inner chamber (22). Along the valve rod advancing direction on the first valve rod (24), there are successively arranged a first valve rod end plate (241), a first valve disc (242), a second valve disc (243), and a third valve disc (244), which divide the first inner chamber (22) into independent first space (221), second space (222), third space (223), and fourth space (224). Along the valve rod advancing direction, the first inner chamber (22) is successively provided with a first through hole (225), a cold air inlet (226), a first inner chamber ventilation port (227), a cold mixture outlet (228), and a second through hole (229). The first through hole (225) and the second through hole (229) communicate with the first outer chamber (23). The first inner chamber ventilation port (227) communicates with the first ventilation port (211). The first outer chamber (23) is provided with a first outer chamber ventilation port (231), and the first outer chamber ventilation port (231) communicates with the fourth ventilation port (252); The second valve assembly includes a second inner chamber (26) and a second outer chamber (27) arranged coaxially. A second valve rod (28) is provided inside the second inner chamber (26). Along the valve rod advancing direction on the second valve rod (28), there are successively arranged a second valve rod end plate (281), a fourth valve disc (282), a fifth valve disc (283), and a sixth valve disc (284), which divide the second inner chamber (26) into independent fifth space (261), sixth space (262), seventh space (263), and eighth space (264). Along the valve rod advancing direction, the second inner chamber (26) is successively provided with a third through hole (265), a hot mixture inlet (266), a second inner chamber ventilation port (267), a hot air outlet (268), and a fourth through hole (269). The third through hole (265) and the fourth through hole (269) communicate with the second outer chamber (27). The second inner chamber ventilation port (267) communicates with the second ventilation port (212). The second outer chamber (27) is provided with a second outer chamber ventilation port (271), and the first outer chamber ventilation port (231) communicates with the third ventilation port (251); When the switching valve is switched to the first state, that is, when the hot mixed gas heats the first regenerator (21) while the cold air cools the second regenerator (25), the first valve stem (24) retracts to the first position and the second valve stem (28) advances to the third position. The first through hole (225) and the cold air inlet (226) are located in the second space (222), the first inner cavity ventilation port (227) and the cold mixed gas outlet (228) are located in the third space (223), the second through hole (229) is located in the fourth space (224), the third through hole (265) is located in the fifth space (261), the hot mixed gas inlet (266) and the second inner cavity ventilation port (267) are located in the sixth space (262), and the hot air outlet (268) and the fourth through hole (269) are located in the seventh space (263). When the switching valve is switched to the second state, that is, when the cold air cools the first regenerator (21) while the hot mixed gas heats the second regenerator (25), the first valve stem (24) advances to the second position and the second valve stem (28) retracts to the fourth position. The first through hole (225) is located in the first space (221), the cold air inlet (226) and the first inner cavity ventilation port (227) are located in the second space (222), the cold mixed gas outlet (228) and the second through hole (229) are located in the third space (223), the third through hole (265) and the hot mixed gas inlet (266) are located in the sixth space (262), the second inner cavity ventilation port (267) and the hot air outlet (268) are located in the seventh space (263), and the fourth through hole (269) is located in the eighth space (264).

[0008] Preferably, the heat exchange device (2) further includes a purging system for purging the double regenerator with inert gas.

[0009] Preferably, the heat exchange device (2) further includes a PLC for synchronously controlling the advancing and retracting movements of the first valve stem (24) and the second valve stem (28) by using cylinders. When the switching valve is switched to the first state, the first valve stem (24) retracts to the first position and the second valve stem (28) advances to the third position. When the switching valve is switched to the second state, the first valve stem (24) advances to the second position and the second valve stem (28) retracts to the fourth position.

[0010] Preferably, the PLC is set with a switching time and a purging time. When the first regenerator (21) is in the heating state and the second regenerator (25) is in the cooling state, when the set switching time is reached, the PLC controls the valve assembly to stop admitting gas, and the PLC controls the purging of inert gas. When the set purging time is reached, the PLC controls the purging system to stop operating, completing the purging process. The PLC controls the valve assembly to switch the valves, controlling the flow direction of the gas, so that the first regenerator (21) is in the cooling state and the second regenerator (25) is in the heating state.

[0011] The present invention has at least the following beneficial effects: First, through the arrangement of two groups of hot gas mixing pipelines (3), cold gas mixing pipelines (4) and a group of air pipelines, the hot mixed gas of the biochar preparation device (1) enters the heat exchange device (2) through the hot gas mixing pipeline (3) to be cooled and then flows back through the cold gas mixing pipeline (4) for purification and recovery. The cold air in the greenhouse (7) enters the heat exchange device (2) through the air pipeline to be heated and then passes through the greenhouse (7) again. The heat energy in the biochar preparation process is used to increase the temperature of the greenhouse (7), transferring the heat of the hot mixed gas to the cold air in the greenhouse (7), improving the energy utilization efficiency, reducing the cost of increasing the temperature of the greenhouse (7), realizing the effective utilization of heat energy in the biochar preparation process, and having good economic and environmental benefits.

[0012] Second, the design of the double regenerator and the valve assembly in the present invention realizes the periodic heat exchange between the hot mixed gas and the cold air. The ceramic regenerator can efficiently store and release heat, improving the heat exchange efficiency. Through the switching of the valves, the hot mixed gas and the cold air can be alternately heated and cooled in different regenerators, ensuring the continuous and stable operation of the system.

[0013] Third, through the position control of the valve stem, the present invention realizes the connection and partition of different spaces, ensuring that the hot mixed gas and the cold air can flow and exchange heat accurately under different working conditions, guaranteeing the reliability and stability of the system, and improving the heat exchange effect.

[0014] Fourth, the design of the purging system in the present invention can effectively solve the problem of gas residue in the double regenerator. Using inert gas for purging can prevent the mixing of different gases, ensuring environmental protection and no pollution. Fifth, the present invention uses the PLC and the cylinder to synchronously control the forward and backward movements of the valve stem, improving the accuracy and stability of valve switching. The automated control method reduces the errors and labor intensity of manual operation, enabling the system to operate more precisely according to the set state, and improving the operation efficiency and reliability of the system.

[0015] Sixthly, by setting the switching time and purging time through the PLC, the present invention can automatically perform valve switching and purging operations according to the set time, ensuring the continuity and stability of the heat exchange process, enabling the system to operate more precisely according to the set state, and improving the automation level of the system.

[0016] Other advantages, objectives, and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a technical solution of the present invention; Figure 2 is a schematic structural diagram of the heat exchange device when the valve of a technical solution of the present invention is switched to the first state; Figure 3 is a schematic structural diagram of the heat exchange device when the valve of a technical solution of the present invention is switched to the second state. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The following further describes the present invention in detail with reference to the drawings so that those skilled in the art can implement it according to the description in the specification.

[0019] It should be understood that the terms such as "having", "comprising", and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0020] It should be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified; in the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "set" should be understood in a broad sense. For example, they can be fixedly connected and set, or detachably connected and set, or integrally connected and set. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. The orientation or positional relationship indicated by the terms "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0021] As Figure 1 shown, the present invention provides a biochar heat exchange system for greenhouse heating, including: A pair of biochar preparation devices (1) are arranged on both the head and tail sides outside the greenhouse (7); A pair of heat exchange devices (2) are arranged on both the head and tail sides outside the greenhouse (7). One heat exchange device (2) is connected to one biochar preparation device (1) on this side through a group of hot mixing gas pipelines (3) and cold mixing gas pipelines (4). The pair of heat exchange devices (2) are connected through a group of upward air pipelines (5) and downward air pipelines (6). The two groups of hot mixing gas pipelines (3) and cold mixing gas pipelines (4) are arranged outside the greenhouse (7), and a group of upward air pipelines (5) and downward air pipelines (6) pass through the inside of the greenhouse (7); Among them, the hot mixing gas of the biochar preparation device (1) enters the heat exchange device (2) through the hot mixing gas pipeline (3), is cooled after heat exchange, and then flows back to the biochar preparation device (1) through the cold mixing gas pipeline (4) for purification and recovery. The cold air passing through the greenhouse (7) enters one heat exchange device (2) through the upward air pipeline (5) or downward air pipeline (6), is heated after heat exchange, and then passes through the greenhouse (7) again through the downward air pipeline (6) or upward air pipeline (5) and enters another heat exchange device (2).

[0022] In the above technical solution, through the setting of two groups of hot mixing gas pipelines (3) and cold mixing gas pipelines (4) and a group of air pipelines, the hot mixing gas of the biochar preparation device (1) enters the heat exchange device (2) through the hot mixing gas pipeline (3), is cooled and then flows back through the cold mixing gas pipeline (4) for purification and recovery. The cold air in the greenhouse (7) enters the heat exchange device (2) through the air pipeline, is heated and then passes through the greenhouse (7) again. The heat energy in the biochar preparation process is used to increase the temperature of the greenhouse (7), so that the heat of the hot mixing gas is transferred to the cold air in the greenhouse (7), improving the energy utilization efficiency, reducing the cost of increasing the temperature of the greenhouse (7), realizing the effective utilization of heat energy in the biochar preparation process, and having good economic and environmental benefits.

[0023] In practical applications, first, a pair of biochar preparation devices (1) and a pair of heat exchange devices (2) are respectively installed on both ends of the greenhouse (7) from beginning to end. The biochar preparation device (1) can be a common biomass pyrolysis device, such as a fixed-bed pyrolysis furnace or a fluidized-bed pyrolysis furnace. Taking the fixed-bed pyrolysis furnace as an example, biomass raw materials (such as straw, wood chips, etc.) are loaded into the furnace, and pyrolysis reactions are carried out under anaerobic or oxygen-limited conditions to produce biochar and hot gas mixture. The hot gas mixture pipeline (3) and the cold gas mixture pipeline (4) are made of high-temperature resistant and corrosion-resistant metal pipes, such as stainless steel pipes, and heat insulation materials, such as rock wool or glass wool, are wrapped outside the pipes to reduce heat loss during transmission. The air pipeline is made of materials with a certain strength, such as double-layer hollow PVC pipes, to ensure the smooth flow of air. When the biochar preparation device (1) starts to work, the temperature of the generated hot gas mixture is usually between 300 - 800 °C, and it enters the heat exchange device (2) through the hot gas mixture pipeline (3). In the heat exchange device (2), the hot gas mixture exchanges heat with cold air, and after the temperature drops, it returns to the biochar preparation device (1) through the cold gas mixture pipeline (4) for purification and recovery. The cold air in the greenhouse (7) enters a heat exchange device (2) through the upward air pipeline (5) or the downward air pipeline (6). After being heated and raised in temperature in the heat exchange device (2), it passes through the downward air pipeline (6) or the upward air pipeline (5) again to pass through the greenhouse (7) again, providing heat for the greenhouse (7). During installation, it is necessary to ensure the tight connection of the pipelines. Welding or flange connection methods can be used, and sealant is used for sealing to prevent air leakage. At the same time, regularly inspect and maintain the biochar preparation device (1) and the heat exchange device (2), such as checking whether the furnace lining of the pyrolysis furnace is damaged and whether the pipelines are corroded, to ensure the normal operation of the system.

[0024] The traditional greenhouse (7) heating method has low energy utilization efficiency, high cost, and pollutes the environment. At the same time, the heat energy in the biochar preparation process is not effectively utilized. The system constructed by the above technical solution combines the biochar preparation device (1) with the greenhouse (7) heating to achieve efficient utilization of heat energy, reduce the greenhouse (7) heating cost, and reduce environmental pollution.

[0025] In another technical solution, the heat exchange device (2) includes: A double heat storage chamber, which includes a first heat storage chamber (21) and a second heat storage chamber (25). The first heat storage chamber (21) and the second heat storage chamber (25) are filled with ceramic heat storage bodies; A valve assembly, which includes a first valve assembly and a second valve assembly. The switching valve controls the flow direction of the air flow to realize the switching of the heating cycle of the hot gas mixture to the first heat storage chamber (21) while the cold air cools the second heat storage chamber (25), and the heating cycle of the cold air to the first heat storage chamber (21) while the hot gas mixture heats the second heat storage chamber (25).

[0026] In the above technical solution, the design of double regenerators and valve assemblies realizes the periodic heat exchange between hot mixed gas and cold air. The ceramic regenerator can efficiently store and release heat, improving the heat exchange efficiency. By switching the valves, the hot mixed gas and cold air can be alternately heated and cooled in different regenerators, ensuring the continuous and stable operation of the system.

[0027] For the double regenerators in the heat exchange device (2), ceramic regenerators with high temperature resistance and good heat storage performance are selected and filled in the first regenerator (21) and the second regenerator (25). The ceramic regenerator can be made into honeycomb or spherical shapes to increase the contact area with the gas and improve the heat storage and heat exchange efficiency. The manufacturing material of the valve assembly needs to be a metal with high temperature resistance and wear resistance, such as chromium molybdenum alloy steel. After installation, commissioning is required to ensure that the switching valve can accurately control the flow direction of the air flow, realizing the switching of the cycle of heating the first regenerator (21) with hot mixed gas while cooling the second regenerator (25) with cold air, and cooling the first regenerator (21) with cold air while heating the second regenerator (25) with hot mixed gas. The accuracy of valve switching and the heat exchange effect can be verified by installing pressure sensors and temperature sensors in the pipeline to monitor the pressure and temperature changes of the air flow in real time.

[0028] On the basis of realizing the combination of the biochar preparation device (1) and the greenhouse (7) for temperature increase, an efficient heat exchange device (2) is required to complete the heat exchange process. The above technical solution realizes the periodic heat exchange between hot mixed gas and cold air by setting double regenerators and valve assemblies, improving the heat exchange efficiency.

[0029] As Figures 2-3 shown, in another technical solution, the first regenerator (21) has a first ventilation port (211) and a second ventilation port (212); the second regenerator (25) has a third ventilation port (251) and a fourth ventilation port (252); The first valve assembly includes a first inner chamber (22) and a first outer chamber (23) arranged coaxially. A first valve rod (24) is provided inside the first inner chamber (22). Along the valve rod traveling direction on the first valve rod (24), there are successively arranged a first valve rod end plate (241), a first valve plate (242), a second valve plate (243), and a third valve plate (244), which divide the first inner chamber (22) into independent first space (221), second space (222), third space (223), and fourth space (224). Along the valve rod traveling direction, the first inner chamber (22) successively has a first through hole (225), a cold air inlet (226), a first inner chamber ventilation port (227), a cold mixture outlet (228), and a second through hole (229). The first through hole (225) and the second through hole (229) communicate with the first outer chamber (23). The first inner chamber ventilation port (227) communicates with the first ventilation port (211). The first outer chamber (23) is provided with a first outer chamber ventilation port (231), and the first outer chamber ventilation port (231) communicates with the fourth ventilation port (252); The second valve assembly includes a second inner chamber (26) and a second outer chamber (27) arranged coaxially. A second valve rod (28) is provided inside the second inner chamber (26). Along the valve rod traveling direction on the second valve rod (28), there are successively arranged a second valve rod end plate (281), a fourth valve plate (282), a fifth valve plate (283), and a sixth valve plate (284), which divide the second inner chamber (26) into independent fifth space (261), sixth space (262), seventh space (263), and eighth space (264). Along the valve rod traveling direction, the second inner chamber (26) successively has a third through hole (265), a hot mixture inlet (266), a second inner chamber ventilation port (267), a hot air outlet (268), and a fourth through hole (269). The third through hole (265) and the fourth through hole (269) communicate with the second outer chamber (27). The second inner chamber ventilation port (267) communicates with the second ventilation port (212). The second outer chamber (27) is provided with a second outer chamber ventilation port (271), and the first outer chamber ventilation port (231) communicates with the third ventilation port (251); Among them, when the switching valve is in the first state, that is, when the hot mixture heats the first regenerator (21) and at the same time the cold air cools the second regenerator (25), the first valve stem (24) retracts to the first position and the second valve stem (28) advances to the third position. The first through hole (225) and the cold air inlet (226) are located in the second space (222), the first inner cavity ventilation port (227) and the cold mixture outlet (228) are located in the third space (223), the second through hole (229) is located in the fourth space (224), the third through hole (265) is located in the fifth space (261), the hot mixture inlet (266) and the second inner cavity ventilation port (267) are located in the sixth space (262), and the hot air outlet (268) and the fourth through hole (269) are located in the seventh space (263). When the switching valve is in the second state, that is, when the cold air cools the first regenerator (21) and at the same time the hot mixture heats the second regenerator (25), the first valve stem (24) advances to the second position and the second valve stem (28) retracts to the fourth position. The first through hole (225) is located in the first space (221), the cold air inlet (226) and the first inner cavity ventilation port (227) are located in the second space (222), the cold mixture outlet (228) and the second through hole (229) are located in the third space (223), the third through hole (265) and the hot mixture inlet (266) are located in the sixth space (262), the second inner cavity ventilation port (267) and the hot air outlet (268) are located in the seventh space (263), and the fourth through hole (269) is located in the eighth space (264).

[0030] In the above technical solution, through the position control of the valve stem, the connection and isolation of different spaces are realized, ensuring that the hot mixture and the cold air can flow and exchange heat accurately under different working states, guaranteeing the reliability and stability of the system, and improving the heat exchange effect.

[0031] When constructing the specific structure of the double regenerator and the valve assembly, the vent positions of the first regenerator (21) and the second regenerator (25) need to be determined according to the best effect of gas flow and heat exchange. For example, the first vent (211) and the second vent (212) should be respectively arranged on the opposite sides of the first regenerator (21), close to the bottom and the top, and the third vent (251) and the fourth vent (252) should be respectively arranged on the opposite sides of the second regenerator (25), close to the bottom and the top, so as to promote the full flow of gas in the chamber. When processing the components of the first valve assembly and the second valve assembly, the dimensional accuracy should be ensured. During the assembly process, the valve plates on the first valve stem (24) and the second valve stem (28) are installed in sequence according to the design requirements, and it is ensured that they can move smoothly in the first inner cavity (22) and the second inner cavity (26), and the sealing effect with the first inner cavity (22) and the second inner cavity (26) is ensured. The first valve stem end plate (241) and the second valve stem end plate (281) are the power ends. By pushing the first valve stem end plate (241) and the second valve stem end plate (281), the first valve stem (24) and the second valve stem (28) move forward, and by pulling the first valve stem end plate (241) and the second valve stem end plate (281), the first valve stem (24) and the second valve stem (28) retract.

[0032] When the first valve rod (24) is in the first position, the first through hole (225) and the cold air inlet (226) are located in the second space (222). Cold air enters the first inner cavity (22) from the cold air inlet (226), enters the first outer cavity (23) through the first through hole (225), and enters the second heat storage chamber (25) through the first outer cavity ventilation port (231). That is, cold air enters the second heat storage chamber (25). The first inner cavity ventilation port (227) and the cold mixed gas outlet (228) are located in the third space (223). The cold mixed gas enters the first inner cavity (22) from the first heat storage chamber (21) via the first inner cavity ventilation port (227) and is discharged from the cold mixed gas outlet (228) and flows back to the biochar preparation device (1). That is, the cold mixed gas in the first heat storage chamber (21) flows back to the biochar preparation device (1). At the same time, when the second valve rod (28) is in the third position, the hot mixed gas inlet (266) and the second inner cavity ventilation port (267) are located in the sixth space (262). The hot mixed gas enters the second inner cavity (26) from the hot mixed gas inlet (266) and enters the first heat storage chamber (21) through the second inner cavity ventilation port (267). That is, the hot mixed gas enters the first heat storage chamber (21). The hot air outlet (268) and the fourth through hole (269) are located in the seventh space (263). The hot air enters the second outer cavity (27) from the second heat storage chamber (25) via the second outer cavity ventilation port (271), enters the second inner cavity (26) through the fourth through hole (269), and is discharged to the upper air pipeline (5) or the lower air pipeline (6) and enters the interior of the greenhouse (7). That is, the hot air enters the greenhouse (7). When the valve is in the first state, the first valve rod (24) is in the first position and the second valve rod (28) is in the third position, realizing the heating of the first heat storage chamber (21) by the hot mixed gas and the cooling of the second heat storage chamber (25) by the cold air.

[0033] When the first valve stem (24) is in the second position, the cold air inlet (226) and the first inner chamber ventilation port (227) are located in the second space (222). Cold air enters the first heat storage chamber from the cold air inlet (226) via the first inner chamber ventilation port (227), that is, cold air enters the first heat storage chamber (21). The cold mixed gas outlet (228) and the second through hole (229) are located in the third space (223). The cold mixed gas enters the outer first inner chamber from the second heat storage chamber (25) via the first outer chamber ventilation port, enters the first inner chamber (22) through the second through hole (229), and is discharged from the cold mixed gas outlet (228) and flows back to the biochar preparation device (1), that is, the cold mixed gas in the second heat storage chamber (25) flows back to the biochar preparation device (1). At the same time, when the second valve stem (28) is in the fourth position, the hot mixed gas inlet (266) and the third through hole (265) are located in the sixth space (262). The hot mixed gas enters the second inner chamber (26) from the hot mixed gas inlet (266), enters the second outer chamber (27) through the third through hole (265), and enters the second heat storage chamber (25) through the second outer chamber ventilation port (271), that is, the hot mixed gas enters the second heat storage chamber (25). The second inner chamber ventilation port (267) and the hot air outlet (268) are located in the seventh space (263). The hot air enters the second inner chamber (26) from the first heat storage chamber (21) via the second inner chamber ventilation port (267), and is discharged from the hot air outlet (268) into the upward air pipeline (5) or the downward air pipeline (6) and enters the interior of the greenhouse (7), that is, the hot air enters the greenhouse (7). When the valve is in the second state, the first valve stem (24) is in the second position and the second valve stem (28) is in the fourth position, realizing the cooling of the first heat storage chamber (21) by cold air and the heating of the second heat storage chamber (25) by hot mixed gas at the same time.

[0034] After the installation is completed, the valve assembly is debugged. By manual operation or with the help of control equipment, the process of simulating the valve switching to the first state and the second state is carried out to check whether the connection of each space meets the design requirements. At the same time, tracer gas is used to test the flow path of the gas in the heat storage chamber and the valve assembly under different states to verify whether it is consistent with the theoretical design. If there is a deviation, it is adjusted in time. The above technical solution further clarifies the specific structure and working state of the double heat storage chamber and the valve assembly, ensuring that the hot mixed gas and cold air can accurately flow and exchange heat in the heat storage chamber under different states, and guaranteeing the stable operation of the system.

[0035] In another technical solution, the heat exchange device (2) further includes a purging system for purging the double regenerators with inert gas. During the operation of the double regenerators, problems such as gas residue may occur, affecting the heat exchange effect and the stability of the system. The above technical solution solves the problem of gas residue by setting up a purging system to purge the double regenerators with inert gas. Purging with inert gas can prevent the mixing of different gases and ensure environmental protection and no pollution.

[0036] In another technical solution, the heat exchange device (2) further includes a PLC for synchronously controlling the forward and backward movements of the first valve stem (24) and the second valve stem (28) by using a cylinder. When the valve is switched to the first state, the first valve stem (24) retracts to the first position and the second valve stem (28) moves forward to the third position. When the valve is switched to the second state, the first valve stem (24) moves forward to the second position and the second valve stem (28) retracts to the fourth position. In order to achieve accurate switching of the valve assembly, a reliable control method is required. The above technical solution uses a PLC and a cylinder to synchronously control the forward and backward movements of the valve stems, ensuring the accuracy and stability of valve switching. The automated control method reduces the errors and labor intensity of manual operation, enabling the system to operate more precisely according to the set state and improving the operation efficiency and reliability of the system.

[0037] In another technical solution, the PLC sets a switching time and a purging time. When the first regenerator (21) is in the heating state and the second regenerator (25) is in the cooling state, when the set switching time is reached, the PLC controls the valve assembly to stop admitting gas, and the PLC controls the purging of inert gas. When the set purging time is reached, the PLC controls the purging system to stop operating, completing the purging process. The PLC controls the valve assembly to switch the valve and control the flow direction of the gas, so that the first regenerator (21) is in the cooling state and the second regenerator (25) is in the heating state. In order to enable the system to operate automatically and orderly, it is necessary to reasonably set the switching time and the purging time. The above technical solution sets the switching time and the purging time through the PLC, and can automatically perform valve switching and purging operations according to the set time, ensuring the continuity and stability of the heat exchange process, enabling the system to operate more precisely according to the set state, and improving the automation degree and operation efficiency of the system.

[0038] In another technical solution, it further includes: Pressure sensors are arranged in the first regenerator (21) and the second regenerator (25) to collect the pressure in the regenerator in real time. It is necessary to ensure that the installation position of the sensors will not affect the normal gas flow and can accurately reflect the pressure change in the regenerator. At least 3 temperature sensors are evenly arranged along the height direction of the regenerative material, for example, arranged every 0.5 m, to collect temperature data at different height positions in real time and calculate the temperature gradient value; The PLC continuously analyzes the collected temperature and pressure data. When the temperature gradient between adjacent temperature sensors changes by more than 5 °C / m within 10 minutes, and the pressure sensor detects that the pressure in the regenerator changes by more than ±500 Pa within 5 minutes, the PLC determines that there may be a problem of local blockage of the regenerative material or gas leakage. At this time, the PLC immediately issues an audible and visual warning to the operator, and at the same time automatically switches the heat exchange system to the standby operation mode. In this standby operation mode, by adjusting the flow regulating valve on the intake pipe, the intake flow is reduced to 50% of the normal flow to reduce the system load, avoid further expansion of the fault, and start the fault troubleshooting program. The valves of each intake branch are closed in turn to detect the pressure and temperature changes and locate the fault position. By real-time monitoring of the temperature and pressure changes in the regenerator, potential problems such as local blockage of the regenerative material or gas leakage can be detected in time, and an early warning can be issued quickly to avoid further deterioration of the fault, ensuring the safety of the operator and the stable operation of the equipment. After determining a fault, automatically switching to the standby operation mode and reducing the intake flow can reduce the system load, prevent the expansion of the fault, reduce the maintenance cost and production losses. At the same time, the fault position can be quickly located through the fault troubleshooting program, shortening the maintenance time.

[0039] In another technical solution, the PLC has the functions of optimizing the dynamic switching time and the purging time: At least 5 temperature sensors are arranged in the greenhouse (7) to collect the greenhouse temperature in real time and calculate the greenhouse temperature change rate; When the average temperature drop value T of the greenhouse (7) within 1 h a exceeds 2 °C, and the average temperature T of the first regenerator (21) or the second regenerator (25) b is higher than the set regenerator threshold value T o , the PLC automatically shortens the heating duration t of the first regenerator (21) and the second regenerator (25) 减少 , which is calculated according to the temperature drop rate and the biochar heat storage situation through the following formula: t 减少 (min) = (T a - 2 °C) × 10 + (T b - T o ) × 2 Dynamically adjusting the heating duration based on the real-time data of the greenhouse temperature and the heat storage chamber temperature can avoid overheating, apply thermal energy to greenhouse warming more precisely, and improve the energy utilization efficiency.

[0040] Gas sensors are arranged in the first heat storage chamber (21) and the second heat storage chamber (25). Thermal conductivity gas sensors are used with an accuracy of ±5%. The gas sensors are connected to a gas composition analyzer, which can detect main components such as CO2, O2, N2, etc., with an accuracy of up to ±1%. If the residual gas volume exceeds 20% of the evacuation volume during normal operation and the content of harmful gas (CO) exceeds the safety threshold, the PLC automatically extends the purging time by 5 - 10 min. While ensuring the purging effect, it avoids energy waste caused by over-purging. Automatically adjusting the purging time according to the gas composition detection results can not only ensure the effective removal of residual gas and harmful gas in the heat storage chamber, guarantee the normal operation of the system and environmental safety, but also avoid energy waste caused by over-purging.

[0041] Furthermore, introducing a fuzzy control algorithm, the PLC takes multiple variables such as the greenhouse temperature change rate, the heat storage chamber temperature change curve (collecting temperature data at 10 - minute intervals and fitting the curve), the intake air flow rate (monitored in real time by a mass flow meter with an accuracy of ±1%), and the pressure (monitored in real time by a pressure transmitter with an accuracy of ±0.5%) as input variables, and sets fuzzy language variables, such as "fast", "medium", "slow" for the greenhouse temperature change rate, and "rapid rise", "stable", "rapid decline" for the heat storage chamber temperature change curve, etc. Through a pre-established rule base containing no less than 20 fuzzy inference rules, such as when the greenhouse temperature change rate is "fast" and the heat storage chamber temperature change curve is "stable", appropriately shorten the switching time, dynamically determine the optimal switching time and purging time. The PLC updates the fuzzy inference calculation every 15 min according to the latest collected data, making the system always operate in a highly efficient state.

[0042] 1. Determine the input and output variables Input variables: Greenhouse temperature change rate: denoted as V , with the unit of °C / h, reflecting the speed of greenhouse temperature change.

[0043] Characteristics of the heat storage chamber temperature change curve: denoted as K , obtained by fitting and analyzing the temperature data collected at 10 - minute intervals, characterizing the temperature change trend of the heat storage chamber.

[0044] Intake air flow deviation: denoted as Δ F , the difference between the actual intake air flow and the set intake air flow, with the unit of m³ / h, reflecting the stability of the intake air flow.

[0045] Output variables: Switching time adjustment amount: denoted as Δ t , with the unit of min, used to adjust the switching time of the first regenerator and the second regenerator.

[0046] 2. Define fuzzy language variables and membership functions Greenhouse temperature change rate: Slow (S): The membership function adopts a trapezoidal distribution. For example, when it is less than or equal to 1 °C / h, the membership degree is 1; it linearly decreases to 0 between 1 - 2 °C / h.

[0047] Medium (M): The membership function is a triangular distribution. Between 1 - 3 °C / h, the membership degree is 1 at 2 °C / h in the middle, and gradually decreases to 0 at both ends.

[0048] Fast (F): The membership function adopts a trapezoidal distribution. When it is greater than or equal to 3 °C / h, the membership degree is 1; it linearly increases to 1 between 2 - 3 °C / h.

[0049] Characteristics of the regenerator temperature change curve: Rise fast (RU): Judged according to the slope of the curve fitting. When the slope is greater than a certain set value (such as 0.5 °C / 10 min), the membership degree is 1; it linearly decreases to 0 within a certain range (such as 0.3 - 0.5 °C / 10 min).

[0050] Steady (S): The slope is between (-0.1) - 0.1 °C / 10 min, and the membership degree is 1; it linearly decreases to 0 outside this range.

[0051] Drop fast (RD): When the slope is less than a certain set value (such as -0.5 °C / 10 min), the membership degree is 1; it linearly increases to 1 within a certain range (such as (-0.5) - (-0.3) °C / 10 min).

[0052] Intake air flow deviation: Negative large (NB): When the flow deviation is less than -10 m³ / h, the membership degree is 1; it linearly decreases to 0 between (-10) - (-5) m³ / h.

[0053] Negative small (NS): Between (-5) - 0 m³ / h, the membership function is a triangular distribution, and the membership degree is 1 at -2.5 m³ / h, and decreases to 0 at both ends.

[0054] Zero (Z): The flow deviation is between (-1) - 1 m³ / h, and the membership degree is 1; it linearly decreases to 0 outside this range.

[0055] Positive small (PS): Between 0 - 5 m³ / h, the membership function is a triangular distribution, and the membership degree is 1 at 2.5 m³ / h, and decreases to 0 at both ends.

[0056] Zhengda (PB): When the flow deviation is greater than 10 m³ / h, the membership degree is 1; it increases linearly to 1 between 5 - 10 m³ / h.

[0057] Switching time adjustment amount: Substantially shortened (SS): When the adjustment amount is less than -10 min, the membership degree is 1; it decreases linearly to 0 between (-10) - (-5) min.

[0058] Shortened (S): Between (-5) - 0 min, the membership function is triangular distribution, the membership degree is 1 at -2.5 min, and decreases to 0 at both ends.

[0059] Unchanged (Z): When the adjustment amount is between (-1) - 1 min, the membership degree is 1; it decreases linearly to 0 outside this range.

[0060] Extended (L): Between 0 - 5 min, the membership function is triangular distribution, the membership degree is 1 at 2.5 min, and decreases to 0 at both ends.

[0061] Substantially extended (LL): When the adjustment amount is greater than 10 min, the membership degree is 1; it increases linearly to 1 between 5 - 10 min.

[0062] 3. Establish a fuzzy inference rule base According to the system operation experience and actual requirements, establish no less than 20 fuzzy inference rules. For example: If it is fast (F) and stable (S) and zero (Z), then it is substantially shortened (SS).

[0063] If it is medium (M) and rising fast (RU) and positive small (PS), then it is shortened (S).

[0064] If it is slow (S) and falling fast (RD) and negative large (NB), then it is substantially extended (LL).

[0065] By introducing the fuzzy control algorithm, comprehensively considering multiple variables for dynamic inference and calculation, the system can automatically adjust the switching time and purging time according to the actual operation conditions, always maintaining an efficient operation state, and improving the intelligent level and adaptability of the system.

[0066] The equipment quantity and processing scale described here are used to simplify the description of the present invention. The application, modification, and variation of the present invention are obvious to those skilled in the art.

[0067] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those skilled in the art, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. A biochar heat exchange system for greenhouse warming, characterized in that: include: A pair of biochar preparation devices (1) are arranged at the front and rear sides of the outside of the greenhouse (7); A pair of heat exchange devices (2) are arranged at both ends of the greenhouse (7), one heat exchange device (2) is connected to a biochar preparation device (1) on the side through a set of hot mixed air pipelines (3) and cold mixed air pipelines (4), and the pair of heat exchange devices (2) are connected through a set of ascending air pipelines (5) and descending air pipelines (6), the two sets of hot mixed air pipelines (3) and cold mixed air pipelines (4) are arranged outside the greenhouse (7), and one set of ascending air pipelines (5) and descending air pipelines (6) pass through the interior of the greenhouse (7); The hot mixed air of the biochar preparation device (1) enters the heat exchange device (2) through the hot mixed air pipeline (3), and after heat exchange and temperature reduction, flows back to the biochar preparation device (1) through the cold mixed air pipeline (4) for purification and recovery. The cold air after passing through the greenhouse (7) enters one heat exchange device (2) through the ascending air pipeline (5) or the descending air pipeline (6), and after heat exchange and temperature increase, passes through the greenhouse (7) again through the descending air pipeline (6) or the ascending air pipeline (5) and enters another heat exchange device (2).

2. The biochar heat exchange system for greenhouse warming according to claim 1, characterized in that: The heat exchange device (2) comprises: A double heat storage chamber, comprising a first heat storage chamber (21) and a second heat storage chamber (25), wherein the first heat storage chamber (21) and the second heat storage chamber (25) are filled with ceramic heat storage bodies; The valve assembly comprises a first valve assembly and a second valve assembly, and the valve is switched to control the flow direction of the airflow, so as to realize the switching of the cycle of heating the first heat storage chamber (21) by the hot mixed air while cooling the second heat storage chamber (25) by the cold air, and heating the second heat storage chamber (25) by the hot mixed air while cooling the first heat storage chamber (21) by the cold air.

3. The biochar heat exchange system for greenhouse warming according to claim 2, characterized in that: The first heat storage chamber (21) has a first vent (211) and a second vent (212); The second heat storage chamber (25) has a third vent (251) and a fourth vent (252); The first valve assembly comprises a first inner chamber (22) and a first outer chamber (23) which are coaxially arranged. A first valve stem (24) is arranged inside the first inner chamber (22). A first valve stem end plate (241), a first valve disc (242), a second valve disc (243), and a third valve disc (244) are arranged on the first valve stem (24) in sequence along the direction of travel of the valve stem, so as to divide the first inner chamber (22) into an independent first space (221), a second space (222), a third space (223), and a fourth space (224). The first inner chamber (22) A first through hole (225), a cold air inlet (226), a first inner chamber ventilation port (227), a cold mixed air outlet (228), and a second through hole (229) are sequentially provided along the travel direction of the valve stem; the first through hole (225) and the second through hole (229) are connected to the first outer chamber (23); the first inner chamber ventilation port (227) is connected to the first ventilation port (211); the first outer chamber (23) is provided with a first outer chamber ventilation port (231); and the first outer chamber ventilation port (231) is connected to the fourth ventilation port (252); The second valve assembly comprises a second inner chamber (26) and a second outer chamber (27) which are coaxially arranged. A second valve stem (28) is arranged inside the second inner chamber (26). A second valve stem end plate (281), a fourth valve disc (282), a fifth valve disc (283) and a sixth valve disc (284) are arranged on the second valve stem (28) in sequence along the direction of travel of the valve stem, so as to divide the second inner chamber (26) into an independent fifth space (261), a sixth space (262), a seventh space (263) and an eighth space (264). The second inner chamber (26) A third through hole (265), a hot mixed gas inlet (266), a second inner chamber ventilation port (267), a hot air outlet (268), and a fourth through hole (269) are sequentially provided along the travel direction of the valve stem; the third through hole (265) and the fourth through hole (269) are connected to the second outer chamber (27); the second inner chamber ventilation port (267) is connected to the second ventilation port (212); the second outer chamber (27) is provided with a second outer chamber ventilation port (271); and the first outer chamber ventilation port (231) is connected to the third ventilation port (251); When the valve is switched to the first state, that is, when the hot mixed air heats the first heat storage chamber (21) and the cold air cools the second heat storage chamber (25), the first valve stem (24) retracts to the first position and the second valve stem (28) moves to the third position, the first through hole (225) and the cold air inlet (226) are located in the second space (222), the first inner chamber ventilation port (227) and the cold mixed air outlet (228) are located in the third space (223), the second through hole (229) is located in the fourth space (224), the third through hole (265) is located in the fifth space (261), the hot mixed air inlet (266) and the second inner chamber ventilation port (267) are located in the sixth space (262), and the hot air outlet (268) and the fourth through hole (269) are located in the seventh space (263); When the valve is switched to the second state, that is, when the cold air cools the first heat storage chamber (21) and the hot mixed air heats the second heat storage chamber (25), the first valve stem (24) moves to the second position and the second valve stem (28) retracts to the fourth position, the first through hole (225) is located in the first space, the cold air inlet (226) and the first inner chamber ventilation port (227) are located in the second space, the cold mixed air outlet (228) and the second through hole (229) are located in the third space, the third through hole (265) and the hot mixed air inlet (266) are located in the sixth space (262), the second inner chamber ventilation port (267) and the hot air outlet (268) are located in the seventh space (263), and the fourth through hole (269) is located in the eighth space (264).

4. The biochar heat exchange system for greenhouse warming according to claim 3, characterized in that: The heat exchange device (2) also includes a purge system for purging the double heat storage chambers using an inert gas.

5. The biochar heat exchange system for greenhouse warming according to claim 4, characterized in that: The heat exchange device (2) also includes a PLC, which uses a cylinder to synchronously control the advancement and retreat of the first valve stem (24) and the second valve stem (28). When the valve is switched to a first state, the first valve stem (24) retreats to a first position and the second valve stem (28) advances to a third position. When the valve is switched to a second state, the first valve stem (24) advances to a second position and the second valve stem (28) retreats to a fourth position.

6. The biochar heat exchange system for greenhouse warming according to claim 5, characterized in that: The PLC sets a switching time and a purging time, the first heat storage chamber (21) is in a heating state, and the second heat storage chamber (25) is in a cooling state. When the set switching time is reached, the PLC controls the valve assembly to stop air intake, and the PLC controls the purging of inert gas. When the set purging time is reached, the PLC controls the purging system to stop running, completing the purging process. The PLC controls the valve assembly to switch the valve, and controls the flow direction of the airflow, so that the first heat storage chamber (21) is in a cooling state, and the second heat storage chamber (25) is in a heating state.

7. The biochar heat exchange system for greenhouse warming according to claim 6, characterized in that: Also includes: Pressure sensors are arranged in the first heat storage chamber (21) and the second heat storage chamber (25) to collect the pressure in the heat storage chamber in real time, and no less than three temperature sensors are evenly arranged along the height direction of the heat storage material to collect temperature data at different height positions in real time and calculate the temperature gradient value; When the temperature gradient of adjacent temperature sensors changes by more than 5°C / m within 10 minutes, and the pressure sensor detects that the pressure in the heat storage chamber changes by more than ±500 Pa within 5 minutes, the PLC determines that there may be a local blockage of the heat storage material or a gas leakage problem. At this time, the PLC immediately issues an audible and visual warning to the operator, and automatically switches the heat exchange system to the backup operation mode. In this backup operation mode, the intake flow rate is reduced to 50% of the normal flow rate, and the fault detection program is started. The valves of each intake branch are closed in turn, the pressure and temperature changes are detected, and the fault position is located.

8. The biochar heat exchange system for greenhouse warming according to claim 6, characterized in that: The PLC has the function of dynamic switching time and purge time optimization: Arrange no less than 5 temperature sensors in the greenhouse (7) to collect the greenhouse temperature in real time and calculate the rate of change of the greenhouse temperature; When the average temperature drop value Ta of the greenhouse (7) exceeds 2°C within 1 hour, and the average temperature Tb of the first heat storage chamber (21) or the second heat storage chamber (25) is higher than the set heat storage chamber threshold To, the PLC automatically shortens the heating time t of the first heat storage chamber (21) and the second heat storage chamber (25) according to the temperature drop rate and the biochar heat storage situation by the following formula: t reduction (min) = (Ta-2℃) × 10 + (Tb-To) × 2 Gas sensors are arranged in the first heat storage chamber (21) and the second heat storage chamber (25), and the gas sensors are connected to a gas composition analyzer. If the amount of residual gas exceeds 20% of the exhaust amount during normal operation, and the content of harmful gases exceeds a safety threshold, the PLC automatically extends the purge time by 5-10 minutes.

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