Sunlight greenhouse water circulation temperature control buffer system and control method

Abstract

The invention relates to the technical field of greenhouse planting, and provides a sunlight greenhouse water circulation temperature control buffer system and a control method.The sunlight greenhouse water circulation temperature control buffer system comprises an underground reservoir, a greenhouse structure body, a water circulation assembly and a control module; the water circulation assembly comprises a circulating pump, a heat pump unit and a temperature control unit, and the circulating pump is arranged between the water storage tank and the reservoir and forms a fluid loop; the heat pump unit is communicated with the water storage tank through a circulating pipeline; the water inlet end of the temperature control unit is communicated with the water storage tank, and the water return end is communicated with the reservoir; the temperature control unit comprises a heat dissipation module and a heat absorption module which are arranged in parallel, the heat dissipation module cools circulating water in the system, and the heat absorption module cools the interior of the greenhouse main body structure; the water storage tank is higher than the temperature control unit. Pressure difference is formed through height difference to promote water circulation, low-energy-consumption cooling is achieved through the heat absorption module, and the problems that other water circulation temperature adjusting methods are low in heat efficiency and high in operation cost are solved. The whole system is simple in structure, low in cost and easy to manufacture and use.

Description

Technical Field

[0001] The present invention relates to the technical field of greenhouse planting, and in particular to a water circulation temperature control buffer system and a control method for a solar greenhouse. Background Art

[0002] A solar greenhouse is a simplified, low-cost, and energy-efficient facility. It consists primarily of three insulated, heat-storage walls and a daylighting roof covered with an insulated blanket. It offers excellent thermal insulation and storage capabilities in winter, low heating energy consumption, and low management costs. However, due to its relatively small size, high summer temperatures (30-80°C or even higher) can be detrimental to vegetable growth and development, reducing facility utilization and vegetable production. Even in winter, the temperature is affected by external climatic factors, resulting in a less stable internal environment, adversely affecting vegetable production.

[0003] Therefore, inventing a low-energy, low-cost, and easy-to-maintain temperature control system has always been a hot demand in industry research and production applications. Exploring low-carbon, low-energy insulation and energy-saving methods to improve the environmental control capabilities of solar greenhouses has become a top priority. Summary of the Invention

[0004] The present invention provides a water circulation temperature control buffer system and a control method for a solar greenhouse, which are used to solve the defects of the prior art in that the internal environment of the solar greenhouse is poorly stable and the actual use and maintenance costs are high.

[0005] The first aspect of the present invention provides a solar greenhouse water circulation temperature control buffer system, comprising: a greenhouse structure body, a water circulation component and a control module; a water reservoir is preset under the ground in the main structure of the greenhouse; the water circulation component comprises a water storage tank, a circulation pump, a heat pump unit and a temperature control unit, the circulation pump is arranged on the water supply pipeline between the water storage tank and the water reservoir, the water storage tank forms a fluid loop with the water reservoir through the water supply pipeline; the heat pump unit is connected to the water storage tank through a pipeline to form a water circulation emergency heating system; the water inlet end of the temperature control unit is connected to the water storage tank through a distribution pipeline, and the return water end of the temperature control unit is connected to the water storage tank through a distribution pipeline. It is connected to the water tank through a collecting pipe; the control module includes a temperature acquisition module for sensing the indoor temperature; wherein, the temperature control unit includes a heat absorption module and a heat dissipation module arranged in parallel, the heat dissipation module is arranged outside the main structure of the greenhouse to cool the circulating water in the system, and the heat absorption module is arranged inside the main structure of the greenhouse to cool or heat the internal space and soil of the main structure of the greenhouse; the bottom surface elevation of the water tank is higher than the temperature control unit, and a liquid level sensor is provided in the water tank, and the control module is configured to control the operation of the circulation pump and the heat pump unit based on temperature information and liquid level information.

[0006] According to the solar greenhouse water circulation temperature control buffer system provided by the present invention, the heat dissipation module includes a plurality of outdoor radiators arranged in series, the water inlet end of the outdoor radiator is connected to the water storage tank through the distribution pipeline, and the return water end of the outdoor radiator is connected to the heat absorption module and the water storage tank in sequence through the collecting pipeline.

[0007] According to the solar greenhouse water circulation temperature control buffer system provided by the present invention, a boosting water channel is provided in parallel on the connecting water channel between the outdoor radiator and the water storage tank, a boosting pump is provided on the boosting water channel, and the boosting pump is electrically connected to the control module.

[0008] According to the solar greenhouse water circulation temperature control and buffer system provided by the present invention, the heat absorption module includes multiple indoor heat exchangers and multiple hot water storage bags; wherein, multiple indoor heat exchangers are arranged in series, at least one hot water storage bag is connected in series with the indoor heat exchanger, and at least one hot water storage bag is arranged in parallel with the indoor heat exchanger. According to the solar greenhouse water circulation temperature control and buffer system provided by the present invention, the multiple indoor heat exchangers connected in series are arranged on one side along the length direction of the greenhouse main structure, and the multiple hot water storage bags connected in series are arranged on the other side opposite the indoor heat exchangers.

[0009] According to the solar greenhouse water circulation temperature control buffer system provided by the present invention, a first regulating valve is provided on the inlet connecting pipe of the hot water storage bag located at the head end of the multiple hot water storage bags connected in series, and a second regulating valve is provided on the outlet connecting pipe of the hot water storage bag located at the tail end. The first regulating valve and the second regulating valve are used to adjust the flow rate of the circulating water circuit.

[0010] According to the solar greenhouse water circulation temperature control buffer system provided by the present invention, the remaining part of the heat storage bag is arranged between the rows of cultivated crops in the greenhouse main structure to form soil with heat storage bags.

[0011] According to the solar greenhouse water circulation temperature control buffer system provided by the present invention, the main body of the hot water storage bag is a polyvinyl chloride hot water storage bag.

[0012] A second aspect of the present invention provides a method for controlling the water circulation temperature control buffer system of a solar greenhouse as described above, comprising the following steps: Select the control mode based on the ambient temperature in the greenhouse; Based on the selected control mode and in combination with the temperature information and the liquid level information, at least one action of the circulation pump and / or the booster pump is controlled, or at most one action of the heat pump unit and / or the circulation pump is controlled.

[0013] According to the control method provided by the present invention, controlling the operation of one of the circulation pump, the booster pump and the heat pump unit or the simultaneous operation of the two based on the selected control mode specifically includes the following steps: When the liquid level information is lower than the preset liquid level threshold, the circulation pump is turned on to transport the water in the reservoir to the water tank; When t1≤the ambient temperature in the greenhouse≤t2, and the temperature information is higher than a preset first temperature threshold, the booster pump is controlled to operate; When t3≤the ambient temperature in the greenhouse≤t4, and the temperature information is lower than the preset second temperature threshold, the heat pump unit is controlled to operate; Among them, t4 <t1。

[0014] The water circulation temperature control buffer system and control method provided by the present invention utilizes pressure potential energy generated by elevation differences to promote water circulation. Low-energy cooling is achieved by placing a heat absorption module within the main structure of the greenhouse, thereby resolving the problems of low thermal efficiency and high operating costs associated with other water circulation temperature control methods. A water circulation system typically involves a heat exchange process, wherein water circulates within the system as a cooling medium. In summer, the heat absorption module absorbs heat within the greenhouse, which is then dissipated through the water circulation assembly to a heat dissipation module outside the greenhouse, removing the heat from the greenhouse and achieving low-energy cooling. In winter, the external circulation is shut down, and the heat absorption module absorbs excess heat within the greenhouse during the day and stores it in the water, reducing the high daytime temperature within the greenhouse. At night, the heat is circulated back into the greenhouse, raising the nighttime temperature within the greenhouse. During extreme temperatures and continuous cloudy days, when the outside temperature is high during the day, a heat pump unit can be used to capture external energy, increasing the heat capacity of the circulating water. This internal circulation system heats the greenhouse, shaving peaks and filling valleys in the greenhouse temperature, buffering the greenhouse's temperature control capabilities, and repeating this cycle. The entire circulation system has a simple structure, is easy to manufacture, and is inexpensive to manufacture and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is one of the overall layout structural diagrams of the solar greenhouse water circulation temperature control buffer system provided by the present invention.

[0017] Figure 2 This is the second schematic diagram of the overall layout structure of the solar greenhouse water circulation temperature control buffer system provided by the present invention.

[0018] Figure 3 It is a flow chart of the control method of the water circulation temperature control buffer system of the solar greenhouse provided by the present invention.

[0019] Reference numerals: 10. Greenhouse main structure; 11. Water reservoir; 111. Float valve; 20. Water circulation assembly; 21. Water storage tank; 22. Circulation pump; 23. Heat dissipation module; 231. Outdoor radiator; 24. Heat absorption module; 241. Indoor heat exchanger; 242. Hot water storage bag; 243. First control valve; 244. Second control valve; 25. Heat pump unit; 26. Booster pump; 30. Control module. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of explaining the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0022] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0023] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0024] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0025] Related research in this field has shown that high temperatures in summer increase plant respiration rates, affecting carbohydrate accumulation, causing seedlings to grow too tall, and plants to drop flowers and fruits, which also reduces vegetable biological and economic yields. High temperatures in summer greenhouses can have many adverse effects on cherry tomato growth, such as burning tomato leaves, reduced tomato photosynthesis, and an increased risk of tomato disease. The temperature range suitable for tomato growth in a solar greenhouse is generally between 20°C and 30°C, with the most suitable temperature being approximately 22°C to 25°C. During the fruiting period of tomato growth, the ideal daytime temperature is 22°C to 28°C, and the nighttime temperature is 12°C to 17°C. Therefore, regulating the high summer temperature environment is key to achieving year-round greenhouse crop production. Winter temperatures, however, are unstable due to external climatic factors, making it common for greenhouse temperatures to fall below the growth and development temperature of vegetables. This leads to extremely unstable indoor ambient temperatures, which adversely affects vegetable production.

[0026] Among the related technologies, typical solutions include solar water circulation systems, water circulation matrix cooling systems, etc. These systems require complex layouts and sophisticated and complex controls, which leads to high overall layout costs, high energy consumption, difficulty in subsequent maintenance, and high usage costs.

[0027] In response to the problems in the related art, the present invention provides a solar greenhouse water circulation temperature control buffer system, including a greenhouse main structure 10, a water circulation component 20 and a control module 30; a water reservoir 11 is preset under the ground in the greenhouse main structure 10; the water circulation component 20 includes a water storage tank 21, a circulation pump 22, a heat pump unit 25 and a temperature control unit, the circulation pump 22 is arranged on the water supply pipeline between the water storage tank 21 and the water reservoir 11, and the water storage tank 21 forms a fluid loop with the water reservoir 11 through the water supply pipeline; the heat pump unit 25 is connected to the water storage tank 21 through the circulation pipeline to form a water circulation heating system; the water inlet end of the temperature control unit It is connected to the water tank 21 through a distribution pipeline, and the return water end of the temperature control unit is connected to the heat absorption module 24 and the water tank 11 in sequence through a collecting pipeline; the control module 30 includes a temperature acquisition module for sensing the indoor temperature; wherein, the temperature control unit includes a heat absorption module 24 and a heat dissipation module 23 arranged in parallel, the heat dissipation module 23 is arranged outside the greenhouse main structure 10, and the heat absorption module 24 is arranged inside the greenhouse main structure 10; the bottom surface elevation of the water tank 21 is higher than the temperature control unit, and a liquid level sensor is provided in the water tank 21, and the control module 30 is configured to control the operation of the circulation pump 22 and the heat pump unit 25 based on temperature information and liquid level information. The growth of crops in a solar greenhouse requires a stable temperature environment to facilitate their growth. In the summer, the long-term exposure to the sun will cause the temperature inside the greenhouse to be too high, and the interior of the greenhouse needs to be cooled. In the winter, the low external ambient temperature will cause the temperature inside the greenhouse to be too low, and the interior of the greenhouse needs to be heated. In this embodiment, when the interior of the greenhouse needs to be cooled, the water storage tank 21 is located at a high position, and the height difference between the water storage tank 21 and the temperature control unit is used to realize the self-flow of circulating water. The heat dissipation module 23 is used to cool the circulating water, and the heat absorption module 24 is used to absorb heat from the interior of the greenhouse, thereby realizing the cooling control of the temperature inside the greenhouse. When the temperature inside the greenhouse needs to be heated, the heat pump unit 25 is turned on to heat the circulating water, so that the heat can be dissipated during the circulation process, thereby realizing the temperature control of the interior of the greenhouse.

[0028] The greenhouse main structure 10 comprises a frame structure, a roof structure, and a wall structure. The frame structure serves as the main support structure, and the roof and wall structures are connected to the frame structure, forming an internal space for crop cultivation. A water reservoir 11 is pre-installed and contains circulating water. Alternatively, a water tank can be installed within the water reservoir 11 to store circulating water, thereby achieving water circulation and regulating the temperature of the interior space of the greenhouse main structure 10 during the water circulation process.

[0029] Specifically, the circulating pump 22 and heat pump unit 25 are both electrically connected to the control module 30. The control module 30 executes corresponding control decisions based on the control model stored within the controller, thereby controlling the equipment. For example, after receiving liquid level information, the control module 30 can use feedback to control the circulating water pump to fill the water reservoir 11 and transfer it to the water storage tank 21. If temperature information is received and the feedback indicates that the temperature exceeds a threshold, the circulating water needs to be rapidly cooled. In this case, the circulating water can be quickly passed through the outdoor radiator 231 for water circulation cooling.

[0030] During the circulation process, the water storage tank 21 is positioned higher than the other components, creating a height difference that allows the circulating water to flow automatically and exchange heat during the flow. Specifically, in scenarios where the indoor temperature is high and needs to be cooled, the circulating water is forced to flow due to the height difference. A portion of the circulating water passes through the heat absorption module 24 to exchange heat with the indoor temperature, achieving heat exchange with the indoor temperature, while the other portion of the circulating water passes through the heat dissipation module 23 to cool the circulating water. This allows the circulating water to flow at a temperature lower than the indoor ambient temperature, allowing the circulating water to quickly cool the internal environment of the greenhouse main structure 10 as it flows within the heat absorption module 24.

[0031] In a specific configuration, the heat dissipation module 23 can cool the circulating water by exchanging heat with other refrigerants or other low-temperature environments, thereby reducing the temperature of the circulating water. The heat absorption module 24 can also be a heat exchanger or other heat exchange device, so that the water can remove heat from the interior space of the greenhouse body during the flow process.

[0032] As can be appreciated, compared to the complex control schemes and high energy consumption of related art, this embodiment, by locating the water tank 21 at a higher position, places the water inside the water tank 21 above the heat absorption module 24 and the heat dissipation module 23. This allows the water to flow through the height difference during operation, reducing operating costs. Furthermore, the circulating pump 22 operates intermittently during operation. That is, when the water level in the water tank 21 is too low, the circulating pump 22 is turned on to fill the water, and then turned off after filling is complete. This avoids the energy consumption associated with continuous water filling, reducing the overall system's energy consumption. Furthermore, the water tank 21 ensures stable circulating water flow, improving the stability of the overall system's cooling. Furthermore, in winter, by closing the external heat dissipation module 23 to form an external circulation path, the heat absorption module absorbs excess heat from the greenhouse during the day and stores it in the water, lowering the higher daytime greenhouse temperature. At night, the heat is circulated back into the greenhouse, raising the nighttime temperature. In extreme temperatures and continuous cloudy days, when the outside temperature is high during the day, the heat pump unit can be used to obtain external energy, increase the heat capacity of the circulating water, and heat the greenhouse through internal circulation, which plays the role of "peak shaving and valley filling" of the greenhouse temperature and buffers the greenhouse temperature control ability.

[0033] In conjunction with the above embodiment, the heat dissipation module 23 includes a plurality of outdoor radiators 231 arranged in series. The water inlet of the outdoor radiator 231 is connected to the water storage tank 21 via a distribution pipeline, and the water return of the outdoor radiator 231 is connected to the water reservoir 11 via a collecting pipeline. In the summer, the ambient temperature inside the greenhouse main structure 10 is often high, which requires heat dissipation indoors. In this embodiment, the provision of the outdoor radiator 231 allows the circulating water that absorbs heat from the interior of the greenhouse main structure 10 to dissipate heat to the outside through the radiator, thereby reducing the circulating water temperature, improving the heat absorption capacity, and achieving rapid heat dissipation within the greenhouse main structure.

[0034] Specifically, the water inlet of the heat dissipation group is connected to the water tank 21 through a pipeline, and the water return end of the radiator is connected to the water reservoir 11 through a pipeline, thereby forming a heat dissipation loop to achieve continuous heat dissipation of the circulating water.

[0035] In specific configurations, a control valve is installed on the pipe connecting the water inlet of the outdoor radiator 231 to the distribution pipe, and a control valve is also installed on the pipe connecting the water return end of the outdoor radiator 231 to the collecting pipe. The control valve can control the flow rate of circulating water in and out, thereby adjusting the overall flow rate of the circulating water circuit according to demand and achieving the purpose of controlling the water temperature.

[0036] It is understandable that in the summer, the outdoor temperature is often lower than the indoor temperature, and the internal temperature is approximately 10°-20° higher than the external temperature. If the internal temperature is too high, it will affect the growth of crops. In this embodiment, to solve the problem of cooling the water during the water circulation process, an outdoor radiator 231 is provided externally, so that the radiator unit is located externally, achieving heat exchange with the external environment, thereby reducing the water temperature. The entire cooling process is efficient and does not generate additional energy consumption.

[0037] In a specific embodiment, the main structure of the circulating pump 22 is located in the water tank 11. The water tank 11 is 2.2 meters long and 1.3 meters in diameter. The distance between the water tank 11 and the ground is 50-100 cm. This allows the water in the water tank 21 to have a sufficient height difference to generate a pressure difference, so that the water can flow under the action of the high pressure difference. Preferably, the power of the circulating pump 22 is 0.88 kw, and the water flow rate is 10 m 3 ·h -1 , with a maximum head of 25m. Of course, actual requirements can be adjusted based on the actual size of the greenhouse space and the degree of water regulation. The circulation pump 22 automatically starts and stops based on the thresholds set by the water level sensors in the elevated water tank 21 and the underground water reservoir 11. When the water level in the elevated water tank 21 falls below the set value, the circulation pump 22 starts pumping water from the underground water reservoir 11 into the elevated water tank 21, creating a high-pressure potential difference that drives the water to circulate by gravity.

[0038] In specific applications, a reflux port is provided on one side of the water reservoir 11, which is connected to the collecting pipe so that the reflux water flows back through the reflux port. A float valve 111 is installed at the reflux port to control the inflow state of the reflux water channel.

[0039] Furthermore, the high-level water tank 21 can be a 2m*1.6m*1.35m plastic water tank 21 or other material water tank, with a capacity of approximately 4000L. Of course, the capacity can be expanded or the number of water tanks 21 can be increased according to the specific site size and needs. The specific setting includes a support frame, and the water tank 21 is placed on the support frame so that the distance between the water tank 21 and the ground is greater than 2m. This ensures that the water tank 21 has a sufficient height and can achieve a smoother flow of circulating water.

[0040] In conjunction with the above embodiment, a booster water circuit is provided in parallel on the connecting water path between the outdoor radiator 231 and the water storage tank 21. The booster water circuit is provided with a booster pump 26, and the booster pump 26 is electrically connected to the control module 30. The flow rate of water within the outdoor radiator 231 affects the cooling capacity of the entire system. In this embodiment, the provision of the booster water circuit increases the flow rate of water within the outdoor radiator 231, thereby improving the efficiency of water flow and heat exchange, achieving rapid cooling of the water, and thus quickly dissipating the temperature within the greenhouse main structure 10.

[0041] Specifically, if Figure 1 As shown, with the direction of water flow as a reference, the water inlet of the outdoor radiator 231 at the head end is connected to the water tank 21 via a connecting pipe. A booster water circuit is connected in parallel to the head end connecting pipe. Both the booster water circuit and the connecting pipe are equipped with control valves to control the opening of their respective flow paths, thereby achieving control of water flow. The outdoor radiators 231 in the middle section are connected end to end to form a series structure, and the return water connection pipe of the outdoor radiator 231 at the tail end is also equipped with a control valve to control the flow rate of the outflowing water.

[0042] It is understandable that when the temperature of the internal space of the greenhouse main structure 10 exceeds the threshold, it needs to be cooled down quickly, which requires increasing the flow rate of the water body and lowering the temperature of the circulating water. This embodiment sets a booster valve on the flow path of the outdoor radiator 231 so that it can be opened in time when needed to provide a faster water flow rate, and can achieve rapid heat dissipation of the entity, lower the water temperature, and thus improve the rapid heat dissipation of the space inside the greenhouse main body.

[0043] In a specific embodiment, the outdoor fan heater is a finned tube radiator with a size of 2m×1m, 9 fins per group, and the number can be adjusted according to actual needs and site space. The finned radiator can adopt the same specifications as the heat exchanger, fixed on the outside of the north wall of the solar greenhouse, and connected to the PPR pipe to form a closed loop. The power of the booster pump 26 is 0.75kw, and the water flow rate is 6m 3 ·h -1 , with a maximum lift of 14m and a frequency of 50Hz. Of course, actual needs can be adjusted based on the actual greenhouse space size and water volume adjustment level. When the temperature in the solar greenhouse is too high, the booster pump is activated to increase the water flow rate and flow capacity, increasing the heat dissipation capacity of the fins outside the greenhouse, effectively lowering the greenhouse temperature.

[0044] In some embodiments, the heat absorption module 24 includes a plurality of indoor heat exchangers 241 and a plurality of hot water storage bags 242; wherein, the plurality of indoor heat exchangers 241 are arranged in series, with some of the hot water storage bags 242 being connected in series with the indoor heat exchangers 241, and the remaining hot water storage bags 242 being connected in parallel with the indoor heat exchangers 241. When dissipating heat from the interior of a greenhouse, it is necessary to maintain internal stability under normal conditions, while also being able to quickly adjust the temperature in the event of a sudden abnormal temperature change. This embodiment uses a plurality of hot water storage bags 242 as the heat exchanger. On the one hand, the parallel hot water storage bags can achieve temperature regulation during daily operations, and on the other hand, the series hot water storage bags 242 can cooperate with the indoor heat exchangers 241 to achieve rapid temperature regulation, thereby achieving the purpose of rapid regulation.

[0045] Specifically, the heat exchanger's inlet can be connected directly to the water tank, and the outlet to the reservoir. The hot water bag's inlet can also be connected directly to the water tank, and the outlet to the reservoir. Alternatively, the water tank can be connected sequentially to the heat exchanger, the hot water bag, and then back to the reservoir.

[0046] like Figure 1 As shown, the distribution pipeline output of the water tank 21 has three flow paths. One flow path is connected to the heat dissipation module 23 (i.e., the outdoor radiator 231), and ultimately returns to the water reservoir 11 through the collecting pipe to realize a closed loop. Another flow path is a series return formed by the indoor heat exchanger 241 and the hot water storage bag 242 in the series connection, and ultimately returns to the water reservoir 11 through the collecting pipe to realize a closed loop. The remaining flow path is connected to the hot water storage bag 242 in the parallel connection, and the hot water storage bag 242 in the parallel connection returns to the water reservoir 11 through the collecting pipe to realize a closed loop. This method can realize the hierarchical treatment of temperature heat dissipation in the greenhouse main structure 10, realize targeted treatment of daily status and abnormal status, improve the efficiency of treatment, and reduce energy consumption in daily use.

[0047] In a specific embodiment, the main body of the hot water bag 242 is a polyvinyl chloride hot water bag 242, and the specifications of the hot water bag 242 are 10 meters long and 40 cm in diameter. The hot water bags in series are connected end to end by a connecting pipe to form a series structure. This method can facilitate the installation and connection of the hot water bag 242 and reduce the difficulty of its connection and installation.

[0048] Specifically, by using the hot water bag 242 as the main heat exchange structure, it can make the water circulation in the circulating water more stable, improving the stability of the entire system. In addition, the water bag is easy to arrange, and the cost of use and subsequent maintenance costs are lower.

[0049] In combination with the above embodiments, Figure 1As shown, multiple indoor heat exchangers 241 are connected in series on one side of the greenhouse main structure 10 along the longitudinal direction, and multiple hot water storage bags 242 are connected in series on the other side opposite the indoor heat exchangers 241. By arranging the hot water storage bags 242 and the indoor heat exchangers 241 on opposite sides, temperature regulation can be achieved on both sides, which increases the flexibility of indoor temperature regulation.

[0050] Specifically, the series-connected indoor heat exchanger 241 is located on the north side of the greenhouse main structure 10, and the series-connected hot water storage bags are located on the south side of the greenhouse main body. By setting differentiated heat absorption bodies on the north and south sides, it is possible to flexibly adjust the temperature of different areas in the greenhouse.

[0051] It is understandable that the temperature on the south side of the greenhouse main structure 10 is higher than that on the north side because in the Northern Hemisphere, sunlight is primarily concentrated in the south. The south side of the greenhouse receives more sunlight, resulting in higher daytime temperatures. In this embodiment, the south-side hot water bag 242 directly contacts the ground, cooling the soil there, thereby preventing the soil temperature from becoming too high and affecting crop growth.

[0052] In conjunction with the above embodiment, the inlet connection pipe of the hot water bag 242 at the head end of the series connection is equipped with a first regulating valve, and the outlet connection pipe of the hot water bag 242 at the tail end is equipped with a second regulating valve. The first and second regulating valves are used to adjust the flow rate of the circulating water circuit. The flow rate of the water in the hot water bag 242 affects the temperature control rate of that part. In this embodiment, the provision of control valves at the head and tail ends allows for adjustment based on demand, thereby increasing the flexibility of regulation.

[0053] Specifically, if Figure 1 As shown, a control valve is installed on the connecting pipe at the end of the series heat exchanger section, and the return end of the flow path of the outdoor radiator 231 and the return end of the series heat exchanger share a return manifold. In other words, the series section of the indoor heat exchanger 241 and the series section of the outdoor radiator 231 are connected in parallel and are both connected in series with the series section of the hot water storage bag 242. This ensures that the water temperature of the series section of the hot water storage bag 242 is lower than the temperature of the water flowing out of the series section of the indoor heat exchanger 241 during regulation, effectively regulating the temperature on this side.

[0054] It is understandable that the configuration of the first and second regulating valves can achieve temperature regulation on the one hand, and stabilize the soil temperature near the root system on the other. In summer, the regulating valves are used to adjust the water flow rate and capacity of each water bag. Due to the difference in heat capacity of the greenhouse space, the regulating valves need to be increased to make the water flow and water capacity faster than the east and west sides, accelerating heat absorption and heat exchange. The east and west sides can adjust the flow rate at a low level. In winter, the process is reversed, with the flow rate and flow rate increased on the east and west sides and reduced in the middle. Specific adjustments are made based on actual conditions.

[0055] It should be noted that in the series structure, the circulating water has a specific flow direction. The hot water bag 242 through which the circulating water flows first is the hot water bag 242 at the head end. Similarly, the hot water bag 242 that passes through the series end last is the hot water bag 242 at the tail end. By setting regulating valves at the head and tail of the series section, the flow speed of the series section can be controlled, thereby achieving flexible control of the cooling efficiency of this part.

[0056] In conjunction with the above embodiment, the remaining hot water bags 242 are placed between the rows of cultivated crops within the greenhouse main structure 10. By placing the hot water bags 242 between the rows, the temperature can be regulated more quickly and the surrounding soil can be cooled.

[0057] Specifically, the hot water bag 242 is connected in series with the indoor heat exchanger 241, distributed on the east and west sides. The hot water bag 242 and the indoor heat exchanger 241 connected in parallel are distributed on the south and north sides. This ensures that the hot water bag 242 and the indoor heat exchanger 241 are evenly arranged within the interior space of the greenhouse main structure 10, improving heat dissipation uniformity. The hot water bag and heat exchanger can also operate independently, with the return water directly connected to the water reservoir.

[0058] Another aspect of the present invention provides a method for controlling the water circulation temperature control buffer system of a solar greenhouse provided by any one of the above, comprising the following steps: Step S10: Selecting a control mode based on the ambient temperature in the greenhouse. When the control module 30 outputs control information, it is necessary to select a control model based on the ambient temperature in the greenhouse, and automatically control the system based on the control model.

[0059] Specifically, different control modes are called based on the ambient temperature inside the greenhouse to issue control signals to achieve control of various components.

[0060] Step S20: Based on the selected control mode and in combination with the temperature information and the liquid level information, at least one of the circulation pump 22 and / or the booster pump 26 is controlled, or at most one of the heat pump unit 25 and / or the circulation pump 22 is controlled. After the control mode is selected, component operation control can be implemented through feedback information.

[0061] Specifically, when the liquid level information is lower than the preset liquid level threshold, the circulation pump 22 is turned on to transport the water in the water reservoir 11 to the water storage tank 21; when t1≤the ambient temperature in the greenhouse≤t2 (in summer when the temperature is high), and the temperature information is higher than the preset first temperature threshold, the booster pump 26 is controlled to operate; when t3≤the ambient temperature in the greenhouse≤t4 (that is, in winter), and the temperature information is lower than the preset second temperature threshold, the heat pump unit 25 is controlled to operate; wherein, t4 <t1。

[0062] Specifically, when the temperature is higher than the set point during spring, summer, autumn, and winter, this embodiment uses the summer and winter temperature ranges as control mode selection criteria. In winter, the external circulation is shut down, and outdoor heat dissipation is not performed. When the liquid level in the water tank 21 falls below the set point, typically 10-20 cm below the tank bottom, the circulation pump 22 is activated, pumping water from the reservoir 11 into the water tank 21. A high-pressure water potential difference is created through the elevated water tank 21, driving the water circulation through the hot water bag 242, the outdoor radiator, and the indoor heat exchanger 241. During spring, summer, and autumn, when the greenhouse temperature is sensed to be higher than the set point, typically 28-30°C, the booster pump 26 is activated to increase the water flow rate and circulating volume, accelerating heat dissipation and reducing the temperature as quickly as possible. In winter, the solar greenhouse's outdoor circulation is shut down, and the water in the radiator and pipes is drained to prevent freezing and damage to the pipes. When the greenhouse temperature drops below 10-15°C during the day, the air-source heat pump can be activated to heat the water circulation system, increasing its heat capacity and addressing the low temperatures both day and night. Circulation pump 22 can also be activated to increase the water flow rate and circulation capacity, speeding up heat exchange within the greenhouse to stabilize and raise the greenhouse temperature, thereby meeting the production and growth needs of crops. The set value can be customized based on the crops being cultivated, management requirements, greenhouse space size, and operational performance.

[0063] The following describes the specific implementation of each control variable in the control method of the control module. Based on the experimental data and physical model of the solar greenhouse water circulation temperature control buffer system, the mathematical formula for estimating the water and heat required for the solar greenhouse is as follows: The water circulation heat transfer rate is derived from the sensible heat exchange formula, which is: ; in, is the heat exchange rate (J), and the heat exchange rate range is selected from 85.4 to 123.1 J based on the heat dissipation performance of the outdoor radiator 231 selected according to the experimental results; wherein: is the mass of water (kg), which needs to be calculated by flow rate; is the specific heat capacity of water, which is 4186 J / (kg·K); The water inlet and outlet temperature difference (K) is measured to be 4.6℃ for indoor and outdoor water circulation.

[0064] Since the heat transfer efficiency is directly related to the water volume, water flow rate, heat transfer performance of the radiator and the outside temperature, in order to simplify the calculation, the inlet and outlet temperature difference of the heat sink of the test group actually measured is used as the calculation basis. Since the inlet and outlet temperature difference of the heat sink of the test group already includes the influence of the outside temperature, in order to simplify the calculation amount, the outside temperature is ignored in this calculation. The matching calculation of water capacity and heat can be calculated using the following formula for a preliminary estimate.

[0065] Calculate the water flow required per unit time Assume that the system running time is t (seconds), the heat exchange , where: p is the heat transfer power (W).

[0066] The mass flow rate can be obtained from the sensible heat formula: ; Volume flow rate: ; in, kg / m 3 ; The forced circulation water flow rate is selected to be 6m³ / h, corresponding to the mass flow rate 𝑚=6×1000 / 3600≈1.67 kg / s. Substituting it into the formula can estimate the heat dissipation power: ; The actual heat exchange capacity is 85.4-123.1 J, indicating that the cooling capacity in the test is an instantaneous value or there are other heat losses, which needs to be corrected in combination with the COP value.

[0067] Energy balance in combination with the COP value COP (coefficient of performance) is defined as the ratio of heat exchange to input power: ; The COP value is 1.5-3.7, assuming the input power (corresponding to the circulating pump power), the upper limit of heat exchange is: ; According to the calculation, the water required for each exchange of 1kJ of heat is V waterApproximately 0.052L; if the water flow rate is 6 m³ / h, it can continuously provide 2778W of heat transfer power (at a COP of 3.7). Therefore, increasing the water flow rate or temperature difference can increase heat transfer, but this requires balancing energy consumption with efficiency (COP). Taking a solar greenhouse with a total area of 1500 m² as an example, based on thermal calculations, it is preliminarily recommended that 15-20 finned heat sinks be used for optimal heat dissipation, thus meeting the higher heat load requirements. Based on the heat transfer requirements and circulation efficiency, the water volume needs to be increased to improve heat storage capacity. The total water volume of the solar greenhouse water circulation temperature control buffer system is recommended to be increased to approximately 25-30 m³, with a set number of 15-20 hot water storage bags. The water volume can be adjusted based on the actual installation and application. Water bags can be placed between the cultivation rows. This configuration significantly improves heat storage and release efficiency, meeting the requirements of high summer temperatures. This estimate is based on the maximum set value, allowing for a larger water volume to achieve temperature balance.

[0068] As can be seen above, and verified by summer trials, the results show that, especially under sunny conditions, the maximum temperature difference can reach 7.1°C, and the COP reaches 1.5 to 3.7. This indicates that the solar greenhouse water circulation temperature control buffer system has better energy efficiency than traditional ventilation and cooling methods, and has the advantages of low material cost, simple installation and maintenance, and low operating costs. Installation between cultivated plants can effectively balance rhizosphere temperature, which is conducive to normal crop growth and development. It has good application prospects and plays a positive role in year-round temperature control and balance management. Through the synergistic effect of closed-loop water circulation and finned heat sinks, this system achieves precise control of the temperature and humidity environment in the solar greenhouse during the summer, providing reliable technical support for energy-saving and efficient production in facility agriculture.

[0069] Through the description of the above embodiments, those skilled in the art will clearly understand that each embodiment uses water as the circulating medium. Heat within the greenhouse is absorbed into the water body through the greenhouse heat exchanger 241 and water bag, which then flows to the underground water pool. The circulating pump 22 is then activated to pump water from the underground water pool into the elevated water tank. The elevated water tank, through high pressure, drives the closed-loop water pipeline to circulate to the heat exchanger fins and water bag within the greenhouse, exchanging heat within the greenhouse again. A control system is established, using the water level sensor and temperature as decision-making basis, and the system circulates sequentially. When the temperature is too high, the pressurized water pump can be activated to accelerate the water flow rate, enhance the heat exchange rate, and achieve "peak shaving" of the greenhouse temperature, balancing the greenhouse temperature and creating an ideal environment for crop growth. When the temperature is too low in winter, the air source heat pump can be activated during the day to heat the water circulation system within the greenhouse, improving the winter temperature control buffer capacity. Furthermore, the overall structure is simple, easy to install and construct, and operates stably and reliably, achieving significant cost savings and energy reduction, with low operating costs.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A solar greenhouse water circulation temperature control buffer system, characterized in that: include: A greenhouse main structure, wherein a water reservoir is preset under the ground inside the greenhouse main structure; A water circulation assembly, comprising a water tank, a circulation pump, a heat pump unit, and a temperature control unit. The circulation pump is disposed on a water delivery pipeline between the water tank and the water reservoir, and the water tank forms a fluid loop with the water reservoir through the water delivery pipeline. The heat pump unit is connected to the water tank through a circulation pipeline to form a water circulation heating system. The water inlet end of the temperature control unit is connected to the water tank through a distribution pipeline, and the water return end of the temperature control unit is connected to the water reservoir through a collecting pipeline. A control module, the control module including a temperature acquisition module for sensing indoor temperature; The temperature control unit includes a heat absorption module and a heat dissipation module arranged in parallel. The heat dissipation module is arranged outside the main structure of the greenhouse to dissipate heat and cool the circulating water in the system. The heat absorption module is arranged inside the main structure of the greenhouse to absorb heat and cool the internal space of the main structure of the greenhouse and the soil. The bottom elevation of the water tank is higher than the temperature control unit, and a liquid level sensor is provided in the water tank. The control module is configured to control the operation of the circulation pump and the heat pump unit based on temperature information and liquid level information.

2. The solar greenhouse water circulation temperature control buffer system according to claim 1, characterized in that: The heat dissipation module includes a plurality of outdoor radiators arranged in series, the water inlet end of the outdoor radiator is connected to the water storage tank through the distribution pipeline, and the return water end of the outdoor radiator is connected to the heat absorption module and the water storage tank in sequence through the collecting pipeline.

3. The solar greenhouse water circulation temperature control buffer system according to claim 2, characterized in that: A boosting water channel is provided in parallel on the connecting water channel between the outdoor radiator and the water tank. A boosting pump is provided on the boosting water channel. The boosting pump is electrically connected to the control module.

4. The solar greenhouse water circulation temperature control buffer system according to claim 1, characterized in that: The heat absorption module includes several indoor heat exchangers and several hot water storage bags; Wherein, a plurality of the indoor heat exchangers are arranged in series, and at least one of the hot water storage bags is connected in series with the indoor heat exchanger, and at least one of the hot water storage bags is connected in parallel with the indoor heat exchanger.

5. The solar greenhouse water circulation temperature control buffer system according to claim 4, characterized in that: A plurality of indoor heat exchangers connected in series are arranged on one side of the greenhouse main structure along the length direction, and a plurality of hot water storage bags connected in series or in parallel are arranged on the other side opposite to the indoor heat exchanger.

6. The solar greenhouse water circulation temperature control buffer system according to claim 4, characterized in that: Among the multiple hot water storage bags connected in series, a first regulating valve is provided on the inlet connecting pipe of the hot water storage bag at the head end, and a second regulating valve is provided on the outlet connecting pipe of the hot water storage bag at the tail end. The first regulating valve and the second regulating valve are used to adjust the flow rate of the circulating water circuit.

7. The solar greenhouse water circulation temperature control buffer system according to claim 4, characterized in that: The remaining part of the heat storage bag is arranged in the position between the rows of cultivated crops in the main structure of the greenhouse to form soil with heat storage bags.

8. The solar greenhouse water circulation temperature control buffer system according to claim 1 or 4, characterized in that: The main body of the hot water storage bag is a polyvinyl chloride hot water storage bag.

9. A method for controlling the water circulation temperature control buffer system of a solar greenhouse according to any one of claims 1 to 8, characterized in that: The steps include: Select the control mode based on the ambient temperature in the greenhouse; Based on the selected control mode and in combination with the temperature information and the liquid level information, at least one action of the circulation pump and / or the booster pump is controlled, or at most one action of the heat pump unit and / or the circulation pump is controlled.

10. The control method according to claim 9, characterized in that: Controlling one of the circulation pump, booster pump, and heat pump unit to operate or both to operate simultaneously based on the selected control mode specifically includes the following steps: When the liquid level information is lower than the preset liquid level threshold, the circulation pump is turned on to transport the water in the reservoir to the water tank; When t1≤the ambient temperature in the greenhouse≤t2, and the temperature information is higher than a preset first temperature threshold, the booster pump is controlled to operate; When t3≤the ambient temperature in the greenhouse≤t4, and the temperature information is lower than the preset second temperature threshold, the heat pump unit is controlled to operate; Among them, t4 <t1。

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