A desert greenhouse ventilation system

Abstract

The present invention relates to a desert greenhouse ventilation system, comprising: a ventilation unit for regulating air circulation between the interior and exterior of the greenhouse body; the ventilation unit comprising at least two exhaust ducts, each equipped with a different type of water collection assembly, for recovering moisture entrained in the exhaust air by alternately and / or in parallel activation; wherein, when a first exhaust duct is switched off and a second exhaust duct is switched on, the water collection assembly provided in the first exhaust duct can share the same heat exchange unit with the water collection assembly provided in the second exhaust duct, utilizing the heat source and cold source of the heat exchange unit respectively. The water collection assembly provided in the first exhaust duct can include an adsorbent, and the water collection assembly provided in the second exhaust duct can include a metal component.

Description

Technical Field

[0001] The present invention relates to the technical field of greenhouse ventilation, and in particular to a desert greenhouse ventilation system. Background Art

[0002] Greenhouse ventilation technology is the main way to regulate greenhouse temperature, humidity, and carbon dioxide concentration. Common greenhouse ventilation technologies usually include natural ventilation and forced ventilation. Natural ventilation mainly allows air convection ventilation by opening side windows and top windows, and uses natural air convection to regulate the temperature, humidity, and air conditions of the greenhouse. However, this type of ventilation method usually has poor airtightness and thermal insulation effects, and its applicable scenarios are limited. Forced ventilation can be a ventilation method that achieves air circulation by installing negative pressure fans and wet curtains on the basis of existing window openings, which can achieve rapid ventilation and cooling; it can also install positive pressure fans and air ducts in a closed greenhouse to achieve ventilation between the greenhouse and the outside.

[0003] In order to successfully grow plants in the desert, scientific researchers have established a desert greenhouse. However, due to the extremely low precipitation, high evaporation and low vegetation coverage in desert areas, water resources are often the most scarce but most important resource in the desert greenhouse.

[0004] However, in the ventilation system of the prior art, while providing negative or positive pressure for the greenhouse, it often lacks the step of collecting and processing the moisture in the air inside the greenhouse. The moisture in the greenhouse air, especially the water vapor generated by the transpiration of the plant crown cuticle and stomata, will be directly brought out of the greenhouse, further leading to the loss of moisture in the greenhouse. This part of moisture is an extremely important water resource for greenhouses in desert areas.

[0005] Patent publication number CN114679989A discloses a ventilation system for a multi-span greenhouse and a multi-span greenhouse, comprising: air inlet devices arranged at intervals on the windward side of the multi-span greenhouse body and capable of rotating with the wind direction; a ventilation duct network, the air inlets of which are respectively connected to the air outlets of the air inlet devices, and the air outlets are connected to the multi-span greenhouse body; and exhaust devices arranged at intervals on the leeward side of the multi-span greenhouse body, each exhaust device being connected to the multi-span greenhouse body. The ventilation system for a multi-span greenhouse provided in this application provides air inlet devices on the windward side of the multi-span greenhouse body. The air inlet devices do not require a dedicated drive mechanism and can adjust the direction of the air inlet under the action of wind. The ventilation devices are also provided to ensure the air intake volume, thereby reducing the energy consumption and cost of the ventilation system. However, this application does not collect air moisture during the ventilation process, which makes this existing technology unsuitable for use in desert greenhouses located in desert environments.

[0006] In addition, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making the present invention, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present invention does not have the characteristics of these prior arts. On the contrary, the present invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present invention provides a desert greenhouse ventilation system to solve at least some of the above technical problems.

[0008] The invention discloses a desert greenhouse ventilation system, which comprises a ventilation unit for regulating the air flow process between the inside and outside of the greenhouse body.

[0009] The ventilation unit includes at least two exhaust ducts, each of which is provided with a different type of water collection component, so as to recover moisture contained in the exhaust air by alternating activation and / or parallel activation. When the first exhaust duct is switched to inactive and the second exhaust duct is switched to active, the water collection component provided in the first exhaust duct can share the same heat exchange unit with the water collection component provided in the second exhaust duct by respectively utilizing the heat source and cold source of the heat exchange unit.

[0010] The purpose of setting up two different exhaust ducts in the present invention is that different exhaust ducts can have different water resource recovery methods, so that they can be connected to the corresponding exhaust ducts according to different application scenarios, thereby achieving the maximum recovery of water resources. The reason why the present invention considers the switching problem between multiple exhaust ducts is that the exhaust process in the prior art is usually relatively independent. Even if various water collection equipment is provided to achieve water resource recycling, it can usually only achieve the purpose of recycling water, and at most only reduces operating costs. The desert greenhouse ventilation system of the present invention can include multiple working modes to utilize the switching of exhaust ducts to cope with different scenarios. It not only achieves efficient water resource recovery in various scenarios, but also helps to assist in regulating the environmental parameters inside the greenhouse body, thereby achieving scientific operation of the desert greenhouse. In the prior art, the water collected by the heat exchange unit is usually still used by natural evaporation or centralized collection for plant irrigation. This part of the water cannot be combined with the environmental parameter control process inside the greenhouse body. This invention addresses the varying temperature control and water resource recycling requirements during the day and night, linking the water resource recycling process in the desert greenhouse with the environmental parameter control process within the greenhouse body to maximize energy utilization, avoiding the energy waste caused by existing technologies that only utilize the single energy source side of the heat exchange unit. In other words, this invention leverages the switching control relationship between two different exhaust ducts within a specific time period and the relationship between the heat source and cold source utilization of a single heat exchange unit during different time periods. This allows for the coordination of the alternating first and second exhaust ducts at different times to maximize water resource recycling.

[0011] According to a preferred embodiment, the water collection component arranged in the first exhaust duct includes an adsorption component with a porous structure, and the water collection component arranged in the second exhaust duct includes a metal component whose surface is made of super-hydrophobic metal material, wherein an auxiliary component is arranged downstream of the adsorption component in the first exhaust duct and / or downstream of the metal component in the second exhaust duct. Since the conventional planting greenhouses in the prior art are located in an environment with relatively high air humidity, there is no need to collect moisture in the exhaust air. On the contrary, the present invention is aimed at desert greenhouses located in a desert environment. If the moisture in the exhaust air is not collected, a large amount of water vapor produced by the transpiration of the cuticle of the crown of the plants and the stomata in the greenhouse will be directly taken out of the greenhouse, further causing water loss in the greenhouse. This part of moisture is an extremely important water resource for greenhouses in desert areas. Therefore, the exhaust ducts in the prior art usually do not use water collection components. Even if there is a small amount of water collection demand, the water collection components of the same structure are used. This is obviously different from the setting method of different water collection components used in different exhaust ducts in the present invention. The combination of conventional exhaust ducts in the prior art cannot obtain the exhaust duct structure of the present invention. The present invention uses the adsorption components in the first exhaust duct connected to the heat source side of the heat exchange unit to perform a full-time moisture collection process during the day, and at night, the metal parts in the second exhaust duct connected to the cold source side of the heat exchange unit are alternately used to perform a full-time moisture collection process, thereby realizing the all-weather collection process of moisture in the exhaust air. This can fully utilize the energy provided by the heat exchange unit, improve the efficiency of energy use, and reduce the overall greenhouse operation cost, which is very beneficial for the large-scale promotion and application of desert greenhouses.

[0012] According to a preferred embodiment, the adsorbent arranged in the first exhaust duct can vaporize liquid water into gaseous water by contacting a heat source to release the moisture after intercepting at least part of the moisture, wherein the adsorbent that has adsorbed at least part of the moisture can be moved from the first exhaust duct to the heat source side of the heat exchange unit under the drive of the moving unit.

[0013] An adsorbent that has absorbed at least part of the water can be used for a long time by alternating between absorbing and releasing water. The process of releasing water can also be called the "regeneration" of the adsorbent. In particular, for an adsorbent that has absorbed enough water and has basically reached a saturated state, the water needs to be released before it can be put into use again, otherwise the water absorption effect will be greatly affected. However, the release of water requires that the liquid water be vaporized into water vapor through heating and other means within a period of time in order to separate it from the adsorbent. This requires not only time costs but also energy costs. If multiple batches of adsorbents are used for rotation around the clock, not only will a large amount of purchase costs be incurred, but the "regeneration" process of the adsorbent also needs to be carried out basically around the clock, which also requires a large amount of energy costs. Therefore, the present invention only purchases adsorbents in a quantity that meets or slightly exceeds the quantity required for use during the daytime period, which not only saves a lot of configuration costs, but also controls the "regeneration" period of the adsorbents. That is, the "regeneration" process of the adsorbents during the nighttime period can further reduce energy costs. This is because, for example, the use of electric energy is usually stipulated to have different unit prices corresponding to different time periods, and the price during the off-peak period (roughly corresponding to the nighttime period) will be much lower than the price during the peak period and the off-peak period, which also matches the "regeneration" period of the adsorbent selected by the present invention.

[0014] According to a preferred embodiment, a metal part arranged in the second exhaust duct can condense moisture in the exhaust air on the surface of the metal part when its own temperature is not higher than the current dew point temperature, wherein the metal part can reduce its temperature by contacting a cold source and maintain it at no higher than the current dew point temperature.

[0015] According to a preferred embodiment, the heat exchange unit can be turned on only when the first exhaust duct is switched to disabled and the second exhaust duct is switched to enabled, so that the energy on the heat source side and the cold source side of the heat exchange unit can be maximized per unit time.

[0016] Such a setting can not only make full use of the heat source and cold source of the heat exchange unit, avoiding the energy waste caused by the existing technology of only utilizing a single energy source, but also achieve the maximum recycling of water resources by alternately activating the first exhaust duct and the second exhaust duct at different times.

[0017] According to a preferred embodiment, when multiple exhaust ducts are switched, the switching timing can be preliminarily ranged based on the sunrise time and / or sunset time, and then determined based on the outdoor temperature obtained by a temperature sensor installed outside the greenhouse body.

[0018] According to a preferred embodiment, a temperature sensor located outside the greenhouse body can shorten the interval between outdoor temperature acquisitions by temporarily increasing its sampling frequency at sunrise or sunset, wherein the rate of change of the temperature sensor's sampling frequency gradually increases with the duration of the delay process. The delay process is the process from sunrise or sunset to any time later than that sunrise or sunset. Furthermore, the end point of a delay process is typically the time point when the outdoor temperature acquired by the temperature sensor reaches a set temperature threshold.

[0019] This configuration is designed so that even after sunrise or sunset, the outdoor temperature still experiences a delay before experiencing a sharp increase or decrease. Switching the exhaust duct at sunrise or sunset is likely inappropriate for the current scenario. By utilizing this delay, the switching point can be determined more accurately. Furthermore, during normal operation, the temperature sensor located outside the greenhouse body can acquire the outdoor temperature using an interval sampling method to reduce excessive, redundant, and unnecessary data, thereby alleviating computational and storage loads. Furthermore, the daily sunrise and sunset times can be estimated in advance. When the sunrise or sunset time of the day is reached, the sampling frequency of the temperature sensor located outside the greenhouse body is temporarily increased to more quickly acquire outdoor temperature data. The exact switching point is determined by comparing the sampling frequency with a preset threshold. The rate of change of the temperature sensor's sampling frequency can gradually increase as the delay increases. Once the exact switching point is determined, the first and second exhaust ducts are switched, and the temperature sensor located outside the greenhouse body returns to its original sampling frequency. This not only reduces the amount of data that needs to be processed during normal operation, thereby reducing the load on software and hardware, but also accurately determines the switching node by temporarily increasing the sampling frequency of the temperature sensor, avoiding the mismatch with the current scene due to inaccurate switching nodes (for example, too early or too late). In particular, when the switching node is too late, the outdoor temperature has already risen or fallen sharply. If the sudden temperature change cannot be responded to in time, it may affect the plants cultivated inside the main body of the greenhouse.

[0020] According to a preferred embodiment, the ventilation unit is provided with a humidifying element for pre-treating the air to be introduced from the outside of the greenhouse body, and the temperature and / or humidity of the air entering the interior of the greenhouse body are adjusted by the pre-treatment of the humidifying element, wherein the humidifying element, which is formed by alternatingly stacking at least two corrugated sheets of different angles, has a structural feature similar to a honeycomb. Preferably, the humidifying element can be configured as a wet curtain or have the same or similar structural features as the wet curtain, wherein the structural feature is roughly honeycomb-shaped and is formed by alternatingly stacking at least two corrugated sheets of different angles. Preferably, the air introduced from the outside of the greenhouse body or the air circulated from the inside of the greenhouse body can be connected to the corrugated sheet areas of different angles, so that the appropriate convection angle can be selected according to different temperature control requirements, thereby improving the efficiency of temperature control.

[0021] According to a preferred embodiment, when the first exhaust duct is switched to enabled and the second exhaust duct is switched to disabled, the moisture collected by the water collection assembly provided in the second exhaust duct can be drained to the top of the humidifying element, so that the liquid water can flow along the inclined corrugated sheet to the bottom of the humidifying element to moisten the air flowing through the humidifying element.

[0022] According to a preferred embodiment, when the first exhaust duct is switched to inactive and the second exhaust duct is switched to active, the water collection component arranged in the first exhaust duct can utilize the heat source of the heat exchange unit to release the moisture in the form of gaseous water and drain it to the bottom of the humidifying component, so that the gaseous water can escape to the top of the humidifying component along the inclined corrugated sheet to moisten the air flowing through the humidifying component. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the heat exchange process of a desert greenhouse ventilation system according to a preferred embodiment of the present invention;

[0024] Figure 2 It is a structural schematic diagram of a humidifying component according to a preferred embodiment of the present invention.

[0025] Reference Signs List

[0026] 100: ventilation unit; 110: humidification component; 120: adsorption component; 130: metal component; 140: water storage component; 200: heat exchange unit; 210: heat source side; 220: cold source side. DETAILED DESCRIPTION

[0027] The following is a detailed description with reference to the accompanying drawings.

[0028] While desert regions are rich in solar energy, they also face water scarcity. Greenhouses are often used in agriculture to address this water shortage, but current greenhouses are typically semi-enclosed. This is because solar radiation can cause temperatures inside the greenhouse to overheat, necessitating ventilation to cool the environment. However, ventilation removes water vapor released by plant transpiration, and 95% of the water absorbed by plants is used for transpiration. Directly relying on natural ventilation inevitably wastes water resources, especially in hot, dry, and water-scarce desert regions. Utilizing this renewable water resource would undoubtedly reduce greenhouse operating costs and facilitate long-term, stable greenhouse operation in the desert.

[0029] The present invention discloses a desert greenhouse ventilation system, which can realize the recycling and utilization of water resources in the air while meeting the ventilation requirements of the greenhouse, so as to avoid direct discharge of water vapor into the atmosphere during ventilation.

[0030] Preferably, the desert greenhouse ventilation system of the present invention is disposed within a closable greenhouse body, such that air flow between the interior and exterior of the greenhouse body can be controlled and regulated by the desert greenhouse ventilation system. Preferably, the greenhouse body is provided with one or more air inlets and one or more air outlets, allowing the interior of the greenhouse body to communicate directly or indirectly with the exterior.

[0031] Preferably, the desert greenhouse ventilation system may include a ventilation unit 100, wherein the ventilation unit 100 may be equipped with an air supply duct and an exhaust duct at the air inlet and air outlet, respectively. This ensures that air entering the greenhouse through the air inlet must first pass through the air supply duct before reaching the interior of the greenhouse body, and that air inside the greenhouse body must first pass through the exhaust duct before reaching the exterior of the greenhouse body. Furthermore, the ventilation unit 100 may be equipped with a power element to achieve the aforementioned air circulation process through negative or positive pressure.

[0032] This configuration is because there is typically a significant temperature difference between the interior and exterior of a greenhouse. Directly introducing air from outside the greenhouse into the interior can easily cause frequent temperature fluctuations, impacting the normal growth of the cultivated plants. Furthermore, the air inside the greenhouse contains a large amount of water vapor generated by transpiration from the plant's crown cuticle and stomata. Directly discharging the air from the greenhouse into the atmosphere would waste water resources. Therefore, the provision of ventilation unit 100 allows for effective regulation of the air flow between the interior and exterior of the greenhouse. Preferably, ventilation unit 100 is also configured with a circulation element to promote air flow within the greenhouse.

[0033] Preferably, the ventilation unit 100 may be provided with a humidifying element 110 on the outside of the power element, and the air moistened and temperature-controlled by the humidifying element 110 may enter the air supply duct under the drive of the power element. Further preferably, the humidifying element 110 may be configured as a wet curtain or have the same or similar structural features as the wet curtain, wherein the structural features are roughly honeycomb-shaped and composed of at least two corrugated sheets with different angles alternately stacked. Preferably, liquid water may be introduced from the top of the humidifying element 110, so that the liquid water can flow between the interlayers of the humidifying element 110 by utilizing gravity, thereby achieving the purpose of moistening and temperature-controlling the air passing through the humidifying element 110, wherein the liquid water flowing to the bottom of the humidifying element 110 can be collected in the water storage element 140 for recycling. Furthermore, the air entering the air supply duct may also include dry air that has not been moistened by the humidifying element 110. However, this air can be temperature-controlled through other heat exchange means to adjust the humidity of the air entering the greenhouse body. The mixing ratio of the air in the air supply duct can be adjusted by adjusting the opening of the corresponding valves. Furthermore, the amount of moist air entering the duct can be adjusted by the first valve, while the amount of dry air entering the duct can be adjusted by the second valve.

[0034] Preferably, the desert greenhouse ventilation system can be configured with a variety of sensors, including temperature and humidity sensors installed both inside and outside the greenhouse body to obtain environmental parameters inside and outside the greenhouse body. Furthermore, the ventilation unit 100 can be activated when the temperature outside the greenhouse body is higher than a preset standard temperature and the temperature inside the greenhouse body is higher than the temperature outside the greenhouse body, and execute the air circulation process based on the following control scheme:

[0035] According to the sampling period, the temperature inside the greenhouse body and the temperature outside the greenhouse body are collected through the temperature sensor, and the humidity inside the greenhouse body and the humidity outside the greenhouse body are collected through the humidity sensor;

[0036] Normalize the above parameters in turn to determine the input layer vector x = {x1, x2, x3, x4} of the three-layer BP neural network, where the input layer vectors are the internal temperature coefficient of the greenhouse body, the external temperature coefficient of the greenhouse body, the internal humidity coefficient of the greenhouse body, and the external humidity coefficient of the greenhouse body respectively;

[0037] Map the input layer vector to the middle layer to obtain the middle layer vector y={y1,y2,…y n}, where n is the number of middle-layer nodes;

[0038] Obtain an output layer vector o = {o1, o2, o3, o4}, where the output layer vectors are the speed adjustment coefficient of the circulating component, the speed adjustment coefficient of the power component, the opening adjustment coefficient of the first valve, and the opening adjustment coefficient of the second valve, respectively;

[0039] The rotation speed of the circulation part, the rotation speed of the power part, the opening of the first valve and the opening of the second valve are controlled to satisfy the following equation:

[0040] n c(i+1) =o1 i n c_max

[0041] n f(i+1) =o2 i n f_max

[0042] δ a(i+1) =o3 i δ a_max

[0043] δ b(i+1) =o4 i δ b_max

[0044] Among them, o1 i 、o2 i 、o3 i 、o4 i are the output layer vector parameters of the i-th sampling period, n c_max 、n f_max , δ a_max , δ b_max are the maximum speed of the circulation part, the maximum speed of the power part, the maximum opening of the first valve and the maximum opening of the second valve, respectively. c(i+1) 、n f(i+1) , δ a(i+1) , δ b(i+1) They are respectively the rotation speed of the circulation part, the rotation speed of the power part, the opening degree of the first valve and the opening degree of the second valve in the (i+1)th sampling period.

[0045] Preferably, the sensors configured for the desert greenhouse ventilation system may further include one or more concentration sensors, wherein when the concentration sensor detects that the oxygen concentration and / or carbon dioxide concentration inside the greenhouse body is lower than a preset value, the ventilation unit 100 may be activated.

[0046] Preferably, the exhaust duct may include a first exhaust duct and a second exhaust duct to achieve different exhaust processes by switching or operating in parallel, wherein different exhaust ducts may be provided with different water collection components. The purpose of providing two different exhaust ducts in the present invention is to enable different exhaust ducts to have different water resource recovery methods, so that they can be connected to corresponding exhaust ducts according to different application scenarios, thereby achieving maximum water resource recovery.

[0047] Preferably, a plurality of movable adsorbents 120 are provided in the first exhaust duct. The adsorbents 120 can be made of a porous material so that when air containing moisture passes through the adsorbents 120, the moisture is trapped within the adsorbents 120, thereby separating the moisture from the air. Preferably, the adsorbents 120 can be configured as metal-organic frameworks (MOFs), a highly versatile ultra-porous nanomaterial that captures and adsorbs moisture from the air through a specific framework structure formed by metal and organic coordination.

[0048] Exemplarily, when the adsorbent 120 is configured as a metal-organic framework, the following materials may be selected: MOF-303, MOF-801, MOF-841, aluminum fumarate, MIL-160, MIL-53, and / or aluminum phosphate. Preferably, the adsorbent 120 of the present invention may be composed of one or more materials. Preferably, the pore size of the metal-organic framework may be limited to a range of 0.5 to 1 nm, more preferably a range of 0.7 to 0.9 nm. Preferably, some types of metal-organic frameworks may have a hydrophilic pore structure, more preferably a hydrophilic pore structure having acid and / or amine functional groups.

[0049] Preferably, a metal part 130 with higher thermal conductivity is provided in the second exhaust duct, wherein the surface of the metal part 130 can adopt super-hydrophobic metal material or FTO glass material with nanostructure array.Alternatively, super-hydrophobic metal material includes copper, aluminum, iron or stainless steel.Preferably, considering that the exhaust duct is in a humid and oxygen-containing environment for a long time, it is easy to cause metal corrosion, stainless steel can be given priority when selecting the material on the surface of the metal part 130, and the metal part 130 can be configured to various structures such as plate-like, sheet-like or tubular.Preferably, because the metal part 130 usually has higher thermal conductivity, it can reach a lower temperature (for example, below dew point temperature) by means of the cold source provided by the lower night temperature in desert areas and / or other heat exchange devices, so that when the air containing moisture blows through the metal part 130, the moisture therein can be condensed on the metal part 130 surface, to achieve separation of moisture and air. Furthermore, since the surface of the metal part 130 is made of superhydrophobic material, water droplets condensed on its surface can flow along a predetermined route into the water storage part 140, wherein a guide groove can be set in a partial area of ​​the surface of the metal part 130 to achieve the effect of drainage and water collection.

[0050] Furthermore, the metal part 130 can also be the frame structure of the greenhouse body itself, so as to save costs by using one thing for multiple purposes. In other words, the second exhaust duct can contain part of the frame structure of the greenhouse body in its internal cavity, so that when the air flowing out from the interior of the greenhouse body passes through the second exhaust duct, the moisture contained in it can condense on the frame structure of the greenhouse body, and the water droplets can be drained into the water storage part 140 through the guide groove.

[0051] Preferably, considering that it is usually difficult for the adsorption member 120 or the metal member 130 to fully recover the moisture in the exhausted air, some moisture will still escape with the air to the outside of the greenhouse body, thereby causing a waste of water resources. The present invention can be provided with an auxiliary member downstream of the adsorption member 120 in the first exhaust duct and / or downstream of the metal member 130 in the second exhaust duct, wherein the movable auxiliary member can be placed at any specified position in the first exhaust duct and / or the second exhaust duct according to actual needs. Further preferably, since fertilizers are generally hygroscopic, the fertilizers to be applied can be placed in the auxiliary member so that the fertilizers can be moistened in advance before being put into use, thereby at least partially reducing the amount of water to be added to the corresponding plants after the fertilizers are applied to the plants.

[0052] Preferably, the first and second exhaust ducts are typically activated alternately in a switching manner. However, if any one exhaust duct fails to maintain a sufficient water recovery rate, both ducts can be activated in parallel to connect to the interior of the greenhouse body. Situations where water recovery is difficult to maintain include: excessive air flow through ventilation unit 100, excessive humidity inside the greenhouse body, or excessively high temperatures outside the greenhouse body. However, extreme situations are typically considered during design and a certain amount of redundancy is provided to ensure the proper operation of the desert greenhouse ventilation system.

[0053] Preferably, during normal operation, the first and second exhaust ducts can be alternately activated as follows: the first exhaust duct is activated approximately during the daytime period, and the second exhaust duct is activated approximately during the nighttime period. The daytime and nighttime periods can be roughly defined based on the daily sunrise and sunset times, and then fine-tuned based on the actual temperature monitored by a temperature sensor located outside the greenhouse body. In other words, in the present invention, the "daytime" and "nighttime" periods are not entirely separated by sunrise and sunset times. This is because even after sunrise or sunset, the outdoor temperature still experiences a delay before experiencing a sharp increase or decrease. Switching the exhaust duct at sunrise or sunset is likely inappropriate for the current scenario. Utilizing this delay allows for more accurate determination of the switching point. Furthermore, during normal operation, the temperature sensor located outside the greenhouse body can acquire the outdoor temperature using an interval sampling method to reduce unnecessary redundant data, thereby reducing computational and storage loads. Furthermore, the sunrise and sunset times of each day can usually be calculated in advance. When the sunrise or sunset time of the day is reached, the outdoor temperature data information is obtained more quickly by temporarily increasing the sampling frequency of the temperature sensor disposed outside the greenhouse body. The accurate switching node is determined by comparing the sampling frequency with a preset threshold, wherein the rate of change of the sampling frequency of the temperature sensor can gradually increase as the delay process increases. After the accurate switching node is obtained, the first exhaust duct and the second exhaust duct are switched, and the temperature sensor disposed outside the greenhouse body is restored to its original sampling frequency. This not only reduces the amount of data that needs to be processed during normal operation, thereby reducing the software and hardware load, but also accurately determines the switching node by temporarily increasing the sampling frequency of the temperature sensor, avoiding the situation where the switching node is inaccurate (for example, too early or too late) and does not match the current scene. In particular, when the switching node is too late, the outdoor temperature has already increased or decreased sharply. If the temperature change cannot be responded to in time, it may affect the plants cultivated inside the greenhouse body.

[0054] The reason why the present invention takes into account the switching problem between multiple exhaust ducts is that the exhaust process in the existing technology is usually relatively independent. Even if various water collection equipment is provided to realize the recycling of water resources, it can usually only achieve the function of recycling water, and at most it only reduces the operating costs. The desert greenhouse ventilation system of the present invention can include multiple working modes, so as to utilize the switching of exhaust ducts to cope with different scenarios. It not only realizes the efficient recovery of water resources in various scenarios, but also helps to assist in the regulation of the environmental parameters inside the greenhouse body, thereby realizing the scientific operation of the desert greenhouse.

[0055] Preferably, when a metal-organic framework (MOF) is selected as the adsorbent 120, considering procurement costs, it is generally advisable to purchase only the quantity required for daytime use. It is further preferred to purchase slightly more adsorbents 120 than this quantity to maintain a certain redundancy to facilitate replacement of damaged or failed adsorbents 120. Furthermore, the reason for preparing at least the number of adsorbents 120 required for daytime use is that plant transpiration is relatively higher during the daytime than during the nighttime. Therefore, the air discharged during the daytime contains more moisture, requiring adsorbents 120 with superior adsorption performance to capture this moisture, thereby reducing water waste. Furthermore, adsorbents 120 that have absorbed at least some moisture can be used for extended periods by alternating between absorbing and releasing moisture. This process of releasing moisture can also be referred to as "regeneration" of the adsorbent 120. In particular, adsorbents 120 that have absorbed sufficient moisture and reached a substantially saturated state must release this moisture before continued use; otherwise, the water absorption efficiency will be significantly affected. However, the release of water requires that the liquid water be vaporized into water vapor by heating or other means within a period of time in order to achieve separation from the adsorbent 120, which requires not only time costs but also energy costs. If multiple batches of adsorbents 120 are used for rotation around the clock, not only will a large amount of purchase costs be incurred, but the "regeneration" process of the adsorbent 120 will also basically need to be carried out around the clock, which also requires a large amount of energy costs. Therefore, the present invention only purchases adsorbents 120 that meet or slightly exceed the number required for use during the daytime period, which not only saves a large amount of configuration costs, but also controls the "regeneration" period of the adsorbent 120, that is, performing the "regeneration" process of the adsorbent 120 during the nighttime period can further reduce energy costs. This is because, for example, the use of electrical energy is usually stipulated to have different unit prices corresponding to different time periods, and the price during the valley period (roughly corresponding to the nighttime period) will be much lower than the price during the peak period and the off-peak period, which also matches the "regeneration" period of the adsorbent 120 selected by the present invention.

[0056] Preferably, the first exhaust duct can be activated roughly during the daytime, and the adsorbents 120 placed in the first exhaust duct can adsorb moisture in the exhaust air, and when switching to the second exhaust duct, the adsorbents 120 are "regenerated".

[0057] Preferably, if Figure 1As shown, for the "regeneration" process of the adsorbent 120, the desert greenhouse ventilation system may be configured with a heat exchange unit 200 to utilize the heat source generated by the heat exchange unit 200 to heat the adsorbent 120, thereby separating moisture from the adsorbent 120. Preferably, the desert greenhouse ventilation system may also be configured with a moving unit to move the adsorbent 120 that has absorbed sufficient moisture from the first exhaust duct to the heat exchange unit 200, and to move the adsorbent 120 that has substantially released all moisture out of the heat exchange unit 200. The adsorbent 120 removed from the heat exchange unit 200 may be moved back to the first exhaust duct or used for other purposes.

[0058] Preferably, the adsorbent element 120, having absorbed sufficient moisture, can be moved by a mobile unit to the heat source side 210 of the heat exchange unit 200. The heat provided by the heat exchange unit 200 can cause the liquid water stored in the porous structure of the adsorbent element 120 to be vaporized and separated from the adsorbent element 120 in the form of water vapor. Preferably, the "movement to the heat source side 210 of the heat exchange unit 200" described above can include any form of the adsorbent element 120 utilizing the heat source generated by the heat exchange unit 200, such as being positioned in the flow path of gas heated by the heat source. Furthermore, the separated hot and humid gas can be immediately utilized to maximize energy utilization. This utilization can include heating and humidifying the dry, cold air that has passed through the humidifying element 110. Due to the significant temperature difference between day and night in desert regions, the outdoor temperature of the greenhouse body is typically much lower than the indoor temperature during the nighttime hours. In other words, the outdoor temperature of the greenhouse body is lower than the normal growth temperature of the plants. Therefore, directly introducing dry, cold air from outside may cause significant fluctuations in the environmental parameters within the greenhouse body, which is detrimental to normal plant growth. Precisely for the reasons described above, the present invention cleverly implements a rapid secondary utilization of the hot and humid gas separated from the adsorption element 120. While minimizing energy loss, the hot and humid gas is directed to the humidifying element 110. Preferably, the hot and humid gas enters from the bottom of the humidifying element 110 to fill the entire interlayer space of the humidifying element 110. This allows the hot and humid gas to be fully mixed with the dry and cold air introduced into the humidifying element 110 by the power element, ensuring that the mixed gas entering the greenhouse body has an appropriate temperature and humidity. Preferably, upon reaching the top of the humidifying element 110, the hot and humid gas entering the humidifying element 110 can be returned to the heat source side 210 of the heat exchange unit 200 through a circulation pipeline to be reheated before being supplied to the humidifying element 110.

[0059] Preferably, if Figure 2As shown, to accommodate the aforementioned secondary utilization of hot and humid air, the present invention improves and optimizes the humidifying element 110. On the one hand, when the humidifying element 110 is needed to humidify and cool the introduced outside air (e.g., during daytime hours), liquid water can be introduced from the top of the humidifying element 110, allowing the liquid water to flow through the interlayer of the humidifying element 110 under the action of gravity. During this flow, part of the liquid water, driven by the power element, enters the interior of the greenhouse body along with the introduced outside air, while the remaining liquid water reaches the bottom of the humidifying element 110 and can be drained to the water storage element 140 for storage and recovery. On the other hand, when the humidifying element 110 is needed to humidify and heat the introduced external air (e.g., at night), gaseous water can be introduced from the bottom of the humidifying element 110, allowing liquid water to escape from the interlayer of the humidifying element 110 to the top of the humidifying element 110. During the escape process, part of the gaseous water enters the interior of the greenhouse body along with the introduced external air due to the driving action of the power element, while the remaining gaseous water reaches the top of the humidifying element 110 and can be drained to the heat source side 210 for recycling. Therefore, the present invention is provided with gaseous water and liquid water circulation channels at both the top and bottom of the humidifying element 110 to adapt to different situations.

[0060] Preferably, to avoid wasting energy on the cold source side 220 of the heat exchange unit 200, the metal member 130 in the second exhaust duct, which is put into use during the nighttime period, can fully utilize the cold source. Specifically, in a conventional process, after entering the nighttime period, the adsorbent 120 in the first exhaust duct is moved to the heat exchange unit 200, causing the first exhaust duct to temporarily lose its ability to recover water resources. The water recovery task is then taken over by switching to the second exhaust duct and utilizing the metal member 130 in the second exhaust duct. Furthermore, due to the lower outdoor temperature during the nighttime period, gaseous water is more likely to condense into liquid water on the surface of the metal member 130, thereby achieving water collection. Furthermore, since the gas exhausted from the interior of the greenhouse body typically has a certain temperature, more precisely, a temperature higher than the outdoor temperature, it is difficult to achieve a temperature of the metal member 130 that reaches or even falls below the dew point throughout the nighttime period solely by utilizing the cooling effect of the outdoor temperature. In particular, as time passes, the temperature of the metal member 130 will continue to rise, causing the condensation efficiency of the water to gradually decrease, thus failing to achieve the goal of efficient water recovery. The heat exchange unit 200 of the present invention can provide a continuous cold source for the metal part 130 to reduce the temperature of the metal part 130 (especially its surface) and maintain it at or below the dew point temperature of the current environment, thereby meeting the condensation conditions.

[0061] Such a setting can not only make full use of the heat source and cold source of the heat exchange unit 200, avoiding the energy waste caused by the existing technology of only utilizing a single energy source, but also achieve the maximum recycling of water resources by alternately activating the first exhaust duct and the second exhaust duct at different times.

[0062] Preferably, if the greenhouse body does not need to be ventilated during the night period, the heat source side 210 and the cold source side 220 of the heat exchange unit 200 can also be directly connected to form a circulation channel, so that the gaseous water separated from the adsorption element 120 on the heat source side 210 can be directly introduced into the cold source side 220 for cooling and liquefaction, and then the liquid water can be directly collected into the water storage element 140.

[0063] Preferably, humidity sensors may be installed upstream and downstream of the first exhaust duct where the adsorbents 120 are installed, respectively, to determine the overall moisture absorption level of all adsorbents 120. For first exhaust ducts that also include auxiliary components, the humidity sensors may be installed upstream of the auxiliary components. Preferably, corresponding humidity sensors may also be installed in the second exhaust duct, similar to those in the first exhaust duct, i.e., the humidity sensors in the second exhaust duct may also be installed upstream of the auxiliary components.

[0064] Furthermore, the unit water absorption capacity of each adsorbent 120 can be calculated based on the overall moisture absorption degree of all adsorbents 120, and then the output power of the heat exchange unit 200 can be calculated in combination with the operating parameters of the ventilation unit 100 and the current dew point temperature, the length of the night period and other factors.

[0065] Preferably, the desert greenhouse ventilation system of the present invention may be configured with a processing unit for receiving signals, processing data and generating instructions.

[0066] It should be noted that the above-mentioned specific embodiments are exemplary, and those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the present invention specification and its drawings are illustrative and do not constitute a limitation on the claims. The scope of protection of the present invention is defined by the claims and their equivalents. The present invention specification contains multiple inventive concepts, such as "preferably", "according to a preferred embodiment" or "optionally", all of which indicate that the corresponding paragraph discloses an independent concept, and the applicant reserves the right to file a divisional application based on each inventive concept. Throughout the text, the features guided by "preferably" are only an optional method and should not be understood as having to be set, so the applicant reserves the right to abandon or delete the relevant preferred features at any time.

Claims

1. A desert greenhouse ventilation system, comprising: The ventilation unit (100) is used to regulate the air flow between the inside and outside of the greenhouse body, It is characterized by: The ventilation unit (100) comprises at least two exhaust pipes respectively provided with different types of water collecting components, so as to recover moisture contained in the exhaust air by alternate activation and / or parallel activation, wherein: When the first exhaust duct is switched to inactive and the second exhaust duct is switched to active, the water collection component provided in the first exhaust duct can share the same heat exchange unit (200) with the water collection component provided in the second exhaust duct by respectively utilizing the heat source and the cold source of the heat exchange unit (200).

2. The system according to claim 1, wherein: The water collection component arranged in the first exhaust duct includes an adsorption component (120) having a porous structure, and the water collection component arranged in the second exhaust duct includes a metal component (130) whose surface is made of a super-hydrophobic metal material, wherein an auxiliary component is arranged downstream of the adsorption component (120) arranged in the first exhaust duct and / or downstream of the metal component (130) arranged in the second exhaust duct.

3. The system according to claim 2, characterized in that The adsorption element (120) disposed in the first exhaust duct can, after intercepting at least a portion of the moisture, vaporize liquid water into gaseous water by contacting a heat source to release the moisture, wherein the adsorption element (120) that has adsorbed at least a portion of the moisture can be moved from the first exhaust duct to the heat source side (210) of the heat exchange unit (200) under the drive of a moving unit.

4. The system according to claim 2, wherein: The metal part (130) arranged in the second exhaust duct can condense moisture in the exhaust air on the surface of the metal part (130) when its own temperature is not greater than the current dew point temperature, wherein the metal part (130) can reduce its temperature by contacting a cold source and maintain it at a temperature not greater than the current dew point temperature.

5. The system according to claim 1, wherein: The heat exchange unit (200) can be turned on only when the first exhaust duct is switched to inactive and the second exhaust duct is switched to active, so that the energy of the heat source side (210) and the cold source side (220) of the heat exchange unit (200) can be maximized within a unit time.

6. The system according to claim 1, wherein: When multiple exhaust ducts are switched, the switching timing can be preliminarily ranged based on the sunrise time and / or sunset time, and then determined according to the outdoor temperature obtained by the temperature sensor installed outside the greenhouse body.

7. The system according to claim 6, characterized in that The temperature sensor arranged outside the greenhouse body can shorten the outdoor temperature acquisition interval by temporarily increasing the sampling frequency when reaching the sunrise time or sunset time node, wherein the rate of change of the sampling frequency of the temperature sensor gradually increases with the length of the delay process.

8. The system according to claim 1, wherein: The ventilation unit (100) is provided with a humidifying element (110) for pre-treating air to be introduced from outside the greenhouse body, and the temperature and / or humidity of the air entering the interior of the greenhouse body are adjusted through the pre-treatment of the humidifying element (110). The humidifying element (110) is composed of at least two corrugated sheets with different angles alternately stacked together and has a honeycomb-like structural feature.

9. The system according to claim 8, characterized in that When the first exhaust duct is switched to enabled and the second exhaust duct is switched to disabled, the moisture collected by the water collecting assembly arranged in the second exhaust duct can be drained to the top of the humidifying element (110), so that the liquid water can flow along the inclined corrugated sheet to the bottom of the humidifying element (110) to moisten the air flowing through the humidifying element (110).

10. The system according to claim 8, wherein: When the first exhaust duct is switched to inactive and the second exhaust duct is switched to active, the water collecting component arranged in the first exhaust duct can utilize the heat source of the heat exchange unit (200) to release the moisture in the form of gaseous water and guide it to the bottom of the humidifying component (110), so that the gaseous water can escape along the inclined corrugated sheet to the top of the humidifying component (110) to moisten the air flowing through the humidifying component (110).

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