Plant factory temperature and humidity control method based on targeted ventilation

Abstract

The invention provides a plant factory temperature and humidity control method based on targeted ventilation, which comprises the following steps: firstly controlling the temperature of a cultivation layer to reach a preset target temperature range, then controlling the humidity of the cultivation layer to reach a preset target humidity range, in the humidity control process, firstly calculating to obtain the required humidification humidity time, carrying out humidification for a corresponding humidification time length, and then controlling the temperature of the cultivation layer to reach the preset target humidity range. The real-time humidity of the cultivation layer is detected again, if the real-time humidity is lower than or higher than the target humidity range, the humidification device and the electromagnetic valve are switched on and off through different switching frequency cycles, so that the real-time humidity of the cultivation layer accurately reaches the target humidity range, and the situation that when humidification is stopped after the humidification duration, the humidification time is shortened is avoided. A large amount of fog drops continuously enter the cultivation layer, so that the humidity of the cultivation layer exceeds the target humidity range, and healthy growth of plants is affected.

Description

Technical Field

[0001] This invention relates to the field of intelligent control technology for plant factories, specifically to a method for controlling temperature and humidity in plant factories based on targeted ventilation. Background Technology

[0002] In recent years, with the rapid development of modern agriculture, especially with the development of emerging software and information technology services, these technologies have been widely applied in agriculture to achieve intelligent control, resulting in different agricultural cultivation and planting models. For example, plant factories are a highly efficient agricultural model that achieves year-round continuous crop production through artificial environmental control. In such agricultural models, temperature and humidity are key environmental factors affecting crop growth, yield, and quality, playing a crucial role in plant factories. By precisely controlling environmental factors such as temperature, humidity, and carbon dioxide concentration, plant growth conditions can be optimized, thereby improving crop yield and quality.

[0003] For example, Chinese patent application No. 202510074958.3, published on April 4, 2025, and classified under G06F30, discloses a method for determining the optimal ventilation volume in a plant factory. By simulating the ventilation conditions of a plant factory, it was found that the Reynolds number and Archimedes number can well characterize the changes in environmental parameters in the plant factory. Specific values ​​of the Reynolds number and Archimedes number that can balance the distribution of optimal environmental parameters and lower ventilation energy consumption in the plant factory were selected as the basis for calculating and judging the optimal ventilation volume in the plant factory. This method maximizes the achievement of an ideal cultivation environment in the cultivation area while using the minimum ventilation volume to save energy consumption for environmental control and ensures a stable flow field in the cultivation area.

[0004] The aforementioned literature calculates the total ventilation volume Qin,1 by setting a target temperature difference ΔT, and judges the flow field stability based on the Reynolds number Re and Archimedes number Ar. When the flow field is unstable, the optimal ventilation volume is calculated based on the critical values ​​of the Reynolds number and Archimedes number. However, it only controls the ventilation volume by the difference between the actual temperature and the target temperature. When the actual temperature is high, simple ventilation cannot quickly cool the temperature. Furthermore, ventilation makes it impossible to meet the humidity requirements. Humidity is also an essential factor for plant growth. A certain humidity level needs to be maintained during the initial growth stage of plants to ensure crop growth. Simply adding humidifiers without proper humidity control cannot accurately achieve the appropriate humidity and temperature requirements. Summary of the Invention

[0005] The purpose of this invention is to provide a plant factory temperature and humidity control method based on targeted ventilation, which improves the reliability of temperature and humidity regulation in the cultivation layer, effectively reduces relative humidity overshoot, and achieves precision crop cultivation.

[0006] To achieve the above objectives, the present invention provides a plant factory temperature and humidity control method based on targeted ventilation, which is implemented by a plant factory temperature and humidity control device. The plant factory temperature and humidity control device includes a control module, a humidification device, a cooling device, and two or more cultivation layers stacked vertically. The humidification device and the cooling device are both installed on the main pipe, and the targeted ventilation pipe embedded in the cultivation layer is connected to the main pipe through a solenoid valve. It also includes the following steps: S1 presets a target temperature T and a target temperature deviation value δ. The target temperature T then ranges from [T-δ, T+δ]. The real-time temperature T inside the culture layer is then detected by a temperature and humidity sensor installed on the culture layer. s If the real-time temperature is not within the preset target temperature range, the solenoid valve of the corresponding culture layer will be opened to input cold air through the refrigeration device. S2 repeats step S1 until the real-time temperature T of all culture layers is reached. s When the target temperature T is within the specified range, turn off the refrigeration device; proceed to step S3; S3 presets the target humidity RH and the target humidity range, and detects the real-time humidity RH within the culture layer. s The real-time humidity (RH) is calculated by measuring the atomization rate of droplets delivered by the humidification device within the cultivation layer and the amount of water vapor reaching the target temperature. s Humidification time to reach the target humidity (RH) t 1. Open the solenoid valve of the culture layer via the control module to activate the humidification device and humidify the culture layer. t After 1 hour, turn off the humidifier and check the real-time humidity (RH) of each culture layer. s If the real-time humidity is lower than the preset range, the control module controls the humidifier and solenoid valve to open by cycling between the first preset frequency and the second preset frequency. The first preset frequency and the second preset frequency are the preset opening time and the preset closing time, until the real-time humidity is within the target humidity range.

[0007] In the above method, during the process of controlling the temperature and humidity of the cultivation layer, since the humidity is greatly affected by the temperature formed by the refrigeration device, the temperature of the cultivation layer is first controlled to reach the preset target temperature range, and then the humidity of the cultivation layer is controlled to reach the preset target humidity range. During the process of controlling the humidity, the required humidification time is first calculated based on the target humidity water vapor amount and the atomization rate, and after humidifying for the corresponding humidification duration, the real-time humidity of the cultivation layer is detected again. If the real-time humidity is lower or higher than the target humidity range, the humidification device and the solenoid valve are cycled through different switching frequencies so that the real-time humidity of the cultivation layer accurately reaches within the target humidity range. This avoids a large number of droplets continuing to enter the cultivation layer when humidifying after the humidification duration and the humidity does not meet the requirements, which may cause the humidity of the cultivation layer to exceed the target humidity range and thus affect the healthy growth of plants. Instead, by a frequency of closing for a period of time and then opening for a period of time, and the opening frequency gradually decreases, it makes the humidification process gradually enter after the humidification time through pulse control, so that there will be no problem of a large number of droplets entering the cultivation layer, and the relative humidity is relatively large, so that the target humidity can be more reliably achieved and it is also more beneficial to the growth of plants.

[0008] Further, step S3 includes: S3.1 Preset the target humidity deviation value as γ, and the target humidity value range is [RH - γ, RH + γ]. When RH s < RH - γ, open the humidification device and the solenoid valve. The first preset frequency is to close for 1 s after opening for 2 s, and the second preset frequency is to close for 2 s after opening for 1 s. The control module controls the humidification device and the solenoid valve through the frequency cycle between the first preset frequency and the second preset frequency until the real-time humidity RH s is within the value range [RH - γ, RH + γ] of the target humidity RH, then close the humidification device and the corresponding solenoid valve; when RH s > RH + γ, close the humidification device and the solenoid valve; S3.2 Repeat step S3.1 until the real-time humidity RH of all cultivation layers s is within the value range of the target humidity RH, then close the humidification device and the humidification ends.

[0009] With the above settings, when the real-time humidity is greater than the humidity value range, the humidification device and the solenoid valve are directly closed, so that the humidity amount can be controlled more quickly.

[0010] Further, the temperature and humidity control device of the plant factory further includes a fixed frame body, and the control module, the humidification device, and the refrigeration device are all fixedly installed on the fixed frame body, and the cultivation layers are stacked along the height direction of the fixed frame body.

[0011] The above settings facilitate the connection of the humidifying device and the refrigerating device to multiple cultivation layers on the fixed frame body through the main pipeline, thereby precisely controlling the temperature and humidity.

[0012] Further, one end of the main pipeline close to the refrigerating device is provided with a fan and a flowmeter on one side of the fan. The main pipeline is divided into a first main pipeline and a second main pipeline on one side of the flowmeter. The first main pipeline is respectively connected to each target ventilation pipeline embedded in the cultivation layer, and a solenoid valve is provided on the target ventilation pipeline. The second main pipeline is connected to the humidifying device. A cultivation tank is provided in the cultivation layer. The target ventilation pipeline is arranged at the inner top end of the cultivation layer. A temperature and humidity sensor is provided in the cultivation layer. A target ventilation hole is provided on one side of the target ventilation pipeline close to the cultivation tank.

[0013] The above settings separate the humidifying device from the refrigerating device through the second main pipeline, so as to facilitate the precise control of temperature and humidity successively, and facilitate the spraying of cold air and droplets to the cultivation tank through the target ventilation holes to control the temperature and humidity required by the plants in the cultivation layer at different growth stages.

[0014] Further, in the step S1, it further includes: When the real-time temperature T in the cultivation layer s = T + δ or T s > T + δ, the refrigerating device conveys cold air to the main pipeline, and the flowmeter on the main pipeline detects the cold air flow. Then, the solenoid valve on the target ventilation pipeline in the corresponding cultivation layer is opened, and the cold air is sprayed to the cultivation tank through the target ventilation holes of the target ventilation pipeline until the temperature and humidity sensor detects that the real-time temperature T in the cultivation layer s = T - δ, and the control module closes the solenoid valve of the corresponding cultivation layer.

[0015] The above settings can timely convey cold air through the refrigerating device and open the corresponding solenoid valve when the real-time temperature T in the cultivation layer s > T + δ, so that the cold air is conveyed into the cultivation layer, achieving the effect of timely and precise cooling, and avoiding the excessive real-time temperature in the cultivation layer from affecting the growth of plants. When the real-time temperature T in the cultivation layer s = T - δ, the solenoid valve of the corresponding cultivation layer is closed. In this way, only the residual cold air in the target ventilation pipeline is connected to the cultivation layer. Compared with closing the solenoid valve when T s < T - δ, it can effectively reduce the excessive cold air from continuing to enter the target ventilation pipeline, avoiding the real-time temperature T in the cultivation layer s < T - δ and causing the temperature to be too low to affect the growth of plants, thereby ensuring that the real-time temperature T in the cultivation layer s is precisely controlled within the target temperature T value range [T - δ, T + δ].

[0016] Further, in step S1, it further includes: If the real-time temperature T in the cultivation layer is detected by the temperature and humidity sensor s < T - δ, the solenoid valve of the corresponding cultivation layer is closed, and then it is left standing until the real-time temperature T in the cultivation layer is detected by the temperature and humidity sensor s When it is within the target temperature T value range [T - δ, T + δ], step S2 is entered.

[0017] With the above settings, it can ensure that the real-time temperature T in each cultivation layer s is within the target temperature T value range [T - δ, T + δ], avoiding affecting the subsequent humidity control in the cultivation layer.

[0018] Further, in step S3, it further includes the humidification time t 1 is calculated by formula (1): (1) t 1 is the humidification time; Δ m is the mass of water vapor required for humidification; S is the total surface area of the fog droplets; G is the fog droplet evaporation coefficient, which is calculated by formula (2): (2) T is the preset target temperature, RH is the preset target humidity, is the wind speed.

[0019] With the above settings, the time required to humidify to the preset target humidity can be accurately calculated. <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0021] With the above settings, it is possible to accurately calculate the amount of water vapor Δ required to change from the real-time temperature T s to the target temperature T m and the corresponding atomization rate a .

[0022] Furthermore, in the step S3, it further includes: the atomization rate a corresponding to the number of atomized droplets n is: (5), R where represents the droplet diameter, is the density of water, kg / m 3 ; Then, through the number of atomized droplets n calculate the total area S of the atomized droplets, (6), By联立公式(在这里“联立公式”直接保留中文表述即可,因为它是一个特定的术语,在专利文本中可能不需要翻译得太详细,以免影响专业性和准确性)(1), (5) and (6), we get: (7).

[0023] With the above settings, it is possible to accurately calculate the total area of the atomized droplets, and further calculate the humidification time.

[0024] Furthermore, in the step S3.1, it further includes: When RH s < RH - γ, the control module controls the switches of the humidification device and the solenoid valve in a cycle of turning on for 2 s and then turning off for 1 s until the real-time humidity RH s = RH + γ, then turn off the humidification device and the corresponding solenoid valve; when RH s > RH + γ, turn off the humidification device and the solenoid valve of the corresponding cultivation layer.

[0025] With the above settings, when the real-time humidity in the cultivation layer is, the solenoid valve of the corresponding cultivation layer is turned off, so that only the residual droplets in the targeted ventilation duct are connected to the cultivation layer. Compared with turning off the solenoid valve when RH s > RH + γ, it can effectively reduce the excessive droplets from continuing to enter the targeted ventilation duct, and avoid the real-time humidity RH in the cultivation layer s > RH + γ, which may cause excessive humidity and affect plant growth. When RH s > RH + γ, turning off the humidification device and the solenoid valve of the corresponding cultivation layer can timely stop the humidification device from delivering droplets, and avoid continuing to deliver excessive droplets into the targeted ventilation duct, so as to prevent excessive droplets remaining in the targeted ventilation duct from flowing into the cultivation layer and causing excessive humidity in the cultivation layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flowchart of the present invention.

[0027] Figure 2 This is a schematic diagram showing the humidity comparison at different points on the culture tank in this invention.

[0028] Figure 3 This is a structural block diagram of the present invention. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 As shown, a plant factory temperature and humidity control method based on targeted ventilation is implemented through a plant factory temperature and humidity control device. The plant factory temperature and humidity control device includes a fixed frame, a control module 11, a humidifier 6, a refrigeration device 1, and two or more cultivation layers 8 stacked vertically. The control module 11, the humidifier 6, and the refrigeration device 1 are all fixedly installed on the fixed frame. The humidifier 6 and the refrigeration device 1 are both set on the main pipe 2. The cultivation layers 8 are stacked along the height direction of the fixed frame. A fan 12 and a flow meter 13 located on one side of the fan 12 are provided on one end of the main pipe 2 near the refrigeration device 1. A first main pipe 3 and a second main pipe 5 are formed on the side of the flow meter 13 on the main pipe 2. The first main pipe 3 is connected to each targeted ventilation pipe 10 embedded in the cultivation layer, and a solenoid valve 4 is provided on the targeted ventilation pipe 10. The second main pipe 5 is connected to the humidifier 6. In this way, the humidifier 6 and the refrigeration device 1 are separated by the second main pipe 5 to facilitate precise control of temperature and humidity. In this embodiment, the humidification device is a humidifier and the refrigeration device is a refrigerator, both of which are existing technologies and will not be described in detail here.

[0031] In this embodiment, a cultivation trough is provided inside the cultivation layer, and a targeted ventilation duct 10 is set at the top inner side of the cultivation layer. A temperature and humidity sensor 7 is provided inside the cultivation layer, and a targeted ventilation hole 9 is provided on the side of the targeted ventilation duct 10 near the cultivation trough. In this embodiment, the targeted ventilation hole is a through-hole structure set on the targeted ventilation duct. The specific structure of the targeted ventilation hole is the prior art and will not be described in detail here. This facilitates the spraying of cold air and mist droplets onto the cultivation trough through the targeted ventilation hole to control the temperature and humidity required by the plants in the cultivation layer at different growth stages.

[0032] like Figure 1 As shown, a method for controlling temperature and humidity in a plant factory based on targeted ventilation includes the following specific steps: S1 presets a target temperature T and a target temperature deviation value δ. The target temperature T then ranges from [T-δ, T+δ]. The real-time temperature T inside the culture layer is then detected by a temperature and humidity sensor installed on the culture layer.s When the real-time temperature T in the cultivation layer s = T + δ or T s > T + δ, the refrigeration device conveys cold air to the main pipeline through the exhaust fan, and detects whether cold air enters the main pipeline through the flowmeter on the main pipeline. At the same time, the solenoid valve corresponding to the cultivation layer is opened through the control module, and the cold air is conveyed to the cultivation tank in the cultivation layer through the target ventilation holes of the target ventilation pipeline to achieve temperature reduction. When the real-time temperature T in the cultivation layer detected by the temperature and humidity sensor s = T - δ, the solenoid valve corresponding to the cultivation layer can be closed in advance, so that only the residual cold air in the target ventilation pipeline is connected to the cultivation layer. Compared with closing the solenoid valve when T s < T - δ, it can effectively reduce excessive cold air from continuing to enter the target ventilation pipeline. When the real-time temperature T in the cultivation layer detected by the temperature and humidity sensor s < T - δ, the solenoid valve corresponding to the cultivation layer is closed through the control module, and then it is left to stand until the real-time temperature T in the cultivation layer is detected by the temperature and humidity sensor s When it is within the target temperature T value range [T - δ, T + δ], step S2 is entered, so as to ensure that the real-time temperature T in the cultivation layer s is accurately controlled within the target temperature T value range [T - δ, T + δ].

[0033] S2 Repeat step S1 until the real-time temperature T of all cultivation layers s is within the target temperature T value range [T - δ, T + δ], the refrigeration device is turned off, and the temperature reduction ends; step S3 is entered; S3 Preset the target humidity RH and the target humidity deviation value γ. The target humidity RH value range is [RH - γ, RH + γ], and then the real-time humidity RH in the cultivation layer is detected by the temperature and humidity sensor s , when the temperature and humidity sensor detects the real-time temperature T in the cultivation layer s = T and the real-time humidity RH s = RH, record the mass of the corresponding environmental water vapor in the cultivation layer at this moment m 2; at the same time, record the real-time temperature T s and the real-time humidity RH s when the mass of the corresponding environmental water vapor in the cultivation layer m 1, and then calculate the water vapor amount Δ s from the real-time temperature T m to the target temperature T through formula (3), and record the corresponding time t 2, (3), In this embodiment, at the real-time temperature T s and the real-time humidity RHs The mass of environmental water vapor within the cultivation layer at that time m 1. Calculated using formula (3.1): (3.1), in, V It is the volume of gas, and the unit is m. 3 ; r It is a preset proportional coefficient, which is related to the type of air. P 1 is the real-time temperature. T s Absolute humidity and pressure, in Pa; absolute humidity and pressure P 1. Calculated using formula (3.2): (3.2), P 0.1 This is the saturated vapor pressure, expressed in Pa. Real-time temperature T s =T and real-time humidity RH s Mass of water vapor at RH m 2. Calculated using formula (3.3): (3.3), in, V It is the volume of gas, in meters (m). 3 ; r It is a proportionality coefficient, which is related to the type of air. P 2 is the target temperature T Absolute humidity and pressure, in Pa; absolute humidity and pressure P 2. Calculated using formula (3.4): (3.4), P 0.1 This is the saturated vapor pressure, expressed in Pa. This allows us to calculate the atomization rate of the humidifier. a , (4), Then, since the droplet diameter of ultrasonic atomization follows a normal distribution, the atomization rate is calculated. a The corresponding number of atomized droplets n : (5), In the formula R Represents the droplet diameter. This is the density of water, expressed in kg / m³. 3 ; Next, by the number of atomized dropletsn Calculate the total surface area S of the atomized droplets, (6), And the humidification time t 1 is calculated through formula (1), (1), In the formula, t 1 is the humidification time, with the unit of s; Δ m is the mass of water vapor required for humidification, with the unit of kg; S is the total surface area of the fog droplets, with the unit of m 2 ; G is the evaporation coefficient of the fog droplets, with the unit of kg / m 2 / s, which is calculated through formula (2): (2), In the formula, T is the preset target temperature, RH is the preset target humidity, is the wind speed; Combining formulas (1), (5) and (6) gives: (7); In this way, the atomization rate of the fog droplets transported by the humidification device in the cultivation layer a、 the evaporation coefficient of the fog droplets G and the mass of water vapor required for humidification Δ m are used to calculate the real-time humidity RH s the humidification time to humidify to the target humidity RH t 1, then the solenoid valve of the cultivation layer is opened through the control module, and the humidification device is turned on to humidify the cultivation layer t After 1 duration, the humidification device is turned off and the real-time humidity RH of each cultivation layer is detected s , and step S3.1 is entered, S3.1 When RH s < RH - γ, the humidification device and the solenoid valve are opened again. In this embodiment, the control module controls the opening and closing of the humidification device and the solenoid valve in a cycle with a frequency of turning on for 2 s and then turning off for 1 s. When the real-time humidity RH s = RH + γ, the humidification device and the corresponding solenoid valve are turned off in advance. In this way, only the residual fog droplets in the target ventilation duct are connected to the cultivation layer. Compared with turning off the solenoid valve when RH s > RH + γ, it can effectively reduce the excessive fog droplets from continuing to enter the target ventilation duct, and avoid the real-time humidity RH in the cultivation layer s > RH + γ, which may cause excessive humidity and affect plant growth. And when RH sWhen RH+γ, shut off the humidifier and solenoid valve to promptly stop the humidifier from delivering droplets, thus preventing excessive droplets from being delivered into the targeted ventilation duct. This would prevent excessive droplets remaining in the targeted ventilation duct from flowing into the cultivation layer and causing the humidity of the cultivation layer to be too high. Proceed to step S3.2. S3.2 Repeat step S3.1 until the real-time humidity (RH) of all culture layers is reached. s When the target humidity RH is within the range of [RH-γ, RH+γ], turn off the humidifier and humidification ends.

[0034] In this embodiment, the test data obtained after steps S1 to S3 are shown in Table 1 below. Table 1

[0035] Based on the test data in Table 1 and combined with Figure 2 By performing steps S1-S3, the real-time humidity (RH) within the culture layer can be obtained. s All humidity levels fluctuated within the target RH range, while the real-time humidity of the control group was both too low and too high, indicating that humidification was more effective for the plants in the cultivation layer.

[0036] The working principle of this invention is as follows: During the temperature and humidity control of the cultivation layer 8, since the humidity is greatly affected by the temperature generated by the refrigeration device, the temperature of the cultivation layer 8 is first controlled to reach the preset target temperature range, and then the humidity of the cultivation layer 8 is controlled to reach the preset target humidity range. During humidity control, the required humidification time is calculated based on the target humidity water vapor content and atomization rate. After humidification for the corresponding duration, the real-time humidity of the cultivation layer is detected again. If the real-time humidity is lower or higher than the target humidity range, the humidification device 6 and the solenoid valve are cyclically switched on and off at different switching frequencies to ensure the humidity of the cultivation layer... Real-time humidity is precisely maintained within the target humidity range. This avoids the situation where humidification is applied after the required duration but the humidity level is not yet met, causing a large number of droplets to continue entering the cultivation layer and exceeding the target humidity range, thus affecting plant health. Instead, it uses a frequency of turning off the humidifier for a period of time and then turning it on for a period of time, with the frequency of turning it on gradually decreasing. This pulse control ensures that the humidification process is gradual after the required duration, preventing a large number of droplets from entering the cultivation layer and causing relatively high humidity. This allows for more reliable achievement of the target humidity and is more conducive to plant growth.

Claims

1. A method for controlling temperature and humidity in a plant factory based on targeted ventilation, implemented through a plant factory temperature and humidity control device, the plant factory temperature and humidity control device comprising a control module, a humidification device, a cooling device, and two or more cultivation layers stacked vertically, wherein the humidification device and the cooling device are both mounted on a main duct, and a targeted ventilation duct embedded in the cultivation layer is connected to the main duct via a solenoid valve; characterized in that: Includes the following steps: S1 presets a target temperature T and a target temperature deviation value δ. The target temperature T ranges from [T-δ, T+δ]. It detects the real-time temperature T within the culture layer. s If the real-time temperature is not within the preset target temperature range, the solenoid valve of the corresponding culture layer will be opened to input cold air through the refrigeration device. S2 repeats step S1 until the real-time temperature T of all culture layers is reached. s When the target temperature T is within the range, turn off the refrigeration device and proceed to step S3; S3 presets the target humidity (RH) and target humidity range, and detects the real-time humidity (RH) within the culture layer. s The real-time humidity (RH) is calculated by measuring the atomization rate of droplets delivered by the humidification device within the cultivation layer and the amount of water vapor reaching the target temperature. s Humidification time to reach the target humidity (RH) t 1. Open the solenoid valve of the culture layer via the control module to activate the humidification device and humidify the culture layer. t After 1 hour, turn off the humidifier and check the real-time humidity (RH) of each culture layer. s If the real-time humidity is lower than the preset range, the control module controls the humidifier and solenoid valve to open by cyclically controlling the frequency between the first preset frequency and the second preset frequency. The first preset frequency and the second preset frequency are the preset opening time and the preset closing time, until the real-time humidity is within the target humidity range.

2. The method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 1, characterized in that: Step S3 includes: S3.1 Preset the target humidity deviation value as γ, and the target humidity value range is [RH - γ, RH + γ]. When RH s < RH - γ, turn on the humidifying device and the solenoid valve. The first preset frequency is to close for 1 s after 2 s of opening, and the second preset frequency is to close for 2 s after 1 s of opening. The control module controls the humidifying device and the solenoid valve through the frequency cycle between the first preset frequency and the second preset frequency until the real-time humidity RH s is within the target humidity value range, then turn off the humidifying device and the corresponding solenoid valve; when RH s > RH + γ, turn off the humidifying device and the solenoid valve; S3.2 Repeat step S3.1 until the real-time humidity (RH) of all culture layers is reached. s When the humidity is within the target range, turn off the humidifier to end humidification.

3. The method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 1, characterized in that: The plant factory temperature and humidity control device also includes a fixed frame, and the control module, humidification device and refrigeration device are all fixedly installed on the fixed frame. The cultivation layer is stacked along the height direction of the fixed frame. The cultivation layer is provided with a cultivation trough, and the targeted ventilation duct is located at the top of the inner side of the cultivation layer. The cultivation layer is provided with a temperature and humidity sensor, and the targeted ventilation duct is provided with a targeted ventilation hole on the side near the cultivation trough.

4. The method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 1, characterized in that: The main pipe is equipped with a fan and a flow meter on one side of the fan at one end near the cooling device. A first main pipe and a second main pipe are formed on the side of the flow meter. The first main pipe is connected to each of the targeted ventilation pipes embedded in the cultivation layer, and a solenoid valve is provided on the targeted ventilation pipe. The second main pipe is connected to the humidification device.

5. The method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 1, characterized in that: Step S1 further includes: When the real-time temperature T in the culture layer s =T+δ or T s When the temperature exceeds T+δ, the refrigeration unit delivers cold air to the main pipeline and detects the flow rate using a flow meter on the main pipeline. Then, it opens the solenoid valve on the targeted ventilation duct within the corresponding culture layer, spraying the cold air onto the culture tank through the targeted ventilation holes in the targeted ventilation duct until the temperature and humidity sensor detects the real-time temperature T within the culture layer. s When the value is equal to T-δ, the control module closes the solenoid valve of the corresponding culture layer.

6. The method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 1, characterized in that: Step S1 further includes: If the temperature and humidity sensor detects the real-time temperature T in the cultivation layer s <When T < T - δ, close the solenoid valve of the corresponding cultivation layer, and then wait statically until the temperature and humidity sensor detects the real-time temperature T in the cultivation layer s When the target temperature T is within the value range [T - δ, T + δ], proceed to step S2.

7. The method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 1, characterized in that: Step S3 also includes humidification time. t 1 is obtained by calculation using formula (1). （1）， t 1 represents the humidification time; Δ m The mass of water vapor required for humidification; S This represents the total surface area of ​​the droplets; G The droplet evaporation coefficient is calculated using formula (2): （2）， T represents the preset target temperature, and RH represents the preset target humidity. This refers to wind speed.

8. The method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 1, characterized in that: Step S3 further includes: Real-time temperature T within the preset culture layer s =T and real-time humidity RH s The mass of ambient water vapor at =RH m 2; Simultaneously record the real-time temperature T s Real-time humidity (RH) s The mass of environmental water vapor within the cultivation layer at that time m 1. Then, the real-time temperature T is calculated using formula (3). s The amount of water vapor Δ when it changes to the target temperature T m And record the corresponding time. t 2, （3）， Simultaneously, the atomization rate of the humidifier can be calculated. a , （4）。 9. A method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 8, characterized in that: Step S3 further includes: atomization rate a Corresponding number of atomized droplets n for: （5）， R Represents the droplet diameter. The density of water; Then, based on the number of atomized droplets... n Calculate the total area S of the atomized droplets. （6）， Combining formulas (1), (5), and (6), we get: （7）。 10. A method for controlling temperature and humidity in a plant factory based on targeted ventilation according to claim 1, characterized in that: Step S3.1 further includes: When RH s <When RH < RH - γ, the control module controls the switches of the humidifying device and the solenoid valve in a cycle of turning on for 2 s and then turning off for 1 s until the real-time humidity RH s = RH + γ, the humidifying device and the corresponding solenoid valve are turned off; when RH s > RH + γ, the humidifying device and the solenoid valve of the corresponding cultivation layer are turned off.

Images