Test method for testing temperature and humidity coupling change rule of wall body of sunlight greenhouse

Abstract

The invention relates to the technical field of agricultural facility environment monitoring, and discloses a test method for testing a temperature and humidity coupling change rule of a wall body of a sunlight greenhouse, which comprises the following steps: establishing a three-dimensional rectangular coordinate system on the wall body of the sunlight greenhouse, and setting a test section along the wall body; wall body temperature and humidity measuring points are arranged in the thickness direction of the wall body, meanwhile, heat flux density measuring points are arranged on the inner surface and the outer surface of the wall body, solar net radiation measuring points and air temperature and humidity measuring points are arranged on the inner surface of the wall body, and meteorological measuring points are arranged outside the greenhouse; synchronously acquiring data of all measuring points; and analyzing a heat and humidity distribution rule of the wall body along the vertical direction and a heat and humidity coupling rule along the thickness direction, and distinguishing different meteorological conditions for comparison. According to the invention, synchronous full-coverage monitoring of the heat and humidity parameters of the wall body is realized, the coupling change rule can be accurately revealed, and a reliable basis is provided for greenhouse wall body structure optimization and thermal environment regulation and control.

Description

Technical Field

[0001] This invention belongs to the field of agricultural facility environmental monitoring, and specifically relates to the walls of solar greenhouses, specifically a test method for testing the coupled change law of temperature and humidity in the walls of solar greenhouses. Background Technology

[0002] As a core component of facility agriculture, the stability of the indoor thermal and humidity environment of a solar greenhouse directly affects crop growth and yield. The walls, as the key enclosure structure of the greenhouse, are the core factor in regulating the indoor environment due to their heat and humidity transfer performance.

[0003] Existing research on greenhouse walls largely focuses on horizontal heat and moisture transfer, i.e., along the wall thickness. It lacks in-depth exploration of the vertical temperature and humidity coupling mechanism, i.e., research along the wall height. In fact, in the vertical direction, greenhouse walls are affected by numerous factors, including the ground and indoor air, resulting in significant temperature and humidity gradients. Current research neglects the vertical heat and moisture transfer within the walls, failing to accurately reflect changes in this gradient and to respond to differences in temperature, moisture content, and heat flux density at different heights. Therefore, the current level of research cannot fully reveal the true three-dimensional heat and moisture response of the walls.

[0004] Moreover, existing testing methods suffer from problems such as unreasonable measurement point layout, incomplete data collection, and inability to accurately capture the dynamic coupling relationship between heat and humidity, making it difficult to support the zonal structural design of walls in both the vertical and thickness directions.

[0005] The walls of residential buildings, as a similar subject of study, differ significantly from those of solar greenhouses. These differences stem from the unique conditions of solar greenhouses, such as direct contact between the greenhouse wall base and the soil, the lack of a moisture-proof vapor barrier, and the high humidity environment inside. Directly applying the methods used for residential building walls would lead to significant discrepancies between measured data and actual heat and moisture transfer patterns, thus reducing their reference value.

[0006] Meanwhile, most existing experiments only monitor temperature or humidity independently, or the measured data are studied in isolation, lacking corresponding connections. However, those skilled in the art know that thermal migration and moisture migration processes influence each other, and isolated studies cannot reflect the coupled thermal and moisture migration patterns within the wall, thus limiting the scientific rigor and accuracy of the optimized design of greenhouse wall structures.

[0007] To address the aforementioned problems, this invention proposes an experimental method for testing the coupled changes in temperature and humidity in the walls of a solar greenhouse. Summary of the Invention

[0008] To address the problem that existing technologies cannot systematically and accurately measure the temperature and humidity coupling changes of greenhouse walls in the horizontal and vertical directions under special working conditions, this invention provides a test method for testing the temperature and humidity coupling changes of greenhouse walls.

[0009] This invention is achieved using the following techniques: This invention provides an experimental method for testing the coupled change law of temperature and humidity in the walls of a solar greenhouse, comprising the following steps: a. Establish a three-dimensional rectangular coordinate system The greenhouse wall structure is selected from that of a typical solar greenhouse in northern China. The greenhouse wall is the north wall and is a three-layer composite structure, consisting of an inner plaster layer, a middle layer of red bricks, and an outer insulation layer from the inside out. The wall base is in direct contact with the soil and has no waterproofing measures.

[0010] Establish a three-dimensional rectangular coordinate system on the walls of the greenhouse, with the intersection of the inner surface of the greenhouse wall and the ground as the origin, the positive Y-axis pointing north horizontally, the positive Z-axis pointing upward vertically, and the positive X-axis pointing east horizontally.

[0011] b. Set the test section Test sections are set at the wall, with the XOZ plane as the second test section. A first test section and a third test section, parallel to the second test section, are symmetrically set on both sides of the second test section. The first test section and the third test section are set at X = ±2m.

[0012] c, Data Acquisition Data was collected from wall measuring points and outdoor meteorological measuring points: Sensors were used to synchronously collect data from wall measuring points on each test section. These wall measuring points included wall temperature and humidity measuring points, heat flux density measuring points, net solar radiation measuring points, and air temperature and humidity measuring points. Correspondingly, wall temperature, volumetric moisture content, heat flux density, net solar radiation intensity, and indoor air temperature and humidity were collected. At least three sets of temperature and humidity measuring points should be installed along the height of the wall, with five points in each set along the thickness of the wall. The heat flux density measuring points are closely fitted to the inner and outer surfaces of the wall. The net solar radiation measuring point is located on the inner surface of the wall. The air temperature and humidity measuring point is set on the inside of the wall and 1cm away from the wall surface; Furthermore, the specific steps for setting up wall measuring points include: ca, set test hole Test holes are set at equal intervals along the positive Z-axis on each test section until the height range of the greenhouse wall is covered. The test holes are opened along the Y-axis and the diameter of the test holes is 3~5cm. cb, Setting up wall temperature and humidity measuring points Temperature and humidity measuring points are set in the test holes and at the hole openings. A set of temperature and humidity sensors is installed at each temperature and humidity measuring point. The temperature and humidity sensors are integrated temperature-volume moisture content sensors. Furthermore, the temperature and humidity measuring points are evenly distributed along the wall thickness direction and are denoted as Y1 to Y5 from the inside to the outside. The distance between two adjacent temperature and humidity measuring points is equal. cc, sealing backfill The holes were sealed and backfilled using wall material, and the temperature and humidity sensors on the inner and outer surfaces of the wall were covered with the material to avoid direct exposure to radiant heat. CD, heat flux density measurement point settings Apply Vaseline evenly to the sensing surface of the heat flux density sensor to ensure it adheres tightly to the wall surface. Place heat flux density sensors on the inner and outer surfaces of the wall at the test hole openings. ce, Setting up solar net radiation measurement points A net solar radiation meter is installed on the inner surface of the wall at the test hole opening; cf, Air temperature and humidity measurement point settings An air temperature and humidity sensor is placed on the inner surface of the wall, 1 cm away from the wall surface.

[0013] An outdoor meteorological station was set up in an open and unobstructed area on the south side of the greenhouse as an outdoor meteorological measuring point to collect outdoor air temperature, humidity and total solar radiation.

[0014] The wall temperature and humidity sensor, heat flux density sensor, solar net radiation meter, air temperature and humidity sensor, and outdoor weather station are all connected to the data acquisition and analysis equipment, and all instruments need to be calibrated for accuracy in advance.

[0015] The data acquisition period is the complete growth cycle of the plant, including consecutive sunny days and consecutive cloudy days, and may also include other special weather conditions. During data acquisition, the data acquisition time interval of all sensors is set to 10 minutes.

[0016] d, Data Analysis Based on the measurement point data collected synchronously in step c, the vertical heat and humidity distribution pattern of the wall along the Z-axis and the heat and humidity coupling pattern along the thickness direction of the Y-axis are analyzed respectively, and the data under two meteorological conditions, namely sunny day and cloudy day, are distinguished.

[0017] In particular, if there are obvious outliers in the observation data, they should be removed and the data from the other two test sections should be used to infer the pattern and make up the gap.

[0018] Observations revealed that, in the vertical direction (Z-axis), analysis of parameters such as net solar radiation, temperature, and heat flux density showed that the lower half of the wall plays a more significant role in heat storage and release during the actual thermal cycle. Therefore, it is necessary to specifically improve the heat storage and release performance of this area. Furthermore, based on the temperature distribution pattern along the wall's height, it is proposed that active or passive control methods be used to transfer heat stored in the upper half to the lower half for release during the heat release phase, and to guide some of the heat from the lower half to the upper half for storage during the heat storage phase, thereby optimizing the overall thermal performance.

[0019] In the thickness direction, i.e., the Y-axis direction, through comparative analysis of the attenuation and lag patterns of temperature and humidity, it was clarified that the temperature amplitude significantly decreases from the outside to the inside, the peak time lags layer by layer, and the moisture content change is mainly concentrated in the shallow inner surface layer. These patterns provide a direct basis for rationally determining the arrangement and thickness of the phase change layer and the heat storage layer, as well as strengthening the moisture-proof measures of the inner surface.

[0020] In summary, this method can reveal the thermal and moisture coupling law of the wall in the vertical and thickness directions, and propose a systematic optimization direction and solution for the performance optimization of wall structures.

[0021] Compared with the prior art, the present invention has the following beneficial effects: This invention provides an experimental method for testing the temperature and humidity coupling change law of greenhouse walls. Taking the greenhouse walls as the measurement object, it achieves spatiotemporal full coverage monitoring of thermal and humidity parameters through long-term, full-scale measurements tailored to the special working conditions of greenhouse walls. This solves the problem of limited measurement points in existing methods, helps to reveal the vertical thermal and humidity coupling transmission law of the north wall, and allows those skilled in the art to propose targeted vertical layered construction schemes for the walls based on the experimental results, providing a scientific basis for the optimized design of greenhouse wall structures.

[0022] This invention integrates multiple sensing devices, including a temperature-volume moisture content integrated sensor, a heat flux density sensor, and a solar net radiance meter, and connects them to a unified data acquisition and analysis device for synchronous data collection. This ensures the consistency of multi-source data such as temperature, volumetric moisture content, heat flux density, and solar radiation, establishing a coupled correlation between "radiation-temperature-humidity-heat flux." This overcomes the analytical limitations of traditional methods caused by isolated data collection and a lack of corresponding connections.

[0023] This invention distinguishes between typical sunny and cloudy weather, quantifies the impact of meteorological conditions on heat and humidity transfer, and improves the stability of the greenhouse thermal environment and energy-saving effect. Attached Figure Description

[0024] Figure 1 This indicates the structure of the greenhouse wall in this invention.

[0025] Figure 2This is a schematic diagram of the three-dimensional rectangular coordinate system in step a.

[0026] Figure 3 The graph shows the change of net solar radiation intensity at different altitudes over time in the embodiment.

[0027] Figure 4 The graph shows the change of internal surface heat flux density over time at different heights in the embodiment.

[0028] Figure 5 The graph shows the temperature change of the wall at different heights over time in the embodiment.

[0029] Figure 6 The graph shows the temperature change over time inside the wall at different thicknesses in the embodiment.

[0030] Figure 7 The graph shows the change in internal moisture content of the wall at different thicknesses over time in the embodiments.

[0031] In the diagram: 1-Outdoor weather station, 2-Wall temperature and humidity sensor, 3-Heat flux density sensor, 4-Solar net radiation meter, 5-Air temperature and humidity sensor, 6-Inner plaster layer, 7-Red brick middle layer, 8-Outer insulation layer. Detailed Implementation

[0032] The specific embodiments of the present invention will be described in detail below. Example 1

[0033] An experimental method for testing the coupled temperature and humidity changes in the walls of a solar greenhouse includes the following steps: a. Establish a three-dimensional rectangular coordinate system like Figure 1 As shown, a representative greenhouse wall structure from northern China was selected. In this embodiment, a greenhouse located in Taiyuan City was chosen as the test object. The greenhouse faces south, with a net length of 60m in the east-west direction, a span of 8.4m, a ridge height of 3.6m, a north wall height of 2.7m, and a thickness of 430mm. The greenhouse wall is a three-layer composite structure, consisting of an inner plastering layer 6, a middle layer of red bricks 7, and an outer insulation layer 8 from the inside out. That is, this embodiment is a traditional three-layer composite structure: the inner layer is a 10mm thick cement mortar plastering layer, the outer layer is a 50mm thick polystyrene insulation board, and the middle layer is a 370mm thick solid sintered red brick. The wall base is in direct contact with the soil and has no waterproofing measures. The south-facing light-transmitting surface is a single-column steel frame structure, covered with a 0.08mm thick PVC film, and equipped with a 50mm thick textile insulation quilt. During the trial period in March, the quilt was rolled up at 09:00 and covered for insulation at 16:00. There were no heating measures inside the greenhouse. High temperatures were controlled by roof ventilation. Cucumbers in the mature stage were grown indoors.

[0034] like Figure 2As shown, a three-dimensional rectangular coordinate system is established on the wall of the greenhouse. The origin is the intersection of the middle of the inner surface of the greenhouse wall and the ground. The positive Y-axis is the horizontal northward direction, the positive Z-axis is the vertical upward direction, and the positive X-axis is the horizontal eastward direction.

[0035] b. Set the test section Test sections are set at the wall, with the XOZ plane as the second test section. A first test section and a third test section, parallel to the second test section, are symmetrically set on both sides of the second test section. The first test section and the third test section are set at X = ±2m.

[0036] c, Data Acquisition Data was collected from wall measuring points and outdoor meteorological measuring points: Specifically, the setting of wall measuring points includes the following steps: ca, set test hole Test holes are equidistantly arranged along the positive Z-axis on each test section. In this embodiment, the height of the large test hole is Z1=0.7m, Z2=1.4m, and Z3=2.1m. The test holes are opened along the Y-axis and the diameter of the test holes is 5cm. cb, Setting up wall temperature and humidity measuring points Temperature and humidity measurement points are set in the test holes and at the hole openings. A set of wall temperature and humidity sensors 2 is installed at each wall temperature and humidity measurement point. The wall temperature and humidity sensor 2 adopts an integrated temperature-volume moisture content sensor. Its temperature measurement range is -40~80℃ with an accuracy of ±0.5℃. Its moisture content measurement range is 0%~100% with an accuracy of ±2%.

[0037] At least three groups of temperature and humidity measuring points are arranged along the height of the wall, labeled Z1 to Z3 from low to high. In this embodiment, Z1 = 0.7m, Z2 = 1.4m, and Z3 = 2.1m. Each group is evenly arranged along the thickness of the wall, with a total of five points. The distance between two adjacent temperature and humidity measuring points is equal, labeled Y1, Y2, Y3, Y4, and Y5 from the inside out. In this embodiment, Y1 = 0m, Y2 = 0.1m, Y3 = 0.2m, Y4 = 0.3m, and Y5 = 0.4m. The wall temperature and volumetric moisture content are collected at each location.

[0038] cc, sealing backfill The holes were sealed and backfilled using wall material, and the wall temperature and humidity sensors 2 on the inner and outer surfaces were covered with the material to avoid direct exposure to radiant heat.

[0039] CD, heat flux density measurement point settings Apply Vaseline evenly to the sensing surface of the heat flux density sensor 3 to ensure close adhesion to the wall surface. The measurement range of the heat flux density sensor 3 is -500~500W / m. 2 The accuracy is <5%; heat flux density sensors 3 are respectively arranged on the inner and outer surfaces of the wall at the test hole opening to collect heat flux density.

[0040] ce, Setting up solar net radiation measurement points A net solar radiation meter 4 is installed on the inner surface of the wall at the opening of the test hole. The accuracy of the net solar radiation meter 4 is <5%, and the net solar radiation intensity is collected.

[0041] cf, Air temperature and humidity measurement point settings An air temperature and humidity sensor 5 is installed on the inner surface of the wall and away from the wall surface. The air temperature and humidity sensor 5 has a temperature measurement range of -30~85℃ and an accuracy of ±0.2℃; a humidity measurement range of 0%~100% and an accuracy of ±1.5%, and collects indoor air temperature and humidity data.

[0042] Setting up outdoor meteorological monitoring points includes the following steps: An outdoor meteorological station 1 was set up in an open and unobstructed area on the south side of the greenhouse as an outdoor meteorological measuring point to collect outdoor air temperature, humidity and total solar radiation.

[0043] The wall temperature and humidity sensor 2, heat flux density sensor 3, solar net radiation meter 4, air temperature and humidity sensor 5, and outdoor weather station 1 are all connected to the data acquisition and analysis equipment. The data acquisition period is the complete growth cycle of the plant. In this embodiment, the experimental period is set to the coldest period of the year (November 15, 2024 to March 31, 2025), including consecutive sunny days and consecutive cloudy days. Typical weather data are selected for analysis: March 14 (cloudy) and March 15 to March 19 (sunny).

[0044] During data acquisition, the data acquisition time interval for all sensors was set to 10 minutes.

[0045] d, Data Analysis Based on the measurement point data collected synchronously in step c, the vertical heat and humidity distribution pattern of the wall along the Z-axis and the heat and humidity coupling pattern along the thickness direction of the Y-axis are analyzed respectively, and the data under two meteorological conditions, namely sunny day and cloudy day, are distinguished.

[0046] The method described in this embodiment is used for data analysis.

[0047] Vertical (Z-axis) heat and moisture distribution pattern analysis: 1) Distribution pattern of net solar radiation along the Z-axis like Figure 3 As shown, under clear weather conditions, net solar radiation decreases with altitude: the peak net radiation near the ground (Z1) can reach approximately 90 W·m.-2 At higher elevations (Z3), the concentration is below 50 W·m. -2 At night, the net radiation of both is negative, and the radiation intensity of Z1 is always greater than that of Z3.

[0048] Specifically, under sunny conditions, the net solar radiation intensity on the inner surface of the wall decreases with increasing height along the Z-axis. After the insulation blankets were rolled up at 09:00, between 10:00 and 11:00, the net solar radiation gradually increased as the solar altitude angle increased, with the net radiation at Z1 being higher than that at Z3, but the difference was not significant. Between 11:00 and 14:00, the net solar radiation intensified, and the difference between the net radiation at Z1 and Z3 gradually increased, reaching a maximum of 90 W / m at Z1. 2 At Z3, the highest value is only close to 50W / m. 2 From 14:00 to 17:00, as the solar altitude angle decreases, the net solar radiation gradually decreases, and the difference between the two measuring points begins to narrow. From 18:00 to 09:00 the next day, after the insulation blanket is placed, the net radiation is only the thermal radiation between the surface of the north wall and other enclosure structures and soil. Its value is negative, indicating that the wall is releasing heat. The net radiation at the two measuring points is also different. The absolute value of the net radiation intensity at Z1 is higher than that at Z3. This is because the solar radiation absorbed at Z1 during the day is higher and the irradiation time is longer, and at the same time, the soil at the bottom of the wall is heated at night.

[0049] On cloudy days, the distribution pattern of daytime net solar radiation differs from that on sunny days. The weakening effect of clouds makes the radiation distribution more uniform. As the wall height increases, the net solar radiation remains essentially the same, and the difference in net radiation at two different heights essentially disappears. The value throughout the day does not exceed 10 W·m. -2 However, on cloudy nights, the net radiation characteristics are consistent with those on sunny nights, with the net radiation intensity at Z1 being higher than that at Z3, fully demonstrating the effect of the soil in supplementing the wall's heat at night.

[0050] Therefore, in sunny conditions, the main portion of solar radiation absorbed by the wall is concentrated in its lower half, and the lower half should be a key consideration when optimizing the wall structure. It is also important to utilize the soil to supplement the wall's heat, increasing the duration of heat release at night to maintain indoor air temperature.

[0051] 2) Distribution pattern of heat flux density along the Z-direction on the inner surface like Figure 4As shown, under sunny conditions, the wall absorbs heat as a whole between 9:00 and 15:00, with the heat absorption at the near-ground level (Z1) being higher than at the higher level (Z3). During the remaining time, it primarily releases heat, with the heat release intensity at Z1 continuously increasing and consistently exceeding that at Z3. The reason for this is that during the day, the wall absorbs heat as a whole under solar radiation. Due to the higher intensity of solar radiation received at Z1, its heat absorption is also greater than that at Z3. At night, the wall transitions to overall heat release. Although both the air and wall temperatures decrease at this time, the temperature distribution along the Z-axis remains relatively stable: the surface temperature at Z1 is consistently 2-3°C higher than at Z3. This results in a greater temperature difference between the inner surface of the wall and the air at Z1 compared to Z3. Furthermore, Z1 is closer to the soil and continuously receives heat replenishment from the soil, thus the heat release at Z1 is also greater.

[0052] On cloudy days, the wall only absorbs heat briefly around noon, and releases heat for the rest of the time. This indicates that the lower half of the wall plays a more significant role in heat storage and release during the actual heat cycle. To maintain a stable thermal environment, it is necessary to specifically improve the heat storage and release performance of this part through dynamic compensation.

[0053] 3) Variation of internal surface temperature along the Z-axis like Figure 5 As shown, under clear weather conditions, the temperature variations at different heights (Z1, Z2, Z3) on the inner surface of the north wall exhibit periodic fluctuations, highly coupled with the solar radiation cycle. Near the ground (Z1), the diurnal temperature range is the largest (11-15℃), with peak temperatures reaching 25-35℃, dropping to 14-20℃ at night, resulting in a diurnal temperature range of 11-15℃. The peak temperatures at Z2 and Z3 are approximately 25-32℃, dropping to 12-15℃ at night. After 11:00 PM, the temperature at Z3 can surpass that of Z2. Under cloudy weather conditions, the characteristics differ from those under clear weather conditions. Although different heights have similar temperature gradients, there are significant differences in peak temperatures. The temperature at Z1 is generally higher, with the highest temperature remaining at 18-20℃ and the lowest at 12-13℃, resulting in a diurnal temperature range of 5-7℃. At Z2 and Z3, the highest temperature is 17–18℃, and the lowest temperature is 15–16℃, with a diurnal temperature range of 1–2℃. The daytime maximum temperature fluctuates between 15 and 17℃, showing a gradual decrease in the temperature gradient along the Z direction. The diurnal temperature range at each altitude decreases significantly (1–7℃). Unlike under clear weather conditions, there is no reversal phenomenon, and the overall trend of "hotter at lower altitudes and colder at higher altitudes" is still maintained, but the temperature gradient is significantly gentler.

[0054] Based on the above temperature distribution pattern, the heat stored in the upper part of the wall can be transferred to the lower part for release during the heat release stage, and some of the heat in the lower part can be guided to the upper part for storage during the heat storage stage, thereby improving the overall thermal performance.

[0055] Analysis of thermal and moisture coupling in the thickness direction (Y direction): 1) Temperature variation pattern inside the wall like Figure 6 As shown, the temperature change inside the wall exhibits a clear attenuation and lag pattern. Along the Y direction, the temperature amplitude decreases significantly from the inside to the outside, with a daily temperature range of 19℃ at the inner surface (Y=0m), but only 0.4℃ at a depth of 0.3m. The maximum temperature drops from 35℃ at the inner surface to 16℃ at Y4. Simultaneously, the time of the temperature peak occurs with increasing thickness, lagging by approximately 3 hours per layer, with a maximum delay of up to 9 hours. Specifically, the maximum temperature occurs at approximately 15:00 at Y1, delayed to 18:00 at Y2, delayed to 21:00 at Y3 where the temperature has basically stabilized, and at Y4, the temperature fluctuation increases again due to the influence of outdoor air temperature. It can be assumed that, under the influence of the 24-hour solar radiation cycle, the thermal radius of this type of greenhouse wall is approximately equal to Y3, i.e., 0.3m. The maximum thermal radius during the heating period of the greenhouse can serve as the main basis for optimizing the thickness of the passive heat storage layer, after which an external insulation layer can be added. For active heat storage walls, the thickness of the heat storage layer should be smaller than that of the passive wall. The daily temperature range of the wall decreases significantly with increasing thickness, and the temperature change is greater closer to the inner surface.

[0056] Under cloudy conditions, the overall temperature fluctuation is relatively small, and the greater the depth, the more stable the temperature tends to be. Specifically, the inner surface area of ​​Y1 is most significantly affected by weather, with temperature variations ranging from 14 to 35℃ on sunny days and 18 to 20℃ on cloudy days. The areas of Y2 and Y3 are less affected by external factors, with fluctuations of 15 to 22℃ on sunny days and 18 to 19℃ on cloudy days. The thickness area of ​​Y4 is relatively stable, with fluctuations ranging from 15 to 16℃ on sunny days and 18 to 19℃ on cloudy days. In contrast, the temperature variation pattern of the outer surface differs from other locations, being directly and significantly affected by outdoor weather conditions. However, due to the insulation effect of the outermost insulation layer, the impact of outdoor air temperature fluctuations on the interior of the wall is limited by its thickness.

[0057] Based on the above temperature distribution and phase delay characteristics, the design can be optimized, and the arrangement and thickness of the phase change layer and the heat storage layer can be reasonably determined.

[0058] 2) The pattern of moisture content variation inside the wall like Figure 7As shown, the moisture content inside the wall exhibits significant spatial differences, fluctuating significantly only near the inner surface (0-0.1m depth), ranging from 21% to 24%, and showing a trend of fluctuation in tandem with temperature. The moisture content in deeper layers (0.2-0.3m) remains relatively stable, between 21% and 22%. This indicates that the inner surface of the wall is more susceptible to the influence of the external humid environment. The moisture content changes lag behind those changes inside the wall due to the material's inherent ability to impede moisture migration. On cloudy days, the volumetric moisture content along the Y-axis tends to stabilize at different thicknesses, generally remaining within the range of 21% to 22%. The variation in volumetric moisture content along the thickness direction is smaller than along the vertical direction; generally, the volumetric moisture content decreases from the inner surface to the outer surface. Therefore, to maintain the overall performance and durability of the wall, it is crucial to focus on and strengthen the moisture-proof design and treatment measures for the inner surface.

[0059] Based on the above analysis of heat flux density distribution and heat-moisture coupling transfer laws, an optimized design scheme was developed. The optimized wall structure adopts a vertically layered material combination. Specifically, the lower half of the wall uses high-heat-storage materials with active heat conduction measures to enhance its heat storage and conduction performance, ensuring rapid heat storage and release. The upper half of the wall primarily uses materials with high thermal insulation and high heat storage performance. This zoning design achieves the goals of maintaining a stable indoor environment and reducing energy consumption.

[0060] For example, a vertically functional, layered composite structure is used for the walls. Specifically, in the lower part of the wall (Z=0~1.4m), a combination of high-heat-storage phase change materials and high-density clay blocks is used to enhance heat storage and regulate humidity; in the upper part of the wall (Z=1.4~2.7m), low-latent-heat phase change materials and lightweight ceramsite concrete blocks are selected to enhance insulation and reduce weight. The overall structure follows the differentiated design principle of "heavy heat storage and temperature regulation in the lower part, and lightweight insulation in the upper part."

[0061] In summary, the experimental methods described above, through measurement and analysis, provide direct and reliable data support and theoretical basis for the refined design and performance optimization of greenhouse walls. Specifically, this is reflected in: First, in this embodiment, the wall temperature, moisture content, and net radiation decrease along the height. During sunny days, the wall absorbs heat as a whole, with the lower part absorbing more heat than the upper part; during other times, it releases heat, with the lower part releasing more heat than the upper part. This clarifies the gradient variation of the wall's thermal and moisture parameters along the vertical direction and identifies the functional differences in heat storage and release processes at different heights. To fully transfer the free heat from daytime to nighttime use, the focus is on improving the heat storage and release performance of the lower part of the wall. Therefore, a vertical layered structure is adopted, along with differentiated material selection for the upper and lower sections. Specifically, the lower section uses materials with high heat storage and release performance to enhance the wall's heat storage and release capacity, while the upper section can use materials with lower heat storage and release performance or have its thickness adjusted. This approach improves economic efficiency while meeting the heat absorption and release requirements of different parts.

[0062] Secondly, in this embodiment, the method clearly quantifies the periodic temperature change pattern of different thicknesses inside the wall. As the thickness increases, the temperature wave amplitude decreases and the delay time increases. The thermal radius is determined to be 0.3m. Therefore, the maximum thermal radius of passive heat storage and release walls with different structures in the solar greenhouse during the heating season can be used as the basis for thickness optimization. This allows for material and land saving, economical and practical results while ensuring the thermal performance of the wall, and provides a scientific basis for rationally determining the wall and the thickness of each layer of the wall.

[0063] Third, this embodiment confirms the influence of soil moisture evaporation and moisture transfer between the soil and the wall. Specifically, the volumetric moisture content of the wall decreases along the height direction and decreases from the inner surface to the outer surface along the thickness direction, eventually stabilizing. Unlike moisture-proof and vapor-barrier walls in residential environments, a targeted moisture-proof and vapor-barrier layer can be constructed between the external insulation layer and the wall. This fully utilizes the increased volumetric moisture content, which raises the wall's thermal conductivity and increases the rate of heat storage and release. It also appropriately leverages soil moisture evaporation and moisture transfer between the soil and the wall to improve heat transfer performance.

[0064] The scope of protection claimed by this invention is not limited to the specific embodiments described above. Moreover, for those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A test method for measuring the coupled temperature and humidity changes in the walls of a solar greenhouse, characterized in that, Includes the following steps: a. Establish a three-dimensional rectangular coordinate system Establish a three-dimensional rectangular coordinate system on the greenhouse wall, with the intersection of the middle of the inner surface of the greenhouse wall and the ground as the origin, the positive Y-axis direction of horizontal north, the positive Z-axis direction of vertical upward, and the positive X-axis direction of horizontal east. b. Set the test section A test section is set at the wall, wherein the XOZ surface is used as the second test section, and a first test section and a third test section parallel to the second test section are symmetrically set on both sides of the second test section. c, Data Acquisition Sensors were used to synchronously collect data from wall measuring points on each test section. These wall measuring points included wall temperature and humidity measuring points, heat flux density measuring points, net solar radiation measuring points, and air temperature and humidity measuring points. Correspondingly, wall temperature, volumetric moisture content, heat flux density, net solar radiation intensity, and indoor air temperature and humidity were collected. The wall temperature and humidity measuring points shall be arranged in at least 3 sets along the height of the wall, with 5 points in each set along the thickness of the wall. The heat flux density measuring points are closely fitted to the inner and outer surfaces of the wall. The net solar radiation measuring point is located on the inner surface of the wall. The air temperature and humidity measuring point is set on the inside of the wall and 1cm away from the wall surface; An outdoor meteorological station (1) was set up in an open and unobstructed area on the south side of the greenhouse as an outdoor meteorological measuring point to collect outdoor air temperature and humidity and total solar radiation. The data collection period is the complete growth cycle of the plant, including consecutive sunny days and consecutive cloudy days; d, Data Analysis Based on the measurement point data collected synchronously in step c, the vertical heat and humidity distribution pattern of the wall along the Z-axis and the heat and humidity coupling pattern along the thickness direction of the Y-axis are analyzed respectively, and the data under two meteorological conditions, namely sunny day and cloudy day, are distinguished.

2. The experimental method for testing the coupled change law of temperature and humidity in the walls of a solar greenhouse according to claim 1, characterized in that, In step b, the first test section and the third test section are set at X = ±2m.

3. The experimental method for testing the coupled temperature and humidity change law of a solar greenhouse wall according to claim 1, characterized in that, Step c, setting up wall measuring points specifically includes the following steps: ca, set test hole Test holes are set at equal intervals along the positive Z-axis on each test section until the height range of the greenhouse wall is covered. The test holes are opened along the Y-axis and the diameter of the test holes is 3~5cm. cb, Setting up wall temperature and humidity measuring points Temperature and humidity measuring points are set in the test hole and at the hole opening, and a set of wall temperature and humidity sensors are installed at each wall temperature and humidity measuring point (2). cc, sealing backfill The holes were sealed and backfilled using wall material, and the wall temperature and humidity sensors (2) on the inner and outer surfaces were covered with material. CD, heat flux density measurement point settings Apply Vaseline evenly to the sensing surface of the heat flux density sensor (3), and place the heat flux density sensor (3) on the inner and outer surfaces of the wall at the test hole openings respectively. ce, Setting up solar net radiation measurement points A net solar radiation meter is placed on the inner surface of the wall at the test hole opening (4). cf, Air temperature and humidity measurement point settings An air temperature and humidity sensor is placed on the inner surface of the wall and 1 cm away from the wall surface (5).

4. The experimental method for testing the coupled change law of temperature and humidity in the walls of a solar greenhouse according to claim 1, characterized in that, In step c, the data acquisition time interval is set to 10 minutes.

5. The experimental method for testing the coupled change law of temperature and humidity in the walls of a solar greenhouse according to claim 3, characterized in that, The wall temperature and humidity sensor (2), heat flux density sensor (3), solar net radiation meter (4), air temperature and humidity sensor (5), and outdoor weather station (1) are all connected to the data acquisition and analysis equipment.

6. The experimental method for testing the coupled change law of temperature and humidity in the walls of a solar greenhouse according to claim 1, characterized in that, The greenhouse wall is a three-layer composite structure, consisting of an inner plastering layer (6), a middle layer of red bricks (7), and an outer insulation layer (8) from the inside out.

7. The experimental method for testing the coupled change law of temperature and humidity in the walls of a solar greenhouse according to claim 6, characterized in that, In step cb, the temperature and humidity measuring points on the wall are evenly distributed along the wall thickness direction, and the distance between two adjacent temperature and humidity measuring points is equal.

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