A bowen water-heat flux monitoring system and method for measuring dry-wet bulb temperature

Abstract

The application provides a Bowen water-heat flux monitoring system and method for measuring dry-wet bulb temperature, comprising a wet bulb temperature measuring air duct, a dry bulb temperature measuring air duct, a support, a telescopic ventilation system and a controller; the support is provided with the telescopic ventilation system on both sides, and the telescopic ventilation system is provided with a telescopic sleeve; the telescopic sleeve of the telescopic ventilation system on one side is provided with the wet bulb temperature measuring air duct at the upper end and the lower end respectively, and the telescopic sleeve of the telescopic ventilation system on the other side is provided with the dry bulb temperature measuring air duct at the upper end and the lower end respectively; the wet bulb temperature measuring air duct is provided with a wet bulb infrared temperature measuring instrument inside, which is used for measuring the wet bulb temperature; the dry bulb temperature measuring air duct is provided with a dry bulb infrared temperature measuring instrument inside, which is used for measuring the dry bulb temperature; the wet bulb temperature measuring air duct and the dry bulb temperature measuring air duct are communicated with the telescopic ventilation system respectively; and the controller is connected with the wet bulb infrared temperature measuring instrument, the dry bulb infrared temperature measuring instrument and a driving motor respectively. The application effectively improves the measurement precision of the dry-wet bulb temperature, and further improves the measurement precision of the sensible heat flux and the latent heat flux.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of automatic monitoring of water and heat flux in an ecological system, and particularly relates to a Bowen ratio water and heat flux monitoring system and method for measuring dry and wet bulb temperatures. BACKGROUND

[0002] The Bowen ratio energy balance (BREB) method is based on energy balance and near-surface diffusion theory, and is used to study the water and heat flux relationship of crops. Due to its mobility and practicality, the method is widely used in current evapotranspiration research.

[0003] In the BREB method, the Bowen ratio β can be represented by the ratio of the actual vapor pressure difference Δe a to the temperature difference ΔT a . The actual vapor pressure e a can be determined by measuring the dry and wet bulb temperatures using a dry and wet bulb thermometer, and the calculation formula of the actual vapor pressure e a is as follows:

[0004] e a = e s - γ (Td - Tw)

[0005] In the formula, Td is the dry bulb temperature, ℃;

[0006] Tw is the wet bulb temperature, ℃;

[0007] γ is the instrument humidity constant,

[0008] e s is the saturated water vapor pressure, kPa.

[0009] The wet bulb temperature e s can be calculated using the formula:

[0010]

[0011] Therefore, by setting two height dry and wet bulb temperature sensors, the actual vapor pressure difference Δe a and the temperature difference ΔT a can be obtained, the Bowen ratio β can be calculated, and the sensible heat flux H and the latent heat flux ρλE can be obtained.

[0012]

[0013] In the formula, H is the sensible heat flux, Wm -2 ;

[0014] ρλE is the latent heat flux, Wm -2 ;

[0015] γ is the instrument's hygrometer constant;

[0016] ΔT a The difference in air temperature between two altitudes, in K;

[0017] Δe a The actual vapor pressure difference between the two altitudes is expressed in kPa.

[0018] However, this method has accuracy issues in gradient temperature and humidity observation.

[0019] Since β is determined by the temperature difference (ΔT) between the two heights a The value β is determined by the actual vapor pressure difference (Δea). Even a small observational error in the temperature T and relative humidity RH at the two observed altitudes can have a significant impact on β. The observation terms are established at the same time and location, ΔT... a and Δe a β is usually very small, so estimating it accurately is extremely challenging.

[0020] A wet-bulb and dry-bulb thermometer is an instrument for measuring air temperature and humidity. It is widely used due to its low cost, ease of installation, and stable performance. However, existing wet-bulb and dry-bulb thermometers rely on manual reading of the dry-bulb and wet-bulb temperatures, which is prone to significant errors and requires fixed-point observation, consuming considerable manpower and time. The wet-bulb temperature measurement in a wet-bulb thermometer involves wrapping a gauze around the wet-bulb bulb. The gauze becomes wet and absorbs water capillarily, thus providing the wet-bulb temperature. However, the thermometer is wrapped in water-soaked gauze for an extended period, resulting in a single-point measurement of the wet-bulb temperature, which is easily affected by moisture.

[0021] Traditional Bowenb hydrothermal monitoring systems have a fixed monitoring height. However, environmental factors such as temperature and wind speed vary greatly at different geographical locations or at different times at the same location. Measuring at the same height will result in a significant difference in ΔT. a The large error between Δea and β makes it impossible to accurately estimate the Bowen ratio β. Summary of the Invention

[0022] To address the aforementioned technical problems, this invention provides a Bowen ratio hydrothermal flux monitoring system and method for measuring dry-bulb and wet-bulb temperatures. By measuring the Bowen ratio hydrothermal flux of dry-bulb and wet-bulb temperatures using an infrared thermometer, the accuracy of dry-bulb and wet-bulb temperature measurement is effectively improved, thereby enhancing the accuracy of sensible heat flux and latent heat flux measurement. This provides an important basis for accurately simulating the evolution of crop evapotranspiration (ETc) throughout the entire growth period, formulating reasonable farmland irrigation systems, and promoting efficient water-saving agriculture.

[0023] Note that the description of these objects does not preclude the existence of other objects. One embodiment of the present application does not necessarily achieve all the above objects. Other objects can be drawn from the description, the drawings, and the claims.

[0024] The application changes the traditional temperature measurement method, improves the accuracy of calculating water heat flux by monitoring the dry and wet bulb temperature through the infrared thermometer, the infrared thermometer measures the infrared energy of the object itself, and then accurately determines the surface temperature, has the advantages of fast response time, non-contact, safe use and long service life, so as to overcome the unnecessary error caused by manual reading of temperature, realize the observation from point to plane, and effectively reduce the influence of moisture on the measurement of wet bulb temperature, save labor and time cost, and realize data collection automation.

[0025] The application can improve the adaptability of Bowen ratio to environmental changes and improve the monitoring accuracy through the setting of the telescopic ventilation system.

[0026] The application sets the same fan in the telescopic ventilation system, so that the air dry and wet bulb temperature measuring wind cylinder and the air dry bulb temperature inlet flow at two heights of the telescopic ventilation system remain consistent, and then the measurement of the air dry and wet bulb temperature is more accurate.

[0027] A Bowen ratio water heat flux monitoring system for measuring dry and wet bulb temperature, comprising a wet bulb temperature measuring wind cylinder, a dry bulb temperature measuring wind cylinder, a support, a telescopic ventilation system and a controller.

[0028] The telescopic ventilation system is provided on both sides of the support, the telescopic ventilation system is provided with a telescopic sleeve, a driving motor is arranged in the telescopic sleeve to drive the telescopic sleeve to telescope, the telescopic sleeve of the telescopic ventilation system on one side is provided with a wet bulb temperature measuring wind cylinder at the upper end and the lower end, and the telescopic sleeve of the telescopic ventilation system on the other side is provided with a dry bulb temperature measuring wind cylinder at the upper end and the lower end; a wet bulb infrared thermometer is arranged in the wet bulb temperature measuring wind cylinder and used for measuring the wet bulb temperature; a dry bulb infrared thermometer is arranged in the dry bulb temperature measuring wind cylinder and used for measuring the dry bulb temperature.

[0029] The wet bulb temperature measuring wind cylinder and the dry bulb temperature measuring wind cylinder are in communication with the telescopic ventilation system.

[0030] The controller is connected with the wet bulb infrared thermometer, the dry bulb infrared thermometer and the driving motor of the telescopic ventilation system.

[0031] In the above scheme, the wet bulb temperature measuring wind cylinder comprises a wet bulb temperature measuring wind cylinder outer cylinder and a wet bulb temperature measuring wind cylinder inner cylinder.

[0032] One end of the wet bulb temperature measurement air cylinder outer cylinder and one end of the wet bulb temperature measurement air cylinder inner cylinder are connected by a ball plate; the inner wall of the wet bulb temperature measurement air cylinder outer cylinder is provided with a wet bulb temperature measurement sliding groove, and the wet bulb infrared temperature measuring instrument is arranged on the wet bulb temperature measurement sliding groove; the wet bulb temperature measurement air cylinder outer cylinder and the wet bulb temperature measurement air cylinder inner cylinder are connected in communication, the wet bulb temperature measurement air cylinder inner cylinder is internally provided with a wetted gauze, a water tank is connected below the wetted gauze, the water tank is arranged at the lower part of the wet bulb temperature measurement air cylinder inner cylinder, the wetted gauze is connected with the water tank, and the wetted gauze is vertically arranged in the inner part of the wet bulb temperature measurement air cylinder inner cylinder. The wet bulb infrared temperature measuring instrument detects the temperature of the entire cross section of the wetted gauze.

[0033] In the above scheme, the dry bulb temperature measurement air cylinder comprises a dry bulb temperature measurement air cylinder outer cylinder and a dry bulb temperature measurement air cylinder inner cylinder;

[0034] One end of the dry bulb temperature measurement air cylinder outer cylinder and one end of the dry bulb temperature measurement air cylinder inner cylinder are connected; the inner wall of the dry bulb temperature measurement air cylinder outer cylinder is provided with a dry bulb temperature measurement sliding groove, and the dry bulb infrared temperature measuring instrument is arranged on the dry bulb temperature measurement sliding groove; the dry bulb temperature measurement air cylinder outer cylinder and the dry bulb temperature measurement air cylinder inner cylinder are connected in communication, the dry bulb temperature measurement air cylinder inner cylinder is internally provided with a dry gauze, and the dry gauze is vertically arranged in the inner part of the dry bulb temperature measurement air cylinder inner cylinder. The dry bulb infrared temperature measuring instrument detects the temperature of the entire cross section of the dry gauze.

[0035] In the above scheme, a rotating machine is further included, the rotating machine is installed on the support, and the two sides of the telescopic ventilation system are respectively connected with the rotating machine, and the rotating machine drives the telescopic ventilation system to rotate.

[0036] Further, the upper and lower ends of the telescopic sleeve of the telescopic ventilation system are respectively provided with communicating T-shaped cylinders, and the intersection of the upper part of the T-shaped cylinder and the telescopic sleeve has an included angle.

[0037] Further, the two ends of the T-shaped cylinder of the telescopic ventilation system on one side of the rotating machine are respectively provided with two wet bulb temperature measurement air cylinders, and the four wet bulb temperature measurement air cylinders are connected in pairs opposite to the two ends of the telescopic ventilation system; the two ends of the T-shaped cylinder of the telescopic ventilation system on the other side of the rotating machine are respectively provided with two dry bulb temperature measurement air cylinders, and the four dry bulb temperature measurement air cylinders are connected in pairs opposite to the two ends of the telescopic ventilation system.

[0038] In the above scheme, the outer wall of the telescopic ventilation system is marked with a scale.

[0039] In the above scheme, a fan is arranged on the telescopic ventilation system, the fan generates suction to suck external air at two heights into corresponding wet bulb temperature measurement air cylinders and dry bulb temperature measurement air cylinders, and the fan is connected with a controller.

[0040] A control method of a Bowen ratio water heat flux monitoring system according to the measurement of dry and wet bulb temperatures, comprising the following steps:

[0041] The wet-bulb infrared thermometer inside the wet-bulb temperature measuring tube measures the wet-bulb temperature and transmits it to the controller; the dry-bulb infrared thermometer inside the dry-bulb temperature measuring tube measures the dry-bulb temperature and transmits it to the controller.

[0042] The controller calculates ΔT a and Δe a Value, and according to ΔT a and Δe a The Bowen ratio β is calculated, thus obtaining the sensible heat flux H and latent heat flux ρλE, when ΔT a and Δe a If the value is lower than the set minimum measurement threshold, the controller controls the retractable ventilation system to extend until the measured value is higher than the minimum threshold.

[0043] In the above scheme, the wet-bulb temperature measurement value is taken as the average value of two wet-bulb infrared thermometers at the same height; the dry-bulb temperature measurement value is taken as the average value of two dry-bulb infrared thermometers at the same height.

[0044] The rotating machine causes the retractable ventilation systems on both sides to rotate 180° simultaneously around the rotating machine's axis at set intervals, thereby swapping the positions of the dry-bulb and wet-bulb temperature measuring tubes.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] This invention replaces the traditional method of using a thermometer for wet-bulb and dry-bulb temperature monitoring with an infrared thermometer. By measuring the wet-bulb and dry-bulb temperatures using an infrared thermometer and calculating the Bowen ratio β, the sensible heat flux H and latent heat flux ρλE are obtained. This effectively improves the measurement accuracy of wet-bulb and dry-bulb temperatures, and consequently improves the measurement accuracy of sensible heat flux and latent heat flux. This provides an important basis for accurately simulating the evolution of crop evapotranspiration (ETc) throughout the growth period, formulating reasonable farmland irrigation systems, and promoting efficient water-saving agriculture.

[0047] The retractable ventilation system of this invention automatically adjusts the observation height according to the measured value, avoiding large measurement errors caused by changes in environmental temperature, wind speed and other meteorological factors at different geographical locations or at different times in the same location.

[0048] This invention improves upon existing methods for measuring wet and dry bulb temperatures. Based on the principle of wet-bulb temperature measurement, using an infrared thermometer for wet and dry bulb temperature monitoring can effectively improve measurement accuracy, avoid unnecessary manpower and time costs, and enhance monitoring efficiency.

[0049] This invention uses a retractable ventilation system instead of a fixed-height support, improving the ΔT (ventilation time) under different environments or at the same location at different times. a The measurement accuracy of Δea.

[0050] The present application can be provided with a fan in the telescopic ventilation system, the fan generates suction, and air at two heights is sucked into a wet bulb temperature measuring air duct and a dry bulb temperature measuring air duct connected to two ends of the telescopic ventilation system, the wet bulb temperature measuring air duct and the dry bulb temperature measuring air duct are internally provided with infrared temperature measuring instruments, the temperature of the effective cross section of gauze is measured by the infrared temperature measuring instruments, and then temperature monitoring of air at upper and lower layers of the Bowen ratio water heat flux monitoring system is realized.

[0051] The wet bulb temperature measuring air duct is provided with a wet bulb sliding groove in the outer cylinder of the wet bulb temperature measuring air duct, the wet bulb infrared temperature measuring instrument is arranged on the wet bulb temperature measuring sliding groove, the wet bulb infrared temperature measuring instrument can move forward and backward through the wet bulb temperature measuring sliding groove, and then monitoring of the effective wetting surface of gauze is realized.

[0052] The outer cylinder of the wet bulb temperature measuring air duct and the inner cylinder of the wet bulb temperature measuring air duct are connected by a ball disc, which can effectively ensure that the water tank can continuously be located below the wetted gauze when the Bowen ratio water heat flux monitoring system is rotating.

[0053] The dry bulb temperature measuring air duct comprises a dry bulb temperature measuring air duct outer cylinder and a dry bulb temperature measuring air duct inner cylinder, a dry bulb sliding groove is arranged in the dry bulb temperature measuring air duct outer cylinder, a dry bulb infrared temperature measuring instrument is arranged on the dry bulb temperature measuring sliding groove, the dry bulb infrared temperature measuring instrument can move forward and backward through the dry bulb temperature measuring sliding groove, and dry gauze is arranged in the dry bulb temperature measuring air duct inner cylinder.

[0054] The present application changes the traditional fixed support into a telescopic ventilation system, and automatically telescopes through measured real-time ΔT a and Δea values, and when the measured value is lower than the specified minimum measurement threshold, the support will be automatically elongated until the measured value is higher than the minimum threshold, thereby improving the measurement accuracy of ΔT a and Δea.

[0055] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present application does not necessarily have all the above-mentioned effects. Effects other than the above-mentioned effects can be clearly seen and extracted from the description, drawings, claims, etc. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 is a schematic diagram of a Bowen ratio water heat flux monitoring system of an embodiment of the present application arranged in a field;

[0057] Figure 2 is a structural schematic diagram of a Bowen ratio water heat flux monitoring system of an embodiment of the present application;

[0058] Figure 3 is an internal cross-sectional schematic diagram of a wet bulb temperature measuring air duct of an embodiment of the present application;

[0059] Figure 4 is an internal cross-sectional schematic diagram of a dry bulb temperature measuring air duct of an embodiment of the present application;

[0060] Figure 5 is a perspective view of a wet-bulb temperature measuring air duct according to an embodiment of the present application;

[0061] Figure 6 is a perspective view of a dry-bulb temperature measuring air duct according to an embodiment of the present application;

[0062] Figure 7 is a side view of a wet-bulb temperature of a Bowen ratio system for monitoring water and heat fluxes according to an embodiment of the present application;

[0063] Figure 8 is a side view of a dry-bulb temperature of a Bowen ratio system for monitoring water and heat fluxes according to an embodiment of the present application.

[0064] In the figure: 1, field; 2, Bowen ratio system for monitoring water and heat fluxes; 3, wet-bulb temperature measuring air duct; 4, dry-bulb temperature measuring air duct; 5, rotating machine; 6, fan; 7, telescopic ventilation system; 301, outer cylinder of wet-bulb temperature measuring air duct; 302, ball plate; 303, wetted gauze; 304, inner cylinder of wet-bulb temperature measuring air duct; 305, water tank; 307, wet-bulb infrared temperature measuring instrument; 306, wet-bulb temperature measuring chute; 401, outer cylinder of dry-bulb temperature measuring air duct; 402, inner cylinder of dry-bulb temperature measuring air duct; 403, dry gauze; 404, dry-bulb infrared temperature measuring instrument; 405, dry-bulb temperature measuring chute. DETAILED DESCRIPTION

[0065] Embodiments of the present application are described below in detail with reference to the accompanying drawings, in which the same or similar components have the same or similar designations throughout the several views, and a repeated description is omitted. The embodiments described below are examples intended to explain the present application, and are not to be understood as limiting the present application.

[0066] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inner", "outer", and the like are based on the orientations or positional relationships shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or components referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0067] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0068] Figure 1 and 2 The image shows a preferred embodiment of the Bowen ratio hydrothermal flux monitoring system for measuring wet and dry bulb temperatures. The Bowen ratio hydrothermal flux monitoring system for measuring wet and dry bulb temperatures includes a wet-bulb temperature measuring duct 3, a dry-bulb temperature measuring duct 4, a support frame, a retractable ventilation system 7, and a controller.

[0069] The bracket is equipped with retractable ventilation systems 7 on both sides. Each retractable ventilation system 7 has a telescopic sleeve, and a drive motor is installed inside the telescopic sleeve to drive the telescopic sleeve to extend and retract. The upper and lower ends of the telescopic sleeve of one side of the retractable ventilation system 7 are respectively equipped with wet-bulb temperature measuring air ducts 3, and the upper and lower ends of the telescopic sleeve of the other side of the retractable ventilation system 7 are respectively equipped with dry-bulb temperature measuring air ducts 4. The wet-bulb temperature measuring air duct 3 is equipped with a wet-bulb infrared thermometer 307 for measuring wet-bulb temperature, and the dry-bulb temperature measuring air duct 4 is equipped with a dry-bulb infrared thermometer 404 for measuring dry-bulb temperature.

[0070] The wet-bulb temperature measuring air duct 3 and the dry-bulb temperature measuring air duct 4 are respectively connected to the retractable ventilation system 7;

[0071] The controller is connected to the drive motors of the wet-bulb infrared thermometer 307, the dry-bulb infrared thermometer 404, and the retractable ventilation system 7, respectively.

[0072] like Figure 1 As shown, the Bowen ratio hydrothermal flux monitoring system 2 of this invention is placed in the field 1 for operation. It measures the Bowen ratio hydrothermal flux of dry and wet bulb temperatures using an infrared thermometer, effectively improving the measurement accuracy of dry and wet bulb temperatures, and thus improving the measurement accuracy of sensible heat flux and latent heat flux. This provides an important basis for accurately simulating the evolution of crop evapotranspiration (ETc) throughout the growth period, formulating reasonable farmland irrigation systems, and promoting efficient water-saving agriculture.

[0073] Combination Figure 3 and 5 As shown, in one embodiment of the present invention, the wet-bulb temperature measuring air duct 3 includes a wet-bulb temperature measuring air duct outer cylinder 301 and a wet-bulb temperature measuring air duct inner cylinder 304;

[0074] One end of the wet bulb temperature measuring air cylinder outer cylinder 301 and one end of the wet bulb temperature measuring air cylinder inner cylinder 304 are connected by a ball plate 302; the inner wall of the wet bulb temperature measuring air cylinder outer cylinder 301 is provided with a wet bulb temperature measuring sliding groove 306, and a wet bulb infrared temperature measuring instrument 307 is arranged on the wet bulb temperature measuring sliding groove 306; the wet bulb temperature measuring air cylinder outer cylinder 301 and the wet bulb temperature measuring air cylinder inner cylinder 304 are connected in communication, the wet bulb temperature measuring air cylinder inner cylinder 304 is internally provided with a wetted gauze 303, a water tank 305 is connected below the wetted gauze 303, and the wetted gauze 303 is connected with the water tank 305; the wetted gauze 303 is vertically arranged in the wet bulb temperature measuring air cylinder inner cylinder 304, the wet bulb infrared temperature measuring instrument 307 detects the temperature of the entire cross section of the wetted gauze 303, and the water tank 305 is provided with a water inlet and outlet, and the water in the water tank 305 is replaced and supplemented.

[0075] In combination Figure 4 and 6 As shown in FIGS. 1-3, in one embodiment of the present application, the dry bulb temperature measuring air cylinder 4 comprises a dry bulb temperature measuring air cylinder outer cylinder 401 and a dry bulb temperature measuring air cylinder inner cylinder 402.

[0076] One end of the dry bulb temperature measuring air cylinder outer cylinder 401 and one end of the dry bulb temperature measuring air cylinder inner cylinder 402 are connected; the inner wall of the dry bulb temperature measuring air cylinder outer cylinder 401 is provided with a dry bulb temperature measuring sliding groove 405, and a dry bulb infrared temperature measuring instrument 404 is arranged on the dry bulb temperature measuring sliding groove 405; the dry bulb temperature measuring air cylinder outer cylinder 401 and the dry bulb temperature measuring air cylinder inner cylinder 402 are connected in communication, the dry bulb temperature measuring air cylinder inner cylinder 304 is internally provided with a dry gauze 403, and the dry gauze 403 is vertically arranged in the dry bulb temperature measuring air cylinder inner cylinder 402; the dry bulb infrared temperature measuring instrument 404 detects the temperature of the entire cross section of the dry gauze 403.

[0077] The Bowen ratio water heat flux monitoring system for measuring dry and wet bulb temperatures further comprises a rotating machine 5, the rotating machine 5 is installed on a support, and the two sides of the telescopic ventilation system 7 are respectively connected with the rotating machine 5, and the rotating machine 5 drives the telescopic ventilation system 7 to rotate.

[0078] In one embodiment of the present application, the upper and lower ends of the telescopic sleeve of the telescopic ventilation system 7 are respectively provided with a communicating T-shaped cylinder, the intersection of the upper part of the T-shaped cylinder and the telescopic sleeve has an included angle, preferably an included angle of 15 degrees; when the wet bulb temperature measuring air cylinder 3 drives the telescopic ventilation system 7 to rotate through the rotating machine 5, the wet bulb temperature measuring air cylinder outer cylinder 301 and the wet bulb temperature measuring air cylinder inner cylinder 304 are connected by the ball plate 302, so that the Bowen ratio water heat flux monitoring system can be effectively ensured to rotate, and the water tank 307 can continuously be located below the wetted gauze.

[0079] The T-shaped cylinder of the telescopic ventilation system 7 on one side of the rotating machine 5 is provided with two wet bulb temperature measuring air ducts 3 at both ends, respectively, and four wet bulb temperature measuring air ducts 3 are symmetrically arranged at both ends of the telescopic ventilation system 7 in two groups, and the average value of the two wet bulb infrared temperature measuring instruments 307 at the same height is taken as the measurement value; the T-shaped cylinder of the telescopic ventilation system 7 on the other side of the rotating machine 5 is provided with two dry bulb temperature measuring air ducts 4 at both ends, respectively, and four dry bulb temperature measuring air ducts 4 are symmetrically arranged at both ends of the telescopic ventilation system 7 in two groups, so as to avoid the change of the orientation position of the dry bulb temperature measuring air duct 4 and the wet bulb temperature measuring air duct 3 after rotation and cause measurement error, and the average value of the two dry bulb infrared temperature measuring instruments 404 at the same height is taken as the measurement value, so that the temperature measured at the layer height is more representative.

[0080] In an embodiment of the present application, the outer wall of the telescopic ventilation system 7 is marked with a scale, when the measured ΔT a and Δe a value is lower than the specified minimum measurement threshold, the controller controls the telescopic ventilation system 7 to extend until the measurement value is higher than the minimum threshold. Effectively reduce the influence of the large difference of environmental temperature, wind speed and other meteorological factors in different geographical positions or different times at the same position on the measurement of the psychrometric ratio, and improve the measurement effectiveness.

[0081] In combination with Figure 7 and 8 In an embodiment of the present application, the telescopic ventilation system 7 is provided with a fan 6, the fan 6 generates suction to suck external air at two heights into the corresponding wet bulb temperature measuring air duct 3 and dry bulb temperature measuring air duct 4, and then measures the dry bulb temperature and wet bulb temperature at two heights, the fan 6 is connected with the controller, the intersection between the upper part of the T-shaped cylinder and the telescopic sleeve has an included angle to reduce the mutual interference of the fans 6. The suction generated by the same fan 6 can keep the air intake flow rate of the wet bulb temperature measuring air duct 3 and the dry bulb temperature measuring air duct 4 at two heights on the left and right sides of the telescopic ventilation system 7 consistent, and then make the measurement of the air dry and wet bulb temperature more accurate and reduce the error.

[0082] In an embodiment of the present application, the telescopic ventilation system 7 on both sides of the rotating machine 5 is provided with a fan 6, respectively, which can keep the air intake flow rate at two heights consistent and make the temperature measurement more accurate, and the fan 6 is connected with the controller to control the fan speed through the controller to achieve the best measurement condition of the air dry and wet bulb temperature.

[0083] The fan 6 in the telescopic ventilation system 7 generates suction to suck air at two heights into the wet bulb temperature measuring air duct 3 and the dry bulb temperature measuring air duct 4 connected to both ends of the telescopic ventilation system 7, and the wet bulb temperature measuring air duct 3 and the dry bulb temperature measuring air duct 4 are internally provided with infrared temperature measuring instruments to measure the temperature of the effective cross section of the gauze and further realize temperature measurement of the air at the upper and lower layers of the Bowen ratio water heat flux monitoring system.

[0084] In an embodiment of the present application, the wet bulb infrared temperature measuring instrument 307 is arranged on the wet bulb temperature measuring sliding groove 306, and the wet bulb infrared temperature measuring instrument 307 can move forward and backward on the wet bulb temperature measuring sliding groove 306 to realize effective observation of the wetted surface of the wetted gauze 303.

[0085] In an embodiment of the present application, the wetted gauze 303 is vertically arranged inside the wet bulb temperature measuring air duct inner cylinder 304, the wet bulb infrared temperature measuring instrument 307 observes the entire cross section of the wetted gauze 303, the dry gauze 403 is vertically arranged inside the dry bulb temperature measuring air duct inner cylinder 402, and the dry bulb infrared temperature measuring instrument 404 observes the entire cross section of the dry gauze 403 to realize point-to-surface observation and effectively improve the temperature measurement accuracy.

[0086] In an embodiment of the present application, the wet bulb temperature measuring air duct outer cylinder 301 and the wet bulb temperature measuring air duct inner cylinder 304 in the wet bulb temperature measuring air duct 3 are connected through the ball disc 302, and when the rotation machine 5 drives the two telescopic ventilation systems 7 to rotate, the water tank 305 connected to the lower end of the wet bulb temperature measuring air duct inner cylinder 304 can be always located below the wetted gauze 303, so that the wetted gauze 303 in the wet bulb temperature measuring air duct inner cylinder 304 is always in a wet state to ensure the accuracy of the wet bulb temperature observation.

[0087] A control method of the Bowen ratio water heat flux monitoring system according to the measured wet and dry bulb temperatures, comprising the following steps:

[0088] The wet bulb infrared temperature measuring instrument 307 in the wet bulb temperature measuring air duct 3 measures the wet bulb temperature and transmits it to the controller; the dry bulb infrared temperature measuring instrument 404 in the dry bulb temperature measuring air duct 4 measures the dry bulb temperature and transmits it to the controller;

[0089] The controller calculates ΔT a and Δe a values, and calculates the Bowen ratio β according to the ΔT a and Δe a values, so as to obtain the sensible heat flux H and the latent heat flux ρλE, when the ΔT a and Δe a values are lower than the set minimum measurement threshold value, the controller controls the telescopic ventilation system 7 to be elongated until the measurement value is higher than the minimum threshold value.

[0090] The wet bulb temperature measurement value takes the average value of two same height wet bulb infrared temperature measuring instruments 307; the dry bulb temperature measurement value takes the average value of two same height dry bulb infrared temperature measuring instruments 404; the rotating machine 5 makes the telescopic ventilation system 7 on both sides rotate 180° at the same interval time around the rotating machine 5 rotating shaft, so that the dry bulb temperature measuring air cylinder 4 and the wet bulb temperature measuring air cylinder 3 are transposed up and down. The automatic transposition up and down can realize that the same layer air temperature and humidity sensor monitors the air temperature and humidity of the upper and lower two layers, so that the system error of the air temperature and humidity sensor itself can be eliminated, and the final latent heat flux and sensible heat flux are more accurate.

[0091] The present application changes the traditional dry and wet bulb temperature monitoring using a thermometer to temperature monitoring using an infrared temperature measuring instrument, the dry and wet bulb temperature is measured by the infrared temperature measuring instrument, the wave number beta is calculated, and the sensible heat flux H and the latent heat flux ρλE are obtained, so that the measurement accuracy of the dry and wet bulb temperature is effectively improved, and the measurement accuracy of the sensible heat flux and the latent heat flux is improved, which provides an important basis for accurately simulating the evolution process of crop evapotranspiration (ETc) in the whole growth period, reasonably formulating the farmland irrigation system and promoting the implementation of efficient water-saving agriculture.

[0092] The telescopic ventilation system 7 of the present application can automatically adjust the observation height according to the measured value, so as to avoid the change of environmental temperature, wind speed and other meteorological factors at different geographical positions or at different times in the same position, thereby avoiding the large measurement error.

[0093] The present application improves the existing dry and wet bulb temperature measurement method, based on the measurement principle of the wet bulb temperature, the dry and wet bulb temperature monitoring using the infrared temperature measuring instrument can effectively improve the measurement accuracy, avoid unnecessary labor and time cost, and improve the monitoring efficiency.

[0094] The telescopic ventilation system 7 of the present application is used instead of the fixed height support, so as to improve the measurement accuracy of ΔT a and Δea in different environments or at different times in the same position.

[0095] In one embodiment of the present application, the dry-bulb temperature measuring air duct 4 and the wet-bulb temperature measuring air duct 3 are respectively connected to the left and right telescopic ventilation systems 7, the telescopic ventilation systems 7 are connected to the rotating machine 5, the rotating machine 5 rotates the left and right telescopic ventilation systems 7 180° forward and backward simultaneously every half an hour, so that the four dry-bulb temperature measuring air ducts 4 and the four wet-bulb temperature measuring air ducts 3 can be automatically transposed up and down. The four dry-bulb temperature measuring air ducts 4 are symmetrically distributed in two groups, and are placed at the upper and lower ends of the left telescopic ventilation system 7, and the four wet-bulb temperature measuring air ducts 3 are symmetrically distributed in two groups, and are placed at the upper and lower ends of the right telescopic ventilation system 7, so as to avoid measurement errors caused by changes in the orientation of the dry-bulb temperature measuring air duct 4 and the wet-bulb temperature measuring air duct 3 after rotation, and the average values of the front and rear dry-bulb temperature measuring air ducts 4 and the wet-bulb temperature measuring air ducts 3 are taken as the monitoring data of the same layer. The automatic transposition up and down can realize the monitoring of the air temperature and humidity of the upper and lower two layers by using the same layer air temperature and humidity sensor, so as to eliminate the system error of the air temperature and humidity sensor itself, and make the final latent heat flux and sensible heat flux more accurate. The telescopic ventilation system 7 is marked with a scale, when the measured ΔT a and Δe a values are lower than the specified minimum measurement threshold, the support will be automatically extended by one unit, and the distance of one unit is 0.2 m, until the measurement value is higher than the minimum threshold. This effectively reduces the influence of large differences in environmental temperature, wind speed and other meteorological factors at different geographical locations or at different times in the same location on the psychrometric measurement, and improves the measurement effectiveness. Each of the left and right telescopic ventilation systems 7 is provided with a fan 6, and the speed of the fan is adjusted by the controller to control the wind speed in the air duct to be 3 m / s to 5 m / s, so as to achieve the best measurement conditions of the air wet-bulb temperature, and reduce the measurement errors caused by too low or too high wind speed.

[0096] It should be understood that although the present specification is described in terms of various embodiments, not every embodiment contains only one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

[0097] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present application, and are not used to limit the protection scope of the present application, and any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A Bowen ratio hydrologic flux monitoring system for measuring dry-bulb and wet-bulb temperatures, the system comprising: It comprises a wet bulb temperature measuring air duct (3), a dry bulb temperature measuring air duct (4), a support, a telescopic ventilation system (7) and a controller. The telescopic ventilation system (7) is provided with a telescopic sleeve, and a driving motor is arranged in the telescopic sleeve to drive the telescopic sleeve to extend or retract; the telescopic sleeve of the telescopic ventilation system (7) on one side is provided with a wet bulb temperature measuring air duct (3) at the upper end and the lower end, and the telescopic sleeve of the telescopic ventilation system (7) on the other side is provided with a dry bulb temperature measuring air duct (4) at the upper end and the lower end; the wet bulb temperature measuring air duct (3) is provided with a wet bulb infrared temperature measuring instrument (307) for measuring the temperature of the wet bulb; the dry bulb temperature measuring air duct (4) is provided with a dry bulb infrared temperature measuring instrument (404) for measuring the temperature of the dry bulb; The wet bulb temperature measuring air duct (3) and the dry bulb temperature measuring air duct (4) are in communication with the telescopic ventilation system (7); The controller is connected with the wet bulb infrared temperature measuring instrument (307), the dry bulb infrared temperature measuring instrument (404) and the driving motor of the telescopic ventilation system (7); The wet bulb temperature measuring air duct (3) comprises a wet bulb temperature measuring air duct outer cylinder (301) and a wet bulb temperature measuring air duct inner cylinder (304); One end of the wet bulb temperature measuring air duct outer cylinder (301) and one end of the wet bulb temperature measuring air duct inner cylinder (304) are connected through a ball plate (302); a wet bulb temperature measuring sliding groove (306) is arranged on the inner wall of the wet bulb temperature measuring air duct outer cylinder (301), and the wet bulb infrared temperature measuring instrument (307) is arranged on the wet bulb temperature measuring sliding groove (306); the wet bulb temperature measuring air duct outer cylinder (301) and the wet bulb temperature measuring air duct inner cylinder (304) are in communication, the wet bulb temperature measuring air duct inner cylinder (304) is internally provided with a wetted gauze (303), a water tank (305) is connected below the wetted gauze (303), the water tank (305) is arranged at the lower part of the wet bulb temperature measuring air duct inner cylinder (304), the wetted gauze (303) is connected with the water tank (305), the wetted gauze (303) is vertically arranged in the wet bulb temperature measuring air duct inner cylinder (304), and the wet bulb infrared temperature measuring instrument (307) detects the temperature of the whole cross section of the wetted gauze (303); The dry bulb temperature measuring air duct (4) comprises a dry bulb temperature measuring air duct outer cylinder (401) and a dry bulb temperature measuring air duct inner cylinder (402); One end of the dry bulb temperature measuring air duct outer cylinder (401) and one end of the dry bulb temperature measuring air duct inner cylinder (402) are connected; a dry bulb temperature measuring sliding groove (405) is arranged on the inner wall of the dry bulb temperature measuring air duct outer cylinder (401), and the dry bulb infrared temperature measuring instrument (404) is arranged on the dry bulb temperature measuring sliding groove (405); the dry bulb temperature measuring air duct outer cylinder (401) and the dry bulb temperature measuring air duct inner cylinder (402) are in communication, the dry bulb temperature measuring air duct inner cylinder (402) is internally provided with a dry gauze (403), the dry gauze (403) is vertically arranged in the dry bulb temperature measuring air duct inner cylinder (402), and the dry bulb infrared temperature measuring instrument (404) detects the temperature of the whole cross section of the dry gauze (403); The rotating machine (5) is installed on the support, and the two sides of the telescopic ventilation system (7) are connected with the rotating machine (5) respectively, and the rotating machine (5) drives the telescopic ventilation system (7) to rotate. The telescopic ventilation system (7) is provided with a fan (6), the fan (6) generates suction to suck external air at two heights into the corresponding wet bulb temperature measuring air cylinder (3) and dry bulb temperature measuring air cylinder (4), and the fan (6) is connected with the controller.

2. The Bowen ratio hydrologic flux monitoring system measuring psychrometric wet and dry bulb temperatures of claim 1, wherein, The upper and lower ends of the telescopic sleeve of the telescopic ventilation system (7) are respectively provided with communicating T-shaped cylinders, and the intersection of the upper part of the T-shaped cylinder and the telescopic sleeve has an included angle.

3. The Bowen ratio hydrologic flux monitoring system measuring the wet and dry bulb temperature according to claim 2, wherein, The two ends of the T-shaped cylinder of the telescopic ventilation system (7) on one side of the rotating machine (5) are respectively provided with two wet bulb temperature measuring air cylinders (3), and the four wet bulb temperature measuring air cylinders (3) are connected at the two ends of the telescopic ventilation system (7) in pairs opposite to each other; the two ends of the T-shaped cylinder of the telescopic ventilation system (7) on the other side of the rotating machine (5) are respectively provided with two dry bulb temperature measuring air cylinders (4), and the four dry bulb temperature measuring air cylinders (4) are connected at the two ends of the telescopic ventilation system (7) in pairs opposite to each other.

4. The Bowen ratio hydrologic flux monitoring system measuring the wet and dry bulb temperature according to claim 1, wherein, The outer wall of the telescopic ventilation system (7) is marked with a scale.

5. A control method of the Bowen water heat flux monitoring system for measuring the wet and dry bulb temperatures according to any one of claims 1-4, comprising the following steps: The wet bulb infrared temperature measuring instrument (307) in the wet bulb temperature measuring air cylinder (3) measures the wet bulb temperature and transmits it to the controller; the dry bulb infrared temperature measuring instrument (404) in the dry bulb temperature measuring air cylinder (4) measures the dry bulb temperature and transmits it to the controller; The controller calculates ΔT a and Δe a values, and calculates the wet-bulb temperature β from the ΔT a and Δe a values, so as to obtain the sensible heat flux H and the latent heat flux ρλE, when the ΔT a and Δe a values are lower than the set minimum measurement threshold, the controller controls the telescopic ventilation system (7) to extend until the measurement values are higher than the minimum threshold.

6. The control method of the Bowen ratio hydrothermal flux monitoring system measuring the wet-and-dry-bulb temperature according to claim 5, wherein, The wet bulb temperature measurement value is the average value of two wet bulb infrared temperature measuring instruments (307) at the same height; the dry bulb temperature measurement value is the average value of two dry bulb infrared temperature measuring instruments (404) at the same height; the rotating machine (5) makes the two sides of the telescopic ventilation system (7) rotate 180° at the same time at a set interval of time around the rotating shaft of the rotating machine (5), so that the dry bulb temperature measuring air cylinder (4) and the wet bulb temperature measuring air cylinder (3) are transposed up and down.

Images