Convection ventilation structure, regulation and control system and regulation and control method for closed yak breeding house

Abstract

The invention belongs to the field of animal husbandry engineering, discloses a closed yak house convection ventilation structure, a regulation and control system and a regulation and control method, and is mainly used for solving the problems that the ventilation rate and the air quality are reduced due to excessive heat preservation of an existing yak house in winter, the yak body temperature is rapidly reduced due to direct blowing of cold air, and yak growth is affected. By arranging the air inlets and the air outlets which are staggered up and down, air flow in the breeding house body can effectively drive harmful gas and carbon dioxide in all layers of areas in the breeding house body to be exhausted, and the air quality in the breeding house is improved; the upper-inlet and lower-outlet air inlet and outlet device can effectively reduce loss of temperature in the breeding house and can prevent outdoor air from directly blowing to yak bodies, the comfort level of yaks is improved, meanwhile, heat consumption of the yaks is reduced, and the production efficiency of the yaks is guaranteed. In addition, the invention further provides a multi-method fusion yak house ventilation regulation and control system and method based on the heat balance method and the carbon dioxide balance method.

Description

Technical Field

[0001] The present invention belongs to the field of animal husbandry engineering, and more specifically, relates to a closed yak shed convection ventilation structure, a control system and a control method. Background Art

[0002] In the field of animal husbandry engineering, the design and construction of cattle sheds is an important research direction, in which ventilation is a key consideration. In the prior art, natural ventilation and mechanical ventilation are usually used to solve the ventilation problem of cattle sheds.

[0003] Among them, natural ventilation is to use natural wind to ventilate by opening windows and doors in buildings; mechanical ventilation is to use forced ventilation through equipment such as fans. In addition, some existing technologies have proposed to improve the ventilation effect by adjusting the architectural structure of the cowshed. However, the existing ventilation technology in this field still has many problems and shortcomings. First of all, the existing natural ventilation method generally opens vents on both sides of the pen. The position of the vents is roughly in the middle of the height of the pen, and the height of the vents on both sides is consistent, so that the outdoor natural wind can form convection inside the pen to achieve ventilation effect. However, such a ventilation structure has the following problems in closed yak pens: First, the ventilation effect is not significant, and the convection air flow route is difficult to cover the upper, middle and lower areas of the pen, so that the harmful gases in the pen are not completely discharged, affecting the air inside the yak pen. air quality; secondly, the linear ventilation route will cause the outdoor natural wind to flow through the sty too fast, which can easily cause hypothermia in the sty; thirdly, since the building height of the yak sty is about 3 meters, the outdoor natural wind will blow directly to the yak's head and body through the vents in the middle of the sty during ventilation, which can easily cause the yak's skin, ears and other parts to cool down rapidly, especially in the cold winter climate, which will accelerate the drop in yak's body temperature, increase heat consumption, and increase the risk of respiratory tract infection and frostbite in yaks. In addition, the direct blowing of convection cold wind may also make yaks feel uncomfortable and stressed, affecting their ultimate production efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide a closed yak pen convection ventilation structure, aiming to solve the problems of poor ventilation effect, poor heat preservation ability and easy impact on the growth of yaks in the existing ventilation structures for yak pens.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A closed yak shed convection ventilation structure, characterized in that it includes a shed body, and a plurality of vents are arranged on the left and right side walls of the shed body, the vents include air inlets and air outlets, the air inlets and air outlets located on the same side of the shed body are staggered up and down, and the air inlets are arranged close to the top of the shed body, and the air outlets are arranged close to the bottom of the shed body; the air inlets located on either side of the shed body correspond one-to-one with the air outlets located on the other side of the shed body; air duct baffles for opening and closing air outlets are installed on the inner side wall of the shed body corresponding to the air inlets and air outlets, and an air guide duct for controlling the ventilation volume is installed on the outer side wall of the shed body corresponding to the air inlets.

[0006] As a further preferred embodiment of the above technical solution, the air duct baffle is connected to a telescopic cylinder, and the air duct baffle realizes the opening and closing of the air inlet or the air outlet under the telescopic action of the telescopic cylinder.

[0007] As a further preferred embodiment of the above technical solution, the air guide duct includes a straight portion and a curved folded portion for adjusting the opening angle of the air guide duct, the straight portion is fixedly installed perpendicular to the outer wall of the enclosure body, and the curved folded portion is connected to the end of the straight portion; a horizontal rotating shaft is hinged in the opening plane of the straight portion and corresponding to the lower position of the straight portion, and the horizontal rotating shaft is perpendicular to the axis of the straight portion; a rigid fixing ring is fixedly connected to the rotating shaft, and the rigid fixing ring is adapted to the opening of the straight portion; the end of the curved folded portion is sleeved on the rigid fixing ring, and one end of the rotating shaft is connected to a driving motor.

[0008] As a further preferred embodiment of the above technical solution, the initial opening angle of the curved folded portion is vertically downward, and its opening horizontal plane is flush with the lower side of the air guide duct; the maximum bending folded angle of the curved folded portion is 90 degrees, at which time its opening horizontal plane is parallel to the opening plane of the straight portion, and its opening angle is horizontally outward.

[0009] As a further preferred embodiment of the above technical solution, all air inlets or all air outlets located on the same side of the enclosure body are at the same height, and air filters are installed in all air inlets.

[0010] As a further preferred embodiment of the above technical solution, an exhaust port is provided above the housing body.

[0011] The present invention also provides a ventilation control system based on the above technical solution, characterized in that it includes: A data acquisition module is used to collect environmental information data inside and outside the sty, and the data acquisition module includes a wind direction sensor and a wind speed sensor installed outside the sty, temperature sensors installed inside and outside the sty, respectively, carbon dioxide sensors installed inside and outside the sty, and a hydrogen sulfide sensor installed inside the sty; The control panel is used to receive the target temperature in the circle, the allowable concentration of carbon dioxide in the circle and the allowable concentration of hydrogen sulfide in the circle input by the user; A controller, used to integrate the environmental information data collected by the data collection module with the preset target value and the allowable value input by the control panel, obtain the required ventilation volume of the yak shed by calculation, and issue corresponding control instructions to the telescopic cylinder and the drive motor according to the calculation result; The controller is connected with the data acquisition module, the control panel, the telescopic cylinder and the drive motor signal.

[0012] In addition, the present invention also provides a ventilation control method based on the above ventilation control system, which is characterized by comprising the following steps: S1: Ventilation demand judgment, the controller receives the environmental monitoring values ​​collected by the data acquisition module, and compares the monitoring values ​​with the target values ​​and the allowable values ​​set by the user through the control panel one by one; if at least one current value is greater than the corresponding target value and the allowable value, step S2 is executed; if all current values ​​are less than the corresponding target value and the allowable value, step S1 is continued; S2: ventilation channel selection, obtaining the wind direction information outside the current enclosure through the data acquisition module, and transmitting the wind direction information to the controller, and the controller controls the activation of the telescopic cylinder and selects to open the corresponding air duct baffles at the air inlet and the air outlet according to the wind direction information; S3: Ventilation demand calculation, the controller obtains the ventilation volume required for heat balance according to the following heat balance calculation formula : In the formula, is the ventilation rate calculated based on heat balance; is the number of yaks in the pen; is the sensible heat production of a single yak; is the heat transfer coefficient of the pen body; is the area of ​​the enclosure itself; is the heat transfer coefficient of different zones in ground heat transfer; is the length of different zones in ground heat transfer; ρ is the air density; is the specific heat of air; and are the temperatures inside and outside the pen, respectively; The controller obtains the ventilation volume required for carbon dioxide balance according to the following carbon dioxide balance calculation formula : In the formula, For Balance calculated ventilation volume; is the number of yaks in the pen; For a single yak per hour Production volume; for density; and In the enclosure Concentration and outside the enclosure concentration; The controller obtains the final required ventilation volume according to the following heat and carbon dioxide fusion balance calculation formula : In the formula, is the weight coefficient; S4: Calculation of the bending angle of the bending and folding portion of the air guide duct. The controller obtains the control angle of the bending and folding portion of the air guide duct according to the following calculation formula : In the formula, is the ventilation volume; is the wind speed; is the cross-sectional area of ​​the air inlet; is the angle between the natural wind and the Y axis on the vertical cross section; is the initial opening angle of the air duct; S5: Control ventilation, the controller controls the ventilation according to the bending angle of the folded portion of the air guide duct obtained in step S4. , controlling and starting the driving motor, so that the curved folding portion of the air guide duct is bent to a specified angle, and ventilation begins; S6: Ventilation status judgment, the controller receives the environmental monitoring values ​​collected from the data acquisition module, and compares the monitoring values ​​with the target values ​​and the allowed values ​​set by the user through the control panel one by one; if at least one of the current values ​​is greater than the corresponding target value and the allowed value, the ventilation status of the air duct baffle and the air duct is maintained, and ventilation continues; if all the current values ​​are less than the corresponding target value and the allowed value, the air duct baffle is closed and step S1 is executed.

[0013] As a further optimization of the above technical solution, in step S3, the weight coefficient The priority of temperature and carbon dioxide concentration control in yak pens in different seasons is set; in winter, temperature control is more important, and the weight coefficient >0.5; in the transition season, temperature and carbon dioxide concentration control are equally important, and the weight coefficient =0.5; in summer, carbon dioxide concentration control is more important, and the weight coefficient <0.5.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses air inlets and air outlets arranged up and down, so that outdoor natural wind can enter the pen through the air inlet on one side and flow out through the air outlet on the other side, forming convection ventilation while maintaining the air flow route in the pen as an up and down slope type. Compared with the existing linear convection ventilation, it can not only enable outdoor natural wind to flow through the upper, middle and lower layers inside the pen, but also effectively drive the discharge of harmful gases and carbon dioxide in each layer of the pen, thereby improving the ventilation effect; in addition, the positions of the air inlet and the air outlet are respectively close to the top and bottom of the pen body. Due to the gas movement law that hot air moves upward and cold air moves downward, the upper-in and lower-out air inlet and outlet arrangement can effectively reduce the temperature loss in the pen, achieve heat preservation in the pen, and prevent outdoor wind from blowing directly onto the yak's body, thereby improving the comfort of the yak and reducing the yak's own heat consumption, thereby ensuring the yak's production efficiency.

[0015] The present invention has duct baffles for opening and closing the air outlets installed on the inner wall of the enclosure body corresponding to the air inlet and the air outlet, and has an air duct for controlling the ventilation volume installed on the outer wall of the enclosure body corresponding to the air inlet. The arrangement of the duct baffles enables the present invention to select the corresponding air inlet and outlet channels for opening and closing according to the wind direction of outdoor natural wind in different seasons, so that the present invention always maintains an air flow ventilation route of one-side inlet and one-side out and top-inlet and bottom-out, ensuring ventilation needs in different seasons. The arrangement of the air duct enables the present invention to accurately adjust the ventilation effect according to the ventilation time and ventilation volume requirements in different seasons, thereby realizing intelligent regulation.

[0016] The ventilation control system in the present invention collects real-time data through a data acquisition module, inputs user preset target values ​​and allowable values ​​through a control panel, performs data processing and calculation decisions through a controller, and sends work instructions to a drive module for ventilation control, so that the present invention can realize intelligent control of the ventilation volume of yak pens under different environmental conditions, accurately control the temperature, carbon dioxide and harmful gas concentrations in the pens, and ensure the production needs of yaks.

[0017] The ventilation control method of the present invention intelligently senses environmental parameters such as temperature, carbon dioxide concentration, hydrogen sulfide concentration, etc., adopts a ventilation volume intelligent algorithm that combines the heat balance method and the carbon dioxide balance method, intelligently analyzes and determines the weight coefficient of each influencing factor and performs dynamic real-time adjustments to obtain the best ventilation control instructions, so that the best yak growth environment is achieved in the pen, thereby ensuring the healthy growth of yaks and achieving the goal of increasing herders' income. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic structural diagram of the closed yak shed convection ventilation structure of the present invention when no ventilation is performed; Figure 2 It is a structural schematic diagram of the closed yak shed convection ventilation structure of the present invention when the wind comes from the left side horizontally; Figure 3 It is a structural schematic diagram of the closed yak shed convection ventilation structure of the present invention when the wind comes from the right side horizontally; Figure 4 It is a schematic diagram of the overall process of the ventilation control method of the present invention; Figure 5 Schematic diagram of derivation of the calculation formula of step S4 in the ventilation control method of the present invention; Among them, 1-storage body, 2-air inlet, 3-air outlet, 4-air duct baffle, 5-air guide duct, 6-air filter element, 7-exhaust port. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1 like Figures 1 to 3A closed yak shed convection ventilation structure is shown, comprising a shed body 1. In the present embodiment, the shed body 1 is of a square closed type, surrounded by four walls of front, rear, left and right, with a roof above the walls, wherein shed doors are opened on the front and rear end walls, and a plurality of vents are arranged on the left and right side walls, the vents comprising air inlets 2 and air outlets 3, the air inlets 2 and air outlets 3 located on both sides of the shed body 1 are arranged in a staggered manner up and down, and the air inlet 2 is arranged close to the top of the shed body 1, and the air outlet 3 is arranged close to the bottom of the shed body 1; the air inlets 2 located on any one side of the shed body 1 correspond one-to-one to the air outlet 3 located on the other side of the shed body 1; an air duct baffle 4 for opening and closing the air outlet is installed on the inner side wall of the shed body 1 corresponding to the air inlet 2 and the air outlet 3, and an air guide duct 5 for controlling the ventilation volume is installed on the outer side wall of the shed body 1 corresponding to the air inlet 2.

[0021] The above-mentioned air duct baffle 4 is used to open and close different ventilation channels. Specifically, the air duct baffle 4 can control the opening and closing of the air inlets 2 and the air outlets 3 on both sides by translation. In this embodiment, the air duct baffle 4 is slidably installed at the air inlet 2 and the air outlet 3. A telescopic cylinder is installed on either side of the air duct baffle 4, and the air duct baffle 4 is used to open and close the air inlet 2 and the air outlet 3 through the telescopic movement of the telescopic rod. The herders can choose to drive the corresponding air duct baffle 4 to translate to open and close the corresponding ventilation channel according to the change in the direction of natural wind brought about by seasonal climate change. For example, if the direction of the outdoor natural wind is from the left side to the right side of the pen, the air duct baffle 4 at the air inlet 2 on the right wall of the pen and the air outlet 3 on the left wall can be closed, so that the air flow route in the pen is maintained from the air inlet 2 on the left wall to the air outlet 3 on the right wall. In this way, it can be ensured that the air flow route in the pen always maintains one side in and one side out and up in and down out under different conditions to cope with the ventilation needs in different wind directions.

[0022] The above-mentioned air guide duct 5 is used to adjust the ventilation volume at the air inlet 2. Specifically, the air guide duct 5 includes a straight portion and a curved folding portion for adjusting the opening angle of the air guide duct 5. The straight portion is fixedly installed perpendicular to the outer wall of the enclosure body 1, and the curved folding portion is connected to the end of the straight portion. The straight portion is made of a hard plastic tube, and the curved folding portion is made of a foldable flexible material (such as PP material); in this embodiment, a horizontal rotation axis is hinged in the opening plane of the straight portion and corresponding to the lower position of the straight portion, and the horizontal rotation axis is perpendicular to the axis of the straight portion; a rigid fixing ring is fixedly connected to the horizontal rotation axis, and the rigid fixing ring is adapted to the opening of the straight portion; the end of the curved folding portion is sleeved on the rigid fixing ring, and one end of the horizontal rotation axis is connected to a driving motor, which drives the horizontal rotation axis to rotate through the driving motor, thereby driving the rigid fixing ring to rotate around the lower position of the straight portion, thereby realizing the bending and folding of the curved folding portion, and realizing the adjustment of the opening angle of the air guide duct 5.

[0023] More specifically, in this embodiment, the initial opening angle of the curved folded portion is vertically downward, and its opening horizontal plane is flush with the lower side of the air guide duct; the maximum bending folded angle of the curved folded portion is 90 degrees, at which time its opening horizontal plane is parallel to the opening plane of the straight portion, and its opening angle is horizontally outward.

[0024] The position, height and number of the above-mentioned air inlets 2 and air outlets 3 need to be determined according to the area, height of the enclosure body 1 and the weight index of the yaks raised. Generally, it is necessary to ensure that the height of the air inlet 2 is above the height of the yak, and the height of the air outlet 3 is roughly at the height of the yak's legs.

[0025] Compared with the traditional linear ventilation route, the natural convection ventilation method adopted by the present invention has an up and down slope air flow route that can make the outdoor natural wind flow through the upper, middle and lower areas of the pen body 1, effectively driving the discharge of harmful gases and carbon dioxide in each layer of the pen body 1, and improving the ventilation effect; at the same time, following the law that hot air moves upward and cold air moves downward, the upper-in and lower-out air inlet and outlet settings can effectively reduce the temperature loss in the pen, achieve heat preservation in the pen, and prevent the outdoor wind from blowing directly onto the yak's body, thereby improving the comfort of the yak and reducing the yak's own heat consumption, thereby ensuring the yak's production efficiency.

[0026] Furthermore, all the air inlets 2 or all the air outlets 3 located on the same side of the enclosure body 1 are at the same height. Specifically, a row of air inlets 2 and a row of air outlets 3 are arranged on the left and right side walls of the enclosure body 1. The air inlets 2 on the left wall and the air outlets 3 on the right wall form a group of ventilation passages, and the air inlets 2 on the right wall and the air outlets 3 on the left wall form a group of ventilation passages. If the outdoor natural wind blows from the left side to the right side of the enclosure, the air flow route in the enclosure is: from the air inlet 2 on the left wall to the air outlet 3 on the right wall, and vice versa. This arrangement is used to cope with different wind directions in pastoral areas in different seasons.

[0027] Furthermore, an air filter 6 is installed in the air inlet 2, and the air filter 6 can filter out particulate impurities carried in the outdoor natural wind entering the stable, thereby ensuring that the air entering the stable is clean enough.

[0028] Furthermore, an exhaust port 7 for discharging ammonia is provided above the enclosure body 1. Since ammonia has a great influence on the breeding environment of the enclosure and its density is less than that of air, it is mainly dispersed in the upper space in the enclosure. In order to facilitate the discharge of ammonia, a separate exhaust port 7 is provided above the enclosure body 1. At the same time, the opening angle of the air guide duct 5 can be adjusted to promote the discharge of ammonia through the exhaust port 7. Of course, those skilled in the art can easily think of that the exhaust port 7 can also be opened and closed by setting a switch baffle, and an ammonia concentration sensor can be installed in the enclosure. The operation of the switch baffle can be individually controlled according to the monitoring of the ammonia concentration in the enclosure, thereby realizing the opening and closing of the exhaust port and realizing the automatic discharge of ammonia. In this embodiment, the allowable value of ammonia concentration is: 17-34 mg / m³.

[0029] Example 2 The control system in this embodiment is adapted to the closed yak shed convection ventilation structure in the above-mentioned embodiment 1, and includes: A data acquisition module is used to collect environmental information data inside and outside the sty, and the data acquisition module includes a wind direction sensor and a wind speed sensor installed outside the sty, temperature sensors installed inside and outside the sty, respectively, carbon dioxide sensors installed inside and outside the sty, and a hydrogen sulfide sensor installed inside the sty; The control panel is used to receive the target temperature in the circle, the allowable concentration of carbon dioxide in the circle and the allowable concentration of hydrogen sulfide in the circle input by the user; A controller, used to integrate the environmental information data collected by the data collection module with the preset target value and the allowable value input by the control panel, obtain the required ventilation volume of the yak shed by calculation, and issue corresponding control instructions to the telescopic cylinder and the drive motor according to the calculation result; The controller is connected with the data acquisition module, the control panel, the telescopic cylinder and the drive motor signal.

[0030] It should be understood by those skilled in the art that, based on relevant literature and practical experience, the target temperature within the circle, the allowable concentration of carbon dioxide within the circle and the allowable concentration of hydrogen sulfide within the circle input by the user on the control panel are: temperature target value: 10-20°C, CO2 concentration allowable value: 0.15%-0.25%, H2S concentration allowable value: 2-4mg / m³.

[0031] Example 3 The control method in this embodiment is adapted to the control system in the above-mentioned embodiment 2, such as Figure 4 As shown, the following steps are included: S1: Ventilation demand judgment, the controller receives the environmental monitoring values ​​collected by the data acquisition module, and compares the monitoring values ​​with the target values ​​and the allowable values ​​set by the user through the control panel one by one; if at least one current value is greater than the corresponding target value and the allowable value, step S2 is executed; if all current values ​​are less than the corresponding target value and the allowable value, step S1 is continued; S2: ventilation channel selection, obtaining wind direction information outside the current enclosure through the data acquisition module, and transmitting the wind direction information to the controller, and the controller controls the activation of the telescopic cylinder and selects to open the corresponding air duct baffles at the air inlet and the air outlet according to the wind direction information; S3: Ventilation demand calculation, the controller obtains the ventilation volume required for heat balance according to the following heat balance calculation formula : In the formula, is the ventilation rate calculated based on heat balance; is the number of yaks in the pen; is the sensible heat production of a single yak; is the heat transfer coefficient of the pen body; is the area of ​​the enclosure itself; is the heat transfer coefficient of different zones in ground heat transfer; is the length of different zones in ground heat transfer; ρ is the air density; is the specific heat of air; and are the temperatures inside and outside the pen, respectively; The controller obtains the ventilation volume required for carbon dioxide balance according to the following carbon dioxide balance calculation formula : In the formula, For Balance calculated ventilation volume; is the number of yaks in the pen; For a single yak per hour Production volume; for density; and In the enclosure Concentration and outside the enclosure concentration; The controller obtains the final required ventilation volume according to the following heat and carbon dioxide fusion balance calculation formula : In the formula, is the weight coefficient; S4: Calculation of the bending angle of the bending and folding portion of the air guide duct. The controller obtains the control angle of the bending and folding portion of the air guide duct according to the following calculation formula : In the formula, is the ventilation volume; is the wind speed; is the cross-sectional area of ​​the air inlet; is the angle between the natural wind and the Y axis on the vertical cross section; is the initial opening angle of the air duct; Figure 5 In this formula, when the bending and folding portion of the air guide duct is bent and folded from the initial position, the is 0; S5: Control ventilation, the controller controls the ventilation according to the bending angle of the folded portion of the air guide duct obtained in step S4. , controlling and starting the driving motor, so that the curved folding portion of the air guide duct is bent to a specified angle, and ventilation begins; S6: Ventilation status judgment, the controller receives the environmental monitoring values ​​collected from the data acquisition module, and compares the monitoring values ​​with the target values ​​and the allowed values ​​set by the user through the control panel one by one; if at least one of the current values ​​is greater than the corresponding target value and the allowed value, the ventilation status of the air duct baffle and the air duct is maintained, and ventilation continues; if all the current values ​​are less than the corresponding target value and the allowed value, the air duct baffle is closed and step S1 is executed.

[0032] Furthermore, in step S3, the weight coefficient The priority of temperature and carbon dioxide concentration control in yak pens in different seasons is set; in winter, temperature control is more important, and the weight coefficient >0.5; in the transition season, temperature and carbon dioxide concentration control are equally important, and the weight coefficient =0.5; in summer, carbon dioxide concentration control is more important, and the weight coefficient <0.5.

[0033] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A closed yak shed convection ventilation structure, characterized in that: The invention comprises a housing body (1), wherein a plurality of ventilation openings are arranged on the left and right side walls of the housing body (1), wherein the ventilation openings comprise air inlets (2) and air outlets (3), wherein the air inlets (2) and air outlets (3) located on the same side of the housing body (1) are arranged in a staggered manner up and down, and the air inlets (2) are arranged close to the top of the housing body (1), and the air outlets (3) are arranged close to the bottom of the housing body (1); the air inlets (2) located on either side of the housing body (1) correspond to the air outlets (3) located on the other side of the housing body (1); an air duct baffle (4) for opening and closing the air outlets is installed on the inner side wall of the housing body corresponding to the air inlets (2) and the air outlets (3), and an air guide duct (5) for controlling the ventilation volume is installed on the outer side wall of the housing body (1) corresponding to the air inlets (2).

2. The closed yak shed convection ventilation structure according to claim 1 is characterized in that: The air duct baffle (4) is connected to a telescopic cylinder, and the air duct baffle (4) is able to open and close the air inlet (2) or the air outlet (3) under the telescopic action of the telescopic cylinder.

3. The closed yak shed convection ventilation structure according to claim 2 is characterized in that: The air guide duct (5) comprises a straight portion and a curved folded portion for adjusting the opening angle of the air guide duct (5), the straight portion being fixedly installed perpendicularly to the outer wall of the enclosure body (1), and the curved folded portion being connected to the end of the straight portion; a horizontal rotation axis is hingedly connected in the opening plane of the straight portion and corresponding to the lower side position of the straight portion, and the horizontal rotation axis is perpendicular to the axis of the straight portion; a rigid fixing ring is fixedly connected to the rotation axis, and the rigid fixing ring is adapted to the opening of the straight portion; the end of the curved folded portion is sleeved on the rigid fixing ring, and one end of the rotation axis is connected to a drive motor.

4. The closed yak shed convection ventilation structure according to claim 3 is characterized in that: The initial opening angle of the curved folded portion is vertically downward, and its opening horizontal plane is flush with the lower side of the air guide duct; the maximum bending folded angle of the curved folded portion is 90 degrees, at which time its opening horizontal plane is parallel to the opening plane of the straight portion, and its opening angle is horizontally outward.

5. The closed yak shed convection ventilation structure according to claim 3, characterized in that: All air inlets (2) or all air outlets (3) located on the same side of the enclosure body (1) are located at the same height, and air filter elements (6) are installed in all air inlets (2).

6. The closed yak shed convection ventilation structure according to claim 3, characterized in that: An exhaust port (7) is provided above the housing body (1).

7. A control system for the closed yak shed convection ventilation structure based on any one of claims 3 to 6, characterized in that: include: A data acquisition module is used to collect environmental information data inside and outside the stable, and the data acquisition module includes a wind direction sensor and a wind speed sensor installed outside the stable, temperature sensors installed inside and outside the stable, respectively, carbon dioxide sensors installed inside and outside the stable, and a hydrogen sulfide sensor installed inside the stable; The control panel is used to receive the target temperature in the circle, the allowable concentration of carbon dioxide in the circle and the allowable concentration of hydrogen sulfide in the circle input by the user; A controller, used to integrate the environmental information data collected by the data collection module with the preset target value and the allowable value input by the control panel, obtain the required ventilation volume of the yak shed by calculation, and issue corresponding control instructions to the telescopic cylinder and the drive motor according to the calculation result; The controller is connected with the data acquisition module, the control panel, the telescopic cylinder and the drive motor signal.

8. A control method based on the control system of claim 7, characterized in that: The following steps are involved: S1: Ventilation demand judgment, the controller receives the environmental monitoring values ​​collected by the data acquisition module, and compares the monitoring values ​​with the target values ​​and the allowable values ​​set by the user through the control panel one by one; if at least one current value is greater than the corresponding target value and the allowable value, step S2 is executed; if all current values ​​are less than the corresponding target values, step S1 is continued; S2: ventilation channel selection, obtaining wind direction information outside the current enclosure through the data acquisition module, and transmitting the wind direction information to the controller, and the controller controls the activation of the telescopic cylinder and selects to open the corresponding air duct baffles at the air inlet and the air outlet according to the wind direction information; S3: Ventilation demand calculation, the controller obtains the ventilation volume required for heat balance according to the following heat balance calculation formula : In the formula, is the ventilation rate calculated based on heat balance; is the number of yaks in the pen; is the sensible heat production of a single yak; is the heat transfer coefficient of the pen body; is the area of ​​the enclosure itself; is the heat transfer coefficient of different zones in ground heat transfer; is the length of different zones in ground heat transfer; ρ is the air density; is the specific heat of air; and are the temperatures inside and outside the pen, respectively; The controller obtains the ventilation volume required for carbon dioxide balance according to the following carbon dioxide balance calculation formula : In the formula, For Balance calculated ventilation volume; is the number of yaks in the pen; For a single yak per hour Production volume; for density; and In the enclosure Concentration and outside the enclosure concentration; The controller obtains the final required ventilation volume according to the following heat and carbon dioxide fusion balance calculation formula : In the formula, is the weight coefficient; S4: Calculation of the bending angle of the bending and folding portion of the air guide duct. The controller obtains the control angle of the bending and folding portion of the air guide duct according to the following calculation formula : In the formula, is the ventilation volume; is the wind speed; is the cross-sectional area of ​​the air inlet; is the angle between the natural wind and the Y axis on the vertical cross section; is the initial opening angle of the air duct; S5: Control ventilation, the controller controls the ventilation according to the bending angle of the folded portion of the air guide duct obtained in step S4. , controlling and starting the driving motor, so that the curved folding portion of the air guide duct is bent to a specified angle, and ventilation begins; S6: Ventilation status judgment, the controller receives the environmental monitoring values ​​collected from the data acquisition module, and compares the monitoring values ​​with the target values ​​and the allowed values ​​set by the user through the control panel one by one; if at least one of the current values ​​is greater than the corresponding target value and the allowed value, the ventilation status of the air duct baffle and the air duct is maintained, and ventilation continues; if all the current values ​​are less than the corresponding target value and the allowed value, the air duct baffle is closed and step S1 is executed.

9. The control method according to claim 8, characterized in that: In step S3, the weight coefficient The priority of temperature and carbon dioxide concentration control in yak pens in different seasons is set; in winter, temperature control is more important, and the weight coefficient >0.5; in the transition season, temperature and carbon dioxide concentration control are equally important, and the weight coefficient =0.5; in summer, carbon dioxide concentration control is more important, and the weight coefficient <0.5.

Images