Animal house fence air supply device and ventilation system and method

Abstract

The invention belongs to the technical field of animal house ventilation, and relates to an animal house fence air supply device and a ventilation system and method. The air supply device comprises an air inlet branch pipe, a supporting stand column, a ventilation stand column and a plurality of hollow transverse rods. The other end of the hollow cross rod is fixedly connected with the supporting stand column. And a plurality of air outlet short pipes are arranged on the hollow cross rod. The ventilation system comprises a wet curtain cavity, a tunnel air inlet cavity, a tunnel air inlet pipeline, a tunnel air outlet pipeline and an air supply pipeline; the side surface of the air supply pipeline is connected with the air inlet branch pipe; a plurality of wet curtain devices are arranged on one side of the wet curtain cavity; the upper end of the tunnel air outlet pipeline is communicated with the air supply pipeline, and the lower end is communicated with the tunnel air inlet cavity; the tunnel air inlet pipeline is located on the outer side of the tunnel air inlet cavity and communicates with the tunnel air inlet cavity. The outer end of the air supply pipeline is connected with a fan. The problems that fresh air in the animal house is not evenly distributed, and the animal growth environment is not good are solved.

Description

Technical Field

[0001] This invention belongs to the field of livestock housing ventilation technology, specifically relating to a livestock housing fence air supply device, ventilation system and method. Background Technology

[0002] With the intensive and large-scale development of animal husbandry, air quality issues in livestock farms are becoming increasingly prominent. Ventilation, as a crucial technology for regulating the air environment in livestock housing, plays a vital role in ensuring animal health and improving production efficiency. Proper ventilation not only helps maintain suitable temperature, humidity, and air quality for animals but also effectively reduces the concentration of harmful gases, improves the respiratory environment, and promotes stable animal growth. Conversely, improper ventilation airflow organization is not only detrimental to maintaining stable animal growth, easily leading to decreased animal production performance, increased disease incidence, and also affects feed conversion ratio, increases the difficulty of breeding management, and ultimately results in decreased economic benefits.

[0003] Currently, common ventilation methods in livestock sheds are divided into two types: natural ventilation and mechanical ventilation. Natural ventilation utilizes the thermal pressure created by the temperature difference between the inside and outside of the shed, or the pressure difference created by external wind, to achieve natural air exchange and improve the internal environment. This method relies on the coordination between building design and natural environmental conditions. Although natural ventilation has lower initial investment and operating costs, its ventilation effect is greatly affected by natural conditions, resulting in poor environmental stability, high management difficulty, and relatively weaker disease prevention effects. In contrast, mechanical ventilation actively controls airflow and pollutant removal within the livestock shed by installing fans, ventilation ducts, and other equipment. This type of ventilation is less dependent on natural conditions and allows for flexible adjustment of wind speed, air volume, and ventilation time, thus enabling on-demand control of temperature, humidity, and harmful gas concentrations within the shed.

[0004] Currently, most livestock sheds use longitudinal evaporative cooling pads and fans for mechanical ventilation, which can easily lead to uneven distribution of temperature, humidity, air velocity, and pollutant concentration within the shed. Furthermore, longitudinal evaporative cooling pad ventilation consumes a lot of energy, especially when the number and power of the fans are insufficient or when there is high channel resistance, resulting in increased operating costs.

[0005] Therefore, scientifically designing the ventilation and airflow organization of livestock houses is of great significance for improving the quality of the animal growth environment, reducing the incidence of disease, and increasing production efficiency, especially in modern high-density, closed farms. Summary of the Invention

[0006] The purpose of this invention is to provide a ventilation device, system and method for supplying air to livestock sheds, which solves the problems of uneven distribution of fresh air inside livestock sheds and poor animal growth environment.

[0007] This invention is achieved through the following technical solution: This invention discloses a livestock shed fence ventilation device, which is integrated into one side of the livestock shed fence and includes an air inlet branch pipe, a support column, a ventilation column and several hollow crossbars. One end of the hollow crossbar is connected to the ventilation column, and the other end is fixedly connected to the support column; each hollow crossbar is equipped with multiple air outlet pipes; the air outlet pipes on the hollow crossbar are located close to the animal side; The airflow enters the ventilation column through the air inlet branch pipe, then enters the hollow crossbar and is sent out through the air outlet short pipe.

[0008] Furthermore, the cross-sectional diameter or equivalent diameter of the air outlet duct gradually increases from the air inlet end to the outlet end.

[0009] Furthermore, each hollow crossbar is equipped with a first air volume regulating valve near its connection with the ventilation column, which can adjust the air intake of each hollow crossbar as needed.

[0010] Furthermore, a second air volume regulating valve is installed at the connection point between the air inlet branch pipe and the ventilation column to open, close, or adjust the air volume entering each fence air supply device as needed.

[0011] Furthermore, the cross-sectional diameter of the air outlet short pipe of the first row of hollow horizontal bars at the top is 70~90mm, and the cross-sectional diameter of the air outlet short pipe of the lower row of hollow horizontal bars is 60~80mm.

[0012] The present invention also discloses a ventilation system, including a wet curtain cavity, a tunnel air inlet cavity, a tunnel air inlet duct, a tunnel air outlet duct, an air supply duct, and a plurality of the aforementioned livestock shed fence air supply devices; The air supply duct is located above the air supply device in the livestock shed fence, and the air supply duct is connected to the air inlet branch pipe on the side. Several wet curtain devices are installed on one side of the wet curtain cavity, and the air supply duct is installed in the middle of the wet curtain cavity; the upper end of the underground air outlet duct is connected to the air supply duct, and the lower end is connected to the underground air inlet cavity. The underground air intake duct is located outside the underground air intake cavity and is connected to the underground air intake cavity; the outer end of the air supply duct is connected to a fan.

[0013] Furthermore, the lower part of the livestock shed fence is a manure trough, and the side of the manure trough is equipped with an exhaust vent, and an exhaust fan is installed at the exhaust vent.

[0014] Furthermore, a third air volume regulating valve is installed at the connection between the tunnel air intake duct and the tunnel air intake cavity, which can be opened, closed or adjusted as needed to regulate the air volume entering the tunnel air intake cavity.

[0015] Furthermore, a fourth air volume regulating valve is installed on both the underground air outlet duct and the air supply duct, which can be opened, closed, or adjusted according to different seasons to control the air volume entering the air supply duct.

[0016] The present invention also discloses a ventilation method for the ventilation system, comprising the following steps: Under summer conditions, when the wet curtain device is turned on, the outside air is cooled by the wet curtain device, and then the air is sent to the air inlet branch pipe by the fan through the air supply duct. The air inlet branch pipe then sends the air supply air into the hollow crossbar through the ventilation column, and finally sends it out from the air outlet short pipe. In winter, the wet curtain device is closed. The cold air outside the shed is preheated through the tunnel and then enters the tunnel air intake cavity through the tunnel air intake pipe. The air is then sent to the air supply pipe through the tunnel air outlet pipe and into the air supply branch pipe in the air supply device of each livestock shed fence. The air supply branch pipe then sends the air supply through the ventilation column into the hollow crossbar and finally out through the air outlet short pipe.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: This invention proposes a livestock pen enclosure ventilation device that integrates the ventilation system with the animal enclosure, dividing it into multiple ventilation zones. It allows for multi-level distribution and regulation of incoming airflow, ensuring a more even and stable flow into the animal activity area, preventing direct airflow impact on the animals, and providing a comfortable growth environment. This integrated enclosure ventilation device saves space in the livestock pen and directly delivers fresh air to the animal activity area, achieving excellent environmental control. The enclosure ventilation device can combine near-zone and far-zone ventilation through the adjustment of airflow from various rows of air outlets at different heights, ensuring airflow covers the entire animal activity area within the enclosure and achieving a uniform and effective ventilation effect. Furthermore, each animal enclosure area can be independently zoned for ventilation and regulation according to the different growth stages and specific needs of the animals, further optimizing ventilation and meeting their individual air environment requirements. The design of several hollow crossbars at different heights delivers fresh air directly to the animal activity area, achieving precise ventilation. Compared with traditional evaporative cooling pads and fans, this significantly reduces the required air volume. Furthermore, compared to the traditional wet curtain fan ventilation mode, which suffers from uneven wind speed and temperature distribution and severe mixing and diffusion of pollutants, the ventilation method of the present invention can achieve uniform distribution of flow field and temperature field through zoned air supply and personalized control, significantly reducing the diffusion and spread of pollutants and reducing the risk of cross-infection.

[0018] Furthermore, based on the resistance characteristics of the air supply duct, the diameter of the air outlet cross-section of the fence air supply device is designed to gradually increase from the air inlet to the outlet. This allows for better regulation of the pressure and velocity distribution within the air supply duct, improving the uniformity of the airflow from the outlet and preventing localized excessively strong or weak airflow. On the other hand, based on previous research, the design of the outlet short duct can effectively adjust the average outflow angle of the outlet cross-section, achieving uniform and forward air supply.

[0019] Furthermore, the cross-sectional diameters of the exhaust ducts on the hollow crossbars at different heights are designed differently. The upper exhaust ducts have a larger diameter to ensure the air quality in the far zone of the enclosure, while the lower exhaust ducts have a smaller diameter to ensure the air quality in the near zone and lower part of the enclosure. These exhaust ducts work together to achieve full airflow coverage throughout the animal activity area inside the enclosure, resulting in uniform and effective air delivery. Polluted gases inside the livestock shed are then extracted and removed by exhaust fans.

[0020] This invention also proposes a ventilation system, including a wet curtain cavity, a tunnel air intake cavity, a tunnel air intake duct, a tunnel air outlet duct, an air supply duct, and multiple air supply devices for the livestock shed enclosure. Airflow sequentially passes through the tunnel air intake duct, the tunnel air intake cavity, the tunnel air outlet duct, and the air supply duct before entering the air supply branch pipes of the air supply devices for the livestock shed enclosure. This air supply system, combined with the tunnel air intake and wet curtain air intake, achieves effective control of temperature and humidity within the livestock shed. In summer, the wet curtain device cools the air through water evaporation, delivering the cooled air into the livestock shed, effectively reducing the temperature inside and decreasing the frequency of air conditioning system use, thereby reducing energy consumption. In winter, the tunnel air intake system utilizes the relatively stable underground temperature to preheat the cold air entering the livestock shed, reducing the load on the heating system and further reducing energy consumption. This combined approach not only improves the efficiency of the ventilation system but also significantly reduces livestock shed operating costs, achieving energy conservation and carbon reduction in livestock farming. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a livestock pen enclosure ventilation device according to the present invention; Figure 2 This is an enlarged view of the fence air supply device of the present invention; Figure 3 yes Figure 2 The main view; Figure 4 This is a schematic diagram of the overall structure of a ventilation system that includes an air supply device for livestock shed enclosures; Figure 5 This is a schematic diagram of the wet curtain cavity and the underground air supply cavity of the livestock shed ventilation system of the present invention; Figure 6 This is a schematic diagram of the livestock shed ventilation duct system of the present invention; Figure 7a This invention is for summer Z Velocity distribution cloud map of a 9.35 m cross section (transverse section of the pigsty); Figure 7b This invention is for summer Z Temperature distribution cloud map of a 9.35 m cross section (transverse section of the pigsty); Figure 8a This invention is for winter Z Velocity distribution contour map at a cross section of 9.35 m; Figure 8bThis invention is for winter Z Temperature distribution cloud map of section = 9.35 m; Figure 9a This invention is for summer Y Velocity distribution cloud map of a 0.16 m cross section (horizontal section of pigsty, pig breathing height); Figure 9b This invention is for summer Y Temperature distribution cloud map of a 0.16 m cross section (horizontal section of pigsty, pig breathing height); Figure 10a For traditional wet curtain fans ventilating livestock sheds in summer Y Velocity distribution contour map at a cross section of 0.16 m; Figure 10b For traditional wet curtain fans ventilating livestock sheds in summer Y Temperature distribution cloud map of section = 0.16 m; In the diagram: 1. Livestock enclosure ventilation system; 2. Inlet branch pipe; 3. Ventilation column; 4. Hollow crossbar; 5. Support column; 6. Outlet short pipe; 71. First air volume regulating valve; 72. Second air volume regulating valve; 73. Third air volume regulating valve; 74. Fourth air volume regulating valve; 8. Underground air intake duct; 9. Underground air intake cavity; 10. Underground air outlet duct; 11. Evaporative cooling pad device; 12. Evaporative cooling pad cavity; 13. Fan; 14. Supply air duct; 15. Exhaust fan. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0023] The components described and illustrated in the accompanying drawings and embodiments of this invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely to illustrate one selected embodiment of the invention. All other embodiments obtained by those skilled in the art based on the accompanying drawings and embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0024] In recent years, with the increasing scale and intensification of livestock and poultry farming, the environmental control of livestock sheds has gradually gained attention. However, from the perspective of improving air quality, modern livestock shed environmental control technologies are lacking. To date, these sheds have not fully considered the efficient airflow organization and ventilation of the facility environment, nor the improvement of ambient air quality. Currently, livestock shed ventilation commonly uses traditional evaporative cooling systems, which have many problems in practical application. For example, this system often requires a large air volume to achieve ventilation throughout the entire shed, which not only consumes a lot of energy but also easily leads to uneven distribution of wind speed and temperature inside the shed, and the formation of dead air zones in some areas. In addition, traditional evaporative cooling systems have high requirements for the airtightness of the livestock shed; if the airtightness is insufficient, the ventilation efficiency will drop significantly.

[0025] Given the aforementioned shortcomings of traditional evaporative cooling systems, it is necessary to explore a more efficient and energy-saving ventilation method. Considering that integrating the air supply duct 14 with the livestock enclosure to directly supply air to the target area—the animal activity area—can improve ventilation efficiency, reduce the risk of pollutant diffusion and spread in different enclosure areas, and enhance the uniformity of airflow and temperature within the enclosure, this invention designs a novel livestock enclosure air supply device. This device integrates an air supply unit on the side of the animal enclosure, utilizing gradually varying sized outlet ducts 6 and airflow regulating valves to directly deliver fresh air to the livestock's activity and breathing areas, achieving precise air delivery. Compared to traditional evaporative cooling fan systems, this invention's air supply device can directly deliver fresh air to the animal activity area, reducing unnecessary airflow and energy waste, and significantly lowering energy consumption. Through directional and precise air delivery, the quality of the air breathed by the livestock is improved, and the spread and diffusion of pollutants in different areas with the airflow are reduced, thereby lowering the risk of cross-infection among animals.

[0026] Furthermore, the ventilation system of this invention combines the advantages of underground air intake and evaporative cooling pad air intake. By utilizing the underground air intake system to preheat or precool the air, ventilation efficiency is further improved and operating costs are reduced. This design not only saves space but also further improves ventilation efficiency and air quality through precise air delivery and zoned control, demonstrating significant energy-saving effects and practical application value.

[0027] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0028] like Figures 1-3 As shown, this invention proposes a ventilation device for livestock shed enclosures. The enclosure is a rectangular frame with three sides enclosed, and the ventilation device is integrated on one side. The ventilation device includes an air inlet branch pipe 2, ventilation columns 3, support columns 5, and several hollow crossbars 4. This design tightly integrates the ventilation device with the livestock shed enclosure, making full use of the internal space structure of the livestock shed and achieving efficient and precise ventilation.

[0029] like Figure 2 As shown, the hollow horizontal bars 4 are arranged horizontally and parallel. One end of each hollow horizontal bar 4 is connected to the ventilation column 3, and the other end is connected and fixed to the support column 5. The ventilation column 3 and the support column 5 are respectively set at both ends of the hollow horizontal bar 4, which can ensure the structural stability of the fence ventilation device.

[0030] The hollow crossbar 4 is equipped with multiple air outlet pipes 6, which are positioned close to the animal side. Airflow enters the ventilation column 3 from the air inlet branch pipe 2, then enters the hollow crossbar 4, and is delivered out through the air outlet pipes 6. Through the combination of the hollow crossbar 4 and the air outlet pipes 6, multi-level distribution and uniform delivery of airflow are achieved, ensuring that airflow covers the entire animal activity area inside the enclosure.

[0031] Even better, such as Figure 3 As shown, a short air outlet pipe 6 with gradually changing size is installed on the hollow crossbar 4 along the airflow direction. The cross-sectional diameter or equivalent diameter of the short air outlet pipe 6 gradually increases from the air inlet end to the outlet end. The design of the short air outlet pipe 6 can effectively adjust the average outflow angle of the air outlet cross-section to achieve positive air supply. On the other hand, the gradually changing air outlet area can achieve flow equalization, so that the airflow is more evenly distributed in each air supply area and within the animal enclosure.

[0032] like Figure 3 As shown, each row of hollow crossbars 4 is equipped with a first air volume regulating valve 71 near its connection with the ventilation column 3, which can adjust the air intake of each row of hollow crossbars 4 as needed. The first air volume regulating valve 71 can flexibly adjust the air intake of each row of hollow crossbars 4 according to the different growth stages and needs of animals, realizing zoned control. This improves the flexibility and adaptability of the ventilation system, and can better meet the specific environmental needs of different animals at different growth stages.

[0033] like Figure 3 As shown, a second air volume regulating valve 72 is installed at the connection point between the air inlet branch pipe 2 and the ventilation column 3. This valve can open, close, or adjust the air volume entering each enclosure air supply device 1 as needed. By using the second air volume regulating valve 72, the air volume entering each enclosure air supply device can be flexibly adjusted according to the needs of different areas of the livestock house, achieving on-demand air supply and better meeting the specific environmental needs of different areas of the livestock house.

[0034] Specifically, the length of the air outlet duct 6 is 70~100mm. For example... Figure 3As shown, the cross-sectional diameter of the air outlet short pipes 6 on the first row of hollow horizontal bars 4 at the top of the fence is 70-90mm, while the cross-sectional diameter of the air outlet short pipes 6 on the lower row of hollow horizontal bars 4 is 60-80mm. Through the air outlet short pipes 6 at different heights, air supply to both near and far zones is achieved, ensuring that airflow can cover the entire animal activity area inside the fence. The air outlets at different heights can better adapt to the three-dimensional spatial needs of the animal activity area, ensuring that each area receives fresh air.

[0035] like Figures 4-6 As shown, the present invention also discloses a ventilation system for the above-mentioned livestock enclosure ventilation device, including a wet curtain cavity 12, a tunnel air inlet cavity 9, a tunnel air inlet duct 8, a tunnel air outlet duct 10, a supply air duct 14, and an exhaust fan 15. The wet curtain cavity 12 is located above the tunnel air inlet cavity 9. Several wet curtain devices 11 are provided on one side of the wet curtain cavity 12. The supply air duct 14 is installed in the middle of the wet curtain cavity 12. The tunnel air outlet duct 10 is installed below the supply air duct 14 and is connected to the tunnel air inlet cavity 9. The tunnel air inlet duct 8 is located outside the tunnel air inlet cavity 9 and is connected to the tunnel air inlet cavity 9. A fan 13 is connected to the outer end of the supply air duct 14.

[0036] Several of the aforementioned livestock shed enclosure air supply devices 1 are connected to both sides of the air supply duct 14. The livestock shed enclosure air supply device 1 serves as the terminal device of the ventilation system. Its air inlet is connected to the air inlet branch pipe 2 at the top of the livestock shed. Airflow sequentially passes through the underground air inlet duct 8, the underground air inlet cavity 9, the underground air outlet duct 10, and the air supply duct 14 before entering the air inlet branch pipe 2. It then flows into the ventilation column 3 and exits through the hollow crossbar 4 and the short outlet pipe 6, achieving uniform air supply. This ventilation system combines the advantages of wet curtain cooling, underground preheating / precooling, and zoned air supply, effectively controlling the thermal environment and air quality of the livestock shed.

[0037] The ventilation vents of the animal enclosures in the livestock shed are located on the side of the lower manure trough, and an exhaust fan 15 is installed at the ventilation vents. The polluted gas in the livestock shed is drawn out and discharged by the exhaust fan 15 under the slatted floor.

[0038] like Figure 6 As shown, the air supply duct 14 is located at the top of the livestock shed, and the side of the air supply duct 14 is connected to the air inlet branch pipe 2. The air inlet branch pipe 2 is connected to the ventilation column 3 of the corresponding fence air supply device. According to the actual internal conditions of different livestock sheds, the air supply duct 14 and the air inlet branch pipe 2 are set at the top of the livestock shed, realizing the efficient delivery and distribution of fresh air. Compared with traditional ventilation systems, which often require a large air volume to achieve ventilation of the entire livestock shed, the personalized air supply of this invention can significantly reduce the air volume and the mixing of fresh air with polluted gases in the shed, thereby improving ventilation efficiency.

[0039] like Figure 5As shown, a third airflow regulating valve 73 is installed at the connection between the underground air intake duct 8 and the underground air intake cavity 9 to open, close, or adjust the airflow entering the underground air intake cavity 9 as needed. The underground air outlet duct 10 and the supply air duct 14 are connected within the evaporative cooling pad cavity 12. A fourth airflow regulating valve 74 is installed on both the underground air outlet duct 10 and the supply air duct 14 to open, close, or adjust the airflow entering the supply air duct 14 according to seasonal changes. Through the airflow regulating valves at various locations, the airflow entering different ducts can be flexibly adjusted according to seasonal and environmental conditions to achieve energy-saving operation.

[0040] Based on the above structural design, the effectiveness of the livestock enclosure air supply device and ventilation system of this invention was verified: Example 1 The following example, a fattening pig house, verifies the ventilation effect of this invention. Pig houses play a significant demonstrative role and have important application value among livestock housing types. Large-scale pig houses, characterized by centralized feeding and high environmental control requirements, represent the design and management level of modern livestock housing. Therefore, a representative pig house is selected for analysis to verify the performance of the ventilation system.

[0041] Based on the actual conditions of a typical fattening pig house, a computational fluid dynamics (CFD) numerical model was established, such as... Figure 4 As shown. The internal dimensions of the pigsty are 18.0 m × 8.5 m × 3.0 m, with a fully slatted floor and a manure pit depth of 0.8 m. The ventilation device of the pigsty fence of this invention is located along the length of the pigsty and has dimensions of 3.0 m × 0.2 m (length × width).

[0042] The hollow crossbars 4 are 3.0 m × 0.2 m × 0.2 m (length × width × height), with a total of 5 rows. The cross-sectional diameter of the air outlet pipes 6 of the first row of hollow crossbars 4 on the upper side of the pigpen is 70-90 mm, while the cross-sectional diameter of the air outlet pipes 6 of the lower row of hollow crossbars 4 is 60-80 mm, and the length of the air outlet pipes 6 is 100 mm. Eight circular exhaust vents with a diameter of 0.57 m are arranged on the outer wall at the height of the manure pit in the pigpen, and four square exhaust vents with a side length of 0.14 m are provided at the top.

[0043] Using 50 kg growing-finishing pigs as the research subject, six pigs were housed in each pen. Based on previous research and breeding practices, fattening pigs spend approximately 70%–85% of their time lying down and resting. In the simulation, the pigs' legs were simplified to dimensions of 0.9 m × 0.3 m × 0.26 m (length × width × height), with a surface temperature of 33℃. No-slip, constant wall temperature boundary conditions were set. The roof and walls were also set to constant wall temperature boundary conditions. Based on summer measured data, the roof temperature was 25.0℃, the ground temperature was 18.6℃, and the sidewall temperature was 24.5℃. All exhaust vents in the pigsty were pressure outlets. For summer air supply conditions, the supply air temperature was 21℃, and the air volume of each of the six short exhaust ducts from top to bottom was 0.51 m³ / s. 3 / s, 0.51m 3 / s, 0.26 m 3 / s, 0.26 m 3 / s, 0.14 m 3 / s. Ammonia is set to be emitted from the bottom of the latrine, with insulated walls, and its emission rate is 6 g / (head·d).

[0044] Example 2 In winter, the air supply temperature is 23℃. The top two rows of short air ducts (6) supply air horizontally downwards at a 30° angle to prevent hot air from rising and becoming ineffective before reaching the pig activity area. The roof, west wall, and ground are set to constant wall temperature boundary conditions, with the roof and west wall temperatures both at 15℃. The remaining settings are the same as in Example 1.

[0045] Comparative Example The structural parameters and pen layout of the pigsty are the same as in Example 1, and the air supply method adopts the traditional evaporative cooling pad and fan ventilation mode. In the evaporative cooling pad and fan ventilation mode, the pigsty is equipped with two evaporative cooling pads, each measuring 2.1 m × 0.8 m. To simplify the process, the evaporative cooling pads are set as velocity inlets, and the overall ventilation volume in the pigsty is the same as in Example 1, with an air velocity of 1 m / s at the evaporative cooling pad inlet. All other settings are the same as in Example 1.

[0046] The airflow organization and indoor pollutant removal effects of this invention were simulated and calculated using ANSYS Fluent 2022R1 software. Due to the turbulent characteristics of airflow in pig houses, the validated SST was selected. k - ω Numerical calculations were performed using a turbulence model. The finite volume method (FVM) was employed to discretize the governing equations, with the convection term using a second-order upwind scheme. The discrete equations were solved using the SIMPLE algorithm. The goal was to achieve a result where the residuals of the continuity, momentum, and turbulence equations were all less than 10. -3 The residuals of the energy equation and the component transport equation are less than 10. -6 At that time, it is assumed that the governing equations have converged.

[0047] The following analysis is performed on Embodiments 1 and 2 of the present invention: According to GB / T 17824.3, "Environmental Parameters and Environmental Management for Large-Scale Pig Farms," ​​for growing and finishing pig houses, the lower critical temperature range is 13℃, the upper critical temperature range is 27℃, and the comfortable range is 15℃~23℃. [Selection] Z The velocity and temperature distribution cloud map of the 9.35 m cross section (through the center of the pigpen) is used as the monitoring surface in Example 1. Figure 7a and Figure 7b As shown, the design of the air outlet duct 6 further guides the airflow, allowing it to be delivered more evenly into the livestock pen after passing through it. During ventilation, the lower air outlet duct 6 directs air to the nearby pigs, while the upper air outlet duct 6 directs air to the more distant pigs. The two airflows work together to create a large-scale airflow coverage of the controlled area. This coordinated ventilation mode ensures the height of the pigs' breathing zone (…). Y The temperature and wind speed distribution across the entire area (0.3~0.5 m) meets the requirements of relevant standards / specifications. Particularly, the system's advantages are particularly evident in summer conditions: the upper air outlet duct 6 has a higher jet velocity, responsible for remote temperature control and effectively preventing overheating at the far end; the lower air outlet duct 6 has a lower jet velocity, responsible for near-end cooling, maximizing the utilization of cooling capacity. Numerical simulation results show that under this air supply mode, the airflow temperature near the pigs, whether near or far from the air supply device, is between 22.0 and 23.2℃. The average temperature in the main lying area of ​​the pigs (within a 0.5 m height range) is approximately 22.4℃, providing a relatively ideal environment for pig growth.

[0048] Select Z The velocity and temperature distribution cloud map of the 9.35 m cross section (through the center of the pigpen) is used as the monitoring surface in Example 2. Figure 8a and Figure 8bAs shown, under winter operating conditions, the air supply system employs different air supply parameter settings compared to summer to achieve the dual goals of fresh air supply and winter heating. The lower air vents maintain their original air supply parameters, directly delivering airflow to the pig activity area; while the upper air vents, by adjusting the blade angle to a downward 30° angle, deliver hot air directly to the pig's breathing zone. The upper air supply method effectively overcomes the buoyancy effect of the hot airflow, and the two airflows work together to act on the pig area. Under this air supply mode, heat is efficiently distributed to the pig activity area, creating a stable thermal environment. Data shows that, regardless of whether the pig is near or far from the air supply device, the airflow temperature near the pig is between 20.5 and 22.1℃, and the airflow velocity is between 0.1 and 0.2 m / s. The temperature in the main lying area of ​​the pigsty (within a 0.5m height range) is uniformly maintained at around 22.6℃, and the average wind speed is controlled at approximately 0.21 m / s. This effectively removes pollutants while significantly reducing the draft sensation in cold seasons, preventing cold stress in the animals. These environmental parameters meet the requirements of the national standard GB / T 17824.3 "Environmental Parameters and Management for Large-Scale Pig Farms" regarding temperature and wind speed limits in pigsties during winter. While meeting thermal requirements, it also improves air quality in the pigs' breathing area, providing a reliable environmental guarantee for healthy pig farming in winter.

[0049] Comparison of Embodiment 1 of the present invention with the comparative example: Select Y The velocity and temperature distribution contour map of the 0.16 m cross-section (the respiratory height of a recumbent pig) was used as the monitoring surface. Figure 9a For the summer of this invention Y Velocity distribution cloud map of a 0.16 m cross-section (horizontal profile of the pigsty, at the pig's breathing height). Figure 9b For the summer of this invention Y =0.16 m cross-section (horizontal section of pigsty, pig breathing height) temperature distribution cloud map; Figure 10a For comparison, the ventilation of livestock sheds in summer Y Velocity distribution contour map at a cross section of 0.16 m. Figure 10b For comparison, the ventilation of livestock sheds in summer Y Temperature distribution cloud map of the 0.16 m cross section.

[0050] from Figure 9a and Figure 10aThe velocity distribution cloud map clearly shows that, under summer conditions, the traditional evaporative cooling pad fan ventilation system (longitudinal ventilation) suffers from significant uneven wind speed distribution. Wind speeds are higher at the front and middle areas of the pigsty, while the wind speed at the longitudinal ends of the pigsty decreases significantly, averaging 0.10 m / s, which is one-third of the wind speed in the middle area. This significant longitudinal gradient easily leads to uneven heating and cooling of the pigs in different locations within the pigsty, creating dead airflow zones, resulting in poor air quality for the pigs and negatively impacting animal welfare and production performance.

[0051] In contrast, the ventilation method employed in this invention significantly optimizes airflow organization within each pigpen, with the average wind speed in the front, middle, and rear pens consistently maintained at approximately 0.17 m / s. Spatially, the wind speed consistency between different pigpens is high, resulting in a uniform overall velocity field without significant velocity gradients. This demonstrates the significant advantages of this invention in achieving comprehensive airflow coverage and uniform air delivery.

[0052] from Figure 9b and Figure 10b The temperature distribution cloud map results show that, under the same air volume and temperature conditions, the temperature distribution uniformity inside the pigsty under the traditional evaporative cooling pad longitudinal ventilation mode is poor. Figure 10b As can be seen, the temperature range from the air inlet of the wet curtain to the exhaust of the fan on the other side is 22~23.5℃, with the temperature at the end of the pigsty being higher than other areas, reaching a maximum of 23.5℃. The ventilation system of this invention effectively eliminates uneven temperature distribution, resulting in a more consistent and lower overall temperature field within the pigsty, maintained at around 22.3℃, which meets the relevant requirements for pigsty environmental temperature in national standards.

[0053] Based on the distribution characteristics of the wind speed field and temperature field, it can be seen that the present invention not only performs well in improving the uniformity of airflow, but also effectively improves the consistency of the temperature field. Therefore, the overall ventilation and environmental control effect is significantly better than the traditional wet curtain fan ventilation mode (longitudinal ventilation).

[0054] To further illustrate the environmental control effects of different ventilation modes in pigsties, the velocity non-uniformity coefficient, temperature non-uniformity coefficient, ventilation (temperature) efficiency, and pollutant removal efficiency in the respiration zone were used for evaluation.

[0055] Among them, the velocity non-uniformity coefficient and temperature non-uniformity coefficient It reflects the degree of non-uniformity of the velocity field and temperature field in the livestock house, which can be calculated by equations (1) and (2).

[0056]

[0057] In the formula, n The number of measurement points,u i (m / s) and t i (°C) represents the speed and temperature at each measuring point. (m / s) and (°C) represents the average speed and average temperature at each measuring point.

[0058] Ventilation (temperature) efficiency It is an indicator for evaluating the ventilation and heat dissipation effect, and is determined according to formula (3).

[0059]

[0060] In the formula, (°C) represents the supply air temperature. (°C) represents the exhaust air temperature. (°C) represents the average air temperature in the respiratory zone of the livestock.

[0061] The pollutant removal efficiency (CRE) of the breathing zone, also known as the zone air distribution efficiency, is the ratio of the pollutant concentration change between the air inlet and the air outlet to the pollutant concentration change between the air inlet and the breathing zone, as shown in equation (4):

[0062] In the formula, C e The concentration of pollutants at the exhaust vent, in ppm; C s The concentration of pollutants at the air inlet is expressed in ppm. C b The concentration of pollutants in the breathing zone is expressed in ppm.

[0063] Table 1 shows a comparison of the ventilation performance indicators of this invention with that of traditional evaporative cooling fans. It can be seen that, compared to the comparative embodiment, the application example of this invention reduces the velocity non-uniformity coefficient by 34.1%, the temperature non-uniformity coefficient by 44.0%, increases the pollutant removal efficiency by 22.7%, and improves the ventilation efficiency by 41.8%. The data analysis clearly demonstrates that the livestock enclosure ventilation device and system proposed in this invention have better ventilation performance. The wind speed field near the animals is more uniform, the temperature field is more stable, and both the pollutant removal efficiency and ventilation efficiency are higher than those of traditional evaporative cooling fans, effectively improving the air quality for animals in the enclosure.

[0064] Table 1. Comparison of ventilation performance indicators between the present invention and traditional evaporative cooling fan ventilation methods.

[0065] This invention, by observing the structural characteristics of livestock shed enclosures, integrates the enclosure with the air supply ducts, effectively improving the quality of the breathing air for livestock without altering the basic layout of the sheds. It also directly and energy-efficiently meets the thermal environment requirements of the pen area. Compared to traditional wet curtain fan ventilation methods in livestock sheds, the air supply method of this invention results in a more uniform distribution of the airflow and temperature field within the shed, and the internal wind speed better meets relevant standards and specifications. The resulting favorable thermal and airflow environment in the livestock shed is of great significance for reducing the accumulation and spread of pathogenic microorganisms, lowering the risk of animal infection, improving animal growth rate and overall productivity, and ultimately enhancing the economic benefits of the farm.

[0066] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A livestock housing stall ventilation arrangement, characterised in that, Integrated in one side of the livestock enclosure fence, including air inlet branch pipe (2), support column (5), ventilation column (3) and several hollow crossbars (4); One end of the hollow crossbar (4) is communicated with the ventilation column (3), and the other end is fixedly connected with the support column (5); a plurality of air outlet short pipes (6) are arranged on each hollow crossbar (4); the air outlet short pipes (6) on the hollow crossbar (4) are arranged close to the animal side; The air flow enters the ventilation column (3) from the air inlet branch pipe (2), then enters the hollow crossbar (4) and is sent out by the air outlet short pipe (6).

2. A livestock housing enclosure air supply arrangement according to claim 1, characterised in that, The cross-sectional diameter or equivalent diameter of the air outlet short pipe (6) gradually increases from the air inlet end to the end.

3. A livestock housing enclosure air supply arrangement according to claim 1, wherein, The position close to the connection of each hollow crossbar (4) and the ventilation column (3) is provided with a first air volume adjusting valve (71), and the air inlet volume of each hollow crossbar (4) is adjusted according to the need.

4. A livestock housing enclosure air supply arrangement according to claim 1, characterised in that, The position of the connection of the air inlet branch pipe (2) and the ventilation column (3) is provided with a second air volume adjusting valve (72), and the air volume entering each fence air supply device is opened or adjusted according to the need.

5. A livestock housing enclosure air supply arrangement according to claim 1, wherein, The cross-sectional diameter of the air outlet short pipe (6) of the first row of hollow crossbars (4) located at the upper part is 70-90mm, and the cross-sectional diameter of the air outlet short pipe (6) of the lower row of hollow crossbars (4) is 60-80mm.

6. A ventilation system, characterized in that It comprises a wet curtain cavity (12), a tunnel air inlet cavity (9), a tunnel air inlet pipeline (8), a tunnel air outlet pipeline (10), an air supply pipeline (14) and a plurality of livestock enclosure fence air supply devices according to any one of claims 1-5; The air supply pipeline (14) is arranged at the upper part of the livestock enclosure fence air supply device, and the air supply pipeline (14) is connected with the air inlet branch pipe (2) on the side surface; A plurality of wet curtain devices (11) are arranged on one side of the wet curtain cavity (12), and the air supply pipeline (14) is arranged at the middle position in the wet curtain cavity (12); the upper end of the tunnel air outlet pipeline (10) is communicated with the air supply pipeline (14), and the lower end is communicated with the tunnel air inlet cavity (9); The tunnel air inlet pipeline (8) is located outside the tunnel air inlet cavity (9) and is communicated with the tunnel air inlet cavity (9); and the outer end of the air supply pipeline (14) is connected with a fan (13).

7. A ventilation system according to claim 6, wherein The lower part of the livestock enclosure fence is a manure tank, and an air outlet is arranged on the side surface of the manure tank, and an air outlet fan (15) is arranged at the air outlet.

8. A ventilation system according to claim 6, wherein A third air volume adjusting valve (73) is arranged at the connection of the tunnel air inlet pipeline (8) and the tunnel air inlet cavity (9), and the air volume entering the tunnel air inlet cavity (9) is opened or adjusted according to the need.

9. A ventilation system according to claim 6, wherein Fourth air volume adjusting valves (74) are arranged on the tunnel air outlet pipeline (10) and the air supply pipeline (14), and the air volume entering the air supply pipeline (14) is opened or adjusted according to the different seasons.

10. A method of ventilating a ventilation system according to any one of claims 6-9, characterized in that, It comprises the following processes: In summer conditions, the wet curtain device (11) is opened, the air outside the house is cooled by the wet curtain device (11), then the air flow is sent to the air inlet branch pipe (2) through the air supply pipeline (14) by the fan (13), the air inlet branch pipe (2) sends the air flow into the hollow crossbar (4) through the ventilation column (3), and finally the air flow is sent out from the air outlet short pipe (6); In winter, the wet curtain device (11) is closed, the cold air outside the house is preheated by the tunnel and enters the tunnel air inlet cavity (9) through the tunnel air inlet pipeline (8), and then the air supply airflow is sent to the air supply pipeline (14) through the tunnel air outlet pipeline (10), and then enters the air inlet branch pipe (2) in the air supply device of each house fence, and then the air inlet branch pipe (2) sends the air supply airflow to the hollow cross bar (4) through the ventilation column (3), and finally the air supply airflow is sent out from the air outlet short pipe (6).

Images