Layered energy-saving ventilation method for pig house in cold region in winter

Abstract

The application discloses a cold region pig house winter stratified energy-saving ventilation method and relates to the technical field of livestock breeding. In order to solve the ventilation problem of the prior art cold region pig house, the method comprises the following steps: according to the pig house space and pig growth stage, a ventilation system is laid out; real-time monitoring of pig house internal environment parameters is taken as a basis; a CFD simulation is used to optimize the air flow path, and then the operation parameters of the ventilation system are regulated; and according to the heat loss in the pig house, the operation of the ventilation system is assisted and optimized. The application provides a dynamic adjustable air supply mechanism based on the breathing height of pigs, through pig house top layer heat recovery and pig house internal air flow stratified interval ventilation, the heat energy loss is effectively reduced, more than 80% of fresh air is accurately delivered to the pig breathing area, invalid ventilation is avoided, the energy saving rate is more than 50%, the energy consumption is reduced, the air quality in the breathing area reaches more than 99% of the standard rate, and the growth environment and health level of the pigs are improved.

Description

Technical Field

[0001] This invention relates to the field of livestock breeding technology, and in particular to a method for layered energy-saving ventilation in cold-region pig houses during winter. Background Technology

[0002] Since the late 1990s, my country's pig farming industry has gradually developed towards large-scale, intensive, and industrialized operations. The current trend of "southern pigs migrating north" has led many large-scale pig farms to establish operations in Northeast China. Although Northeast China possesses abundant land resources, the cold winters in the north necessitate intensive pig farming in these cold regions, which uses fully enclosed pigsties. To reduce energy consumption, these pigsties primarily focus on insulation, with little or no ventilation. This method leads to the long-term accumulation of harmful gases, moisture, dust, and pathogens inside, easily causing outbreaks of various diseases in pigs. Furthermore, the mixture of ammonia, dust, and condensation in the pigsties is not only dirty but also corrosive, severely impacting the lifespan of the pigsty buildings and the functional lifespan of the electronic and electrical equipment within.

[0003] Ventilation in pigsties during cold winters has always been a challenge for the livestock industry. Traditional ventilation methods often result in significant heat loss within the pigsty and fail to ensure accurate delivery of fresh air to the pigs' breathing areas, impacting their growth and health. Furthermore, ineffective ventilation not only increases energy consumption but can also lead to environmental degradation within the pigsty, such as increased ammonia and carbon dioxide concentrations. Therefore, developing a method to effectively reduce heat loss and achieve tiered, energy-efficient ventilation is crucial. Based on this, we propose a tiered, energy-efficient ventilation method for pigsties in cold regions during winter. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a layered energy-saving ventilation method for pig houses in cold regions during winter.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A layered, energy-saving ventilation method for pigsties in cold regions during winter includes the following steps:

[0007] S1: The ventilation system is designed according to the space of the pigsty and the growth stage of the pigs;

[0008] S2: Real-time monitoring of internal environmental parameters of the pigsty as a basis;

[0009] S3: Optimize airflow paths through CFD simulation, thereby controlling the operating parameters of the ventilation system;

[0010] S4: Optimize the operation of the ventilation system based on heat loss in the pigsty;

[0011] The pig growth stages include the suckling pig stage, the piglet stage, the growing pig stage, and the fattening pig stage.

[0012] Preferred: The layout method of the ventilation system includes the following aspects:

[0013] 1) Based on the vertical stratification of the pigsty space, design longitudinal ventilation openings on the east and west side walls;

[0014] 2) Based on the growth stages of the pigs, set up an array of horizontal ventilation openings on the north and south side walls at equal intervals.

[0015] Preferably, the vertical stratification includes a breathing zone of 0.2-0.6m in height, a transition zone of 0.6-1.5m in height, and a regenerating zone of more than 1.5m in height.

[0016] Preferably, the wind speed in the breathing zone is controlled at 0.1-0.5 m / s, the wind speed in the transition zone is controlled at 0.5-1.0 m / s, and the wind speed in the regenerating zone is controlled at 1.2-1.8 m / s.

[0017] Preferably, the transverse ventilation openings are located within the breathing zone, and the transverse ventilation openings on the north and south side walls are staggered in position.

[0018] Preferably, the wind speed in the breathing zone at the transverse ventilation opening corresponds to the different growth stages of the pig.

[0019] Preferably, the ventilation opening in the breathing zone is provided with an angle-adjustable rectangular air inlet, and the vertical tilt angle of the rectangular air inlet is adjustable within a range of 15°-60°;

[0020] The ventilation openings in the transition zone are fixed.

[0021] The ventilation openings of the regenerating zone are equipped with heat recovery devices, which are heat exchangers with a heat exchange efficiency of ≥70%.

[0022] Preferably, the environmental parameters are implemented through IoT sensors, including temperature and humidity sensors, high-precision hot-wire anemometers, carbon dioxide sensors, and ammonia sensors.

[0023] Preferably, the operating parameters include the ventilation volume, ventilation angle, and ventilation duration of each zone's ventilation mechanism.

[0024] Preferably, the heat loss is calculated as follows: Q = p * L * C * ΔT.

[0025] The beneficial effects of this invention are as follows:

[0026] 1. This invention provides a dynamically adjustable air supply mechanism based on the breathing height of pigs. By recovering heat from the top floor of the pigsty and stratified intermittent ventilation of the airflow inside the pigsty, it effectively reduces heat loss and accurately delivers more than 80% of fresh air to the breathing zone of pigs, avoiding ineffective ventilation, achieving an energy saving rate of more than 50%, while reducing energy consumption and increasing the air quality compliance rate in the breathing zone to more than 99%, thereby improving the growth environment and health level of pigs.

[0027] 2. This invention responds to environmental changes in real time, and the ventilation speed is adapted to different growth stages of pigs, allowing fresh air to be accurately delivered to the pigs' breathing area. This can significantly reduce heat loss during winter ventilation, thereby achieving the goal of reducing heat loss and ensuring that the growth needs of pigs are met while minimizing heat loss and eliminating ineffective ventilation.

[0028] 3. This invention adjusts the angle of the ventilation openings in the breathing zone according to the different growth stages of pigs and the temperature and humidity of the pigsty environment, ensuring that fresh air reaches directly and achieving effective and precise ventilation.

[0029] 4. The ventilation openings of the regenerating zone of this invention are equipped with heat recovery devices. During ventilation, the rising hot air inside the pigsty is used to preheat the newly entering external air, thereby reducing the temperature difference, reducing heat loss during ventilation in the pigsty, and improving energy efficiency. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the process for the layered energy-saving ventilation method for cold-region pig houses in winter proposed in this invention;

[0031] Figure 2 This is a comparison of various parameters between the traditional ventilation mode and the ventilation method of the present invention in practical applications, as shown in Experiment Example 2. Detailed Implementation

[0032] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0033] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0034] Example 1: A layered energy-saving ventilation method for pigsties in cold regions during winter, such as... Figure 1 As shown, it includes the following steps:

[0035] S1: The ventilation system is laid out according to the space of the pigsty and the growth stage of the pigs; the ventilation design is divided into different levels according to the growth stage to meet the needs of pigs at different growth stages.

[0036] Preferably, the pig growth stages include piglet stage, piglet stage, growing stage, and fattening stage; that is, it can be used in nursery pens, fattening pens, gestation pens, farrowing pens, and boar pens.

[0037] Furthermore, the layout method of the ventilation system includes the following aspects:

[0038] 1) Based on the vertical stratification of the pigsty space, design longitudinal ventilation openings on the east and west (i.e., horizontal) side walls;

[0039] Preferably, the vertical stratification includes a breathing zone at a height of 0.2-0.6m, a transition zone at a height of 0.6-1.5m, and a regenerating zone at a height of 1.5m or more.

[0040] The wind speed in the breathing zone is controlled at 0.1-0.5 m / s, the wind speed in the transition zone is controlled at 0.5-1.0 m / s, and the wind speed in the regenerating zone is controlled at 1.2-1.8 m / s.

[0041] Furthermore, the ventilation openings in the breathing zone are equipped with rectangular air inlets with adjustable angles, and the vertical tilt angle of the rectangular air inlets can be adjusted from 15° to 60°, similar to the louvered air inlets of the prior art. The model can be referenced from the ZRH temperature-controlled variable angle jet air inlet. The tilt angle of the ventilation openings in the breathing zone can be adjusted according to the different growth stages of the pigs and the temperature and humidity of the pigsty environment to ensure that fresh air reaches directly and achieve effective and precise ventilation.

[0042] Furthermore, the ventilation openings in the transition zone are fixed and serve only a ventilation function;

[0043] Furthermore, the ventilation openings of the regenerating zone are equipped with heat recovery devices, which are based on patent CN202321431690.7. These devices can recover heat from inside the shed while ventilating. Alternatively, the heat recovery device can be a heat exchanger with a heat exchange efficiency of ≥70%. During ventilation, the rising hot air inside the pigsty is used to preheat the newly entering outside air, thereby reducing the temperature difference, reducing heat loss during ventilation, and improving energy efficiency.

[0044] 2) Based on the growth stages of the pigs, set up an array of horizontal ventilation openings on the north and south (i.e., transverse) side walls at equal intervals;

[0045] Preferably, the horizontal ventilation openings are located within the breathing zone, and the front and rear positions of the horizontal ventilation openings on the north and south side walls are staggered; this ensures ventilation effectiveness and avoids ineffective ventilation.

[0046] S2: Real-time monitoring of internal environmental parameters of the pigsty as a basis;

[0047] Preferably, environmental parameters are monitored by IoT sensors distributed at different angles inside the pigsty, including temperature and humidity sensors, high-precision hot-wire anemometers, carbon dioxide sensors, and ammonia sensors, to monitor parameters such as temperature, humidity, ventilation, carbon dioxide concentration, and ammonia concentration inside the pigsty.

[0048] S3: Optimize airflow path through CFD simulation, thereby controlling the operating parameters of the ventilation system; so that the airflow is distributed to the target area more efficiently.

[0049] Preferably, the operating parameters include the ventilation volume, ventilation angle, and ventilation duration of each zone's ventilation mechanism (fan), to prevent cold air from blowing directly into the pigsty, reduce heat loss, and ensure effective ventilation.

[0050] For example, when the temperature inside the pigsty is detected to be lower than the set value, the ventilation system of the corresponding target area will be adjusted to automatically reduce the ventilation volume in order to reduce heat loss; when the carbon dioxide concentration or ammonia concentration inside the pigsty is detected to exceed the set threshold, the ventilation system of the breathing zone will be adjusted to automatically increase the ventilation volume in order to improve the air quality inside the pigsty.

[0051] S4: Optimize the operation of the ventilation system based on heat loss in the pigsty; respond to environmental changes in real time to further reduce heat loss, ensuring that heat loss is minimized and ineffective ventilation is eliminated while meeting the growth needs of pigs.

[0052] Furthermore, the heat loss is calculated as follows: Q = p * L * C * ΔT; based on the heat loss result, if it exceeds the threshold range, the ventilation system is adjusted to close unnecessary partition mechanisms.

[0053] Where p is the air density, L is the ventilation volume, C is the specific heat capacity of air, and ΔT is the temperature difference between inside and outside the building. ΔT = tin - tout, where tin is the air temperature inside the building and tout is the air temperature outside the building. The air density and specific heat capacity of air are constants, such as ρ = air density 1.2 kg / m³ and C = 1.005 kJ / kg·K. The ventilation volume, air temperature inside the building, and air temperature outside the building are all monitored in real time by IoT sensors.

[0054] In this embodiment, the present invention provides a dynamically adjustable air supply mechanism based on the pig's breathing height. Through heat recovery at the top of the pigsty and layered intermittent ventilation of the airflow inside the pigsty, it effectively reduces heat loss and accurately delivers more than 80% of fresh air to the pig's breathing zone, avoiding ineffective ventilation, achieving an energy saving rate of more than 50%, while reducing energy consumption and increasing the air quality compliance rate in the breathing zone to more than 99%, thereby improving the pig's growth environment and health level.

[0055] Example 2: A layered energy-saving ventilation method for pigsties in cold regions during winter, such as... Figure 1As shown, in order to adapt the wind speed to the different growth stages of pigs, this embodiment makes the following improvements based on embodiment 1: the wind speed in the breathing zone at the transverse ventilation opening corresponds to the different growth stages of pigs, such as from piglet stage → piglet stage → medium-sized pig stage → fattening pig stage, the corresponding wind speeds are 0.1m / s → 0.2m / s → 0.3m / s → 0.5m / s respectively; the ventilation wind speed is adapted to the different growth stages of pigs, so that fresh air is accurately delivered to the pig's breathing area, which can significantly reduce the heat loss of ventilation in winter.

[0056] Experimental Example 1:

[0057] Two pig farms located in cold regions were selected as the experimental group (using the method of this invention) and the control group (using traditional ventilation methods), respectively, for the experiment. During the experiment, the highest outdoor daytime temperature was -15℃ and the lowest nighttime temperature was -38℃. The experimental results are as follows:

[0058] Temperature comparison: The temperature fluctuation in the experimental group pigsty was smaller and could be maintained within a suitable range, while the temperature fluctuation in the control group pigsty was larger and the overall temperature was lower.

[0059] • Ventilation volume comparison: The ventilation volume of the experimental group is more precise and can be automatically adjusted according to the temperature difference inside and outside the pig house and the growth needs of the pigs. In contrast, the ventilation volume of the control group is relatively fixed, resulting in ineffective ventilation and greater heat loss, and higher equipment energy consumption. The heat loss of this invention is 6.3 kW / h, while the heat loss of the traditional method is 35.7 kW / h.

[0060] Environmental parameter comparison: The humidity, carbon dioxide concentration and ammonia concentration in the experimental group pigsty were all better than those in the control group, providing a healthier growth environment for the pigs.

[0061] Experimental Example 2:

[0062] A large-scale pig farm in Heilongjiang Province was selected as the experimental site (winter 2024). Figure 2 As shown, the average outdoor temperature is -32℃, and the heat loss of the traditional ventilation mode is 35.7kW / h. Compared with the traditional ventilation mode, the heat loss of the method of the present invention is reduced by 44%, and the carbon dioxide and ammonia concentrations in the breathing zone are reduced by 49% and 45%, respectively.

[0063] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A layered energy-saving ventilation method for pigsties in cold regions during winter, characterized in that: Includes the following steps: S1: The ventilation system is designed according to the space of the pigsty and the growth stage of the pigs; S2: Real-time monitoring of internal environmental parameters of the pigsty as a basis; S3: Optimize airflow paths through CFD simulation, thereby controlling the operating parameters of the ventilation system; S4: Optimize the operation of the ventilation system based on heat loss in the pigsty; The pig growth stages include the suckling pig stage, the piglet stage, the medium-sized pig stage, and the fattening pig stage; The layout method of the ventilation system includes the following aspects: 1) Based on the vertical stratification of the pigsty space, design longitudinal ventilation openings on the east and west side walls; 2) Based on the growth stages of the pigs, set up an array of horizontal ventilation openings on the north and south side walls at equal intervals; The vertical stratification includes a breathing zone at a height of 0.2-0.6m, a transition zone at a height of 0.6-1.5m, and a regenerating zone at a height of 1.5m or more. The wind speed in the breathing zone is controlled at 0.1-0.5 m / s, the wind speed in the transition zone is controlled at 0.5-1.0 m / s, and the wind speed in the regenerating zone is controlled at 1.2-1.8 m / s. The transverse ventilation openings are located within the breathing zone, and the transverse ventilation openings on the north and south side walls are staggered in position. The wind speed in the breathing zone at the transverse ventilation opening corresponds to the different growth stages of the pigs.

2. The method for layered energy-saving ventilation in cold-region pigsties during winter according to claim 1, characterized in that, The ventilation opening in the breathing area is equipped with an adjustable rectangular air inlet, and the vertical tilt angle of the rectangular air inlet can be adjusted from 15° to 60°. The ventilation openings in the transition zone are fixed. The ventilation openings of the regenerating zone are equipped with heat recovery devices, which are heat exchangers with a heat exchange efficiency of ≥70%.

3. The method for layered energy-saving ventilation in cold-region pigsties during winter according to claim 1, characterized in that, The environmental parameters are implemented through IoT sensors, including temperature and humidity sensors, high-precision hot-wire anemometers, carbon dioxide sensors, and ammonia sensors.

4. The method for layered energy-saving ventilation in cold-region pigsties during winter according to claim 1, characterized in that, The operating parameters include the ventilation volume, ventilation angle, and ventilation duration of each zone's ventilation mechanism.

5. The method for layered energy-saving ventilation in cold-region pigsties during winter according to claim 1, characterized in that, The heat loss is calculated as follows: Q = p * L * C * ΔT; Where p is the air density, L is the ventilation volume, C is the specific heat capacity of the air, ΔT is the temperature difference between the inside and outside of the building, ΔT=tin-tout, tin is the air temperature inside the building, tout is the air temperature outside the building, the air density and the specific heat capacity of the air are constants, and the ventilation volume, the air temperature inside the building and the air temperature outside the building are all monitored in real time by IoT sensors.

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