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

Abstract

The invention discloses a winter layered energy-saving ventilation method for a pig house in a cold region, and relates to the technical field of livestock breeding. The ventilation problem of a pig house in a cold region in the prior art is solved. The method specifically comprises the following steps that a ventilation system is arranged according to pig house space and pig growth stages; monitoring internal environment parameters of the hog house in real time as a basis; an airflow path is optimized through CFD simulation, and then operation parameters of the ventilation system are regulated and controlled; and assisting in optimizing operation of the ventilation system according to heat loss in the hog house. According to the dynamic adjustable air supply mechanism based on the pig breathing height, heat energy loss is effectively reduced and more than 80% of fresh air is accurately conveyed to a pig breathing area through hog house top layer heat recovery and hog house internal air flow layered interval type ventilation, invalid ventilation is avoided, the energy saving rate exceeds 50%, meanwhile, energy consumption is reduced, and the energy-saving effect is good. The air quality standard-reaching rate of a breathing area is increased to 99% or above, and the growth environment and the health level of pigs are improved.

Description

Technical Field

[0001] The invention relates to the technical field of animal husbandry, and in particular to a stratified energy-saving ventilation method for pig houses in cold regions in winter. Background Art

[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 "pigs migrating from the south to the north" has led many large-scale pig farming companies to establish farms in Northeast China. Although Northeast China boasts abundant land resources, northern winters are cold. Intensive pig farming in cold regions employs fully enclosed piggeries. To reduce energy consumption, these houses primarily rely on insulation, with minimal or no ventilation. This farming method allows harmful gases, moisture, dust, and pathogens to accumulate within the houses over extended periods, easily leading to outbreaks of various pig diseases. Furthermore, the combination of ammonia, dust, and condensation in the piggeries creates a foul and corrosive atmosphere, seriously impacting the lifespan of the piggeries and the functional lifespan of the electronic and electrical equipment within them.

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

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and propose a stratified energy-saving ventilation method for pig houses in cold areas in winter.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The winter stratified energy-saving ventilation method for cold-region pig houses includes the following steps:

[0007] S1: Arrange ventilation system according to pig house space and pig growth stage;

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

[0009] S3: Optimize airflow paths through CFD simulation to control ventilation system operating parameters;

[0010] S4: Assist in optimizing ventilation system operation based on heat loss in the pig house;

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

[0012] Preferably, the layout method of the ventilation system includes the following aspects:

[0013] 1) Vertical stratification is carried out according to the pig house space, and longitudinal ventilation holes are designed on the north and south walls;

[0014] 2) Horizontal vents are arranged in an array pattern on the north and south walls at equal intervals according to the growth stage of the pigs.

[0015] Preferably, the vertical stratification includes a breathing zone at a height of 0.2-0.6 m, a transition zone at a height of 0.6-1.5 m, and a heat recovery zone above 1.5 m.

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

[0017] Preferably, the transverse vents are located within the breathing zone, and the front and rear positions of the transverse vents on the north and south side walls are staggered.

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

[0019] Preferably, the ventilation opening of the breathing zone is provided with an angle-adjustable rectangular air inlet, and the upper and lower inclination angles of the rectangular air inlet are adjustable in the range of 15°-60°;

[0020] The vents in the transition zone are fixed;

[0021] The ventilation opening of the heat recovery zone is provided with a heat recovery device, which is a heat exchanger with a heat exchange efficiency of ≥70%.

[0022] Preferably, the environmental parameters are realized by Internet of Things sensors, including temperature and humidity sensors, high-precision hot-bulb wind speed sensors, carbon dioxide sensors and ammonia sensors.

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

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

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention provides a dynamically adjustable air supply mechanism based on the pig's breathing height. By recovering heat from the top floor of the pig house and conducting stratified ventilation inside the pig house, it effectively reduces heat loss and accurately delivers more than 80% of fresh air to the pig's breathing zone, avoiding ineffective ventilation. The energy saving rate exceeds 50%, while reducing energy consumption. The air quality compliance rate in the breathing zone is increased to more than 99%, thereby improving the growth environment and health level of the pigs.

[0027] 2. The present invention responds to environmental changes in real time, and the ventilation speed is adapted to the different growth stages of pigs, allowing fresh air to be accurately delivered to the pigs' breathing area, which can greatly reduce ventilation heat loss in winter, thereby achieving the purpose of reducing heat loss and ensuring that heat loss is minimized and ineffective ventilation is eliminated while meeting the growth needs of pigs.

[0028] 3. The present invention adjusts the inclination angle of the ventilation openings in the breathing zone according to the different growth stages of the pigs and the ambient temperature and humidity in the pig house, ensuring that fresh air reaches directly and achieving effective and precise ventilation.

[0029] 4. The vents in the heat recovery zone of the present invention are equipped with heat recovery devices, which use the rising hot air in the pig house to preheat the newly entering outside air during ventilation, thereby reducing the temperature difference and reducing heat loss during ventilation in the pig house, thereby improving energy saving rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of the stratified energy-saving ventilation method for cold-region pig houses in winter proposed by the present invention;

[0031] Figure 2 The figure compares various parameters of the traditional ventilation mode in Experimental Example 2 and the ventilation method of the present invention in actual application. DETAILED DESCRIPTION

[0032] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.

[0033] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0034] Example 1:

[0035] Layered energy-saving ventilation methods for pig houses in cold areas in winter, such as Figure 1 As shown, the following steps are included:

[0036] S1: Arrange the ventilation system according to the pig house space and the pig growth stage; implement ventilation design at different growth stages and high levels to meet the needs of pigs at different growth stages.

[0037] Preferably, the pig growth stages include suckling pig stage, piglet stage, middle pig stage, fattening pig stage, etc.; that is, it can be applied in nursery house, fattening house, gestation house, delivery room and boar house.

[0038] Furthermore, the layout method of the ventilation system includes the following aspects:

[0039] 1) Vertical stratification is carried out according to the pig house space, and longitudinal ventilation holes are designed on the north-south [i.e. horizontal] side walls;

[0040] Preferably, the vertical stratification includes a breathing zone at a height of 0.2-0.6 m, a transition zone at a height of 0.6-1.5 m, and a heat recovery zone above 1.5 m;

[0041] Among them, the wind speed in the breathing zone is controlled at 0.1-0.5m / s, the wind speed in the transition zone is controlled at 0.5-1.0m / s, and the wind speed in the heat recovery zone is controlled at 1.2-1.8m / s.

[0042] Furthermore, the ventilation openings in the breathing zone are provided with rectangular air inlets with adjustable angles, and the upper and lower inclination angles of the rectangular air inlets are adjustable in the range of 15°-60°, such as the louver air inlets in the prior art, and the model can refer to the ZRH temperature-controlled variable-angle jet air inlet; the inclination angle of the ventilation openings in the breathing zone is adjusted according to the different growth stages of the pigs and the ambient temperature and humidity in the pig house to ensure that fresh air reaches directly and achieves effective and precise ventilation.

[0043] Furthermore, the vents in the transition zone are fixed and serve only for ventilation;

[0044] Furthermore, the ventilation openings in the heat recovery zone are provided with heat recovery devices, which cite patent CN202321431690.7 and can recover the heat inside the shed 1 while ventilating. Alternatively, the heat recovery device is a heat exchanger with a heat exchange efficiency of ≥70%. During ventilation, the rising hot air in the pig house is used to preheat the newly entering external air, thereby reducing the temperature difference and reducing the heat loss during ventilation in the pig house, thereby improving the energy saving rate.

[0045] 2) Horizontal vents are arranged in an array on the north-south (i.e. horizontal) side walls, spaced evenly according to the pigs' growth stages;

[0046] Preferably, the transverse vents are located within the breathing zone, and the front and rear positions of the transverse vents on the north and south side walls are staggered to ensure ventilation effect and avoid ineffective ventilation.

[0047] S2: Real-time monitoring of the internal environmental parameters of the pig house as a basis;

[0048] Preferably, environmental parameters are realized through IoT sensors distributed at different angles inside the pig house, including temperature and humidity sensors, high-precision hot-bulb wind speed sensors, carbon dioxide sensors and ammonia sensors, etc., which are used to monitor parameters such as temperature, humidity, ventilation volume, carbon dioxide concentration and ammonia concentration in the pig house.

[0049] S3: Optimize airflow paths through CFD simulation to control the operating parameters of the ventilation system, so that airflow is distributed more efficiently to the target area.

[0050] Preferably, the operating parameters include the ventilation volume, ventilation angle and ventilation duration of each partition ventilation mechanism [fan], so as to avoid cold air blowing directly into the pig house, reduce heat loss and ensure effective ventilation.

[0051] For example, when the temperature in the pig house is monitored to be lower than the set value, the ventilation system in the corresponding target area is regulated to automatically reduce the ventilation volume to reduce heat loss; when the carbon dioxide concentration or ammonia concentration in the pig house is monitored to exceed the set threshold, the ventilation system in the breathing zone is regulated to automatically increase the ventilation volume to improve the air quality in the pig house.

[0052] S4: Assists in optimizing ventilation system operation based on heat loss within the pig house; responds to environmental changes in real time to further reduce heat loss, ensuring minimal heat loss and eliminating ineffective ventilation while meeting the growth needs of pigs.

[0053] Furthermore, the heat loss is calculated as follows: Q = p*L*C*ΔT; based on the heat loss result, if it is greater than a threshold range, the ventilation system is regulated to close unnecessary partition mechanisms.

[0054] Where p is the air density, L is the ventilation rate, C is the specific heat of air, ΔT is the temperature difference between inside and outside the shed, ΔT = tin - tout, tin is the air temperature inside the shed, tout is the air temperature outside the shed, and air density and specific heat of air are constants, such as ρ = air density 1.2 kg / m 3 , C = 1.005 kJ / kg·K, and the ventilation volume, indoor air temperature, and outdoor air temperature are all monitored in real time through IoT sensors.

[0055] When this embodiment is in use, the present invention provides a dynamically adjustable air supply mechanism based on the pig's breathing height. Through heat recovery from the top floor of the pig house and stratified ventilation of the air flow inside the pig house, it effectively reduces heat energy loss and accurately delivers more than 80% of fresh air to the pig's breathing zone, avoiding ineffective ventilation. The energy saving rate exceeds 50%, and at the same time, energy consumption is reduced. The air quality compliance rate in the breathing zone is increased to more than 99%, thereby improving the growth environment and health level of the pigs.

[0056] Example 2:

[0057] Layered energy-saving ventilation methods for pig houses in cold areas in winter, such as Figure 1 As shown, in order to adapt the wind speed to the different growth stages of pigs, this embodiment makes the following improvements on the basis of Example 1: the wind speed in the breathing zone at the horizontal vent corresponds to the different growth stages of pigs, such as from the suckling pig stage → the piglet stage → the middle pig stage → the 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 can be accurately delivered to the pig's breathing area, which can greatly reduce ventilation heat loss in winter.

[0058] Test Example 1:

[0059] Two pig farms located in cold regions were selected as the experimental group (using the method of the present invention) and the control group (using traditional ventilation methods) for the experiment. During the experiment, the maximum outdoor temperature during the day was -15°C and the minimum temperature at night was -38°C. The experimental results are as follows:

[0060] Temperature comparison: The temperature in the experimental group's pig house fluctuated slightly and was maintained within an appropriate range, while the temperature in the control group's pig house fluctuated significantly and was generally lower.

[0061] Ventilation rate comparison: The experimental group's ventilation rate was more precise, automatically adjusting based on the temperature difference between the inside and outside of the pig house and the pigs' growth needs. The control group's ventilation rate was relatively fixed, resulting in ineffective ventilation and significant heat loss. This resulted in high energy consumption. The heat loss of the present invention was 6.3 kW / h, while the heat loss of the traditional method was 35.7 kW / h.

[0062] Comparison of environmental parameters: The humidity, carbon dioxide concentration, and ammonia concentration in the experimental group's pig house were better than those in the control group, providing a healthier growth environment for the pigs.

[0063] Test Example 2:

[0064] A large-scale pig farm in Heilongjiang was selected as the experimental site (winter 2024). Figure 2 As shown, the average outdoor temperature is -32°C, and the heat loss of the traditional ventilation mode reaches 35.7kW / h. Compared with the traditional ventilation mode, the method of the present invention reduces the heat loss by 44%, and the concentrations of carbon dioxide and ammonia in the breathing zone are reduced by 49% and 45% respectively.

[0065] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A stratified energy-saving ventilation method for pig houses in cold regions in winter, characterized in that: The steps include: S1: Arrange ventilation system according to pig house space and pig growth stage; S2: Real-time monitoring of the internal environmental parameters of the pig house as a basis; S3: Optimize airflow paths through CFD simulation to control ventilation system operating parameters; S4: Assist in optimizing ventilation system operation based on heat loss in the pig house; The pig growth stages include suckling pig stage, piglet stage, middle pig stage and fattening pig stage.

2. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 1, characterized in that: The layout method of the ventilation system includes the following aspects: 1) Vertical stratification is carried out according to the pig house space, and longitudinal ventilation holes are designed on the north and south walls; 2) Horizontal vents are arranged in an array pattern on the north and south walls at equal intervals according to the growth stage of the pigs.

3. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 2, characterized in that: The vertical stratification includes a breathing zone at a height of 0.2-0.6 m, a transition zone at a height of 0.6-1.5 m, and a heat recovery zone above 1.5 m.

4. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 3, characterized in that: The wind speed in the breathing zone is controlled to be 0.1-0.5 m / s, the wind speed in the transition zone is controlled to be 0.5-1.0 m / s, and the wind speed in the reheating zone is controlled to be 1.2-1.8 m / s.

5. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 4, characterized in that: The transverse vents are located within the breathing zone, and the front and rear positions of the transverse vents on the north and south side walls are staggered.

6. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 5, characterized in that: The wind speed in the breathing zone at the transverse vents corresponds to different growth stages of the pigs.

7. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 6, characterized in that: The ventilation opening in the breathing zone is provided with an angle-adjustable rectangular air inlet, and the upper and lower inclination angles of the rectangular air inlet are adjustable in the range of 15°-60°; The vents in the transition zone are fixed; The ventilation opening of the heat recovery zone is provided with a heat recovery device, which is a heat exchanger with a heat exchange efficiency of ≥70%.

8. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 1, characterized in that: The environmental parameters are realized through Internet of Things sensors, including temperature and humidity sensors, high-precision hot-bulb wind speed sensors, carbon dioxide sensors and ammonia sensors.

9. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 8, characterized in that: The operating parameters include the ventilation volume, ventilation angle and ventilation duration of each partition ventilation mechanism.

10. The stratified energy-saving ventilation method for pig houses in cold regions in winter according to claim 9, characterized in that: The heat loss is calculated as follows: Q = p*L*C*ΔT.

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