Methane gas collection device and method for ruminants

Abstract

The methane gas collection device and method for ruminants provided by the present invention relate to the field of methane collection equipment, and include a belching detection device, a controller, and a gas collection device. The air inlet of the gas collection device is located at the mouth and nose of the ruminant. The belching detection device and the gas collection device are connected to the controller. The belching detection device can detect the vertical acceleration of the ruminant's lower jaw. The controller can obtain the acceleration change law of the ruminant's lower jaw according to the vertical acceleration of the ruminant's lower jaw. The controller can determine that the ruminant is about to belch when the acceleration change law of the ruminant's lower jaw is the same as the acceleration change law of the upcoming belching. The controller can turn on the gas collection device before the ruminant is about to belch, and can turn off the gas collection device after the opening time of the gas collection device reaches the set time. The methane gas collection device for ruminants provided by the present invention can ensure the collection rate of methane gas and save energy.

Description

Technical Field

[0001] The present invention relates to the technical field of methane collection equipment, and particularly to a methane gas collection device and method for ruminants. Background Art

[0002] Livestock methane is an important source of global methane emissions, accounting for more than 28% of the total methane emissions. A major source of methane in livestock is dairy cows, and 90%-95% of the methane released by dairy cows is released from the mouth in the form of belching (hiccupping). In order to reduce the negative impact of methane emissions during dairy cow farming on the environment, the methane emitted from dairy cow belching should be efficiently captured.

[0003] Chinese Patent CN115040110A discloses a wearable methane respiration filtration device for dairy cows, which is provided with a gas guiding rod and a respiration filtration device. One end of the gas guiding rod is communicated with the air inlet channel of the respiration filtration device, and the other end of the gas guiding rod is arranged opposite to the mouth and nose of the dairy cow. The methane gas generated by the dairy cow during hiccupping or breathing is absorbed through the gas guiding rod and transmitted into the respiration filtration device for treatment. Its methane respiration filtration device is always in an open state and continuously collects the gas near the mouth and nose of the dairy cow without discrimination, and does not predict the belching behavior of the dairy cow and only starts the methane respiration filtration device to collect methane after judging that the dairy cow has a belching behavior. Since the amount of methane gas generated when the dairy cow is not hiccupping is small, continuously opening the methane respiration filtration device is not only inefficient but also energy-consuming. Summary of the Invention

[0004] The object of the present invention is to provide a methane gas collection device and method for ruminants to solve the problems existing in the above-mentioned prior art, which can not only better ensure the methane gas collection rate but also save energy.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a methane gas collection device for ruminants, comprising a belching detection device, a controller and a gas collection device. The belching detection device, the controller and the gas collection device are all used for being fixedly connected to ruminants. The air inlet of the gas collection device can be located at the mouth and nose of the ruminant. The belching detection device is communicatively connected to the controller, and the controller is connected to the gas collection device. The belching detection device can detect the vertical acceleration of the lower jaw of the ruminant in real time. The controller can obtain the variation law of the acceleration of the lower jaw of the ruminant with time according to the vertical acceleration of the lower jaw of the ruminant detected by the belching detection device. The controller can compare the acceleration variation law of the lower jaw of the ruminant with the preset acceleration variation law of impending belching in the controller, and the controller can determine that the ruminant is about to belch when the lower jaw of the ruminant has an acceleration variation law same as the acceleration variation law of impending belching. The controller can control the gas collection device to be turned on before the ruminant is about to belch, and the controller can control the gas collection device to be turned off after the opening time of the gas collection device reaches a first set time.

[0007] Preferably, the controller can determine that the ruminant is about to belch when the acceleration of the lower jaw of the ruminant changes from fluctuating up and down with time to zero.

[0008] Preferably, the gas collection device comprises a collection hood, a collection pipe, a collection body and a first power device. The collection hood, the collection pipe, the collection body and the first power device are all used for being arranged on the ruminant. The collection hood has a collection cavity, and the opening of the collection cavity can be oppositely arranged to the mouth and nose of the ruminant. Two ends of the collection pipe are respectively fixedly connected to the collection hood and the collection body. The air inlet of the collection pipe is communicated with the collection cavity, and the air outlet of the collection pipe is communicated with the inner cavity of the collection body. The first power device can be communicated with the inner cavity of the collection body. The collection cavity can accommodate the methane gas generated by the ruminant's belching. The first power device can make the methane gas in the collection cavity enter the collection body through the collection pipe. The first power device is connected to the controller. The controller can control the first power device to be turned on before the ruminant is about to belch, and the controller can control the first power device to be turned off after the opening time of the first power device reaches the first set time.

[0009] Preferably, the gas collection device further includes a folding rod and a second power device. The folding rod is connected to the second power device, and both ends of the folding rod are fixedly connected to the collection hood and the collection body respectively. The second power device is connected to the controller. The controller can drive the folding rod to rotate around its folding axis through the second power device before the ruminant is about to belch, so that the air inlet of the gas collection device is located in front of the mouth and nose of the ruminant, and the controller can drive the folding rod to rotate around its folding axis through the second power device to make the gas collection device located at a position that does not block the face of the ruminant.

[0010] Preferably, it further includes a methane fuel cell and a third power device. The air inlet of the third power device is communicated with the collection body, and the air outlet of the third power device is communicated with the air inlet of the methane fuel cell. The third power device can transport the methane gas in the collection body to the methane fuel cell. The methane fuel cell is connected to the controller, the first power device, the second power device and the third power device respectively and supplies power to the controller, the first power device, the second power device and the third power device; an adsorption material capable of adsorbing methane gas is arranged in the collection body.

[0011] The present invention also provides a methane gas collection method based on the above methane gas collection device for ruminants, including the following steps:

[0012] S1. The vertical acceleration of the lower jaw of the ruminant is detected in real time by the belching detection device, and the controller judges whether the ruminant is about to belch. The judgment method includes: obtaining the acceleration change rule of the ruminant when it is about to belch; obtaining the change rule of the acceleration of the lower jaw of the ruminant with time according to the vertical acceleration of the lower jaw of the ruminant detected by the belching detection device, and comparing the acceleration change rule of the lower jaw of the ruminant with the set acceleration change rule of the ruminant when it is about to belch in the controller. When the lower jaw of the ruminant has the same acceleration change rule as the acceleration change rule of the ruminant when it is about to belch, it is determined that the ruminant is about to belch;

[0013] S2. The controller turns on the gas collection device before the ruminant is about to belch, and collects the methane gas generated by the ruminant through the gas collection device; and the controller can control the gas collection device to close after the opening time of the gas collection device reaches the first set time.

[0014] Preferably, the gas collection device includes a collection hood, a collection pipe, a collection body, a first power device, a folding rod, and a second power device. The collection hood has a collection cavity. Two ends of the collection pipe are respectively fixedly connected to the collection hood and the collection body. An air inlet of the collection pipe communicates with the collection cavity, and an air outlet of the collection pipe communicates with an inner cavity of the collection body. The first power device can communicate with the inner cavity of the collection body. The folding rod is connected to the second power device, and two ends of the folding rod are respectively fixedly connected to the collection hood and the collection body. The second power device is connected to the controller.

[0015] S2 further includes: when the ruminant is about to belch, controlling, by the controller, the second power device to drive the folding rod to rotate around its own folding axis and make the air inlet of the gas collection device located in front of the mouth and nose of the ruminant, controlling, by the controller, the first power device to start and inhaling, through the first power device, the methane gas in the collection cavity into the collection body via the collection pipe.

[0016] The controller controls the first power device to close after the opening time of the first power device reaches the first set time. The controller drives, through the second power device, the folding rod to rotate around its own folding axis and makes the gas collection device located at a position that does not block the face of the ruminant.

[0017] Preferably, before collecting methane gas, a three-dimensional model of the ruminant is obtained, and a hydrodynamic numerical simulation is performed on the three-dimensional data model of the ruminant by the finite volume method to obtain the shape of the methane gas belched by the ruminant and the jet distance of the methane gas. The shape and size of the collection hood are determined according to the shape of the methane gas and the jet distance.

[0018] Preferably, a hydrodynamic numerical simulation is performed on the three-dimensional data model of the ruminant by the finite volume method to obtain the diffusion time of the methane gas belched by the ruminant. The controller controls the first power device to complete the collection of the methane gas generated by each belch of the ruminant within the first set time, and the first set time is less than or equal to the diffusion time.

[0019] Preferably, the method for obtaining the acceleration change law of the upcoming belch includes: obtaining the acceleration change law of chewing, and determining that the ruminant is about to belch when the lower jaw of the ruminant changes from the chewing state to zero.

[0020] The method for obtaining the chewing acceleration variation law includes: during the process of the eructation detection device obtaining the vertical acceleration data of the lower jaw of the ruminant, the head of the ruminant is synchronously photographed, and the data corresponding to the eructation detection device within the time period corresponding to the chewing behavior of the ruminant in the photographed video is intercepted, and the chewing acceleration variation law of the lower jaw of the ruminant is obtained through this data.

[0021] The present invention has achieved the following technical effects compared with the prior art:

[0022] For the methane gas collection device and method for ruminants provided by the present invention, the controller can determine that the ruminant is about to eruct when the lower jaw of the ruminant stops moving after moving for a certain time. The controller can control the gas collection device to turn on before the ruminant is about to eruct, and the controller can control the gas collection device to turn off after the opening time of the gas collection device reaches the first set time. The eructation phenomenon of ruminants such as cows generally occurs during chewing. When a cow is about to eruct, the chewing behavior pauses; the eructation behavior generally lasts for <10 seconds. After the eructation ends, the chewing behavior resumes; when a cow chews, its lower jaw moves rhythmically up and down. Utilizing this behavioral characteristic of ruminants, the present invention can predict in advance by the controller whether the ruminant is about to eruct, and control the gas collection device to turn on until the methane gas is collected completely before the ruminant is about to eruct, and the controller can control the gas collection device to turn off after the opening time of the gas collection device reaches the first set time, that is, the gas collection device is turned off for the rest of the time after the methane gas is collected completely. Since 90%-95% of the methane released by ruminants such as cows is released in the form of eructation (hiccups), the methane gas collection device for ruminants provided by the present invention can not only better ensure the methane gas collection rate, but also save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a schematic structural diagram of the methane gas collection device for ruminants in Embodiment 1 (the collection cover covers the mouth and nose);

[0025] Figure 2 It is a schematic structural diagram of the methane gas collection device for ruminants in Embodiment 1 (the collection cover does not block the mouth and nose);

[0026] Figure 3Schematic structural diagram of the collection hood in Embodiment 1;

[0027] Figure 4 Left view of the collection hood in Embodiment 1;

[0028] Figure 5 Schematic diagram of the law of change of belching acceleration in the present invention;

[0029] Figure 6 Flowchart of the method for judging that a ruminant is about to belch in Embodiment 2;

[0030] Figure 7 Flowchart of the method for collecting methane gas for ruminants in Embodiment 2;

[0031] Figure 8 System block diagram of the method for collecting methane gas for ruminants in Embodiment 2;

[0032] Figure 9 Flowchart of the computational fluid dynamics (CFD) numerical simulation in Embodiment 2.

[0033] In the figure, 100, methane gas collection device for ruminants; 1, belching detection device; 2, controller; 3, gas collection device; 301, collection hood; 302, collection pipe; 303, collection body; 304, first power device; 305, collection chamber; 306, folding rod; 4, methane fuel cell; 5, second power device; 6, third power device. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] The purpose of the present invention is to provide a methane gas collection device and method for ruminants to solve the problems existing in the above-mentioned prior art, which can not only better ensure the collection rate of methane gas but also save energy.

[0036] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0037] Embodiment 1

[0038] As Figures 1-4As shown in the figure, this embodiment provides a methane gas collection device 100 for ruminants, including a belching detection device 1, a controller 2, and a gas collection device 3. The belching detection device 1, the controller 2, and the gas collection device 3 are all fixedly connected to the ruminant. The air inlet of the gas collection device 3 can be located at the mouth and nose of the ruminant. The belching detection device 1 is communicatively connected to the controller 2, and the controller 2 is connected to the gas collection device 3. The belching detection device 1 can detect the vertical acceleration of the ruminant's lower jaw in real time. The controller 2 can obtain the change law of the acceleration of the ruminant's lower jaw over time based on the vertical acceleration of the ruminant's lower jaw detected by the belching detection device 1. The controller 2 can compare the acceleration change law of the ruminant's lower jaw with the set acceleration change law of impending belching in the controller 2, and the controller 2 can determine that the ruminant is about to belch when the acceleration change law of the ruminant's lower jaw is the same as the acceleration change law of impending belching. The controller 2 can control the gas collection device 3 to open before the ruminant is about to belch, and the controller 2 can control the gas collection device 3 to close after the opening time of the gas collection device 3 reaches the first set time. The belching phenomenon of ruminants such as cows generally occurs during chewing. When a cow is about to belch, the chewing behavior pauses; the belching behavior generally lasts less than 10 seconds, and after the belching ends, the chewing behavior resumes; when a cow chews, its lower jaw moves rhythmically up and down. Utilizing this behavioral characteristic of ruminants, the present invention can predict in advance whether a ruminant is about to belch through the controller 2, control the gas collection device 3 to open before the ruminant is about to belch until the methane gas is collected completely, and the controller 2 can control the gas collection device 3 to close after the opening time of the gas collection device 3 reaches the first set time, that is, the gas collection device 3 is closed for the rest of the time after the methane gas is collected completely. Since 90%-95% of the methane released by ruminants such as cows is released in the form of belching (hiccupping), the methane gas collection device 100 for ruminants provided by the present invention can not only better ensure the methane gas collection rate but also save energy.

[0039] As Figure 5 shown, as a preferred embodiment, the controller 2 can determine that the ruminant is about to belch when the acceleration of the ruminant's lower jaw changes from fluctuating up and down over time to zero. The acceleration change law of impending belching is that the acceleration changes from fluctuating up and down over time to zero. Therefore, when the belching detection device 1 detects that the acceleration of the ruminant's lower jaw changes from fluctuating up and down over time to zero, it is determined that the ruminant is about to belch.

[0040] As a more preferred embodiment, the acceleration change law of impending belching is that the acceleration changes from continuously fluctuating up and down over time to zero. When the belching detection device 1 detects that the acceleration of the ruminant's lower jaw changes from continuously fluctuating up and down over time to zero, it is determined that the ruminant is about to belch.

[0041] As a preferred embodiment, the eructation detection device 1 is an acceleration sensor, and more preferably, the eructation detection device 1 is a triaxial acceleration sensor.

[0042] The gas collection device 3 includes a collection hood 301, a collection pipe 302, a collection body 303, and a first power device 304. The collection hood 301, the collection pipe 302, the collection body 303, and the first power device 304 are all configured to be disposed on a ruminant animal. The collection hood 301, the collection pipe 302, the collection body 303, and the first power device 304 are all configured to be directly or indirectly fixedly connected to the ruminant animal. The collection hood 301 is disposed in front of the mouth and nose of the ruminant animal. The collection hood 301 has a collection cavity 305, and the opening of the collection cavity 305 is disposed opposite to the mouth and nose of the ruminant animal. To avoid causing discomfort to the ruminant animal, the collection hood 301 does not directly contact the mouth and nose of the ruminant animal. The shape, depth, and other dimensions of the collection hood 301 and the collection cavity 305 should be such that the methane gas generated by the eructation of the ruminant animal does not leak too much; both ends of the collection pipe 302 are fixedly connected to the collection hood 301 and the collection body 303 respectively. The air inlet of the collection pipe 302 is communicated with the collection cavity 305, and the air outlet of the collection pipe 302 is communicated with the inner cavity of the collection body 303. The first power device 304 can be communicated with the inner cavity of the collection body 303. The collection cavity 305 can accommodate the methane gas generated by the eructation of the ruminant animal. The first power device 304 can cause the methane gas in the collection cavity 305 to enter the collection body 303 via the collection pipe 302. The first power device 304 is connected to the controller 2. The controller 2 can control the first power device 304 to be turned on before the ruminant animal is about to eructate, and the controller 2 can control the first power device 304 to be turned off after the opening time of the first power device 304 reaches a first set time. Since the collection cavity 305 of the collection hood 301 can delay the diffusion of methane gas, it is beneficial to improve the collection efficiency. As a preferred embodiment, the first power device 304 is an air pump.

[0043] As a preferred embodiment, the gas collection device 3 provided in this embodiment further includes a folding rod 306 and a second power device 5. The folding rod 306 is connected to the second power device 5. Both ends of the folding rod 306 are fixedly connected to the collection hood 301 and the collection body 303 respectively. The second power device 5 is connected to the controller 2. The controller 2 can drive the folding rod 306 to rotate around its own folding axis through the second power device 5 before the ruminant animal is about to eructate and make the air inlet of the gas collection device 3 be in front of the mouth and nose of the ruminant animal, and the controller 2 can drive the folding rod 306 to rotate around its own folding axis through the second power device 5 and make the gas collection device 3 be in a position that does not block the face of the ruminant animal, thereby reducing the blocking effect of the collection hood 301 on the mouth and nose of the ruminant animal. Since the frequency of a cow's hiccups is not high, about 20 times an hour, covering the collection hood 301 all the time will affect the normal activities of the cow such as eating and communicating with each other.

[0044] The folding rod 306 includes a fixed rod and a rotating rod. One end of the fixed rod is rotatably connected to one end of the rotating rod through a rotating shaft. The other end of the fixed rod is fixedly connected to the collection body 303, and the other end of the rotating rod is fixedly connected to the collection cover 301. The second power device 5 can be connected to the rotating rod, and the second power device 5 can drive the rotating rod to rotate around the axis of the rotating shaft of the rotating rod and the fixed rod. Specifically, the fixed rod is rotatably connected to the rotating shaft, and the rotating shaft is fixedly connected to the rotating rod.

[0045] As a preferred embodiment, the second driving device is a motor. The motor is fixedly connected to the collection body 303 through a bracket, and the output end of the motor is fixedly connected to the rotating shaft.

[0046] As another preferred embodiment, the second driving device is an electric telescopic rod. The two ends of the electric telescopic rod are respectively rotatably connected to the fixed rod and the rotating rod. The telescoping of the electric telescopic rod can drive the rotating rod to rotate around the axis of the rotating shaft of the rotating rod and the fixed rod.

[0047] The methane gas collection device 100 for ruminants provided in this embodiment further includes a methane fuel cell 4 and a third power device 6. The first power device 5 is preferably a pump. The air inlet of the third power device 6 is communicated with the collection body 303, and the air outlet of the third power device 6 is communicated with the air inlet of the methane fuel cell 4. The third power device 6 can transport the methane gas in the collection body 303 into the methane fuel cell 4. The methane fuel cell 4 is connected to the controller 2, the first power device 304, the second power device 5, and the third power device 6 and supplies power to the controller 2, the first power device 304, the second power device 5, and the third power device 6; not only realizes the collection of methane gas, effectively reduces methane emissions in the cowshed, but also realizes the effective utilization of methane gas, which is beneficial to energy conservation; an adsorption material capable of adsorbing methane gas is provided in the collection body 303. When the first power device 304 extracts the gas in the collection cover 301, the gas is a mixture of methane gas and air. The adsorption material can adsorb the methane gas to achieve the enrichment of methane gas for later use. The air in the mixture can be pumped out of the collection body 303 by reversing the first driving device and will not be adsorbed. The adsorption material is preferably a MOF material.

[0048] Embodiment 2

[0049] As Figures 6-9 shown, this embodiment provides a methane gas collection method based on the methane gas collection device 100 for ruminants in Embodiment 1, including the following steps:

[0050] S1. The vertical acceleration of the lower jaw of the ruminant is detected in real time by the eructation detection device 1, and the controller 2 determines whether the ruminant is about to eructate. The determination method includes: obtaining the acceleration change law of the ruminant about to eructate; obtaining the change law of the acceleration of the ruminant's lower jaw over time according to the vertical acceleration of the ruminant's lower jaw detected by the eructation detection device 1, and comparing the acceleration change law of the ruminant's lower jaw with the set acceleration change law of the ruminant about to eructate in the controller 2. When the acceleration change law of the ruminant's lower jaw is the same as the acceleration change law of the ruminant about to eructate, it is determined that the ruminant is about to eructate;

[0051] S2. The controller 2 turns on the gas collection device 3 before the ruminant is about to eructate, and the gas collection device 3 collects the methane gas generated by the ruminant; and the controller 2 can control the gas collection device 3 to close after the opening time of the gas collection device 3 reaches the first set time.

[0052] As a preferred embodiment, the gas collection device 3 includes a collection hood 301, a collection pipe 302, a collection body 303, a first power device 304, a folding rod 306 and a second power device 5. The collection hood 301 has a collection cavity 305. The two ends of the collection pipe 302 are respectively fixedly connected to the collection hood 301 and the collection body 303. The air inlet of the collection pipe 302 is communicated with the collection cavity 305, and the air outlet of the collection pipe 302 is communicated with the inner cavity of the collection body 303. The first power device 304 can be communicated with the inner cavity of the collection body 303; the folding rod 306 is connected to the second power device 5, and the two ends of the folding rod 306 are respectively fixedly connected to the collection hood 301 and the collection body 303. The second power device 5 is connected to the controller 2;

[0053] S2 further includes: when the ruminant is about to eructate, the controller 2 controls the second power device 5 to drive the folding rod 306 to rotate around its own folding axis and make the air inlet of the gas collection device 3 in front of the mouth and nose of the ruminant, and the controller 2 controls the first power device 304 to turn on and inhale the methane gas in the collection cavity 305 into the collection body 303 through the first power device 304 via the collection pipe 302;

[0054] The controller 2 controls the first power device 304 to close after the opening time of the first power device 304 reaches the first set time; the controller 2 drives the folding rod 306 to rotate around its own folding axis through the second power device 5 and makes the gas collection device 3 located at a position that does not block the face of the ruminant.

[0055] As a preferred embodiment, before collecting methane gas, a three-dimensional model of the ruminant is obtained. The hydrodynamic numerical simulation of the three-dimensional data model of the ruminant is carried out by the finite volume method, and the shape and the injection distance of the methane gas belched out by the ruminant are obtained. The shape and size of the collection hood 301 after unfolding are determined according to the shape and injection distance of the methane gas. Preferably, the collection hood 301 is cup-shaped, and the finite volume method is preferably the hydrodynamic (CFD) numerical simulation. It can be known through simulation that after the methane gas is injected into the collection cavity 305, the methane gas will diffuse towards the opening direction of the collection hood 301. When it is difficult to prevent the methane gas from diffusing towards the opening direction of the collection hood 301 only by increasing the pumping flow rate, the depth or the surrounding area of the collection hood 301 (collection cavity 305) can be increased. Since when the collection hood 301 is too close to the cow's mouth, methane is likely to overflow from the edge of the collection hood 301, because the closer to the cow's mouth, the faster the air flow; the farther from the cow's mouth, the smaller the air flow velocity, but if it is too far, it is easy to cause the methane to diffuse. Therefore, through simulation, the critical distance between the collection hood 301 and the cow's mouth can be found, so that methane will not overflow from the edge of the collection hood 301, nor will the methane diffuse too much to be unloaded.

[0056] As a preferred embodiment, the hydrodynamic numerical simulation of the three-dimensional data model of the ruminant is carried out by the finite volume method, and the diffusion time of the methane gas belched out by the ruminant is obtained. The controller controls the first power device 304 to complete the collection of the methane gas generated by each belch of the ruminant within the first set time, and the first set time is less than or equal to the diffusion time. After the methane is completely ejected from the ruminant's mouth, a region with a high methane concentration will be formed directly in front of the ruminant's mouth, and this region is three-dimensional. The three-dimensional methane concentration region will diffuse after a certain time. The diffusion time of the gas collection device 3 starts from predicting that the cow is about to belch until the methane is ejected and formed but not diffused. The gas collection device 3 needs to collect the methane before it diffuses. Therefore, the first set time is set to be less than or equal to the diffusion time.

[0057] As a preferred embodiment, the method for obtaining the acceleration change law of the upcoming belch includes: obtaining the acceleration change law of chewing, and determining that the ruminant is about to belch when the lower jaw of the ruminant changes from the chewing state to zero;

[0058] The method for obtaining the acceleration change law of chewing includes: during the process of the belch detection device 1 obtaining the vertical acceleration data of the ruminant's lower jaw, the head of the ruminant is photographed synchronously, and the data corresponding to the belch detection device 1 within the time period corresponding to the chewing behavior of the ruminant in the photographed video is intercepted, and the acceleration change law of the ruminant's lower jaw chewing is obtained through this data.

[0059] As a preferred embodiment, the variation law of chewing acceleration is that the acceleration fluctuates up and down with time. More preferably, the variation law of chewing acceleration is that the acceleration continuously fluctuates up and down with time. Specifically, as Figure 5 shown, when the acceleration changes from a positive value to a negative value, it is a primary fluctuation of the acceleration. The number of times or duration of the continuous up and down fluctuation of the acceleration with time can be adjusted according to the laws of the chewing and belching behaviors of the corresponding ruminant animals. For example, the variation law of chewing acceleration is that when the acceleration of the lower jaw of the ruminant animal continuously fluctuates up and down with time for 1 minute.

[0060] Such as Figure 9 , the main steps of the computational fluid dynamics (CFD) numerical simulation include: establishing a dairy cow belching model based on the computational fluid dynamics (CFD) numerical simulation, and the model is a three-dimensional bovine body model; the model is established in a three-dimensional geometric software and then discretized by dividing the grid; discretizing the momentum equation and the continuity equation; combining the discretized equations with the discretized geometric model to solve the governing equations. It should be noted that the computational fluid dynamics (CFD) numerical simulation is a prior art and will not be elaborated here.

[0061] In the present invention, specific examples are used to illustrate the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A methane gas collection device for ruminants, characterized in that: It includes a belching detection device, a controller and a gas collection device. The belching detection device, the controller and the gas collection device are all used to be fixedly connected to a ruminant. The air inlet of the gas collection device can be located at the mouth and nose of the ruminant. The belching detection device is communicatively connected to the controller, and the controller is connected to the gas collection device. The belching detection device can detect the vertical acceleration of the ruminant's lower jaw in real time. The controller can obtain the change law of the acceleration of the ruminant's lower jaw with time according to the vertical acceleration of the ruminant's lower jaw detected by the belching detection device. The controller can compare the acceleration change law of the ruminant's lower jaw with the preset acceleration change law of impending belching in the controller, and the controller can determine that the ruminant is about to belch when the acceleration change law of the ruminant's lower jaw is the same as the acceleration change law of impending belching. The controller can control the gas collection device to open before the ruminant is about to belch, and the controller can control the gas collection device to close after the opening time of the gas collection device reaches the first set time; The gas collection device includes a collection hood, a collection pipe, a collection body and a first power device. The collection hood, the collection pipe, the collection body and the first power device are all used to be arranged on the ruminant. The collection hood has a collection cavity, and the opening of the collection cavity can be arranged opposite to the mouth and nose of the ruminant. The two ends of the collection pipe are respectively fixedly connected to the collection hood and the collection body. The air inlet of the collection pipe is communicated with the collection cavity, and the air outlet of the collection pipe is communicated with the inner cavity of the collection body. The first power device can be communicated with the inner cavity of the collection body. The collection cavity can accommodate the methane gas generated by the ruminant's belching. The first power device can make the methane gas in the collection cavity enter the collection body through the collection pipe. The first power device is connected to the controller. The controller can control the first power device to open before the ruminant is about to belch, and the controller can control the first power device to close after the opening time of the first power device reaches the first set time; The gas collection device further includes a folding rod and a second power device. The folding rod is connected to the second power device. The two ends of the folding rod are respectively fixedly connected to the collection hood and the collection body. The second power device is connected to the controller. The controller can drive the folding rod to rotate around its folding axis through the second power device and make the air inlet of the gas collection device be in front of the mouth and nose of the ruminant before the ruminant is about to belch, and the controller can drive the folding rod to rotate around its folding axis through the second power device and make the gas collection device be in a position that does not block the face of the ruminant.

2. The methane gas collection device for ruminants according to claim 1, wherein: The controller can determine that the ruminant is about to eructate when the acceleration of the ruminant's lower jaw changes from fluctuating up and down over time to zero.

3. The methane gas collection device for ruminants according to claim 1, characterized in that: It further includes a methane fuel cell and a third power device. The air inlet of the third power device is communicated with the collection body, and the air outlet of the third power device is communicated with the air inlet of the methane fuel cell. The third power device can transport the methane gas in the collection body into the methane fuel cell. The methane fuel cell is connected to the controller, the first power device, the second power device and the third power device and supplies power to the controller, the first power device, the second power device and the third power device; an adsorption material capable of adsorbing methane gas is arranged in the collection body.

4. A method for collecting methane gas of the methane gas collection device for ruminants according to any one of claims 1-3, characterized in that: It includes the following steps: S1. The vertical acceleration of the ruminant's lower jaw is detected in real time by the eructation detection device, and the controller judges whether the ruminant is about to eructate. The judgment method includes: obtaining the acceleration change rule of the ruminant about to eructate; obtaining the change rule of the acceleration of the ruminant's lower jaw over time according to the vertical acceleration of the ruminant's lower jaw detected by the eructation detection device, and comparing the acceleration change rule of the ruminant's lower jaw with the set acceleration change rule of the ruminant about to eructate in the controller. When the acceleration change rule of the ruminant's lower jaw is the same as the set acceleration change rule of the ruminant about to eructate, it is determined that the ruminant is about to eructate; S2. The controller turns on the gas collection device before the ruminant is about to eructate, and collects the methane gas generated by the ruminant through the gas collection device; and the controller can control the gas collection device to close after the opening time of the gas collection device reaches the first set time.

5. The methane gas collection method for ruminants according to claim 4, characterized in that: The gas collection device includes a collection cover, a collection pipe, a collection body, a first power device, a folding rod and a second power device. The collection cover has a collection cavity. The two ends of the collection pipe are respectively fixedly connected to the collection cover and the collection body. The air inlet of the collection pipe is communicated with the collection cavity, and the air outlet of the collection pipe is communicated with the inner cavity of the collection body. The first power device can be communicated with the inner cavity of the collection body; the folding rod is connected to the second power device, and the two ends of the folding rod are respectively fixedly connected to the collection cover and the collection body. The second power device is connected to the controller; S2 further includes: when the ruminant is about to eructate, the controller controls the second power device to drive the folding rod to rotate around its own folding axis and make the air inlet of the gas collection device located in front of the mouth and nose of the ruminant, and the controller controls the first power device to turn on and inhale the methane gas in the collection cavity into the collection body through the first power device through the collection pipe; The controller controls the first power device to turn off after the startup time of the first power device reaches the first set time; the controller drives the folding rod to rotate around its folding axis through the second power device and positions the gas collection device at a position where it does not block the face of the ruminant animal.

6. The method for collecting methane gas for ruminant animals according to claim 5, wherein: Before collecting methane gas, a three-dimensional model of the ruminant animal is obtained, and the three-dimensional data model of the ruminant animal is subjected to hydrodynamic numerical simulation by the finite volume method to obtain the shape of the methane gas belched by the ruminant animal and the ejection distance of the methane gas, and the shape and size of the collection hood are determined according to the shape of the methane gas and the ejection distance.

7. The method for collecting methane gas for ruminant animals according to claim 6, wherein: The three-dimensional data model of the ruminant animal is subjected to hydrodynamic numerical simulation by the finite volume method to obtain the diffusion time of the methane gas belched by the ruminant animal, and the controller controls the first power device to complete the collection of the methane gas generated by each belch of the ruminant animal within the first set time, and the first set time is less than or equal to the diffusion time.

8. The method for collecting methane gas for ruminant animals according to claim 4, wherein: The method for obtaining the acceleration change law of the upcoming belch includes: obtaining the acceleration change law of chewing, and determining that the ruminant animal is about to belch when the lower jaw of the ruminant animal changes from the chewing state to zero; The method for obtaining the acceleration change law of chewing includes: during the process of the belch detection device obtaining the vertical acceleration data of the lower jaw of the ruminant animal, the head of the ruminant animal is photographed synchronously, and the data corresponding to the belch detection device during the time period corresponding to the chewing behavior of the ruminant animal in the photographed video is intercepted, and the acceleration change law of the chewing of the lower jaw of the ruminant animal is obtained through this data.

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