Methane emission monitoring equipment and monitoring method for open cowshed

Abstract

The invention discloses monitoring equipment and a monitoring method for methane emission of an open cowshed, belongs to the field of greenhouse gas emission monitoring, and solves the problems that only methane emission of a small amount of cattle can be measured by a closed chamber method in the existing monitoring technology, and a method and equipment for monitoring the methane emission flux of the open cowshed are relatively deficient. The equipment comprises a sample inlet group, a gas guide pipe, an electromagnetic valve part, a greenhouse gas detector and an equipment control end, the three-way valve is arranged at the tail end of the sample inlet, one end of the three-way valve is connected to the gas flow divider and the gas pump, gas flow is formed in the gas flow guide pipe through real-time gas collection, the situation that the gas concentration in a pipeline lags behind the site due to the fact that the pipeline is too long is avoided, and therefore the gas concentration of the sampling opening and the gas concentration of the tail end of the gas flow guide pipe are kept consistent; automatic calculation of sampling point data is realized, and real-time intelligent monitoring of the open cowshed methane emission flux of a large-scale cow farm is realized.

Description

Technical Field

[0001] The present invention belongs to the field of greenhouse gas emission monitoring, and particularly relates to a methane emission monitoring device and method for an open cattle shed. Background Art

[0002] The rumination of cattle is one of the important sources of atmospheric methane emissions. In recent years, the attention to methane emissions from cattle farms has gradually increased. However, there are still significant technical difficulties in monitoring methane emissions from open cattle sheds. Currently, the monitoring of greenhouse gas emissions from cattle farms is mostly for methane emissions in a closed chamber state. A small number of cattle are locked in a closed chamber, and the methane emissions are calculated through the difference in the flow rate of inlet and outlet air and the methane concentration. Although the methane emission monitoring by the closed chamber method has high sensitivity and accuracy. However, the closed methane emission monitoring method can only measure the methane emissions of a small number of cattle, and the methane emissions of individual cattle are used to estimate the emissions of the entire farm. Due to the too large individual differences, it is impossible to effectively and accurately estimate the overall emissions of the farm. Moreover, the closed method requires the special establishment of a closed chamber, with a high investment cost, which increases the burden on enterprises. At the same time, the greenhouse gas monitoring equipment can only monitor the atmospheric methane concentration and cannot monitor the emission flux of dairy cows. However, the evaluation of greenhouse gas emissions precisely requires the data of emission flux. Although there are many current devices that can monitor the methane concentration in the atmosphere. However, how to convert the monitored atmospheric methane concentration (in ppm) into the methane emission flux of dairy cows (in g·CH4·head -1 ·d -1 ) is still a difficult problem. For the evaluation of greenhouse gas emissions of dairy cattle breeding enterprises, the emission flux data of dairy cows are required, rather than the atmospheric concentration data.

[0003] In view of the above problems, we propose a methane emission monitoring device and method for an open cattle shed. Summary of the Invention

[0004] The purpose of the present invention is to provide a methane emission monitoring device and method for an open cattle shed in view of the deficiencies of the prior art, and solve the problem that the existing monitoring technology, the closed chamber method, can only measure the methane emissions of a small number of cattle, and there is a lack of monitoring methods and equipment for the methane emission flux of large-scale dairy cattle farms, especially open cattle sheds under natural ventilation conditions.

[0005] The present invention is implemented as follows. A methane emission monitoring device for an open cattle shed, the methane emission monitoring device for an open cattle shed includes:

[0006] A sample inlet group for injecting the gas to be monitored, the sample inlet group includes 12 sample inlets;

[0007] A gas diversion pipe, installed at the rear end of the sampling port, for diverting the gas to be monitored;

[0008] An electromagnetic valve part, which is in communication with the gas diversion pipe;

[0009] A greenhouse gas detector, which is fixedly connected to the electromagnetic valve part. The gas detector is used for continuously measuring the concentrations of methane and carbon dioxide, and

[0010] An equipment control terminal, which is electrically connected to the electromagnetic valve part and the greenhouse gas detector respectively. The equipment control terminal is used for recording and controlling the electromagnetic valve part in real time, and recording the measurement data of the greenhouse gas detector in real time.

[0011] The gas diversion pipe is a white nylon hose, and the diameter of the gas diversion pipe is 6*4 mm. A three-way valve is fixedly installed on the gas diversion pipe, and a gas check valve is sealed on the gas diversion pipe. The gas check valve is used to prevent gas from flowing back.

[0012] The electromagnetic valve part includes:

[0013] At least one group of electromagnetic valves. An air inlet and an air outlet are provided on the electromagnetic valve. Each group of the electromagnetic valves is respectively arranged corresponding to the sampling port, and the air inlet of the electromagnetic valve is fixedly connected to the gas diversion pipe;

[0014] A gas shunt, which is connected to the air outlet of the electromagnetic valve. A total air outlet end is provided on the gas shunt, and the total air outlet end is fixedly connected to the greenhouse gas detector.

[0015] The analysis interval of the greenhouse gas detector is 1 min, and the electromagnetic valve switch is switched once every 1 min.

[0016] On the other hand, the present invention also provides a method for monitoring methane emissions in an open cattle shed. The method for monitoring methane emissions in an open cattle shed includes:

[0017] S10, installing and arranging equipment for monitoring methane emissions in an open cattle shed;

[0018] S20, synchronously turning on the electromagnetic valve part and the greenhouse gas detector;

[0019] S30, setting the analysis interval of the greenhouse gas detector to 1 min; the electromagnetic valve switch is switched once every 1 min, and at the same time, recording the analysis time of the greenhouse gas detector and the switching time of the electromagnetic valve;

[0020] S40, the equipment control terminal records and controls the electromagnetic valve switch in real time, and records the measurement data of the greenhouse gas detector in real time;

[0021] S50. Program and integrate the obtained measurement data into the meteorological data outside the cowshed. When programming and integrating the obtained measurement data, compare the time data of the greenhouse gas detector with the time data of the solenoid valve unit, and determine the points where the time of the measurement data matches the valve opening time, as well as the methane data and carbon dioxide data measured at this point. The final data form is: time, sampling port number, and greenhouse gas measurement value;

[0022] S60. Load the meteorological data outside the cowshed and the cowshed-related data, and calculate the methane emission flux of the cowshed based on the meteorological data outside the cowshed and the cowshed-related data.

[0023] The method for installing and arranging the methane emission monitoring equipment for an open cowshed includes:

[0024] S101. Arrange a sampling port group in the cowshed, and distribute the sampling ports numbered 1 - 12 in the sampling port group;

[0025] S102. Connect a gas diversion pipe with a diameter of 6 * 4 mm to the rear end of each sampling port, add a gas check valve after the gas diversion pipe to prevent gas backflow, and connect a solenoid valve unit to the rear end of the gas diversion pipe;

[0026] S103. Connect the total outlet end of the gas splitter to the greenhouse gas detector, use data cables to connect the greenhouse gas detector and the solenoid valve to the equipment control terminal, set the sampling ports numbered 1 - 12 as three situations: inside the cowshed, outside the cowshed, and not in use according to the actual situation on site, and input the number of cows, average weight, average feeding amount, milk production, average air temperature, relative humidity, wind speed, and wind direction inside the cowshed into the equipment control terminal in advance.

[0027] The meteorological data outside the cowshed includes the number of dairy cows inside the cowshed, the number of non-dairy cows inside the cowshed, the average weight of dairy cows, the average weight of non-dairy cows, the average milk production of dairy cows, the average weight gain of non-dairy cows, the daily feeding amount of non-dairy cows, and the local average air temperature. The cowshed-related data includes the carbon dioxide concentration inside the cowshed, the carbon dioxide concentration outside the cowshed, the methane concentration inside the cowshed, and the methane concentration outside the cowshed.

[0028] The method for calculating the methane emission flux of the cowshed based on the meteorological data outside the cowshed and the cowshed-related data includes:

[0029] S601. Load the meteorological data outside the cowshed and the cowshed-related data, calculate the heat of lactating dairy cows and the heat of non-dairy cows respectively based on the meteorological data outside the cowshed and the cowshed-related data, and accumulate the heat of lactating dairy cows and the heat of non-dairy cows to obtain the total heat of the cowshed;

[0030] Among them, the heat of lactating dairy cows is calculated according to the following formula:

[0031] Φ dc= 5.6 × m + 22 × Y

[0032] Where Φ dc is the heat production (w) per lactating dairy cow, m is the average weight (kg) of the lactating dairy cow, and Y is the average milk production of the lactating dairy cow;

[0033] The heat of non-dairy cows is calculated according to the following formula:

[0034]

[0035] Where Φ b is the heat production (w) per non-dairy cow, m is the average body weight (kg) of the non-dairy cow, G is the average daily weight gain (kg·day -1 ), and D is the daily feeding amount (kg·day -1 of the non-dairy cow, in dry weight);

[0036] The total heat of the cowshed is:

[0037] Φ Total = n1 × Φ dc + n2 × Φ b

[0038] Where Φ Total is the total heat production (w) of the cowshed, n1 is the number of lactating dairy cows in the cowshed, Φ dc is the heat production per lactating dairy cow, n2 is the number of non-dairy cows in the cowshed, and Φ b is the heat production per non-dairy cow;

[0039] S602. Calculate the ventilation volume per unit heat based on the cowshed associated data;

[0040]

[0041] Where V PUH is the ventilation volume per unit heat (m 3 ·h -1 ·w -1 ), CO2 in is the carbon dioxide concentration (ppm) in the cowshed, and CO2 out is the carbon dioxide concentration (ppm) outside the cowshed;

[0042] S603. Calculate the temperature correction factor of heat based on the meteorological data outside the cowshed, and calculate it through the following formula:

[0043] CF = 1 + (20 - Ti) 3 × 4 × 10 -5

[0044] Where CF is the temperature correction factor and Ti is the average temperature (°C) within that hour;

[0045] S604. Load the total heat of the cowshed, the ventilation volume per unit heat, and the temperature correction factor, and calculate the ventilation volume of the cowshed based on the total heat of the cowshed, the ventilation volume per unit heat, and the temperature correction factor;

[0046] V = V PUH × Φ Total × CF

[0047] Where V is the ventilation volume (m 3 ·h -1 ), V PUH is the ventilation volume per unit heat, Φ Total is the total heat of the cowshed, and CF is the temperature correction factor;

[0048] S605. Load the ventilation volume of the cowshed and calculate the methane emission flux of the cowshed based on the ventilation volume of the cowshed;

[0049]

[0050] Where E CH4 is the methane emission flux of the cowshed (g·head· -1 ·h -1 ), CH4 in is the methane concentration (ppm) inside the cowshed, CH4 out is the methane concentration (ppm) outside the cowshed, V is the ventilation volume of the cowshed (m 3 ·h -1 ), and n1 and n2 are the number of milk-producing cows and the number of non-dairy cows in the cowshed, respectively.

[0051] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects:

[0052] In the embodiment of the present invention, a three-way valve is provided at the end of the sampling port. One end is connected to the gas splitter and then to the air pump. By collecting gas in real time, an air flow is formed in the gas guiding pipe, avoiding the lag of the gas concentration in the pipe caused by the too long pipeline. Thus, the gas concentration at the sampling port is kept consistent with that at the end of the gas guiding pipe, realizing the automatic calculation of the data at the sampling point and automatically exporting the methane emission flux of the cowshed. Thereby, the real-time intelligent monitoring of the methane emission flux of the open cowshed in large-scale dairy farms is realized. It overcomes the problem that the existing monitoring technology, the closed chamber method, can only measure the methane emissions of a small number of cows, and there is a lack of monitoring methods and equipment for the methane emission flux of large-scale dairy farms, especially the open cowshed under natural ventilation. Description of the Drawings

[0053] Figure 1It is a schematic structural diagram of a methane emission monitoring device for an open cattle shed provided by the present invention.

[0054] In the figure: 100 - sampling port group, 200 - gas diversion pipe, 210 - three - way valve, 220 - gas check valve, 300 - solenoid valve part, 310 - solenoid valve, 320 - air inlet, 330 - air outlet, 340 - gas splitter, 400 - greenhouse gas detector, 500 - device control terminal. Detailed implementation manners

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims, and drawings of this application are intended to cover non - exclusive inclusion. The terms "first", "second", etc. in the specification, claims, or drawings of this application are used to distinguish different objects and not to describe a specific order.

[0056] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0057] The existing monitoring technology, the closed chamber method, can only measure the methane emissions of a small number of cows. For large-scale dairy farms, especially for the monitoring methods and equipment of methane emission flux in open cow sheds under natural ventilation conditions, there is a lack. To address the above problems, we have proposed a monitoring device and method for methane emissions in open cow sheds. Briefly, the device consists of a sampling port group 100, a gas diversion pipe 200, a solenoid valve 310, a part 300, a greenhouse gas detector 400, and an equipment control terminal 500. A three-way valve 210 is fixedly installed on the gas diversion pipe 200. One end of the three-way valve 210 away from the gas diversion pipe 200 is fixedly connected to an air pump. A gas check valve 220 is sealed and installed on the gas diversion pipe 200, and the gas check valve 220 is used to prevent gas from flowing back. In the embodiment of the present invention, a three-way valve 210 is provided at the end of the sampling port. One end is connected to a gas splitter 340 and then to an air pump. By collecting gas in real time, an air flow is formed in the gas diversion pipe 200, avoiding the lag of gas concentration in the pipeline caused by too long a pipeline, so as to ensure that the gas concentration at the sampling port is consistent with that at the end of the gas diversion pipe 200, and realize automatic calculation of the data at the sampling point and automatic derivation of the methane emission flux of the cow shed. Thus, real-time intelligent monitoring of the methane emission flux of open cow sheds in large-scale dairy farms is achieved. It overcomes the problem that the existing closed chamber method in the existing monitoring technology can only measure the methane emissions of a small number of cows, and there is a lack of monitoring methods and equipment for the methane emission flux in large-scale dairy farms, especially in open cow sheds under natural ventilation conditions.

[0058] An embodiment of the present invention provides a monitoring device for methane emissions in an open cow shed. Figure 1 The structural schematic diagram of the monitoring device for methane emissions in an open cow shed is shown. The monitoring device for methane emissions in an open cow shed specifically includes:

[0059] A sampling port group 100 for injecting the gas to be monitored. The sampling port group 100 includes 12 sampling ports, and the sampling ports are numbered 1-12 respectively.

[0060] A gas diversion pipe 200 installed at the rear end of the sampling port for diverting the gas to be monitored. A three-way valve 210 is fixedly installed on the gas diversion pipe 200. One end of the three-way valve 210 away from the gas diversion pipe 200 is fixedly connected to an air pump. A gas check valve 220 is sealed and installed on the gas diversion pipe 200, and the gas check valve 220 is used to prevent gas from flowing back.

[0061] One air pump is provided at the end of the gas guide pipe 200 of the present invention, and is connected to the gas guide pipe 200 through a gas diverter 340 to keep a real-time air flow in the gas guide pipe 200, so as to make the gas concentrations at the sample inlet and the end of the gas guide pipe 200 consistent. Gas check valves 220 are added between the three-way valve 210 and the air pump, and between the three-way valve 210 and the solenoid valve 310 part 300 respectively to prevent gas backflow, thereby avoiding errors caused by gas backflow.

[0062] The solenoid valve 310 part 300, and the solenoid valve 310 part 300 is communicated with the gas guide pipe 200;

[0063] A greenhouse gas detector 400, which is fixedly connected to the solenoid valve 310 part 300. The gas detector is used for continuously measuring the concentrations of methane and carbon dioxide, and

[0064] An equipment control terminal 500, which is electrically connected to the solenoid valve 310 part 300 and the greenhouse gas detector 400 respectively. The equipment control terminal 500 is used for recording and controlling the solenoid valve 310 part 300 in real time, and recording the measurement data of the greenhouse gas detector 400 in real time.

[0065] In the embodiment of the present invention, by writing an automatic calculation program in the software of the equipment control terminal 500, multiple sample inlet data are automatically compared and calculated to realize the intelligent monitoring of methane flux, simplify the calculation process, and the equipment control terminal 500 can be a computer. The solenoid valve 310 of the solenoid valve 310 part 300 is switched in real time through computer software to realize the switching of the positions of the sample inlets, and the data of the sampling ports are determined by comparing the time with the greenhouse gas detector 400. And the methane emission flux of the cowshed is automatically exported.

[0066] In this embodiment, the gas guide pipe 200 is a white nylon hose, and the diameter of the gas guide pipe 200 is 6*4mm.

[0067] In the embodiment of the present invention, the solenoid valve 310 part 300 includes:

[0068] At least one group of solenoid valves 310. An air inlet 320 and an air outlet 330 are provided on the solenoid valve 310. Each group of the solenoid valves 310 corresponds to a sample inlet respectively. The air inlet 320 of the solenoid valve 310 is fixedly connected to the gas guide pipe 200;

[0069] It should be noted that the number of the solenoid valves 310 is 12, and the solenoid valves 310 are arranged in one-to-one correspondence with the sample inlets.

[0070] A gas diverter 340, which is connected to the gas outlet 330 of the solenoid valve 310. A total gas outlet end is provided on the gas diverter 340, and the total gas outlet end is fixedly connected to the greenhouse gas detector 400.

[0071] The analysis interval of the greenhouse gas detector 400 is 1 minute, and the solenoid valve 310 switches once every 1 minute.

[0072] In the embodiment of the present invention, a three-way valve 210 is provided at the end of the sampling port. One end is connected to the gas diverter 340 and also connected to the air pump. An air flow is formed in the gas guiding pipe 200 through real-time gas sampling, avoiding the lag of the gas concentration in the pipeline caused by the too long pipeline. Thus, the gas concentration at the sampling port is kept consistent with that at the end of the gas guiding pipe 200, realizing the automatic calculation of the data at the sampling point and automatically exporting the methane emission flux of the cowshed. Thereby, the real-time intelligent monitoring of the methane emission flux of the open cowshed in large-scale dairy farms is realized. It overcomes the problem that the existing monitoring technology, the closed chamber method, can only measure the methane emissions of a small number of cows, and there is a lack of monitoring methods and equipment for the methane emission flux of large-scale dairy farms, especially the open cowshed under natural ventilation conditions.

[0073] On the other hand, the embodiment of the present invention also provides a method for monitoring methane emissions from an open cowshed. The method for monitoring methane emissions from an open cowshed specifically includes:

[0074] S10, installing and arranging the equipment for monitoring methane emissions from an open cowshed;

[0075] S20, synchronously turning on the solenoid valve 310 and the greenhouse gas detector 400;

[0076] S30, setting the analysis interval of the greenhouse gas detector 400 to 1 minute; the solenoid valve 310 switches once every 1 minute, and at the same time, recording the analysis time of the greenhouse gas detector 400 and the switching time of the solenoid valve 310;

[0077] S40, the equipment control terminal 500 records and controls the switching of the solenoid valve 310 in real time, and records the measurement data of the greenhouse gas detector 400 in real time;

[0078] S50, programming and integrating the obtained measurement data into the meteorological data outside the cowshed. When programming and integrating the obtained measurement data, comparing the time data of the greenhouse gas detector 400 with the time data of the solenoid valve 310, determining the points where the measurement time matches the valve opening time and the methane data and carbon dioxide data measured at these points. The final data form is: time, sampling port number and greenhouse gas measurement value;

[0079] S60. Load the meteorological data outside the cowshed and the associated data of the cowshed, and calculate the methane emission flux of the cowshed based on the meteorological data outside the cowshed and the associated data of the cowshed.

[0080] In this embodiment, the method for installing and arranging the methane emission monitoring equipment for an open cowshed includes:

[0081] S101. Arrange the sampling port group 100 in the cowshed. The sampling port group 100 is distributed with sampling ports numbered 1 - 12.

[0082] S102. Connect a gas diversion pipe 200 with a diameter of 6 * 4 mm to the rear end of each sampling port. Add a gas check valve 220 after the gas diversion pipe 200 to prevent gas backflow, and connect the solenoid valve 310 to the rear end of the gas diversion pipe 200.

[0083] S103. Connect the total gas outlet end of the gas splitter 340 to the greenhouse gas detector 400. Connect the greenhouse gas detector 400 and the solenoid valve 310 to the equipment control terminal 500 using data lines. Set the sampling ports numbered 1 - 12 to three situations: inside the cowshed, outside the cowshed, and not in use according to the actual situation on site, and input the number of cows, average weight, average feeding amount, milk production, average air temperature, relative humidity, wind speed, and wind direction inside the cowshed into the equipment control terminal 500 in advance.

[0084] It should be noted that the meteorological data outside the cowshed includes the number of dairy cows inside the cowshed, the number of non - dairy cows inside the cowshed, the average weight of dairy cows, the average weight of non - dairy cows, the average milk production of dairy cows, the average weight gain of non - dairy cows, the daily feeding amount of non - dairy cows, and the local average temperature. The associated data of the cowshed includes the carbon dioxide concentration inside the cowshed, the carbon dioxide concentration outside the cowshed, the methane concentration inside the cowshed, and the methane concentration outside the cowshed.

[0085] The embodiment of the present invention provides a method for calculating the methane emission flux of a cowshed based on the meteorological data outside the cowshed and the associated data of the cowshed. The method for calculating the methane emission flux of a cowshed based on the meteorological data outside the cowshed and the associated data of the cowshed specifically includes:

[0086] S601. Load the meteorological data outside the cowshed and the associated data of the cowshed, calculate the heat of lactating cows and non - dairy cows respectively based on the meteorological data outside the cowshed and the associated data of the cowshed, and accumulate the heat of lactating cows and non - dairy cows to obtain the total heat of the cowshed.

[0087] Among them, the heat of lactating cows is calculated according to the following formula:

[0088] Φ dc = 5.6×m + 22×Y

[0089] In the formula, Φ dcwhere \(w\) is the heat production of each lactating dairy cow (W), \(m\) is the average weight of the lactating dairy cow (kg), and \(Y\) is the average milk production of the lactating dairy cow;

[0090] The heat of non - dairy cows is calculated according to the following formula:

[0091]

[0092] where \(\varPhi\) b is the heat production of each non - dairy cow (W), \(m\) is the average body weight of the non - dairy cow (kg), \(G\) is the average daily weight gain of the non - dairy cow (kg·day -1 ), and \(D\) is the daily feeding amount of the non - dairy cow (kg·day -1 , in dry weight);

[0093] The total heat of the cowshed is:

[0094] \(\varPhi\) Total = \(n_1\times\varPhi\) dc +\(n_2\times\varPhi\) b

[0095] where \(\varPhi\) Total is the total heat production of the cowshed (W), \(n_1\) is the number of lactating dairy cows in the cowshed, \(\varPhi\) dc is the heat production of each lactating dairy cow, \(n_2\) is the number of non - dairy cows in the cowshed, and \(\varPhi\) b is the heat production of each non - dairy cow;

[0096] S602. Calculate the ventilation volume per unit heat based on the cowshed - related data;

[0097]

[0098] where \(V\) PUH is the ventilation volume per unit heat (\(m\) 3 ·h -1 ·W -1 ), \(CO_2\) in is the carbon dioxide concentration in the cowshed (ppm), and \(CO_2\) out is the carbon dioxide concentration outside the cowshed (ppm);

[0099] S603. Calculate the temperature correction factor of heat based on the meteorological data outside the cowshed, which is calculated by the following formula:

[0100] \(CF = 1+(20 - T_i)\) 3 ×4×10 -5

[0101] where \(CF\) is the temperature correction factor and \(T_i\) is the average air temperature in that hour (°C);

[0102] S604. Load the total heat of the cowshed, the ventilation volume per unit heat, and the temperature correction factor, and calculate the ventilation volume of the cowshed based on the total heat of the cowshed, the ventilation volume per unit heat, and the temperature correction factor;

[0103] V = V PUH × Φ Total × CF

[0104] In the formula, V is the ventilation volume (m 3 ·h -1 ), V PUH is the ventilation volume per unit heat, Φ Total is the total heat of the cowshed, and CF is the temperature correction factor;

[0105] S605. Load the ventilation volume of the cowshed, and calculate the methane emission flux of the cowshed based on the ventilation volume of the cowshed;

[0106]

[0107] In the formula, E CH4 is the methane emission flux of the cowshed (g·head· -1 ·h -1 ), CH4 in is the methane concentration in the cowshed (ppm), CH4 out is the methane concentration outside the cowshed (ppm), V is the ventilation volume of the cowshed (m 3 ·h -1 ), and n1 and n2 are the number of milk-producing cows and the number of non-dairy cows in the cowshed, respectively.

[0108] In summary, the present invention provides a device and a monitoring method for monitoring methane emissions from an open cowshed. In the embodiment of the present invention, a three-way valve 210 is arranged at the end of the sampling port, one end is connected to the gas splitter 340 and then connected to the air pump, and an air flow is formed in the gas guide pipe 200 through real-time gas sampling, avoiding the lag of the gas concentration in the pipeline caused by too long pipeline, so as to achieve the consistency of the gas concentration between the sampling port and the end of the gas guide pipe 200, and realize the automatic calculation of the data at the sampling point and the automatic export of the methane emission flux of the cowshed. Thus, the real-time intelligent monitoring of the methane emission flux of the open cowshed in a large-scale dairy farm is realized. It overcomes the problem that the existing monitoring technology, the closed chamber method, can only measure the methane emissions of a small number of cows, and there is a lack of monitoring methods and equipment for the methane emission flux of large-scale dairy farms, especially for open cowsheds under natural ventilation conditions.

[0109] It should be noted that, for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0110] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict, make combinations, additions, deletions, or other adjustments to the features in the embodiments of the present invention according to the situation without creative efforts, so as to obtain different technical solutions that essentially do not deviate from the concept of the present invention, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. An open cowshed methane emission monitoring device, characterized in that, The methane emission monitoring device for an open cattle shed includes: A sample inlet group for injecting the gas to be monitored. The sample inlet group includes 12 sample inlets. A gas diversion pipe installed at the rear end of the sample inlet for diverting the gas to be monitored. A three-way valve is fixedly installed on the gas diversion pipe. One end of the three-way valve away from the gas diversion pipe is fixedly connected to a gas pump. A gas check valve is hermetically installed on the gas diversion pipe to prevent gas from flowing back. An electromagnetic valve part, which is in communication with the gas diversion pipe. A greenhouse gas detector fixedly connected to the electromagnetic valve part. The gas detector is used for continuously measuring the concentrations of methane and carbon dioxide, and An equipment control terminal electrically connected to the electromagnetic valve part and the greenhouse gas detector respectively. The equipment control terminal is used for recording and controlling the electromagnetic valve part in real time and recording the measurement data of the greenhouse gas detector in real time.

2. The methane emission monitoring device for an open cattle shed according to claim 1, wherein: The gas diversion pipe is a white nylon hose.

3. The methane emission monitoring device for an open cattle shed according to claim 2, characterized in that: The diameter of the gas diversion pipe is 6*4 mm.

4. The methane emission monitoring device for an open cattle shed according to claim 1, characterized in that: The electromagnetic valve part includes: At least one group of electromagnetic valves. An air inlet and an air outlet are provided on the electromagnetic valve. Each group of the electromagnetic valves is arranged corresponding to the sample inlet. The air inlet of the electromagnetic valve is fixedly connected to the gas diversion pipe. A gas splitter connected to the air outlet of the electromagnetic valve. A total air outlet end is provided on the gas splitter and is fixedly connected to the greenhouse gas detector.

5. The methane emission monitoring device for an open cattle shed according to claim 4, characterized in that: The analysis interval of the greenhouse gas detector is 1 min, and the electromagnetic valve switch is switched once every 1 min.

6. A method for monitoring methane emissions from open cattle barns, which is implemented using the monitoring device for methane emissions from open cattle barns as described in any one of claims 1-5, characterized in that: The method for monitoring methane emissions in an open cattle shed includes: S10, Install and arrange the methane emission monitoring device for an open cattle shed. S20, Synchronously turn on the electromagnetic valve part and the greenhouse gas detector. S30, Set the analysis interval of the greenhouse gas detector to 1 min; the electromagnetic valve switch is switched once every 1 min. At the same time, record the analysis time of the greenhouse gas detector and the switching time of the electromagnetic valve. S40, The equipment control terminal records and controls the electromagnetic valve switch in real time and records the measurement data of the greenhouse gas detector in real time. S50, Program and integrate the obtained measurement data into the meteorological data outside the cattle shed. When programming and integrating the obtained measurement data, compare the time data of the greenhouse gas detector with the time data of the electromagnetic valve part, and determine the point where the time of the measured data matches the valve opening time and the methane data and carbon dioxide data measured at this point. The final data form is: time, sample inlet number and greenhouse gas measurement value. S60, Load the meteorological data outside the cattle shed and the associated data of the cattle shed, and calculate the methane emission flux of the cattle shed based on the meteorological data outside the cattle shed and the associated data of the cattle shed.

7. The methane emission monitoring method for an open cattle shed according to claim 6, wherein: The method for installing and arranging the methane emission monitoring device for an open cattle shed includes: S101, Arrange the sample inlet group in the cattle shed, and the sample inlets are distributed and numbered from 1 to 12. S102, Connect a gas diversion pipe with a diameter of 6*4 mm to the rear end of each sample inlet. Add a gas check valve to the gas diversion pipe to prevent gas from flowing back, and connect the electromagnetic valve part to the rear end of the gas diversion pipe. In S103, the total gas outlet of the gas diverter is connected to the greenhouse gas detector. The greenhouse gas detector and the solenoid valve are connected to the equipment control terminal by data lines. The sampling ports numbered 1 - 12 are set to three situations: inside the cowshed, outside the cowshed, and not in use according to the actual on-site situation. The number of cows inside the cowshed, average weight, average feeding amount, milk production, average air temperature, relative humidity, wind speed, and wind direction are input into the equipment control terminal in advance.

8. The method for monitoring methane emissions in an open cattle shed according to claim 7, characterized in that: The meteorological data outside the cowshed includes the number of dairy cows inside the cowshed, the number of non-dairy cows inside the cowshed, the average weight of dairy cows, the average weight of non-dairy cows, the average milk production of dairy cows, the average weight gain of non-dairy cows, the daily feeding amount of non-dairy cows, and the local average temperature. The cow-shed related data includes the carbon dioxide concentration inside the cowshed, the carbon dioxide concentration outside the cowshed, the methane concentration inside the cowshed, and the methane concentration outside the cowshed.

9. The methane emission monitoring method for an open cattle shed according to claim 8, characterized in that: The method for calculating the methane emission flux of the cowshed based on the meteorological data outside the cowshed and the cow-shed related data includes: S601, load the meteorological data outside the cowshed and the cow-shed related data, calculate the heat of milk-producing cows and the heat of non-dairy cows respectively based on the meteorological data outside the cowshed and the cow-shed related data, and accumulate the heat of milk-producing cows and the heat of non-dairy cows to obtain the total heat of the cowshed; Among them, the heat of milk-producing cows is calculated according to the following formula: Φ dc = 5.6 × m + 22 × Y where Φ dc is the heat production of each milk-producing cow, m is the average weight of milk-producing cows, and Y is the average milk production of milk-producing cows; The heat of non-dairy cows is calculated according to the following formula: where Φ b is the heat production per non - dairy cow, m is the average body weight of non - dairy cows, G is the average daily weight gain of non - dairy cows, and D is the daily feeding amount of non - dairy cows; The total heat of the cowshed is: Φ Total = n1 × Φ dc + n2 × Φ b Where Φ Total is the total heat generation of the cowshed, n1 is the number of milk-producing cows in the cowshed, and Φ dc is the heat generation per milk-producing cow, n2 is the number of non-cows in the cowshed, and Φ b is the heat generation per non-cow; S602, calculate the ventilation volume per unit heat based on the cow-shed related data; where V PUH is the ventilation rate per unit heat, and CO2 in is the carbon dioxide concentration inside the cattle shed, and CO2 out is the carbon dioxide concentration outside the cattle shed; S603, calculate the temperature correction factor of the heat based on the meteorological data outside the cowshed, and calculate it through the following formula: CF = 1 + (20 - Ti) 3 × 4 × 10 -5 In the formula, CF is the temperature correction factor, and Ti is the average air temperature within that hour; S604, load the total heat of the cowshed, the ventilation volume per unit heat, and the temperature correction factor, and calculate the ventilation volume of the cowshed based on the total heat of the cowshed, the ventilation volume per unit heat, and the temperature correction factor; V = V PUH × Φ Total × CF where V is the ventilation volume, and V PUH is the ventilation volume per unit heat, and Φ Total is the total heat of the cattle shed, and CF is the temperature correction factor; S605, load the ventilation volume of the cowshed, and calculate the methane emission flux of the cowshed based on the ventilation volume of the cowshed; where E CH4 is the methane emission flux of the cowshed, CH4 in is the methane concentration inside the cowshed, CH4 out is the methane concentration outside the cowshed, V is the ventilation rate of the cowshed, and n1 and n2 are the numbers of milk-producing cows and non-milk-producing cows in the cowshed, respectively.

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