Photoacoustic spectrum greenhouse gas monitoring device and system for reducing methane emission in paddy field

Abstract

The utility model relates to the technical field of gas monitoring technology, in particular to a photoacoustic spectrum greenhouse gas monitoring device and system for paddy field methane emission reduction, which comprises a heat insulation outer cylinder, the lower end of the heat insulation outer cylinder is opened outwards to form an isolation cover, and a gap is reserved between a flow guide inner cylinder and the heat insulation outer cylinder; a gas collecting pipe is arranged on the monitor, and one end of the gas collecting pipe is bent downwards and located at the circle center of the heat insulation outer cylinder; the device has the beneficial effects that the heat insulation outer barrel is installed above the rice field soil, the flow guide inner barrel concentric with the heat insulation outer barrel is sleeved with the heat insulation outer barrel, and when the fan rotates, gas around the heat insulation outer barrel is driven to flow upwards, so that weak negative pressure is formed in an inner cavity in the upper end of the flow guide inner barrel, and then gas in an inner cavity of the flow guide inner barrel is driven to flow slowly from bottom to top; the flow velocity of gas in the inner cavity of the flow guide inner cylinder is slow, gas is stable, and the monitoring result is closer to the actual greenhouse gas content in the rice field.

Description

TECHNICAL FIELD

[0001] The utility model relates to gas monitoring technical field, concretely is a kind of methane emission reduction for rice field photoacoustic spectroscopy greenhouse gas monitoring device and system. BACKGROUND

[0002] Photoacoustic spectroscopy is the technology for studying the absorption spectrum of matter, which detects mechanical waves generated due to the absorption of light energy by tissues. The strength of such mechanical waves directly reflects the amount of light energy absorbed by the matter. When monitoring using photoacoustic spectroscopy, a collection device is needed to collect greenhouse gases such as methane in the rice field.

[0003] In the prior art, a rice field greenhouse gas collection device is disclosed in Chinese Utility Model No. CN212621761U. The device collects greenhouse gases in the box using a syringe and transfers them into a collection bottle.

[0004] However, when manually operating the syringe to transfer sample gas into the collection bottle, it is difficult to control the gas pressure inside the syringe and the collection bottle. Moreover, due to the repeated extraction of the syringe, the gas around the collection device flows unevenly, resulting in a difference between the actual content of greenhouse gases in the rice field and the content of greenhouse gases in the collected sample gas, which affects the accuracy of the monitoring results. Therefore, the utility model provides a photoacoustic spectroscopy greenhouse gas monitoring device and system for methane emission reduction in rice fields to solve the above problems. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide a photoacoustic spectroscopy greenhouse gas monitoring device and system for methane emission reduction in rice fields to solve the problems raised in the background.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: a photoacoustic spectroscopy greenhouse gas monitoring device for methane emission reduction in rice fields, comprising:

[0007] A heat-insulating outer cylinder, the lower end of the heat-insulating outer cylinder is outwardly flared to form an isolation cover, the inner cavity of the heat-insulating outer cylinder is provided with a flow guide inner cylinder concentric therewith, the lower end of the flow guide inner cylinder is outwardly flared to form a collection cover, a gap is left between the flow guide inner cylinder and the heat-insulating outer cylinder, and the gap is filled with heat-insulating cotton;

[0008] A monitor, the monitor is installed on the outer side of the heat-insulating outer cylinder, a gas collection tube is provided on the monitor, one end of the gas collection tube successively penetrates the heat-insulating outer cylinder and the flow guide inner cylinder and extends to the lower end of the inner cavity of the flow guide inner cylinder, and the one end of the gas collection tube is bent downward and located at the center of the heat-insulating outer cylinder;

[0009] A fan, the fan is rotatably installed on the outer side of the heat-insulating outer cylinder.

[0010] Preferably, the surface of the heat insulation outer cylinder is inwardly recessed in the middle to form an annular groove, the fan comprises concentrically arranged outer ring and inner ring, and the inclined fan blade is arranged between the outer ring and the inner ring, the inner ring is rotationally installed in the inner cavity of the annular groove, and the inner wall of the inner ring is movably embedded with rolling bodies.

[0011] Preferably, the surface of the outer ring is provided with an annular tooth groove, the outer side of the outer ring is provided with a driving gear engaged with the annular tooth groove, and the driving gear is driven to rotate by the motor installed on the surface of the heat insulation outer cylinder.

[0012] Preferably, a connecting frame is fixedly arranged between the heat insulation outer cylinder and the flow guide inner cylinder, a closing cover is fixedly installed on the upper portion of the inner cavity of the flow guide inner cylinder, and the closing cover is in a hollow horn shape and has a smaller upper diameter than lower diameter.

[0013] Preferably, a support is fixedly installed at the lower end of the heat insulation outer cylinder, the lower end of the support is inserted into the ground, and a base plate is fixedly installed at the middle portion of the support.

[0014] Preferably, the top portions of the heat insulation outer cylinder and the flow guide inner cylinder are flush, a plurality of annularly arranged notch grooves are formed in the upper ends of the heat insulation outer cylinder and the flow guide inner cylinder, and the notch grooves on the heat insulation outer cylinder and the flow guide inner cylinder are staggered.

[0015] A photoacoustic spectroscopy greenhouse gas monitoring system for methane emission reduction in a rice field comprises the monitoring device.

[0016] Compared with the prior art, the utility model has the advantages that:

[0017] The heat insulation outer cylinder is installed above the soil in the rice field, the heat insulation outer cylinder is sleeved with the flow guide inner cylinder concentrically, the end portion of the gas collecting pipe penetrates the heat insulation outer cylinder and the flow guide inner cylinder in sequence and extends into the lower portion of the inner cavity of the flow guide inner cylinder, the gas in the inner cavity of the flow guide inner cylinder can be sent into the monitor for monitoring, the fan is rotationally installed on the outer side of the heat insulation outer cylinder, the fan is driven to rotate by the motor, the gas around the heat insulation outer cylinder flows upward when the fan rotates, a weak negative pressure is formed in the inner cavity of the upper end of the flow guide inner cylinder, and the gas in the inner cavity of the flow guide inner cylinder flows slowly from bottom to top, so that the monitor can continuously monitor the surrounding greenhouse gas through the gas collecting pipe, the gas flows slowly in the inner cavity of the flow guide inner cylinder, the gas is relatively stable, and the monitoring result is more close to the actual greenhouse gas content in the rice field. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a whole structure perspective view of the utility model;

[0019] Figure 2 It is a fan structure perspective view of the utility model;

[0020] Figure 3It is the three-dimensional schematic view of the internal structure of the heat insulation outer cylinder and the flow guide inner cylinder.

[0021] Figure 4 It is the schematic view of the overall structure section.

[0022] In the figure: 1, heat insulation outer cylinder; 11, isolation cover; 12, annular groove; 13, connecting frame; 14, heat insulation cotton; 2, flow guide inner cylinder; 21, collection cover; 22, closing cover; 3, fan; 31, outer ring; 32, inner ring; 33, rolling body; 4, monitor; 41, gas collection pipe; 5, support; 51, pad; 6, driving gear. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme of the utility model carry out clearly, completely describe, and the advantage is more clear and clear, the following combining the drawing carries out further detailed explanation to the utility model embodiment. It should be understood that the specific embodiments described here are part of the embodiments of the utility model, not all embodiments, only to explain the embodiments of the utility model, and not for limiting the embodiments of the utility model, all other embodiments obtained by the ordinary skill in the art without creative labor are within the scope of the utility model protection.

[0024] Embodiment one, please refer to Figures 1-4 The utility model provides a kind of technical scheme: a kind of methane emission reduction of paddy field photoacoustic spectroscopy greenhouse gas monitoring device, monitoring device includes: heat insulation outer cylinder 1, monitor 4 and fan 3.

[0025] Specifically, the lower end of the heat insulation outer cylinder 1 is outwardly flared to form an isolation cover 11, and the inner cavity of the heat insulation outer cylinder 1 is provided with a flow guide inner cylinder 2 concentric therewith, and the lower end of the flow guide inner cylinder 2 is outwardly flared to form a collection cover 21, as shown in Figure 3 And Figure 4 As shown, the angle of outward bending and flaring of the isolation cover 11 is greater than the angle of outward bending and flaring of the annular groove 12, and the horizontal distance between the isolation cover 11 and the collection cover 21 gradually increases from top to bottom, when the gas outside the heat insulation outer cylinder 1 keeps flowing fast, the isolation cover 11 and the annular groove 12 can separate the gas in the inner cavity of the flow guide inner cylinder 2, so that the gas in the inner cavity of the flow guide inner cylinder 2 can keep relatively stable, there is a gap between the flow guide inner cylinder 2 and the heat insulation outer cylinder 1, and the gap is filled with heat insulation cotton 14, which has the effect of heat insulation, avoiding the internal gas temperature of the heat insulation outer cylinder 1 rising rapidly due to direct sunlight, and further avoiding the greenhouse gas content in the gas in the inner cavity of the flow guide inner cylinder 2 changing significantly due to temperature influence;

[0026] Secondly, the monitor 4 is installed on the outside of the heat insulation outer cylinder 1, the monitor 4 is internally provided with a photoacoustic spectroscopy gas sensor known in the prior art (such as the photoacoustic spectroscopy gas sensor and its preparation method disclosed in publication No. CN117871422B), and the monitor 4 is provided with a gas collecting pipe 41, one end of the gas collecting pipe 41 penetrates the heat insulation outer cylinder 1 and the flow guide inner cylinder 2 in sequence and extends to the lower end of the inner cavity of the flow guide inner cylinder 2, the one end of the gas collecting pipe 41 is bent downward and located at the center of the heat insulation outer cylinder 1, and the gas collecting pipe 41 is used for sending the gas to be monitored into the inner cavity of the monitor 4 for monitoring, since the gas in the inner cavity of the flow guide inner cylinder 2 is relatively stable and is less affected by temperature, the monitor 4 can continuously monitor the greenhouse gas in the gas in the inner cavity of the flow guide inner cylinder 2 through the gas collecting pipe 41, and more accurate results can be obtained, and the results are more in line with the actual situation of the rice field;

[0027] In addition, the fan 3 is rotatably installed on the outside of the heat insulation outer cylinder 1, as shown in Figure 1 and Figure 4 , the fan 3 can drive the gas around the heat insulation outer cylinder 1 to flow upward when rotating, and a weak negative pressure is formed at the upper end opening of the flow guide inner cylinder 2, so that the gas in the inner cavity of the flow guide inner cylinder 2 can slowly flow from bottom to top, and then the gas at the bottom of the rice field can be collected into the inner cavity of the flow guide inner cylinder 2 in cooperation with the outwardly flared collecting cover 21, and the gas can continuously and slowly flow, since the gas in the inner cavity of the flow guide inner cylinder 2 only flows under the action of negative pressure and is not disturbed by the rotation of the fan 3, the gas in the inner cavity of the flow guide inner cylinder 2 can still remain relatively stable, and the monitoring result of the monitor 4 is not affected by the turbulent airflow.

[0028] In order to install and position the fan 3, the present application also has a ring-shaped groove 12 formed by inwardly recessing the middle part of the surface of the heat insulation outer cylinder 1, the fan 3 includes an outer ring 31 and an inner ring 32 arranged concentrically, and an inclined fan blade is arranged between the outer ring 31 and the inner ring 32, the inner ring 32 is rotatably installed in the inner cavity of the ring-shaped groove 12, and a rolling body 33 is movably embedded in the inner wall of the inner ring 32, as shown in Figure 2 and Figure 3 , the fan 3 can be stably installed in the middle part of the outside of the heat insulation outer cylinder 1 and only rotate, and the inclined fan blade on the fan 3 can drive the gas around the heat insulation outer cylinder 1 to flow upward when rotating.

[0029] In order to drive the fan 3 to rotate, the present application also has a ring-shaped tooth groove formed on the surface of the outer ring 31, a driving gear 6 engaged with the ring-shaped tooth groove is arranged on the outside of the outer ring 31, and the driving gear 6 is driven to rotate by a motor installed on the surface of the heat insulation outer cylinder 1, as shown in Figure 1 , the motor can drive the fan 3 to rotate through the mutual engagement of the driving gear 6 and the ring-shaped tooth groove when the motor is working, so as to adjust the flow rate of the gas around the heat insulation outer cylinder 1 according to the rotating speed of the motor.

[0030] In order to control the gas flow rate in the inner cavity of the flow guide inner cylinder 2, the application also has a connecting frame 13 fixedly arranged between the heat insulation outer cylinder 1 and the flow guide inner cylinder 2, which is used to keep the flow guide inner cylinder 2 and the heat insulation outer cylinder 1 relatively fixed, and a closing cover 22 is fixedly installed on the upper part of the inner cavity of the flow guide inner cylinder 2, which is a hollow horn shape and the upper diameter is smaller than the lower diameter, as shown in Figure 3 and Figure 4 The setting of the closing cover 22 can close the middle part of the flow guide inner cylinder 2, and the lower half of the flow guide inner cylinder 2 presents a trend of gradually decreasing inner diameter from bottom to top. Under the premise of consistent gas flow, the place with larger inner diameter has slower gas flow rate, so the gas flow rate in the inner cavity of the lower end of the flow guide inner cylinder 2 is the slowest and the gas is the most stable, which is most suitable for monitoring the greenhouse gas content.

[0031] In order to install and position the device, the application also has a support 5 fixedly installed at the lower end of the heat insulation outer cylinder 1, the lower end of the support 5 is inserted into the ground, a base plate 51 is fixedly installed in the middle part of the support 5, and the support 5 is inserted into the bottom of the paddy field, which is used to fix the whole device, and the base plate 51 is pressed into the ground, which is used to increase the contact area between the support 5 and the ground, so as to avoid the whole device from moving downward under the action of gravity. Therefore, the heat insulation outer cylinder 1 and the flow guide inner cylinder 2 of the device can be kept floating above the paddy field, and the greenhouse gas generated at the bottom of the paddy field can be collected into the inner cavity of the flow guide inner cylinder 2 from the lower end opening of the flow guide inner cylinder 2, and then transported by the gas collection pipe 41 and monitored by the monitoring instrument 4.

[0032] In order to slow down the gas flow rate around the upper end of the flow guide inner cylinder 2, the top of the heat insulation outer cylinder 1 and the flow guide inner cylinder 2 is flush, and a plurality of annularly arrayed notch grooves are formed in the upper end of the heat insulation outer cylinder 1 and the flow guide inner cylinder 2, as shown in Figure 3 The gas in the upper part of the inner cavity of the flow guide inner cylinder 2 can flow horizontally and outward along the notch grooves, and since the notch grooves on the heat insulation outer cylinder 1 and the flow guide inner cylinder 2 are staggered, the gas flow rate can be slowed down, so as to avoid the vortex and turbulent flow caused by excessive gas flow rate around the upper end of the flow guide inner cylinder 2.

[0033] A photoacoustic spectroscopy greenhouse gas monitoring system for reducing methane emission in a paddy field, comprising the monitoring device.

[0034] Although the embodiments of the present application have been shown and described, it should be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A photoacoustic spectroscopy greenhouse gas monitoring device for methane emission reduction in a rice field, characterized by: The monitoring device comprises: A heat-insulating outer cylinder (1) whose lower end is outwardly flared to form a shielding cover (11), and whose inner cavity is provided with a flow guide inner cylinder (2) concentric therewith, the lower end of the flow guide inner cylinder (2) being outwardly flared to form a collecting cover (21), and a gap being left between the flow guide inner cylinder (2) and the heat-insulating outer cylinder (1) and filled with heat-insulating cotton (14); A monitor (4) installed on the outside of the heat-insulating outer cylinder (1), and provided with a gas collecting pipe (41) on the monitor (4), one end of the gas collecting pipe (41) penetrating the heat-insulating outer cylinder (1) and the flow guide inner cylinder (2) in sequence and extending to the lower end of the inner cavity of the flow guide inner cylinder (2), and the one end of the gas collecting pipe (41) being downwardly bent and located at the center of the heat-insulating outer cylinder (1); A fan (3) rotatably installed on the outside of the heat-insulating outer cylinder (1). 2.The photoacoustic spectroscopy greenhouse gas monitoring device for methane emission reduction in a rice field according to claim 1, characterized in that: The surface of the heat-insulating outer cylinder (1) is inwardly recessed in the middle to form an annular recess (12), the fan (3) comprises an outer ring (31) and an inner ring (32) arranged concentrically and provided with inclined fan blades therebetween, and the inner ring (32) is rotatably installed in the inner cavity of the annular recess (12) and has rolling bodies (33) movably embedded in the inner wall of the inner ring (32). 3.The photoacoustic spectroscopy greenhouse gas monitoring device for methane emission reduction in a rice field according to claim 2, characterized in that: The surface of the outer ring (31) is provided with an annular tooth groove, the outside of the outer ring (31) is provided with a driving gear (6) engaged with the annular tooth groove, and the driving gear (6) is driven to rotate by a motor installed on the surface of the heat-insulating outer cylinder (1). 4.The photoacoustic spectroscopy greenhouse gas monitoring device for methane emission reduction in a rice field according to claim 1, characterized in that: A connecting frame (13) is fixedly arranged between the heat-insulating outer cylinder (1) and the flow guide inner cylinder (2), a closing cover (22) is fixedly installed on the upper part of the inner cavity of the flow guide inner cylinder (2), and the closing cover (22) is hollow and trumpet-shaped and has a smaller diameter at the upper part than at the lower part. 5.The photoacoustic spectroscopy greenhouse gas monitoring device for methane emission reduction in a rice field according to claim 1, characterized in that: A support (5) is fixedly installed on the lower end of the heat-insulating outer cylinder (1), the lower end of the support (5) is inserted into the ground, and a pad (51) is fixedly installed on the middle part of the support (5). 6.The photoacoustic spectroscopy greenhouse gas monitoring device for methane emission reduction in a rice field according to claim 1, characterized in that: The top parts of the heat-insulating outer cylinder (1) and the flow guide inner cylinder (2) are flush, and the upper ends of the heat-insulating outer cylinder (1) and the flow guide inner cylinder (2) are each provided with a plurality of annularly arrayed notch grooves, and the notch grooves on the heat-insulating outer cylinder (1) and the flow guide inner cylinder (2) are mutually staggered.

7. A photoacoustic spectroscopy greenhouse gas monitoring system for methane emission reduction in a rice field, characterized by: The monitoring device comprises the device according to any one of claims 1-6.

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