阅读说明：本技术 用于在线监测的气体稀释装置及方法 (Gas dilution device and method for online monitoring ) 是由 孙晓英 姜素霞 肖安山 王化吉 葛涛 魏新明 于 2019-11-06 设计创作，主要内容包括：本发明公开了一种用于在线监测的气体稀释装置,其包括：取样管线,其一端与取样口相连接,另一端与采样泵相连接；一级稀释管路,其连接在靠近取样口的取样管线上；二级稀释管路,其连接在靠近采样泵的取样管线上；以及监测仪,其连接在采样泵的下游。其中,采样泵将待测气体和稀释气体抽吸至取样管线,并泵送至监测仪进行检测。本发明还公开了一种用于在线监测的气体稀释方法。本发明通过采样泵抽吸待测气体和稀释气体、在取样管线的不同位置设置两级稀释管路,能够满足不同稀释比例要求,并且省去了现有技术中正压式的气源,如空气压缩机、压缩空气罐等装置,本发明用于在线监测的稀释装置结构简单、体积较小。(The invention discloses a gas diluting device for on-line monitoring, which comprises: one end of the sampling pipeline is connected with the sampling port, and the other end of the sampling pipeline is connected with the sampling pump; the primary dilution pipeline is connected to a sampling pipeline close to the sampling port; the second-stage dilution pipeline is connected to a sampling pipeline close to the sampling pump; and a monitor connected downstream of the sampling pump. Wherein, the sampling pump pumps the gas to be measured and the diluent gas to the sampling pipeline and pumps to the monitor for detection. The invention also discloses a gas dilution method for online monitoring. The invention sucks gas to be detected and diluent gas through the sampling pump, and two stages of dilution pipelines are arranged at different positions of the sampling pipeline, so that the requirements of different dilution ratios can be met, and positive pressure gas sources in the prior art, such as an air compressor, a compressed air tank and the like, are saved.)

1. A gas dilution apparatus for on-line monitoring, comprising:

one end of the sampling pipeline is connected with the sampling port, and the other end of the sampling pipeline is connected with the sampling pump;

a primary dilution line connected to the sampling line adjacent to the sampling port;

a secondary dilution line connected to the sampling line adjacent to the sampling pump; and

a monitor connected downstream of the sampling pump,

the sampling pump pumps gas to be detected and diluent gas to the sampling pipeline and pumps the gas to be detected and the diluent gas to the monitor for detection.

2. The gas dilution device for online monitoring according to claim 1, wherein the primary dilution pipe is connected at 1/3-1/2 of the sampling line; the secondary dilution pipeline is connected at 1/2-2/3 of the sampling pipeline.

3. The gas dilution device for online monitoring of claim 1, wherein the diameter of the primary dilution line and the secondary dilution line is 1/2-2/3 of the diameter of the sampling line.

4. The gas dilution device for online monitoring according to claim 1, wherein a first regulating valve and a first flow meter are disposed on the primary dilution line, a second regulating valve and a second flow meter are disposed on the secondary dilution line, and a third flow meter is disposed on the sampling line and is located downstream of the secondary dilution line.

5. The gas dilution device for online monitoring according to claim 4, wherein a first check valve is disposed on the primary dilution pipeline, and a second check valve is disposed on the secondary dilution pipeline.

6. The gas dilution apparatus for online monitoring of claim 4, further comprising:

the wireless handheld terminal can acquire flow signals of the first flowmeter, the second flowmeter and the third flowmeter and control the first regulating valve and the second regulating valve according to a preset dilution ratio.

7. The gas dilution apparatus for online monitoring of claim 1, wherein the dilution gas is filtered ambient air.

8. A gas dilution method for on-line monitoring, which is characterized by adopting the gas dilution device for on-line monitoring as claimed in any one of claims 1 to 7, and the method at least comprises the following steps:

setting a preset dilution ratio;

when the preset dilution ratio is less than 1:3, opening the primary dilution pipeline and closing the secondary dilution pipeline;

when the preset dilution ratio is greater than or equal to 1:3 and less than 1:6, closing the primary dilution pipeline and opening the secondary dilution pipeline; and

and when the preset dilution ratio is greater than or equal to 1:6 and less than 1:9, simultaneously opening the primary dilution pipeline and the secondary dilution pipeline.

9. The gas dilution method for on-line monitoring of claim 8, further comprising the step of calculating an actual dilution ratio, the actual dilution ratio being (Q-Q)₁-Q₂) Q, wherein Q₁Is the flow rate, Q, of the primary dilution line₂And Q is the flow of the secondary dilution pipeline, and is the total flow of the sampling pipeline.

10. The gas dilution method for on-line monitoring of claim 9, further comprising adjusting the actual dilution ratio according to the preset dilution ratio, wherein adjusting the actual dilution ratio is achieved by adjusting the flow rate of the primary dilution line and/or the secondary dilution line.

11. The gas dilution method for on-line monitoring according to claim 8, further comprising the steps of:

when the concentration value detected by the monitor exceeds the measuring range of the monitor, resetting the preset dilution ratio or sending an alarm signal.

Technical Field

The invention relates to the field of petrochemical industry field monitoring, in particular to a gas diluting device and a gas diluting method for online monitoring.

Background

H volatilized by petrochemical equipment such as oil well and storage tank₂The gas concentration of S and VOCs is high, the concentration range of the S and VOCs often exceeds the upper limit of the existing on-site detection equipment, and the S and VOCs are not beneficial to long-period monitoring on site. In order to realize long-period monitoring of on-site gas, the most common means is to dilute the gas and then monitor the gas by a monitoring instrument.

Most of the existing gas dilution devices are fixed dilution devices, the gas concentration configuration is realized in a flow control mode, and gas is supplied by a gas cylinder, namely, the gas cylinder is in positive pressure. The diluting device has the advantages of complex structure, larger volume and low automation degree, and is not beneficial to realizing the workplace test of 24-hour monitoring of field sampling.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

One of the objectives of the present invention is to provide a gas dilution device and a method for online monitoring, so as to overcome the defects of complicated structure, large volume, etc. of the gas dilution device in the prior art.

Another object of the present invention is to provide a gas dilution device and method for online monitoring, so as to achieve more convenient online long-period sampling monitoring.

To achieve one or more of the above objects, according to a first aspect of the present invention, there is provided a gas dilution apparatus for online monitoring, comprising: one end of the sampling pipeline is connected with the sampling port, and the other end of the sampling pipeline is connected with the sampling pump; the primary dilution pipeline is connected to a sampling pipeline close to the sampling port; the second-stage dilution pipeline is connected to a sampling pipeline close to the sampling pump; and a monitor connected downstream of the sampling pump. Wherein, the sampling pump pumps the gas to be measured and the diluent gas to the sampling pipeline and pumps to the monitor for detection.

Further, in the technical scheme, the primary dilution pipeline is connected to 1/3-1/2 parts of the sampling pipeline; the secondary dilution pipeline is connected to 1/2-2/3 parts of the sampling pipeline.

Further, in the technical scheme, the diameters of the primary dilution pipeline and the secondary dilution pipeline are 1/2-2/3 of the diameter of the sampling pipeline.

Further, in the above technical scheme, a first regulating valve and a first flowmeter are arranged on the primary dilution pipeline, a second regulating valve and a second flowmeter are arranged on the secondary dilution pipeline, a third flowmeter is arranged on the sampling pipeline, and the third flowmeter is located at the downstream of the secondary dilution pipeline.

Furthermore, in the above technical scheme, a first check valve is arranged on the primary dilution pipeline, and a second check valve is arranged on the secondary dilution pipeline.

Further, in the above technical solution, the gas dilution device for online monitoring further includes: the wireless handheld terminal can collect flow signals of the first flowmeter, the second flowmeter and the third flowmeter and control the first regulating valve and the second regulating valve according to a preset dilution ratio.

Further, in the above technical solution, the diluent gas is filtered ambient air.

According to a second aspect of the present invention, there is provided a gas dilution method for online monitoring, the method using the gas dilution apparatus for online monitoring according to any one of the above technical solutions, the method at least comprising the following steps: setting a preset dilution ratio; when the preset dilution ratio is less than 1:3, opening the primary dilution pipeline and closing the secondary dilution pipeline; when the preset dilution ratio is greater than or equal to 1:3 and less than 1:6, closing the primary dilution pipeline and opening the secondary dilution pipeline; and when the preset dilution ratio is greater than or equal to 1:6 and less than 1:9, simultaneously opening the primary dilution pipeline and the secondary dilution pipeline.

Further, in the above technical solution, the gas dilution method for on-line monitoring further includes a step of calculating an actual dilution ratio, where the actual dilution ratio is (Q-Q)₁-Q₂) Q, wherein Q₁Is the flow of the primary dilution pipe, Q₂The flow of the secondary dilution line is shown, and Q is the total flow of the sampling line.

Further, in the above technical solution, the gas dilution method for online monitoring further includes adjusting an actual dilution ratio according to a preset dilution ratio, where the adjustment of the actual dilution ratio is achieved by adjusting a flow rate of the primary dilution pipe and/or the secondary dilution pipe.

Further, in the above technical solution, the gas dilution method for online monitoring further includes the steps of: when the concentration value detected by the monitor exceeds the measuring range of the monitor, resetting the preset dilution ratio or sending an alarm signal.

Compared with the prior art, the invention has the following beneficial effects:

1. the gas to be measured and the diluent gas are pumped by the sampling pump, two stages of dilution pipelines are arranged at different positions of the sampling pipeline, the requirements of different dilution ratios can be met, positive pressure gas sources in the prior art, such as an air compressor, a compressed air tank and the like, are omitted, and the diluting device is simple in structure and small in size.

2. The diluting device is convenient to carry and measure on site and realizes more convenient online long-period sampling monitoring.

3. The dilution pipelines at all levels are designed by performing fluid mechanics calculation according to the pumping force of the sampling pump and the on-way resistance of the pipeline, the dilution proportion is accurately calculated according to flow data, dilution at different proportions can be realized, and the measurement of an on-site monitoring instrument is facilitated.

4. And one-way valves are arranged on each stage of dilution pipelines so as to prevent the gas or mixed gas to be detected from flowing back and influencing the detection result.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood and to make the technical means implementable in accordance with the contents of the description, and to make the above and other objects, technical features, and advantages of the present invention more comprehensible, one or more preferred embodiments are described below in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic structural view of a gas dilution device for on-line monitoring according to an embodiment of the present invention.

Description of the main reference numerals:

10-a sampling pipeline, 11-a sampling port, 12-a sampling pump, 13-a third flowmeter, 20-a primary dilution pipeline, 21-a first flowmeter, 22-a first regulating valve, 23-a first one-way valve, 30-a secondary dilution pipeline, 31-a second flowmeter, 32-a second regulating valve, 33-a second one-way valve, 40-a monitor and 50-a wireless handheld terminal.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

Spatially relative terms, such as "below," "lower," "upper," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the object in use or operation in addition to the orientation depicted in the figures. For example, if the items in the figures are turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the elements or features. Thus, the exemplary term "below" can encompass both an orientation of below and above. The article may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative terms used herein should be interpreted accordingly.

In this document, the terms "first", "second", etc. are used to distinguish two different elements or portions, and are not used to define a particular position or relative relationship. In other words, the terms "first," "second," and the like may also be interchanged with one another in some embodiments.

As shown in fig. 1, according to the gas dilution apparatus for on-line monitoring of the embodiment of the present invention, after the gas to be measured is pumped into the sampling pipeline 10 from the sampling port 11 by the sampling pump 12 for sampling, the gas is pumped into the monitor 40 for concentration detection. When the detected concentration of the gas to be measured exceeds the upper measurement limit of the monitor 40, the gas to be measured needs to be diluted and measured. The upper limit of measurement of the general monitor 40 is 100-1000 ppm, which is far lower than the gas emission concentration at the positions of a wellhead, a storage tank breather valve and the like, and the dilution measurement is usually adopted when the positions are monitored for a long period. The gas dilution device of the present invention is provided with a primary dilution pipe 20 and a secondary dilution pipe 30 which are connected to the sampling pipe 10 near the sampling port 11 and near the sampling pump 12, respectively. The sampling pump 12 pumps the gas to be measured and the diluent gas to a sampling pipeline and pumps the gas to a monitor for detection.

Further, the positions and diameters of the dilution pipelines at each stage are designed by performing fluid mechanics calculation according to the suction force of the sampling pump 12 and the on-way resistance of each pipeline, so that dilution with different proportions can be realized. In one or more exemplary embodiments of the present invention, the primary dilution line 20 may be connected at 1/3-1/2 of the sampling line 10, and the secondary dilution line 30 may be connected at 1/2-2/3 of the sampling line 10, the sampling line 10 being a line between the sampling port 11 and the sampling pump 12. Illustratively, the diameters of the primary dilution tunnel 20 and the secondary dilution tunnel 30 are 1/2-2/3 of the diameter of the sampling line 10. It should be understood that the positions and diameters of the primary dilution line 20 and the secondary dilution line 30 can be selected according to practical situations, and the invention is not limited thereto.

Preferably, but not limitatively, in one or more exemplary embodiments of the present invention, the primary dilution line 20 is provided with a first regulating valve 22 and a first flow meter 21, the secondary dilution line 30 is provided with a second regulating valve 32 and a second flow meter 31, the sampling line 10 is provided with a third flow meter 13, and the third flow meter 13 is located downstream of the secondary dilution line 30. The first flow meter 21 can detect the flow rate Q of the dilution gas in the primary dilution line 20₁The second flowmeter 31 may detect the flow rate Q of the dilution gas in the secondary dilution line 30₂The third flow meter 13 can detect the flow rate of the mixed gas in the sampling pipeline 10, that is, the total flow rate Q of the gas to be measured entering the monitor 40 after being mixed with the diluent gas. The actual dilution ratio (Q-Q) can be calculated according to the flow value detected by each flowmeter₁-Q₂) Q. The concentration value of the gas to be detected can be obtained according to the actual dilution ratio and the concentration value detected by the monitor 40, so that the long-period online monitoring of the high-concentration gas to be detected is realized.

Preferably, but not limitatively, in one or more exemplary embodiments of the invention, the primary dilution line 20 is provided with a first check valve 23 and the secondary dilution line 30 is provided with a second check valve 33. And one-way valves are arranged on the dilution pipelines at each stage to avoid the backflow of the gas or mixed gas to be detected from influencing the detection result.

Preferably, but not by way of limitation, in one or more exemplary embodiments of the invention, the gas dilution unit for online monitoring further comprises a wireless handheld terminal 50. The wireless handheld terminal 50 can collect flow signals of the first flowmeter 21, the second flowmeter 31 and the third flowmeter 13 and control the first regulating valve 22 and the second regulating valve 32 according to a preset dilution ratio. Illustratively, the wireless handheld terminal 50 may be battery powered. The wireless handheld terminal 50 is convenient to carry, and realizes more convenient long-period sampling monitoring.

Further, in one or more exemplary embodiments of the present invention, the dilution gas may be filtered ambient air, which is convenient for field use, without the need to provide a positive pressure gas source.

In one or more exemplary embodiments of the present invention, a gas dilution method for online monitoring employs a gas dilution device as in any one of the above technical solutions, the method at least comprising the steps of: setting a preset dilution ratio; when the preset dilution ratio is less than 1:3, opening the primary dilution pipeline 20 and closing the secondary dilution pipeline 30; when the preset dilution ratio is greater than or equal to 1:3 and less than 1:6, closing the primary dilution pipeline 20 and opening the secondary dilution pipeline 30; and simultaneously opening the primary dilution line 20 and the secondary dilution line 30 when the preset dilution ratio is greater than or equal to 1:6 and less than 1: 9. In an exemplary embodiment of the present invention, opening or closing the dilution lines of each stage may be achieved by a regulating valve on the line, and the regulating valve may be controlled wirelessly.

Further, in one or more exemplary embodiments of the present invention, the gas dilution method for online monitoring further includes adjusting an actual dilution ratio according to a preset dilution ratio, wherein the adjustment of the actual dilution ratio is achieved by adjusting the flow rate of the primary dilution line 20 and/or the secondary dilution line 30. The actual dilution ratio can be calculated from the flow values detected by the individual flow meters.

Further, in one or more exemplary embodiments of the present invention, the gas dilution method for online monitoring further includes the steps of: when the concentration value detected by the monitor 40 exceeds the measuring range of the monitor 40, the preset dilution ratio is reset or an alarm signal is sent out. The gas dilution device is used for long-period online measurement, the concentration of gas to be measured is constantly changed, and if the concentration of the gas diluted according to the original preset dilution ratio still exceeds the measuring range of the monitor 40, the preset dilution ratio is not appropriate, and more dilution gas needs to be sucked. If the first-stage dilution pipeline 20 and the second-stage dilution pipeline 30 are both started, the diluted gas concentration still exceeds the range of the monitor 40, and under the condition, the gas dilution device of the invention cannot meet the on-line monitoring requirement, an alarm signal is sent out. After receiving the alarm signal, the operator should take measures and remove the fault to avoid the occurrence of accidents. The alarm signal may be sent to the wireless handheld terminal 50 for the operator to respond in time, which is not limited in the present invention.

The present invention will be described in more detail by way of specific examples, which should be construed as being illustrative only and not limiting.

Example 1

Referring to fig. 1, in the gas dilution device of the present embodiment, the length of the sampling line 10 is 1.5m and the diameter thereof is 10mm, the diameter of the primary dilution line 20 is 6mm and the distance from the sampling port 11 is 0.5m, and the diameter of the secondary dilution line 30 is 6mm and the distance from the sampling port 11 is 1 m. The measuring range of the monitor 40 is 0-1000ppm, and the working flow of the sampling pump 12 is 0-5L/min. The gas diluting device of the embodiment is used for monitoring the gas concentration of VOCs gas volatilized by the breather valve at the top of the normal-pressure storage tank on line.

The preset dilution ratio is 1:2, so that only the primary dilution pipeline 20 needs to be opened to dilute the gas to be measured. The actual dilution ratio is (Q-Q)₁-Q₂) Q, in this embodiment Q₂Is 0. And comparing the actual dilution ratio with the preset dilution ratio in real time according to the flow signal collected by the wireless handheld terminal 50, and adjusting the first adjusting valve 22 of the primary dilution pipeline 20 according to the comparison result. The concentration value of the gas to be detected can be obtained according to the actual dilution ratio and the concentration value detected by the monitor 40, so that the long-period online monitoring of the high-concentration gas to be detected is realized.

Example 2

The gas dilution device of this example is the same as example 1, however, after monitoring for a period of time according to the settings of example 1, it was found that the diluted gas concentration was still above the upper range limit of the monitor 40. In this embodiment, the preset dilution ratio is adjusted to 1:5, so the primary dilution line 20 is closed and the secondary dilution line 30 is opened. The actual dilution ratio is (Q-Q)₁-Q₂) Q, in this embodiment Q₁Is 0. Comparing the actual dilution ratio with the preset dilution ratio in real time according to the flow signal collected by the wireless handheld terminal 50And adjusts the second adjustment valve 32 of the secondary dilution line 30 based on the comparison. The concentration value of the gas to be detected can be obtained according to the actual dilution ratio and the concentration value detected by the monitor 40, so that the long-period online monitoring of the high-concentration gas to be detected is realized.

Example 3

The gas dilution device of this example is the same as example 1, however, after monitoring for a period of time according to the settings of example 2, it was found that the diluted gas concentration was still above the upper range limit of the monitor 40. In this embodiment, the preset dilution ratio is adjusted to 1:7, so that the primary dilution line 20 and the secondary dilution line 30 are opened at the same time. The actual dilution ratio is (Q-Q)₁-Q₂) Q. And comparing the actual dilution ratio with the preset dilution ratio in real time according to the flow signal collected by the wireless handheld terminal 50, and adjusting the first adjusting valve 22 of the primary dilution pipeline 20 and the second adjusting valve 32 of the secondary dilution pipeline 30 according to the comparison result. The concentration value of the gas to be detected can be obtained according to the actual dilution ratio and the concentration value detected by the monitor 40, so that the long-period online monitoring of the high-concentration gas to be detected is realized.

The diluting device of embodiments 1-3 has a simple structure and a small volume. The sampling pump is used for sucking gas to be detected and diluent gas, two-stage dilution pipelines are arranged at different positions of the sampling pipeline, the requirements of different dilution ratios can be met, and positive pressure gas sources in the prior art, such as an air compressor, a compressed air tank and the like, are omitted.

Example 4

Referring to fig. 1, in the gas dilution device of the present embodiment, the length of the sampling line 10 is 1.5m and the diameter thereof is 10mm, the diameter of the primary dilution line 20 is 6mm and the distance from the sampling port 11 is 0.5m, and the diameter of the secondary dilution line 30 is 6mm and the distance from the sampling port 11 is 1 m. The measuring range of the monitor 40 is 0-1000ppm, and the working flow of the sampling pump 12 is 0-5L/min. The gas dilution device of the embodiment is used for monitoring the gas concentration of hydrogen sulfide gas volatilized from the wellhead of an oil and gas field on line.

The preset dilution ratio is 1:7, so that the primary dilution pipeline 20 and the secondary dilution are required to be opened simultaneouslyLine 30 dilutes the gas to be measured. The actual dilution ratio is (Q-Q)₁-Q₂) Q. And comparing the actual dilution ratio with the preset dilution ratio in real time according to the flow signal collected by the wireless handheld terminal 50, and adjusting the first adjusting valve 22 of the primary dilution pipeline 20 and the second adjusting valve 32 of the secondary dilution pipeline 30 according to the comparison result. The concentration value of the gas to be detected can be obtained according to the actual dilution ratio and the concentration value detected by the monitor 40, so that the long-period online monitoring of the high-concentration gas to be detected is realized.

Example 5

The gas dilution device of this example is the same as example 4, however, after monitoring for a period of time according to the settings of example 4, it was found that the diluted gas concentration was still above the upper range limit of the monitor 40. At this time, the monitor 40 can send an alarm signal to the wireless handheld terminal 50 and/or the central control room, and an operator needs to take measures and remove faults, so that the concentration of the gas to be measured is prevented from exceeding the standard or causing safety accidents.

The diluting device of this embodiment can in time send alarm signal when unable completion on-line monitoring task, and operating personnel can take necessary measure, discharge the trouble to avoid taking place the incident.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. Any simple modifications, equivalent changes and modifications made to the above exemplary embodiments shall fall within the scope of the present invention.