Device for measuring water content of pipeline-conveyed carbon dioxide based on ethanol discharge method

Abstract

The utility model further discloses a method for measuring the moisture content of the pipeline-conveyed carbon dioxide. The method comprises the following steps of: S1, pouring sufficient ethanol into the front high-pressure container and the rear high-pressure container; s2, connecting the online connecting pipe with a to-be-detected CO pipeline, opening a valve, enabling CO in the pipeline to slowly enter the front high-pressure container, closing the valve, enabling free water and adsorbed water in the CO to be absorbed by ethanol in the front high-pressure container, enabling the dried CO to enter the rear high-pressure container from the serial connecting pipe, and detecting the CO in the rear high-pressure container. And the ethanol in the rear high-pressure container is discharged from the collecting pipe under the pressure action of CO and enters the storage bottle. According to the device for measuring the water content of the pipeline carbon dioxide based on the ethanol discharge method, the water discharge method and the principle that water is dissolved in ethanol are adopted, the design structure of the device is simplified, meanwhile, the device can be used in most of environments, the accuracy of a detection result is ensured, the water content of CO2 in a pipeline can be accurately tested, and the detection efficiency is improved. And a basis is provided for controlling corrosion of the CO2 pipeline.

Description

Technical Field

[0001] The utility model relates to an on-line measuring device, and more precisely, to a measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method. Background Art

[0002] In a certain place in the eastern part of China, 1 million tons of CO2 are reinjected and stored annually. During pipeline transportation, dry CO2 does not corrode the surface of the pipeline, but after high-concentration CO2 dissolves in water, H2CO3 will be formed, causing serious corrosion (pitting corrosion, tinea corrosion, and mesa corrosion) to the CO2 transportation pipeline, with a corrosion rate as high as 3 - 7 mm / a. Therefore, it is urgent to find a detection method to effectively detect the water content of pipeline-transported CO2.

[0003] Generally, the measurement of the water content in a gas usually includes: the electrolysis method, the dew point method, and the cavity ring-down spectroscopy method.

[0004] The electrolysis method measures the trace moisture in a gas by measuring the electrolysis current. The electrolysis method is applicable to the measurement of moisture in gases that do not react with phosphorus pentoxide except for moisture absorption. Gases that react with phosphorus pentoxide, such as ammonia or mixed gases containing ammonia, cannot be measured using the electrolysis method.

[0005] The dew point method measures the trace moisture in a gas by measuring the dew point of the gas. The dew point method is applicable to the measurement of trace moisture in low-boiling-point gases and is not applicable to the measurement of moisture in gases that condense before the moisture condenses, such as propylene, and gases that can react with moisture.

[0006] The cavity ring-down spectroscopy method measures the trace moisture in a gas by measuring the decay time of the reflected oscillation of light in an optical cavity. However, due to the complex structure and high price of the moisture measuring instrument using this principle, this kind of instrument is mainly used for the measurement of trace moisture in high-purity gases and ultra-high-purity gases. Content of the Utility Model

[0007] Based on this, in view of the above technical problems, it is necessary to provide a measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method.

[0008] To solve the above technical problems, the utility model adopts the following technical solutions:

[0009] A measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method, characterized in that the measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method comprises a pre-stage high-pressure container and a post-stage high-pressure container. The top of the pre-stage high-pressure container is provided with a first interface and a second interface, and the top of the post-stage high-pressure container is provided with a third interface and a fourth interface.

[0010] An on-line connecting pipe is provided at the upper part of the first interface, a valve is provided on the on-line connecting pipe, a first extension pipe is provided at the lower part of the first interface, and the first extension pipe extends to the bottom of the pre-positioned high-pressure container.

[0011] A series connecting pipe is provided between the second interface and the third interface.

[0012] A collecting pipe is provided at the upper part of the fourth interface, a second extension pipe is provided at the lower part of the fourth interface, and the second extension pipe extends to the bottom of the post-positioned high-pressure container.

[0013] As a preferred embodiment of the present utility model, the pre-positioned high-pressure container and the post-positioned high-pressure container are stainless steel containers.

[0014] As a preferred embodiment of the present utility model, the volumes of the pre-positioned high-pressure container and the post-positioned high-pressure container are 1L to 5L.

[0015] The present utility model also discloses a method for measuring the water content of pipeline-transported carbon dioxide, which comprises the measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method as described above, and comprises the steps:

[0016] Step S1: Pour sufficient ethanol into the pre-positioned high-pressure container and the post-positioned high-pressure container.

[0017] Step S2: Connect the on-line connecting pipe to the CO pipeline to be detected, open the valve, and slowly let the CO in the pipeline enter the pre-positioned high-pressure container. Then close the valve. The free water and adsorbed water in the CO are absorbed by the ethanol in the pre-positioned high-pressure container. The dried CO enters the post-positioned high-pressure container through the series connecting pipe. The ethanol in the post-positioned high-pressure container is discharged from the collecting pipe under the pressure of the CO and enters the storage bottle.

[0018] Step S3: Measure the volume of the ethanol that enters the storage bottle. Pour out the ethanol in the pre-positioned high-pressure container and measure its volume V. 总 , and use a Karl Fischer moisture analyzer to measure the water content of the ethanol as θ. 总 ;

[0019] Step S4: According to the formula The water content in the CO2 in the pipeline can be obtained.

[0020] Compared with the prior art, the present utility model has the following beneficial effects:

[0021] The present utility model provides a measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method. This measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method uses the principles of the water displacement method and the solubility of water in ethanol. It collects the water contained in CO2 through two high-pressure resistant containers, and then analyzes the water content through a Karl Fischer moisture titrator. While simplifying its design structure, it can ensure that it can be used in the vast majority of environments and guarantee the accuracy of the detection results, so as to accurately measure the water content of CO2 in the pipeline and provide a basis for controlling the corrosion of CO2 pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the solutions in the present utility model, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the following-described drawings are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is a schematic three-dimensional structure diagram of the measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method of the present utility model;

[0024] Figure 2 is a fitting diagram of the test data of the measuring device of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following will elaborate on the preferred embodiments of the present utility model in conjunction with the drawings, so that the advantages and features of the present utility model can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present utility model.

[0026] As Figure 1 shown, the measuring device for the water content of pipeline-transported carbon dioxide based on the ethanol displacement method includes a front high-pressure container 1 and a rear high-pressure container 2. The top of the front high-pressure container 1 is provided with a first interface 11 and a second interface 12, and the top of the rear high-pressure container 2 is provided with a third interface 21 and a fourth interface 22.

[0027] An on-line connecting pipe 10 is provided above the first interface 11. A valve 101 is provided on the on-line connecting pipe 10. A first extension pipe 13 is provided below the first interface 11, and the first extension pipe 13 extends to the bottom of the front high-pressure container 1.

[0028] A series connecting pipe 3 is provided between the second interface 12 and the third interface 21.

[0029] A collecting pipe 20 is provided above the fourth interface 22. A second extension pipe 23 is provided below the fourth interface 22, and the second extension pipe 23 extends to the bottom of the rear high-pressure container 2.

[0030] It should be noted that the front high-pressure container 1 and the rear high-pressure container 2 are stainless steel containers. The volumes of the front high-pressure container 1 and the rear high-pressure container 2 are 1 L to 5 L.

[0031] The usage method of the measuring device will be described below, including the steps:

[0032] Step S1: Pour sufficient ethanol into the front high-pressure container 1 and the rear high-pressure container 2;

[0033] Step S2: Connect the on-line connecting pipe 10 to the CO2 pipeline to be detected, open the valve 101, and let the CO2 in the pipeline slowly enter the front high-pressure container 1. Then close the valve 101. The free water and adsorbed water in the CO2 are absorbed by the ethanol in the front high-pressure container 1. The dried CO2 enters the rear high-pressure container 2 through the series connecting pipe 3. The ethanol in the rear high-pressure container 2 is discharged from the collection pipe 20 under the pressure of the CO2 and enters the storage bottle;

[0034] Step S3: Measure the volume of the ethanol that enters the storage bottle Pour out the ethanol in the front high-pressure container 1 and measure its volume V 总 , and use a Karl Fischer moisture analyzer to measure the moisture content of the ethanol as θ 总 ;

[0035] Step S4: According to the formula The moisture content in the CO2 in the pipeline can be obtained.

[0036] To verify the accuracy of the present invention, taking the long-distance pipeline transportation of carbon dioxide in a certain place in the eastern part of China as an example, the moisture content of O2 in the pipeline is tested, and samples are taken and measured at four places of the pipeline. The results are shown in Table 1 below.

[0037] Table 1 Treatment results of moisture content of carbon dioxide gas

[0038]

[0039] In addition, the volumes of the front high-pressure container 1 and the rear high-pressure container 2 are adjusted and verified again. The results are shown in Table 2 below.

[0040] Table 2 Moisture content measured by intermediate containers with different volumes

[0041]

[0042] At the same time, linear fitting is performed on the data. As Figure 2 shown, at this time, the slope is the moisture content.

[0043] Obviously, using intermediate containers of different volumes to measure the moisture content of pipeline CO2 and drawing trend lines can help reduce errors and improve accuracy.

[0044] The device for measuring the water content of pipeline carbon dioxide based on the ethanol displacement method adopts the principle of water displacement method and water dissolving in ethanol, and cleverly utilizes the immiscible characteristics of ethanol and carbon dioxide. It collects the water contained in CO2 through two high-pressure containers, and then analyzes the water content through a Karl Fischer titrator. While simplifying its design structure, it can ensure that it can be used in most environments and ensure the accuracy of the test results, so as to accurately test the water content of CO2 in the pipeline and provide a basis for controlling the corrosion of CO2 pipelines.

[0045] Without limitation to this, any changes or substitutions that are not conceived through creative work should be included in the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope defined in the claims.

Claims

1. A device for measuring the water content of pipeline carbon dioxide based on the ethanol exclusion method, characterized in that: The device for measuring the water content of pipeline carbon dioxide based on the ethanol displacement method comprises a front high-pressure container (1) and a rear high-pressure container (2), wherein the top of the front high-pressure container (1) is provided with a first interface (11) and a second interface (12), and the top of the rear high-pressure container (2) is provided with a third interface (21) and a fourth interface (22). An online connection pipe (10) is provided at the upper portion of the first interface (11), and a valve (101) is provided on the online connection pipe (10). A first extension pipe (13) is provided at the lower portion of the first interface (11), and the first extension pipe (13) extends to the bottom of the front high-pressure container (1). A series connection pipe (3) is provided between the second interface (12) and the third interface (21). A collecting pipe (20) is provided at the upper portion of the fourth interface (22), and a second extension pipe (23) is provided at the lower portion of the fourth interface (22), wherein the second extension pipe (23) extends to the bottom of the rear high-pressure container (2).

2. The device for measuring the water content of pipeline carbon dioxide based on the ethanol exclusion method according to claim 1, characterized in that: The front high-pressure container (1) and the rear high-pressure container (2) are stainless steel containers.

3. The device for measuring the water content of pipeline carbon dioxide based on the ethanol exclusion method according to claim 2, characterized in that: The volumes of the front high-pressure container (1) and the rear high-pressure container (2) are 1L to 5L.

Images