Pretreatment unit of on-line chromatographic analyzer for energy metering

Abstract

The invention relates to a pretreatment unit of an on-line chromatographic analyzer for energy metering. Comprising a linear sampler for acquiring a sample in a treatment tower, a driver connected with the linear sampler, a gas-liquid separator, a collection pump connected with the linear sampler and the gas-liquid separator, a plurality of gas collection pipes of which the first ends are connected with the gas-liquid separator, and a gas flow guide pipe connected with an online chromatographic analyzer, the driver is used for driving the linear samplers to do linear reciprocating motion, the second ends of the gas collecting pipes are connected with the gas flow guide pipe, the gas collecting pipes are arranged at intervals along the axis of the gas-liquid separator, and the number of the linear samplers is multiple. According to the pretreatment unit of the on-line chromatographic analyzer for energy metering, sampling and sample pretreatment can be carried out in the treatment process of natural gas, the obtained sample can be used for guiding production after being analyzed by the on-line chromatographic analyzer, and finished natural gas with a higher heat value is obtained.

Description

Technical Field

[0001] The present application relates to the technical field of detection equipment, and in particular to a preprocessing unit of an online chromatographic analyzer for energy metering. Background Art

[0002] The process of selling natural gas has gone through a process from calculating the price based on volume (flow) to calculating the price based on calorific value. The price calculated based on calorific value can more truly reflect the value of natural gas, so it has begun to be accepted by the market. The specific implementation method is to install analysis equipment at the terminal and end to analyze the proportion of components in natural gas and then calculate the calorific value. This method has begun to be passed on to the production end, where the calorific value of natural gas needs to be analyzed. The analysis results are used to guide production and obtain products with higher and more stable calorific values.

[0003] The natural gas production process can be roughly divided into several processes: pretreatment, deacidification, dehydration and NGL recovery. The deacidification and dehydration processes directly affect the calorific value because hydrogen sulfide, carbon dioxide and moisture will have a negative impact on the calorific value of the product.

[0004] One solution is to test the finished product, but this involves reprocessing and product downgrading, which will cause additional economic losses. Another solution is to conduct process testing and then adjust the process based on the test results, but process testing involves sampling and sample pretreatment, so how to achieve this requires further research. Summary of the invention

[0005] The present application provides a pretreatment unit of an online chromatographic analyzer for energy metering, which can sample and pretreat the natural gas processing process. The samples obtained at this time can be used to guide production after being analyzed by the online chromatographic analyzer to obtain finished natural gas with higher calorific value.

[0006] The above-mentioned purpose of the present application is achieved through the following technical solutions: The present application provides a preprocessing unit of an online chromatographic analyzer for energy metering, comprising: Linear samplers for obtaining samples from treatment towers; A driver is connected to the linear sampler, and is used to drive the linear sampler to perform linear reciprocating motion; A gas-liquid separator and a collection pump, wherein the collection pump is connected with the linear sampler and the gas-liquid separator; A plurality of gas collecting pipes, wherein the first ends of the gas collecting pipes are connected to the gas-liquid separator; A gas flow guide tube, used to be connected to the online chromatograph analyzer, and the second end of the gas collection tube is connected to the gas flow guide tube; Wherein, a plurality of gas collecting pipes are arranged at intervals along the axis of the gas-liquid separator; There are multiple linear samplers, which are arranged at intervals along the axis of the processing tower.

[0007] In a possible implementation of the present application, the linear sampler includes: Protect pipelines; The sampling pipeline is arranged inside the protection pipeline, and there is a closed space between the protection pipeline and the sampling pipeline; A plurality of short sampling tubes are arranged at intervals on the protection pipe and connected to the sampling pipe; A solenoid valve is provided on the sampling short tube and is located inside the closed space; The controller is electrically connected to the solenoid valve, and the controller is used to open and close the solenoid valve.

[0008] In a possible implementation of the present application, a slider is provided on the protection pipe, and the slider includes: A base, used for fixing on the inner wall of the treatment tower; A sliding blind hole is provided on the base; The spring is arranged in the sliding blind hole.

[0009] In a possible implementation of the present application, the collection pump has three connection ends, a first connection end of the collection pump is connected to the linear sampler, and a second connection end of the collection pump is connected to the gas-liquid separator; It also includes a liquid return pipe, a first end of which is connected to the third connection end of the collection pump, and a second end of which is used to be connected to the processing tower.

[0010] In a possible implementation of the present application, the gas-liquid separator includes: The gas-liquid separation tube comprises a variable diameter section and a constant diameter section; A plurality of separation nets are arranged at intervals in the fixed section of the gas-liquid separation pipe, and each separation net corresponds to a gas collection pipe.

[0011] In a possible implementation of the present application, one end of the separation network close to the gas collection pipe is inclined in the same direction as the flow direction of the medium in the gas-liquid separation pipe.

[0012] In a possible implementation of the present application, a portion of the separation network extends into the gas collection pipe.

[0013] In a possible implementation of the present application, at least one gas collection pipe is provided with a liquid level sensor, and detection data of the liquid level sensor is used to adjust the flow rate per unit time of the collection pump.

[0014] In a possible implementation of the present application, in the flow direction of the medium in the gas collection pipe, the distance between the gas flow guide pipe and the gas-liquid separation pipe tends to increase.

[0015] The beneficial effects of this application are: The pretreatment unit of the online chromatographic analyzer for energy metering provided in the present application can collect and pretreatment samples at multiple locations inside the treatment tower (deacidification tower, dehydration tower). After the obtained gas samples are subjected to component analysis, they can be used to guide the deacidification process and the dehydration process, and can also be used to calculate the calorific value of the reaction gas samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a preprocessing unit provided in this application.

[0017] Figure 2 This is a schematic diagram of a natural gas dehydration process provided by the present application.

[0018] Figure 3 It is a structural schematic diagram of a linear sampler provided in this application.

[0019] Figure 4 It is a connection diagram of a gas-liquid separator, a gas collection pipe and a gas flow guide pipe provided in the present application.

[0020] Figure 5 This is a schematic diagram of the flow path of bubbles in a gas-liquid separator, a gas collection pipe and a gas guide pipe provided in the present application.

[0021] Figure 6 It is a schematic diagram of a standard reference line provided in this application.

[0022] Figure 7 It is a schematic diagram for comparing an actual value line and a standard reference line provided in this application.

[0023] In the figure, 1. linear sampler, 2. driver, 3. gas-liquid separator, 4. collection pump, 5. gas collection tube, 6. gas flow guide tube, 7. liquid return tube, 11. protection pipeline, 12. sampling pipeline, 13. sampling short tube, 14. solenoid valve, 15. controller, 16. slider, 31. gas-liquid separation tube, 32. separation net, 51. liquid level sensor, 161. base, 162. sliding blind hole, 163. spring. DETAILED DESCRIPTION

[0024] The technical solution in this application is further described in detail below in conjunction with the accompanying drawings.

[0025] In some examples, the pretreatment unit of the online chromatographic analyzer for energy metering disclosed in the present application is mainly used for the acquisition and pretreatment of intermediate samples in the deacidification and dehydration processes of natural gas. After the components of the pretreated samples are analyzed, the calorific value at the corresponding position of the sample can be calculated, and feedback can also be provided on the treatment process.

[0026] It should be understood that the results of the deacidification process and the dehydration process will be determined according to the relevant parameters of the input raw natural gas and the relevant parameters of the treatment process. This is a relatively dynamic process, and problems that need to be treated again may occur. In order to solve this problem, the present application performs sample acquisition and pretreatment of the treatment process by deploying multiple pretreatment units of the online chromatographic analyzer for energy metering disclosed in the present application on the treatment tower (deacidification tower, dehydration tower).

[0027] By analyzing samples at different locations, the deacidification and dehydration effects can be determined. When the sample meets the requirements, the reagent dosage can be appropriately reduced. When the sample does not meet the requirements, the reagent dosage can be increased. In other words, the deacidification and dehydration processes will be dynamically adjusted with the relevant parameters of the input raw natural gas.

[0028] The raw natural gas samples obtained from the deacidification tower and the dehydration tower are sent to the online chromatograph for calorific value analysis. The calorific value analysis is divided into two parts, one is the water content analysis, the other is the component ratio analysis. The calorific value of the combustible component is positive, and the calorific value of the non-combustible component is negative.

[0029] In addition, the analysis results of the deacidification tower can also provide reference for the dehydration tower. For example, if the water content of the raw natural gas entering the dehydration tower is high, it is necessary to adjust it by reducing the gas flow rate and increasing the medium circulation rate. At the same time, this method can also achieve better economic efficiency because it can avoid secondary treatment to a certain extent and achieve reasonable use of the medium.

[0030] In the usage scenario of the present application, both deacidification and dehydration use wet processes.

[0031] See also Figure 1 In some examples, the present application discloses a preprocessing unit of an online chromatographic analyzer for energy metering, comprising a linear sampler 1, a driver 2, a gas-liquid separator 3, a collection pump 4, a gas collection pipe 5 and a gas flow guide pipe 6. There are multiple linear samplers 1, and these linear samplers 1 are installed at intervals from top to bottom inside a processing tower (acid removal tower, dehydration tower), that is, the linear samplers 1 are arranged at intervals along the axis of the processing tower, such as Figure 2 As shown, Figure 2 Indicates the dehydration process, wet natural gas flows from bottom to top in the dehydration tower and then becomes dry natural gas, the dehydrating agent flows from top to bottom in the dehydration tower and is regenerated by the regeneration device outside the dehydration tower at the same time.

[0032] The driver 2 is connected to the linear sampler 1 and is used to drive the linear sampler 1 to perform linear reciprocating motion.

[0033] In some possible implementations, the driver 2 is mounted on a processing tower.

[0034] In some possible implementations, the driver 2 uses an electric cylinder.

[0035] The reason why the linear sampler 1 performs linear reciprocating motion is to fully sample the area where it is located, that is, during the sampling process, the sampling position is moving rather than fixed, which can make the obtained sample more representative.

[0036] The collection pump 4 is connected to the linear sampler 1 and the gas-liquid separator 3. Its function is to send the sample in the linear sampler 1 into the gas-liquid separator 3 for separation. At this time, the sample consists of solution and bubbles. The purpose of separation is to send the bubbles into the gas guide tube 6 through the gas collection tube 5.

[0037] In some possible implementations, the collection pump 4 uses a diaphragm pump.

[0038] See also Figure 1 There are multiple gas collecting tubes 5, the first ends of which are connected to the gas-liquid separator 3, and the second ends are connected to the gas flow tube 6, which is also connected to the online chromatograph analyzer so that the obtained gas samples can enter the online chromatograph analyzer for analysis.

[0039] The arrangement of the multiple gas collection tubes 5 is that the gas collection tubes 5 are arranged at intervals along the axis of the gas-liquid separator 3. The reason why the number of gas collection tubes 5 is multiple and the intervals are arranged is that the separation of the solution and the bubbles takes time, and the volume of the bubbles is also different. When the sample flows in the gas-liquid separator 3, the separation process of the solution and the bubbles continues. Therefore, multiple gas collection tubes 5 are required to be located at different positions on the gas-liquid separator 3 to collect the bubbles separated from the solution.

[0040] In general, the preprocessing unit of the online chromatograph analyzer for energy metering provided in the present application can collect and preprocess samples at multiple locations inside the processing tower (deacidification tower, dehydration tower). After the obtained gas samples are subjected to component analysis, they can be used to guide the deacidification process and the dehydration process, and can also be used to calculate the calorific value of the reaction gas samples.

[0041] For some examples, see Figure 3The linear sampler 1 includes a protective pipe 11, a sampling pipe 12, a sampling short pipe 13, a solenoid valve 14 and a controller 15. The sampling pipe 12 is fixedly installed inside the protective pipe 11. There is a closed space between the protective pipe 11 and the sampling pipe 12, or it can be described that the protective pipe 11 and the sampling pipe 12 form a jacket pipe.

[0042] There are multiple sampling short tubes 13, which are arranged at intervals on the protection pipe 11 and connected to the sampling pipe 12 to achieve communication between the sampling pipe 12 and the treatment tower. The solenoid valve 14 is installed on the sampling short tube 13 and is located inside the closed space. The function of the solenoid valve 14 is to control the opening and closing of the solenoid valve 14.

[0043] It should be noted here that during the sampling process, there are two ways to open the sampling short tubes 13. The first is to open them at the same time, and the second is to open only one at a time. The disadvantage of opening them at the same time is that the sample amounts obtained by each sampling short tube 13 are inconsistent. The sampling short tube 13 close to the collection pump 4 has a large flow rate, and the sampling short tube 13 far away from the collection pump 4 has a small flow rate, which will cause the final analysis results to deviate.

[0044] The present application adopts a processing method of opening only one at a time, and the advantage of this method is that an equal amount of samples can be obtained at each sampling position.

[0045] The controller 15 is electrically connected to the solenoid valve 14 and is used to open and close the solenoid valve 14 . The connection line between the controller 15 and the solenoid valve 14 is arranged in a closed space.

[0046] In some possible implementations, the controller 15 uses a programmable logic controller.

[0047] In some examples, a slider 16 is installed on the protection pipe 11 , and the slider 16 includes a base 161 and a spring 163 . The base 161 is used to be fixed on the inner wall of the processing tower. The base 161 is also provided with a sliding blind hole 162 , and the spring 163 is located in the sliding blind hole 162 .

[0048] A slider 16 is installed at both ends of the protection pipe 11. The function of the slider 16 is to cooperate with the driver 2 to realize the axial movement of the protection pipe 11. The function of the spring 163 is to push the protection pipe 11 to reset.

[0049] For some examples, see Figure 1 , a liquid return pipe 7 is added, and the liquid return pipe 7 is used in conjunction with the collection pump 4 to achieve equal collection of samples at each sampling short tube 13. It should be understood that when the sampling short tube 13 is opened individually, the distance between each sampling short tube 13 and the collection pump 4 is different, resulting in different times for the samples at the sampling short tube 13 to reach the collection pump 4.

[0050] The function of the liquid return pipe 7 is to empty the previous sample in the sampling pipe 12 , so that the sample obtained from each sampling short tube 13 can enter the gas-liquid separator 3 in equal amounts.

[0051] The collection pump 4 has three connection ends, the first connection end of the collection pump 4 is connected to the linear sampler 1, the second connection end of the collection pump 4 is connected to the gas-liquid separator 3, the third connection end of the collection pump 4 is connected to the first end of the return liquid pipe 7, and the second end of the return liquid pipe 7 is used to connect to the treatment tower.

[0052] For some examples, see Figure 4 The gas-liquid separator 3 includes a gas-liquid separation tube 31 and a plurality of separation nets 32. The gas-liquid separation tube 31 is divided into two sections, namely a variable diameter section and a constant diameter section. The function of the variable diameter section is to reduce the flow velocity of the sample.

[0053] A plurality of separation nets 32 are arranged at intervals in the fixed section of the gas-liquid separation tube 31, and each separation net 32 ​​corresponds to a gas collection tube 5. The separation net 32 ​​is located below the corresponding gas collection tube 5, and its function is to intercept the bubbles in the sample and then guide the bubbles into the gas collection tube 5. Figure 5 shown.

[0054] In some possible implementations, one end of the separation net 32 ​​close to the gas collection tube 5 is inclined in the same direction as the flow direction of the medium (sample) in the gas-liquid separation tube 31 .

[0055] In some possible implementations, in the flow direction of the medium (sample) in the gas-liquid separation tube 31 , the pore size on the separation net 32 ​​tends to decrease.

[0056] In some possible implementations, a portion of the separation net 32 ​​extends into the gas collecting pipe 5 .

[0057] In some examples, at least one gas collection tube 5 is provided with a liquid level sensor 51, which is used to detect the liquid level in the gas collection tube 5. The liquid level can reflect the flow rate of the medium (sample) in the gas-liquid separation tube 31 to a certain extent.

[0058] When the liquid level sensor 51 detects the medium (sample), the sampling pump 4 is required to reduce the flow rate per unit time.

[0059] In some possible implementations, at least one gas collecting pipe 5 is provided with two liquid level sensors 51 or the two liquid level sensors 51 are respectively provided on two gas collecting pipes 5 , and the two liquid level sensors 51 are responsible for detecting the highest liquid level and the lowest liquid level respectively.

[0060] In some examples, in the flow direction of the medium in the gas collection tube 5, the distance between the gas flow tube 6 and the gas-liquid separation tube 31 tends to increase, so that the gas in the gas flow tube 6 can be kept in an updated state, and the gas subsequently entering the gas flow tube 6 can push the gas previously entering the gas flow tube 6 into the online chromatograph analyzer.

[0061] It should be understood that the solution (dehydrating agent) in the gas-liquid separator 3 will be returned to the treatment tower or the regeneration device for recycling.

[0062] It should also be understood that the preprocessing unit of the online chromatographic analyzer for energy metering disclosed in the present application uses reference lines to represent the sample values ​​obtained at multiple positions according to the device design. The curve at this time is a standard reference line, such as Figure 6 shown.

[0063] See also Figure 7 , the thick solid line represents the actual value line, which may be too high or too low. In this case, the process parameters need to be adjusted according to the content recorded in the previous article.

[0064] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A preprocessing unit for an online chromatographic analyzer for energy metering, characterized in that: include: A linear sampler (1) for obtaining a sample in a treatment tower; A driver (2) is connected to the linear sampler (1), and the driver (2) is used to drive the linear sampler (1) to perform linear reciprocating motion; A gas-liquid separator (3) and a collection pump (4), wherein the collection pump (4) is connected to the linear sampler (1) and the gas-liquid separator (3); A plurality of gas collection pipes (5), wherein a first end of the gas collection pipe (5) is connected to the gas-liquid separator (3); A gas flow guide tube (6) is used to be connected to the online chromatographic analyzer, and the second end of the gas collection tube (5) is connected to the gas flow guide tube (6); Wherein, a plurality of gas collection pipes (5) are arranged at intervals along the axis of the gas-liquid separator (3); There are multiple linear samplers (1), and the multiple linear samplers (1) are arranged at intervals along the axis of the processing tower.

2. The preprocessing unit of the online chromatographic analyzer for energy metering according to claim 1, characterized in that: The linear sampler (1) comprises: Protect pipeline (11); The sampling pipeline (12) is arranged inside the protection pipeline (11), and there is a closed space between the protection pipeline (11) and the sampling pipeline (12); A plurality of short sampling tubes (13) are arranged at intervals on the protection pipe (11) and connected to the sampling pipe (12); A solenoid valve (14) is provided on the sampling short tube (13) and is located inside the closed space; The controller (15) is electrically connected to the solenoid valve (14), and the controller (15) is used to open and close the solenoid valve (14).

3. The preprocessing unit of the online chromatographic analyzer for energy metering according to claim 2, characterized in that: A slider (16) is provided on the protection pipe (11), and the slider (16) comprises: A base (161) is used to be fixed on the inner wall of the treatment tower; A sliding blind hole (162) is provided on the base (161); The spring (163) is arranged in the sliding blind hole (162).

4. The preprocessing unit of the online chromatographic analyzer for energy metering according to claim 1, characterized in that: The collection pump (4) has three connection ends, a first connection end of the collection pump (4) is connected to the linear sampler (1), and a second connection end of the collection pump (4) is connected to the gas-liquid separator (3); It also comprises a liquid return pipe (7), a first end of the liquid return pipe (7) being connected to the third connection end of the collection pump (4), and a second end of the liquid return pipe (7) being used to be connected to the processing tower.

5. The preprocessing unit of the online chromatographic analyzer for energy metering according to claim 1, characterized in that: The gas-liquid separator (3) comprises: The gas-liquid separation tube (31) comprises a variable diameter section and a constant diameter section; A plurality of separation nets (32) are arranged at intervals in the fixed section of the gas-liquid separation tube (31), and each separation net (32) corresponds to a gas collection tube (5).

6. The preprocessing unit of the online chromatographic analyzer for energy metering according to claim 5, characterized in that: One end of the separation net (32) close to the gas collection pipe (5) is inclined in the same direction as the flow direction of the medium in the gas-liquid separation pipe (31).

7. The preprocessing unit of the online chromatographic analyzer for energy metering according to claim 5, characterized in that: A portion of the separation net (32) extends into the gas collection pipe (5).

8. The preprocessing unit of the online chromatographic analyzer for energy metering according to claim 1 or 5, characterized in that: At least one gas collection pipe (5) is provided with a liquid level sensor (51), and detection data of the liquid level sensor (51) is used to adjust the flow rate per unit time of the collection pump (4).

9. The preprocessing unit of the online chromatographic analyzer for energy metering according to claim 5, characterized in that: In the flow direction of the medium in the gas collection pipe (5), the distance between the gas flow guide pipe (6) and the gas-liquid separation pipe (31) tends to increase.

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