Sampling pretreatment system and sampling monitoring system of high-pressure depropanizing tower

Abstract

The invention provides a sampling pretreatment system and a sampling monitoring system of a high-pressure depropanizer. The sampling pretreatment system comprises a filter, a gasification device, a liquid blocking system, a sampling recovery system and a pretreatment box, the pretreatment box comprises a non-heating area and a heating area; the filter, the gasification device and the connecting pipeline for circulation of a liquid phase to be detected are positioned in the non-heating area; and the liquid blocking system, the sampling and recycling system and the connecting pipeline for circulation of a to-be-detected gas phase are positioned in the heating area. The sampling fraction is in a single gas state when flowing into an analyzer, and the non-heating area prevents C2 and light fractions in a detected liquid phase from overflowing before gasification or C4 and C5 alkadiene polymerization in the detected liquid phase, so that the problem of pipeline coking and blockage is solved; the gasified measured gas phase is not liquefied in the heating area, so that the gas-liquid mixture is prevented from flowing into the analyzer to cause the failure of the chromatographic column, and the accuracy and authenticity of the measurement result of the analyzer are ensured.

Description

Technical Field

[0001] The invention relates to the field of sample pretreatment systems, and in particular to a sampling pretreatment system and a sampling monitoring system for a high-pressure depropanizer. Background Art

[0002] The separation process of the ethylene cracking unit uses refinery dry gas, liquefied gas, light liquid, aromatic raffinate, hydrogenation tail oil, etc. as raw materials, and adopts the process technology of first depropanization and then hydrogenation after cracking. The high-pressure depropanizer is a key equipment for separating ethylene and propylene in the ethylene cracking unit. The high-pressure depropanizer flows C3 and light fractions out of the top of the tower in gas phase, and C4 and heavy fractions flow out of the bottom of the tower in liquid phase. The top and bottom of the high-pressure depropanizer are equipped with online analytical instruments. Continuous monitoring of the content of trace fractions in the gas phase and liquid phase can reflect the separation efficiency of this tower.

[0003] The sampling and monitoring system of the high-pressure depropanizer usually includes a high-pressure sampling pipeline connected to the kettle of the high-pressure depropanizer, a sampling pretreatment system and an analyzer. The high-pressure sampling pipeline at the kettle of the high-pressure depropanizer transports the sampled liquid medium to the sampling pretreatment system. The sampling pretreatment system decompresses, removes impurities, and gasifies the sampled liquid medium, and finally controls the flow rate to the analyzer for analysis. In the liquid medium of the kettle of the high-pressure depropanizer, it is very easy to scale due to the conditions for the self-polymerization of butadiene. Therefore, in the gasification stage of the sampling pretreatment system, if the temperature is controlled slightly higher, it will promote the polymerization of C4 and C5 dienes, thereby causing coking and blockage in the pipeline, and no sample flows through the analyzer, resulting in measurement distortion; on the other hand, if the temperature is controlled slightly lower, the measured liquid phase cannot be completely vaporized, and the mixed gas and liquid phases flowing into the analyzer are likely to cause the chromatographic column in the analyzer to be blocked and fail, resulting in the instrument being unable to measure normally. Summary of the invention

[0004] In view of the above shortcomings of the prior art, the present invention provides a sampling pretreatment system and a sampling monitoring system for a high-pressure depropanizer to improve the technical problem that in the gasification stage of the sampling pretreatment system, improper temperature control in the pretreatment box causes the measured liquid phase to cause coking and blockage in the pipeline of the sampling pretreatment system or blockage and failure of the chromatographic column in the analyzer.

[0005] To achieve the above-mentioned object and other related objects, the present invention provides a sampling pretreatment system and a sampling monitoring system for a high-pressure depropanizer.

[0006] On the one hand, the present invention provides a sampling pretreatment system for a high-pressure depropanizer, the sampling pretreatment system comprising a filter, a gasification device, a liquid blocking system, a sampling recovery system and a pretreatment box; the liquid inlet of the filter is connected to the high-pressure depropanizer sampling pipeline; the liquid inlet of the gasification device is connected to the liquid outlet pipeline of the filter; the air inlet of the liquid blocking system is connected to the air outlet pipeline of the gasification device; the air outlet of the liquid blocking system is connected to the air inlet pipeline of an analyzer; the air inlet of the sampling recovery system is connected to the air outlet pipeline of the analyzer, and the air outlet of the sampling recovery system is connected to the flare system pipeline; the pretreatment box comprises a non-heating area and a heating area; wherein the filter, the gasification device and the connecting pipeline for the flow of the liquid phase to be measured are located in the non-heating area; the liquid blocking system, the sampling recovery system and the connecting pipeline for the flow of the gas phase to be measured are located in the heating area.

[0007] In an example of the sampling pretreatment system of the present invention, the liquid blocking system includes a liquid blocker, a liquid accumulation tank, and an automatic liquid drain tank. The air inlet of the liquid blocker is connected to the air outlet pipe of the gasification device, and the air outlet of the liquid blocker is connected to the air inlet pipe of the analyzer; the liquid inlet of the liquid accumulation tank is connected to the liquid outlet pipe of the liquid blocker; and the liquid inlet of the automatic liquid drain tank is connected to the liquid outlet pipe of the liquid accumulation tank.

[0008] In an example of the sampling pretreatment system of the present invention, the sampling recovery system includes a first pneumatic valve, the air inlet of the first pneumatic valve is connected to the air outlet pipeline of the analyzer, and the air outlet of the first pneumatic valve is connected to the flare system pipeline.

[0009] In an example of the sampling pretreatment system of the present invention, the air outlet of the first pneumatic valve is connected to the liquid inlet pipeline of the liquid accumulation tank.

[0010] In an example of the sampling pretreatment system of the present invention, the sampling recovery system also includes a second pneumatic valve, the air inlet of the second pneumatic valve is connected to the connecting pipe between the air inlet of the first pneumatic valve and the air outlet of the analyzer, and the air outlet pipe of the second pneumatic valve is connected to the outside of the pretreatment box.

[0011] In an example of the sampling pretreatment system of the present invention, the sampling pretreatment system further includes a first stop valve, which is disposed on a connecting pipe of a liquid inlet of the filter, and the first stop valve is located in the non-heating zone.

[0012] In an example of the sampling pretreatment system of the present invention, the sampling pretreatment system also includes a pressure relief valve, the air inlet of the pressure relief valve is connected to the connecting pipe between the gasification device and the liquid resistance system, and the air outlet of the pressure relief valve is connected to the flare system pipeline.

[0013] In an example of the sampling pretreatment system of the present invention, the sampling pretreatment system further includes an electric heater, and the electric heater is located in the heating zone.

[0014] In an example of the sampling pretreatment system of the present invention, the sampling pretreatment system further comprises a nitrogen ball valve, and the gas outlet of the nitrogen ball valve is connected to the connecting pipe between the filter and the gasification device.

[0015] On the other hand, the present invention also provides a sampling and monitoring system for a high-pressure depropanizer, which includes a high-pressure depropanizer sampling pipeline, an analyzer and a flare system, and a sampling pretreatment system as described in any of the above items, wherein the high-pressure depropanizer sampling pipeline is connected to the liquid inlet pipeline of the sampling pretreatment system; the air outlet of the sampling pretreatment system is connected to the air inlet pipeline of the analyzer, the air outlet of the analyzer is connected to the air inlet pipeline of the sampling pretreatment system, and the exhaust port of the sampling pretreatment system is connected to the flare system pipeline.

[0016] The sampling pretreatment system proposed by the present invention divides the pretreatment box into a non-heating zone and a heating zone, so that the sampled fraction is in a single gaseous state when flowing into the analyzer. The non-heating zone prevents the carbon 2 and light fractions in the measured liquid phase from overflowing before gasification or the carbon 4 and carbon 5 dienes in the measured liquid phase from polymerizing, resulting in the problem of coking and clogging of the pipeline; the heating zone keeps the measured gas phase after gasification from being liquefied in the heating zone, prevents the gas-liquid phase from mixing and flowing into the analyzer, causing the chromatographic column in the analyzer to fail, and ensures the accuracy and authenticity of the measurement results of the analyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of an example of a sampling pretreatment system of the present invention;

[0019] Figure 2 It is a structural schematic diagram of an example of a sampling monitoring system of the present invention;

[0020] Figure 3 Schematic diagram of the gas-liquid flow direction in an example of the sampling monitoring system of the present invention.

[0021] Component number description

[0022] 1. Sampling pipeline of high-pressure depropanizer; 101. Sampling pipeline; 102. Sampling ball valve; 103. Return ball valve; 104. Return pipeline; 2. Analyzer; 3. Flare system; 4. Filter; 5. Gasification device; 6. Liquid blocking system; 61. Liquid blocking device; 62. Liquid accumulation tank; 63. Automatic liquid drain tank; 7. Sampling recovery system; 71. First pneumatic valve; 72. Second pneumatic valve; 8. Pretreatment box; 81. Non-heating zone; 82. Heating zone; 9. First stop valve; 10. Pressure relief valve; 11. Electric heater; 12. Nitrogen ball valve; 13. First flow meter; 14. First pressure gauge; 15. Second pressure gauge; 16. Temperature sensor. DETAILED DESCRIPTION

[0023] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0024] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any methods, equipment and materials of the prior art similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0025] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" etc. used in this specification are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0026] To solve the problems existing in the prior art, please refer to Figures 1 to 3The present invention provides a sampling pretreatment system and a sampling monitoring system for a high-pressure depropanizer. The original pretreatment box is technically modified to be divided into a non-heating zone for preventing the overflow of C2 and light fractions in the measured liquid phase before gasification or the polymerization of C4 and C5 dienes in the measured liquid phase; and a heating zone for preventing the gas phase of the measured liquid phase from remaining non-liquefied after gasification, thereby ensuring that the sampling fraction flowing into the analyzer is in a single gaseous state and ensuring normal sampling and measurement.

[0027] See also Figure 2 The present invention provides a sampling pretreatment system for a high-pressure depropanizer. When in use, the sampling pretreatment system is connected to a sampling pipeline 1 of a high-pressure depropanizer to take samples, and the liquid phase medium in the kettle of the high-pressure depropanizer is depressurized, impurities removed, and gasified. When in use, the sampling pretreatment system is connected to an analyzer 2 for sampling and analysis, and the gaseous phase medium that has been gasified is passed into the analyzer 2 in a single gaseous form, and the separation performance of the high-pressure depropanizer is evaluated by analyzing the components in the measured gaseous phase medium. When in use, the sampling pretreatment system is also connected to a flare system 3, which is used to process the gaseous phase medium after sampling and testing and the depressurized sampling gas, and to treat the sampled waste gas to avoid environmental pollution.

[0028] See also Figure 1 The sampling pretreatment system includes a filter 4, a gasification device 5, a liquid blocking system 6, a sampling recovery system 7 and a pretreatment box 8; in order to prevent solid particles or impurities contained in the liquid phase sampled from the high-pressure depropanizer sampling pipeline 1 from entering the analyzer 2, causing the precision pipeline or air inlet in the analyzer 2 to be blocked, thereby protecting the chromatographic column of the analyzer 2 and extending its service life, a filter 4 is arranged in the sampling pretreatment system, and the liquid inlet of the filter 4 is connected to the high-pressure depropanizer sampling pipeline 1 pipeline for removing impurities and filtering the liquid phase to be tested after sampling. The liquid outlet of the filter 4 is connected to the liquid inlet pipeline of the gasification device 5, so that the liquid phase to be tested after being filtered by the filter 4 is passed into the gasification device 5, and the gasification device 5 is decompressed and gasified to convert the liquid phase to be tested into the gas phase to be tested; the gas outlet of the gasification device 5 is connected to the gas inlet pipeline of the liquid blocking system 6, and the liquid blocking system 6 is used to remove the dissolved liquid in the part of the liquid phase to be tested or the gas phase that is not completely gasified, so as to prevent the liquid from passing into the analyzer 2 and affecting the detection performance and accuracy of the analyzer 2. The gas outlet of the liquid blocking system 6 is connected to the gas inlet pipeline of the analyzer 2, and the gas phase to be tested after the liquid phase is filtered is passed into the analyzer 2 for analysis and detection. The gas inlet of the sampling recovery system 7 is connected to the gas outlet pipeline of the analyzer 2, and the gas outlet of the sampling recovery system 7 is connected to the pipeline of the torch system 3, and the gas phase analyzed by the analyzer 2 is returned to the sampling pretreatment system, and the gas phase is prevented from being liquefied through the pipeline of the sampling recovery system 7, and finally flows into the torch system 3 for waste gas treatment.

[0029] The pretreatment box 8 is a closed installation box structure of the sampling pretreatment system, which is used to set the above-mentioned filter 4, gasification device 5, liquid blocking system 6, sampling recovery system 7 and their respective connecting pipelines; wherein, the pretreatment box 8 is divided into a non-heating zone 81 and a heating zone 82, and the non-heating zone 81 is equipped with a filter 4 and a gasification device 5 and a connecting pipeline through which the liquid phase to be tested after sampling from the high-pressure depropanizer sampling pipeline 1 flows. The temperature in the non-heating zone 81 is room temperature, and there is no additional heating or temperature control. When the liquid phase to be tested circulates in the pipeline, it is prevented from being overheated to cause the polymerization and scaling of C4 and C5 dienes in the liquid phase to be tested, thereby causing coking and blockage in the pipeline, and no sample flows through the chromatograph to distort the measurement; and it is prevented from preventing the C2 and light fractions in the liquid phase to be tested from overflowing, and avoiding the generation of bubbles in the liquid phase to be tested, so that the gasification efficiency of the gasification device 5 on the liquid phase to be tested is reduced, affecting the authenticity and accuracy of the analysis results of the analyzer 2. The liquid-blocking system 6, the sampling and recovery system 7, and the connecting pipeline for the gas phase to be measured to circulate are arranged in the heating zone 82; the heating zone 82 has a device for heating and temperature control in the zone, such as heating by a heating device or temperature control of the heating zone 82 by introducing other heat sources in the chemical refining process; the temperature control method can be manually detected and controlled, or it can be detected and controlled by a sensor, so that the temperature of the heating zone 82 is maintained within a certain temperature range, and in the heating zone 82 within this temperature range, the gas phase to be measured after being gasified by the gasification device 5 can be maintained in a gasified state in the conveying pipeline to avoid re-liquefaction, so that the liquid phase to be measured can be passed into the analyzer 2 in a single gas phase state; at the same time, the gas phase analyzed in the sampling and recovery system 7 is maintained in a gas phase state and smoothly flows into the flare system 3 for waste gas treatment, wherein the temperature range of the temperature control in the heating zone 82 is based on avoiding liquefaction of the gas phase transported in the conveying pipeline in its area.

[0030] In this embodiment, the filter 4 can be any suitable type of filter device that can remove impurities from the sampled liquid phase and can be obtained through general commercial means; the gasification device 5 can be any suitable type of device that can reduce the pressure of the liquid phase to be tested and convert it into the gas phase to be tested; in this embodiment, the gasification device 5 adopts an electrical gasification valve, which converts the liquid phase to be tested into the gas phase to be tested. The electrical gasification valve can be obtained through general commercial means and will not be described in detail here.

[0031] See also Figure 1 and Figure 3In an example of the sampling pretreatment system of the present invention, the liquid blocking system 6 includes a liquid blocking device 61, a liquid accumulation tank 62 and an automatic liquid drain tank 63. The air inlet of the liquid blocking device 61 is connected to the air outlet pipeline of the gasification device 5, and the air outlet of the liquid blocking device 61 is connected to the air inlet pipeline of the analyzer 2; the liquid blocking device 61 selectively filters the liquid phase and the gas phase to be measured that are not completely gasified by the gasification device 5, so that the gas phase entering the analyzer 2 is a single-phase gas phase, and prevents the liquid phase and the dissolved liquid in the gas phase from being brought into the analyzer 2; the liquid inlet of the liquid accumulation tank 62 is connected to the liquid outlet pipeline of the liquid blocking device 61, and is used to collect and store the liquid phase selectively filtered by the liquid blocking device 61; the liquid inlet of the automatic liquid drain tank 63 is connected to the liquid outlet pipeline of the liquid accumulation tank 62. When the liquid accumulation height in the liquid accumulation tank 62 reaches the preset liquid level height, the automatic liquid drain tank 63 automatically drains the liquid to prevent the liquid from overflowing back to the liquid blocking device 61 along the pipeline, thereby forming double-sided protection.

[0032] See also Figure 2 In an example of the sampling pretreatment system of the present invention, the sampling recovery system 7 includes a first pneumatic valve 71, the air inlet of the first pneumatic valve 71 is connected to the air outlet pipeline of the analyzer 2, and the air outlet of the first pneumatic valve 71 is connected to the pipeline of the flare system 3, so that the gas phase detected and discharged from the analyzer 2 is passed into the flare system 3 to complete the circulation of the gas phase. Furthermore, the air outlet of the first pneumatic valve 71 is connected to the liquid inlet pipeline of the liquid accumulation tank 62, which is used to conduct the gas in the liquid accumulation tank 62 so that the liquid phase in the liquid accumulation tank 62 can smoothly enter the automatic liquid drain tank 63. At the same time, the liquid phase remaining in the first pneumatic valve 71 is collected. In this embodiment, a first flow meter 13 is also provided on the connecting pipeline between the air inlet of the first pneumatic valve 71 and the air outlet of the analyzer 2. The first flow meter 13 is used to detect the gas flow rate flowing through the pipeline and provide accurate flow data.

[0033] See also Figure 1 In an example of the sampling pretreatment system of the present invention, the sampling recovery system 7 also includes a second pneumatic valve 72, which is used for on-site discharge of the gas flowing through the pipeline system at the initial stage of sampling. The air inlet of the second pneumatic valve 72 is connected to the connecting pipeline between the air inlet of the first pneumatic valve 71 and the air outlet of the analyzer 2. The air outlet pipeline of the second pneumatic valve 72 is connected to the outside of the pretreatment box 8. During the sampling to the detection system, the gas in the system pipeline is discharged directly on-site after passing through a dehydrogenator (not shown). It should be noted that the dehydrogenator is a device specially designed to remove hydrocarbon substances from the air, and is widely used in industries such as petrochemicals. Its function and structure are well known in the industry and can be obtained through general commercial means, so it will not be repeated here.

[0034] See also Figure 2In an example of the sampling pretreatment system of the present invention, the sampling pretreatment system also includes a first stop valve 9, which is arranged on the connecting pipe of the liquid inlet of the filter 4, and the first stop valve 9 is located in the non-heating area 81. The first stop valve 9 is used to control the pipeline on and off of the sampled liquid phase to be tested between the sampling pretreatment system and the high-pressure depropanizer sampling pipeline 1. In this embodiment, the first stop valve 9 adopts a needle valve, and the liquid flow rate flowing through the valve is accurately adjusted by the needle valve to achieve micro-adjustment to meet the micro-supply demand of the analyzer 2.

[0035] See also Figure 1 In an example of the sampling pretreatment system of the present invention, the sampling pretreatment system also includes a pressure relief valve 10, the air inlet of the pressure relief valve 10 is connected to the connecting pipe between the gasification device 5 and the liquid blocking system 6, and the air outlet of the pressure relief valve 10 is connected to the pipeline of the flare system 3; specifically, the pressure relief valve 10 is located in the heating zone 82, and a first pressure gauge 14 is arranged on the connecting pipe at the air inlet end of the gasification device 5, and the first pressure gauge 14 is used to monitor the pressure of the liquid phase to be measured in the sampling pipeline, and a second pressure gauge 15 is arranged on the connecting pipe at the air outlet end of the gasification device 5, and the second pressure gauge 15 is used to monitor the gas pressure on the connecting pipe at the air outlet end of the gasification device 5. When the gas pressure in the connecting pipe exceeds the predetermined safety limit, the pressure relief valve automatically opens to release the pressure, protects the system and the pipeline, and prevents accidents.

[0036] See also Figure 2 In an example of the sampling pretreatment system of the present invention, the high-pressure depropanizer sampling pipeline 1 includes a sampling pipeline 101, a sampling ball valve 102, a return ball valve 103 and a return pipeline 104. The sampling pipeline 101 samples the liquid phase in the bottom part of the high-tower depropanizer and returns it to the bottom of the tower through the sampling ball valve 102, the return ball valve 103 and the return pipeline 104 in sequence. The pipeline between the sampling ball valve 102 and the return ball valve 103 is connected to the liquid inlet of the first stop valve 9, and the liquid phase to be tested flowing in the pipeline is passed into the sampling pretreatment system to complete the sampling.

[0037] See also Figure 1In an example of the sampling pretreatment system of the present invention, the sampling pretreatment system also includes an electric heater 11 and a temperature sensor 16. The electric heater 11 is located in the heating zone 82. The electric heater 11 is used to heat the temperature of the heating zone 82 in the pretreatment box 8 to prevent the gas phase in the pipeline flowing through the heating zone 82 from liquefying; the temperature sensor 16 is used to detect the heating temperature in the heating zone 82 and communicate with the electric heater 11. When the temperature sensor 16 detects that the temperature of the heating zone 82 reaches the required temperature range, the control system can control the electric heater 11 to work intermittently, thereby saving energy consumption. The electric heater 11 and the temperature sensor 16 can be any suitable heating device type that can heat and control the temperature of the space, and can be obtained through general commercial means.

[0038] See also Figure 1 In an example of the sampling pretreatment system of the present invention, the sampling pretreatment system also includes a nitrogen ball valve 12, the air inlet pipe of the nitrogen ball valve 12 is connected to the outside of the pretreatment box 8, and the air outlet of the nitrogen ball valve 12 is connected to the connecting pipe between the filter 4 and the gasification device 5; during system maintenance, nitrogen is back-flushed into the nitrogen ball valve 12 and its connecting pipe to replace and remove the liquid phase in the pipe to ensure work safety during maintenance.

[0039] See also Figure 2 The present invention also provides a sampling monitoring system for a high-pressure depropanizer, comprising a high-pressure depropanizer sampling pipeline 1, an analyzer 2, a flare system 3 and any one of the above-mentioned sampling pretreatment systems, wherein the high-pressure depropanizer sampling pipeline 1 is used for the circulation of the sampled liquid phase of the high-pressure depropanizer, and is connected to the liquid inlet pipeline of the sampling pretreatment system, so that the sampled liquid phase is passed into the sampling pretreatment system; the gas outlet of the sampling pretreatment system is connected to the gas inlet pipeline of the analyzer 2, and the sampling pretreatment system filters and decompresses the sampled liquid phase to be tested, and then converts the single The gas phase is passed into the analyzer 2 for analysis and detection, and the gas outlet of the analyzer 2 is connected to the gas inlet pipeline of the sampling pretreatment system. After the analysis of the analyzer 2 is completed, the gas phase flowing out enters the sampling pretreatment system again, and enters the flare system 3 through the sampling recovery system 7 and its pipeline; the exhaust port of the sampling pretreatment system includes the gas outlet of the connecting pipeline of the sampling recovery system 7, and the outlet of the gas outlet connecting pipeline of the pressure relief valve 10 in the sampling pretreatment system. The sampling gas discharged from the pretreatment box 8 in the form of gas phase is connected to the pipeline of the flare system 3 for gas phase treatment.

[0040] In an example of the sampling monitoring system of the present invention, the analyzer 2 described in any of the above examples adopts an online chromatograph. In this embodiment, the online chromatograph is widely used in the petrochemical field, especially in the real-time monitoring and control of the depropanizer tower due to its high separation efficiency, fast analysis speed, high sensitivity and easy automation. It can be obtained through general commercial means, and its function and structure are well known in the industry. Therefore, its substantial content will not be described in detail here.

[0041] In an example of the sampling monitoring system of the present invention, the flare system 3 described in any of the above examples is a commonly used special combustion facility used in industrial facilities such as petrochemical plants, refineries, chemical plants, etc. to treat flammable and flammable toxic gases and steam that cannot be recovered and reprocessed. It is widely adopted in the field of petrochemicals, and its functions and structure are well known in the industry, so its essential contents are not described in detail.

[0042] The sampling pretreatment system and sampling monitoring system of the high-pressure depropanizer of the present invention have the advantages of realizing decompression gasification in the non-heating zone, preventing carbon two and light fractions from overflowing before gasification, and the fraction after gasification is not liquefied in the heating zone, so that the sampled sample can flow into the analyzer in a single gas phase state for analysis, and achieve the beneficial effect of stable, accurate and long-term operation of the analyzer. Therefore, the present invention effectively overcomes some practical problems in the prior art and has a high utilization value and use significance. The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Anyone familiar with this technology can modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A sampling pretreatment system for a high-pressure depropanizer, characterized in that: include: A filter, wherein the liquid inlet of the filter is connected to a high-pressure depropanizer sampling line pipeline; A gasification device, wherein the liquid inlet of the gasification device is connected to the liquid outlet pipeline of the filter; A liquid-blocking system, wherein the air inlet of the liquid-blocking system is connected to the air outlet pipeline of the gasification device; the air outlet of the liquid-blocking system is connected to the air inlet pipeline of the analyzer; A sampling and recovery system, wherein the air inlet of the sampling and recovery system is connected to the air outlet pipeline of the analyzer, and the air outlet of the sampling and recovery system is connected to the pipeline of the flare system; A pre-treatment box, the pre-treatment box comprising a non-heating zone and a heating zone; Among them, the filter, the gasification device and the connecting pipe for the flow of the liquid phase to be tested are located in the non-heating area; the liquid blocking system, the sampling recovery system and the connecting pipe for the flow of the gas phase to be tested are located in the heating area.

2. The sampling pretreatment system according to claim 1, characterized in that: The liquid blocking system comprises: A liquid blocker, wherein the air inlet of the liquid blocker is connected to the air outlet pipeline of the gasification device, and the air outlet of the liquid blocker is connected to the air inlet pipeline of the analyzer; A liquid storage tank, wherein the liquid inlet of the liquid storage tank is connected to the liquid outlet pipeline of the liquid blocker; An automatic liquid draining tank, wherein the liquid inlet of the automatic liquid draining tank is connected to the liquid outlet pipeline of the liquid accumulation tank.

3. The sampling pretreatment system according to claim 2, characterized in that: The sampling recovery system comprises a first pneumatic valve, the air inlet of the first pneumatic valve is connected to the air outlet pipeline of the analyzer, and the air outlet of the first pneumatic valve is connected to the pipeline of the flare system.

4. The sampling pretreatment system according to claim 3, characterized in that: The air outlet of the first pneumatic valve is connected to the liquid inlet pipeline of the liquid accumulation tank.

5. The sampling pretreatment system according to claim 3, characterized in that: The sampling recovery system also includes a second pneumatic valve, the air inlet of the second pneumatic valve is connected to the connecting pipe between the air inlet of the first pneumatic valve and the air outlet of the analyzer, and the air outlet pipe of the second pneumatic valve is connected to the outside of the pretreatment box.

6. The sampling pretreatment system according to claim 1, characterized in that: The sampling pretreatment system further comprises a first stop valve, which is arranged on a connecting pipeline of a liquid inlet of the filter, and the first stop valve is located in the non-heating area.

7. The sampling pretreatment system according to claim 1, characterized in that: The sampling pretreatment system also includes a pressure relief valve, the air inlet of the pressure relief valve is connected to the connecting pipeline between the gasification device and the liquid blocking system, and the air outlet of the pressure relief valve is connected to the flare system pipeline.

8. The sampling pretreatment system according to claim 1, characterized in that: The sampling pretreatment system further includes an electric heater, which is located in the heating zone.

9. The sampling pretreatment system according to claim 1, characterized in that: The sampling pretreatment system further comprises a nitrogen ball valve, the gas outlet of which is connected to the connecting pipe between the filter and the gasification device.

10. A sampling and monitoring system for a high-pressure depropanizer, comprising a high-pressure depropanizer sampling pipeline, an analyzer and a flare system, characterized in that: It also includes a sampling pretreatment system according to any one of claims 1 to 9, wherein the high-pressure depropanizer sampling pipeline is connected to the liquid inlet pipeline of the sampling pretreatment system; the air outlet of the sampling pretreatment system is connected to the air inlet pipeline of the analyzer, the air outlet of the analyzer is connected to the air inlet pipeline of the sampling pretreatment system, and the exhaust port of the sampling pretreatment system is connected to the flare system pipeline.

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