Gas-liquid dual-purpose device and method for real-time determination of sulfur content in pipeline products

Abstract

The application provides a device and method for real-time determination of sulfur content in pipeline products, which is provided with a liquid-phase interface, a gas-phase interface and a combustion-supporting gas interface, a stop valve is arranged downstream of the liquid-phase interface and is communicated to No. 4 port of a six-way sampling valve, No. 1 port of the six-way sampling valve is communicated to a flash module and then to a reaction tube, the downstream of the reaction tube is communicated to an ultraviolet fluorescence detector; the gas-phase interface is a carrier gas interface or a gas sample interface; the combustion-supporting gas interface is selectively communicated to the gas-phase interface or a combustion-supporting gas inlet of the reaction tube through a three-way mixed gas valve; a fixed-volume quantitative ring is connected between No. 3 port and No. 6 port of the six-way sampling valve. According to the application, whether the sample to be measured is a liquid sample or a gas sample, only a branch pipe from a production line is needed to be introduced to the device, real-time monitoring of the product can be realized, and the test result can be transmitted to a factory control room without delay.

Description

Technical Field

[0001] This invention relates to a device for determining the sulfur content in liquefied petroleum gas, gaseous samples, hydrocarbon fuels, and related chemical products. Background Technology

[0002] Sulfur content is an important indicator for the detection of liquefied petroleum gas (LPG), gaseous hydrocarbon fuels, and related chemical products. With increasingly stringent environmental protection requirements, it is essential to control the sulfur content in fuels and related chemical products to reduce the amount and concentration of pollutants emitted. Online monitoring of sulfur content is of great significance for improving the processing of natural gas and LPG and enhancing the quality of these products.

[0003] In refineries and related petrochemical production enterprises, the equipment used to analyze the total sulfur content in natural gas and liquefied petroleum gas products is an ultraviolet fluorescence analyzer. This equipment is installed in the laboratory, requiring staff to periodically collect samples from designated locations and then send them to the laboratory for analysis. Therefore, the testing cycle is long, taking at least several hours, and cannot promptly reflect problems in the production process. By the time problems are discovered, a large quantity of product has already been produced, resulting in significant losses.

[0004] While instruments capable of continuously analyzing sulfur content in liquids and gases in pipelines have been developed in factories, their measurement intervals are still more than 5 minutes, and they still cannot achieve true real-time continuous analysis. Summary of the Invention

[0005] The purpose of this invention is to provide a gas-liquid dual-purpose device and method for real-time determination of sulfur content in pipeline products, which can be applied to production lines to perform real-time continuous analysis of the sulfur content of materials in production pipelines.

[0006] The technical means employed in this invention are as follows:

[0007] A gas-liquid dual-purpose device for real-time determination of sulfur content in pipeline products, characterized in that it is provided with a liquid phase interface, a gas phase interface, and a combustion-supporting interface, wherein:

[0008] Downstream of the liquid phase interface is a shut-off valve connected to port 4 of the six-way injection valve. Port 1 of the six-way injection valve is connected to a flash evaporation module, which is then connected to the reaction tube. Downstream of the reaction tube is connected to the ultraviolet fluorescence detector.

[0009] The gas phase interface is a carrier gas interface or a gas sample interface, and a shut-off valve is provided downstream of it and connected to port A of a three-way valve. Port B of the three-way valve is connected to port 2 of the six-way injection valve.

[0010] Downstream of the combustion-supporting gas interface is a shut-off valve connected to the common inlet of a three-way mixing valve. The first outlet of the three-way mixing valve is connected to port C of the three-way valve, and the second outlet of the three-way mixing valve is connected to the combustion-supporting gas inlet of the reaction tube.

[0011] A fixed-volume quantitative ring is connected between port 3 and port 6 of the six-way injection valve, and port 5 of the six-way injection valve is connected to the waste liquid outlet through a shut-off valve.

[0012] The six-way injection valve can switch between two connection modes. In the first connection mode, port 2 is connected to port 1, port 4 is connected to port 3, and port 6 is connected to port 5. In the second connection mode, port 2 is connected to port 3, port 4 is connected to port 5, and port 6 is connected to port 1.

[0013] The gas-liquid dual-purpose real-time sulfur content determination device for pipeline products further includes: a calibration interface, which is a standard liquid sample inlet, with a shut-off valve downstream and connected to the first inlet of a three-way switching valve; the liquid phase interface is connected to the second inlet of the three-way switching valve; and the common outlet of the three-way switching valve is connected to port 4 of the six-way injection valve.

[0014] The gas-liquid dual-purpose real-time sulfur content determination device for pipeline products, wherein: the downstream of the reaction tube is connected to a mode dryer and then to the ultraviolet fluorescence detector.

[0015] The aforementioned gas-liquid dual-purpose real-time sulfur content determination device for pipeline products includes: a sample gas outlet and a flow sensor in the ultraviolet fluorescence detector; and flow controllers in the downstream pipeline of the gas phase interface and the downstream pipeline of the combustion-supporting interface.

[0016] A method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose device, characterized by:

[0017] When a liquid sample is connected upstream of the liquid phase interface, the shut-off valve downstream of the liquid phase interface is opened. Clean air is connected upstream of both the gas phase interface and the combustion-supporting gas interface, or an inert gas is connected upstream of the gas phase interface and oxygen is connected upstream of the combustion-supporting gas interface.

[0018] When a gas sample is connected upstream of the gas phase interface, the shut-off valve downstream of the liquid phase interface is closed, and clean air is connected upstream of the combustion-supporting gas interface.

[0019] The method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method, wherein:

[0020] When clean air is connected to both the upstream of the gas phase interface and the upstream of the combustion-supporting interface, the reaction tube is a reaction tube filled with catalyst.

[0021] When an inert gas is connected upstream of the gas phase interface and oxygen is connected upstream of the combustion-supporting interface, the reaction tube is a multi-layer reaction tube in which sample gasification and combustion are independent.

[0022] The method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method, wherein:

[0023] When a liquid sample is connected upstream of the liquid phase interface, the liquid sample in the pipeline to be tested enters port 4 of the six-way injection valve. If the six-way injection valve is in the first connection mode, the liquid sample flows through port 3 through the fixed volume quantitative loop, and then through ports 6 and 5 to be discharged from the waste liquid outlet, which serves to flush the pipeline and the fixed volume quantitative loop. After the predetermined flushing time is over, the shut-off valve at port 5 is closed, and the liquid sample fills the fixed volume quantitative loop.

[0024] Then the six-way injection valve switches to the second connection mode, and the carrier gas entering from port 2 is connected to port 3, carrying the liquid sample stored in the fixed volume quantitative loop into the flash evaporation module through port 6 and port 1; the quantitative liquid sample will undergo flash evaporation in the flash evaporation module and then enter the reaction tube in gas form; the combustion gas will enter the reaction tube through the combustion gas inlet;

[0025] After the six-way injection valve switches to the second connection mode for a certain period of time, the three-way mixing gas valve switches to the new state. The combustion gas in the combustion gas interface is connected to port C of the three-way valve, so that the carrier gas in the gas phase interface and the combustion gas in the combustion gas interface are combined and flow through port 2 of the six-way injection valve. By increasing the gas flow rate through the fixed volume quantitative loop, the liquid sample that may remain inside the fixed volume quantitative loop is brought into the flash evaporation module to avoid subsequent sample contamination.

[0026] Afterwards, the gas that reacted in the reaction tube entered the ultraviolet fluorescence detector for sulfur content detection;

[0027] After the test, the three-way mixing valve switches its state, the combustion gas in the combustion gas interface is connected to the combustion gas inlet of the reaction tube, the six-way injection valve switches to the first connection mode, and the shut-off valve at port 5 is opened, so that the liquid sample is flushed again and filled with the fixed volume quantitative loop. This process is repeated continuously, while maintaining uninterrupted connection between the liquid phase interface and the liquid sample, and high-frequency detection of the liquid sample is performed.

[0028] The method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method, wherein:

[0029] When the sample in the pipeline to be tested is a gas, all the shut-off valves downstream of the liquid phase interface are closed. The gas sample enters port 2 of the six-way injection valve through the gas phase interface, enters the flash evaporation module from port 1, and then enters the reaction tube. The flash evaporation module is not working.

[0030] The combustion gas enters the common inlet of the three-way mixing valve through the combustion gas interface, and then enters the combustion gas inlet of the reaction tube;

[0031] The gas sample reacts with the combustion-supporting gas in the reaction tube to form a combustion reaction, and the gas after the reaction enters the ultraviolet fluorescence detector for continuous detection of sulfur content.

[0032] The method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method, wherein:

[0033] The gas-liquid dual-purpose real-time sulfur content determination device for pipeline products is also equipped with a calibration interface. The calibration interface is a standard liquid sample inlet, and a shut-off valve is provided downstream of it, which is connected to the first inlet of the three-way switching valve. The liquid phase interface is connected to the second inlet of the three-way switching valve. The common outlet of the three-way switching valve is connected to port 4 of the six-way injection valve.

[0034] When a liquid sample is connected upstream of the liquid phase interface, the three-way switching valve switches periodically or irregularly.

[0035] The gas-liquid dual-purpose real-time sulfur content measurement device and method for pipeline products provided by this invention can be installed on the production line. Regardless of whether the sample to be tested is a liquid or gas sample, as long as a branch pipe is led out from the production line to this device, the product can be monitored in real time, and the analysis results can be transmitted to the production department or quality control department. This allows for timely detection of problems in the production process and adjustment of the process to avoid major losses. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0037] Figure labeling: Calibration interface 1; Liquid phase interface 2; Gas phase interface 3; Combustion gas interface 4; Shut-off valve 5; Three-way switching valve 6; Six-way injection valve 7; Flash evaporation module 8; Reaction tube 9; Pressure sensor 10; Flow controller 11; Three-way mixing valve 12; Combustion gas inlet 13; Fixed volume quantitative loop 14; Waste liquid outlet 15; Mode dryer 16; Ultraviolet fluorescence detector 17; Sample gas outlet 18; Flow sensor 19. Detailed Implementation

[0038] like Figure 1As shown, this invention provides a gas-liquid dual-purpose device for real-time determination of sulfur content in pipeline products, comprising a calibration interface 1, a liquid phase interface 2, a gas phase interface 3, and a combustion-supporting interface 4, wherein:

[0039] The calibration interface 1 is a standard liquid sample inlet, which is connected to the first inlet of the three-way switching valve 6 through the shut-off valve 5.

[0040] The liquid phase interface 2 is the inlet for liquid samples (typically liquefied gas samples), which is connected to the second inlet of the three-way switching valve 6 through the shut-off valve 5.

[0041] The common outlet of the three-way switching valve 6 is connected to port 4 of a six-way injection valve 7, and port 1 of the six-way injection valve 7 is connected to a flash evaporation module 8, which is then connected to the reaction tube 9.

[0042] The gas phase interface 3 is a carrier gas interface or a gas sample interface, which is connected to port A of a three-way valve through a shut-off valve 5, a pressure sensor 10, and a flow controller 11. Port B of the three-way valve is connected to port 2 of the six-way injection valve 7.

[0043] The combustion-supporting interface 4 is a combustion-supporting interface 4, which is connected to the common inlet of a three-way mixing valve 12 through a shut-off valve 5, a pressure sensor 10, and a flow controller 11. The first outlet of the three-way mixing valve 12 is connected to the C port of the three-way valve, and the second outlet of the three-way mixing valve 12 is connected to the combustion-supporting inlet 13 of the reaction tube 9.

[0044] A fixed-volume quantitative ring 14 is connected between port 3 and port 6 of the six-way injection valve 7, and port 5 of the six-way injection valve 7 is connected to the waste liquid outlet 15 through the shut-off valve 5.

[0045] The six-way injection valve 7 can switch between two connection modes. In the first connection mode, port 2 is connected to port 1, port 4 is connected to port 3, and port 6 is connected to port 5. In the second connection mode, port 2 is connected to port 3, port 4 is connected to port 5, and port 6 is connected to port 1.

[0046] The downstream of the reaction tube 9 is connected to the mode dryer 16 and then to the ultraviolet fluorescence detector 17. The ultraviolet fluorescence detector 17 is provided with a sample gas outlet 18 and a flow sensor 19.

[0047] The present invention employs the above-described structure and is a device capable of real-time determination of the total sulfur content in different types of hydrocarbons such as liquids, gases, and liquefied petroleum gases in pipelines using ultraviolet fluorescence method. It can use only clean air as the carrier gas and combustion-supporting gas, or it can use argon (or inert gases such as helium) as the carrier gas and oxygen as the combustion-supporting gas.

[0048] The present invention adopts the above structure. When the sample type in the pipeline to be tested changes, there is no need to modify the equipment itself. Only the corresponding setting parameters need to be modified according to the sample type to continue monitoring. There is no need to purchase new equipment or modify the existing equipment according to the sample type in the pipeline, which not only saves time but also avoids a lot of economic expenditure.

[0049] The following examples illustrate how to use this invention:

[0050] 1. When the sample in the pipeline to be tested is a liquid (typically liquefied gas), calibration interface 1 is connected to a standard liquid sample for calibration; liquid phase interface 2 is connected to the pipeline to be tested.

[0051] In this case, clean air can be used as both the gas phase interface 3 and the combustion-supporting interface 4 as the carrier gas and the combustion-supporting gas, or argon (or helium or other inert gas) can be used as the carrier gas while oxygen is used as the combustion-supporting gas at the combustion-supporting interface 4.

[0052] If clean air is used as both the carrier gas and the combustion-supporting gas, a reaction tube 9 filled with an internal catalyst is preferred (e.g., patent number ZL201910403393.3). Clean air contains approximately 20% oxygen. When air mixed with a small amount of oxygen is used as a carrier gas at low temperatures, the sample will not burn. However, at high temperatures, the sample can burn completely under the action of the catalyst. If an inert gas is used as the carrier gas and oxygen is used as the combustion-supporting gas, a multi-layer reaction tube 9 with an internal structure that separates sample vaporization and combustion is preferred (e.g., patent number ZL202011186013.4).

[0053] After calibration is completed (the calibration process is the same as the liquid sample detection process described below), the liquid sample in the pipeline to be tested enters port 4 of the six-way injection valve 7 through the liquid phase interface 2 and the three-way switching valve 6. If the six-way injection valve 7 is in the first connection mode, the liquid sample flows through port 3 through the fixed volume quantitative ring 14, and then through port 6 and port 5 (the shut-off valve 5 of port 5 is open) and is discharged from the waste liquid outlet 15, which serves to flush the pipeline and the fixed volume quantitative ring 14. After the predetermined flushing time is completed, the shut-off valve 5 of port 5 is closed, and the liquid sample fills the fixed volume quantitative ring 14. At this time, the liquid sample in the pipeline is under a fixed pressure, which ensures that there are no air bubbles in the fixed volume quantitative ring 14, thereby ensuring quantitative consistency.

[0054] Then, the six-way injection valve 7 switches to the second connection mode, and the carrier gas (air or inert gas) entering from port 2 is connected to port 3, carrying the liquid sample stored in the fixed volume quantitative loop 14 into the flash evaporation module 8 through ports 6 and 1; the quantitative liquid sample will undergo flash evaporation in the flash evaporation module 8, and then enter the reaction tube 9 in gas form; the combustion gas will enter the reaction tube 9 through the combustion gas inlet 13.

[0055] In order to avoid liquid samples remaining in the fixed volume metering loop 14 due to viscosity differences, after the six-way injection valve 7 switches to the injection state (second connection mode) for a certain period of time, the three-way mixing gas valve 12 switches to the state (the combustion gas in the combustion gas interface 4 is connected to port C of the three-way valve), so that the carrier gas in the gas phase interface 3 and the combustion gas in the combustion gas interface 4 are combined and flow through port 2 of the six-way injection valve 7. By increasing the gas flow rate through the fixed volume metering loop 14, the liquid sample that may remain in the fixed volume metering loop 14 is carried into the flash evaporation module 8, thus avoiding contamination of subsequent samples.

[0056] The flash evaporation module 8 is temperature-adjustable and can be set to a suitable vaporization temperature according to the sample components. Its temperature adjustment range is from room temperature to up to 500°C. During analysis, the flash evaporation temperature only needs to be set in the workstation, which can adapt to liquid samples with different components.

[0057] Afterwards, the gas that reacted in the reaction tube 9 passed through the pattern dryer 16 and entered the ultraviolet fluorescence detector 17 for sulfur content detection.

[0058] After the test, the three-way mixing gas valve 12 switches its state (the combustion gas in the combustion gas interface 4 is connected to the combustion gas inlet 13 of the reaction tube 9), the six-way injection valve 7 switches to the first connection mode, and the shut-off valve 5 at port 5 is opened, so that the liquid sample is flushed again and filled with the fixed volume quantitative ring 14. This process is repeated continuously, and while maintaining uninterrupted connection between the liquid phase interface 2 and the liquid sample, the liquid sample is subjected to high-frequency detection.

[0059] By adopting the above method, liquid samples (including liquefied gas samples) can be quantified through a metering loop. The shut-off valve 5 installed at port 5 can be closed electronically (programmed) during sample quantification, which allows the liquid sample to be quantified in liquid form and prevents the presence of air bubbles, thus ensuring the consistency of the sample quantity.

[0060] In the above method, the standard sample and the liquid sample are independent interfaces, and the three-way switching valve 6 can be switched periodically (or irregularly) through electronic control (program setting), thereby periodically (or irregularly) monitoring and correcting the operating status of the device of the present invention, and ensuring the reliability of the data results.

[0061] 2. When the sample in the pipeline to be tested is a gas, the shut-off valves 5 of calibration interface 1 and liquid interface 2 are closed, gas interface 3 is connected to the pipeline to be tested, and gas-supporting interface 4 is connected to the gas-supporting gas.

[0062] The gas sample enters port 2 of the six-way injection valve 7 through the gas phase interface 3, enters the flash evaporation module 8 through port 1, and then enters the reaction tube 9; wherein, the flash evaporation module 8 is not in operation;

[0063] The combustion gas enters the common inlet of the three-way mixing valve 12 through the combustion gas interface 4, and then enters the combustion gas inlet 13 of the reaction tube 9;

[0064] The gas sample reacts with the combustion-supporting gas in the reaction tube 9 to form a combustion reaction. The gas after the reaction passes through the mode dryer 16 and enters the ultraviolet fluorescence detector 17 for continuous sulfur content detection.

[0065] In this mode, the gas sample is continuously injected without the need for quantitative loops. That is, the gas sample enters the reaction tube 9 continuously at a fixed flow rate, and the test results are output in real time.

[0066] In this mode, the flow sensor 19 installed at the sample gas outlet 18 of the ultraviolet fluorescence detector 17 detects the gas flow rate out of the ultraviolet fluorescence detector 17 in real time. When the gas flow rate out of the ultraviolet fluorescence detector 17 is less than the set value (or less than the sum of the gas flow rates detected by the two flow controllers 11 of the gas phase interface 3 and the combustion gas interface 4), the sample inlet is quickly closed, the carrier gas and combustion gas are shut off, and an early warning is issued to remind the staff to check the equipment to avoid sample leakage and potential danger, which could cause damage to the equipment and personnel.

[0067] In summary, the gas-liquid dual-purpose real-time sulfur content measurement device and method for pipeline products provided by the present invention can measure the sample introduced from the sample pipeline in real time and transmit the test results to the factory control room without delay.

[0068] If you need to analyze static samples, such as those in sample containers, you only need to add a pump suitable for the sample type to make the sample flow.

[0069] The above description is illustrative only and not restrictive of the present invention. Those skilled in the art can make some modifications, changes or equivalents without departing from the spirit and scope defined by the claims, but all such modifications and changes will fall within the protection scope of the present invention.

Claims

1. A gas-liquid dual-purpose device for real-time determination of sulfur content in pipeline products, characterized in that, It is equipped with a liquid phase interface, a gas phase interface, and a combustion-supporting interface, wherein: Downstream of the liquid phase interface is a shut-off valve connected to port 4 of the six-way injection valve. Port 1 of the six-way injection valve is connected to a flash evaporation module, which is then connected to the reaction tube. Downstream of the reaction tube is connected to the ultraviolet fluorescence detector. The gas phase interface is a carrier gas interface or a gas sample interface, and a shut-off valve is provided downstream of it and connected to port A of a three-way valve. Port B of the three-way valve is connected to port 2 of the six-way injection valve. Downstream of the combustion-supporting gas interface is a shut-off valve connected to the common inlet of a three-way mixing valve. The first outlet of the three-way mixing valve is connected to port C of the three-way valve, and the second outlet of the three-way mixing valve is connected to the combustion-supporting gas inlet of the reaction tube. A fixed-volume quantitative ring is connected between port 3 and port 6 of the six-way injection valve, and port 5 of the six-way injection valve is connected to the waste liquid outlet through a shut-off valve. The six-way injection valve can switch between two connection modes. In the first connection mode, port 2 is connected to port 1, port 4 is connected to port 3, and port 6 is connected to port 5. In the second connection mode, port 2 is connected to port 3, port 4 is connected to port 5, and port 6 is connected to port 1.

2. The gas-liquid dual-purpose real-time sulfur content measurement device for pipeline products according to claim 1, characterized in that: It is also equipped with a calibration interface, which is a standard liquid sample inlet. Downstream of the calibration interface is a shut-off valve and connected to the first inlet of the three-way switching valve. The liquid phase interface is connected to the second inlet of the three-way switching valve. The common outlet of the three-way switching valve is connected to port 4 of the six-way injection valve.

3. The gas-liquid dual-purpose real-time sulfur content measurement device for pipeline products according to claim 1, characterized in that: The downstream of the reaction tube is connected to the mode dryer and then to the ultraviolet fluorescence detector.

4. The gas-liquid dual-purpose real-time sulfur content measurement device for pipeline products according to claim 1, characterized in that: The ultraviolet fluorescence detector is equipped with a sample gas outlet and a flow sensor, and flow controllers are respectively installed in the downstream pipeline of the gas phase interface and the downstream pipeline of the combustion-supporting gas interface.

5. A method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method, characterized in that: Using the liquid-liquid dual-purpose real-time sulfur content determination device as described in any one of claims 1, wherein: When a liquid sample is connected upstream of the liquid phase interface, the shut-off valve downstream of the liquid phase interface is opened. Clean air is connected upstream of both the gas phase interface and the combustion-supporting gas interface, or an inert gas is connected upstream of the gas phase interface and oxygen is connected upstream of the combustion-supporting gas interface. When a gas sample is connected upstream of the gas phase interface, the shut-off valve downstream of the liquid phase interface is closed, and clean air is connected upstream of the combustion-supporting gas interface.

6. The method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method according to claim 5, characterized in that: When clean air is connected to both the upstream of the gas phase interface and the upstream of the combustion-supporting interface, the reaction tube is a reaction tube filled with catalyst. When an inert gas is connected upstream of the gas phase interface and oxygen is connected upstream of the combustion-supporting interface, the reaction tube is a multi-layer reaction tube in which sample gasification and combustion are independent.

7. The method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method according to claim 5, characterized in that: When a liquid sample is connected upstream of the liquid phase interface, the liquid sample in the pipeline to be tested enters port 4 of the six-way injection valve. If the six-way injection valve is in the first connection mode, the liquid sample flows through port 3 through the fixed volume quantitative loop, and then through ports 6 and 5 to be discharged from the waste liquid outlet, which serves to flush the pipeline and the fixed volume quantitative loop. After the predetermined flushing time is over, the shut-off valve at port 5 is closed, and the liquid sample fills the fixed volume quantitative loop. Then the six-way injection valve switches to the second connection mode, and the carrier gas entering from port 2 is connected to port 3, carrying the liquid sample stored in the fixed volume quantitative loop into the flash evaporation module through port 6 and port 1. The quantified liquid sample enters the flash evaporation module for flash evaporation and then enters the reaction tube in gas form; the combustion-supporting gas enters the reaction tube through the combustion-supporting gas inlet. After the six-way injection valve switches to the second connection mode for a certain period of time, the three-way mixing gas valve switches to the new state. The combustion gas in the combustion gas interface is connected to port C of the three-way valve, so that the carrier gas in the gas phase interface and the combustion gas in the combustion gas interface are combined and flow through port 2 of the six-way injection valve. By increasing the gas flow rate through the fixed volume quantitative loop, the liquid sample that may remain inside the fixed volume quantitative loop is brought into the flash evaporation module to avoid subsequent sample contamination. Afterwards, the gas that reacted in the reaction tube entered the ultraviolet fluorescence detector for sulfur content detection; After the test, the three-way mixing valve switches its state, the combustion gas in the combustion gas interface is connected to the combustion gas inlet of the reaction tube, the six-way injection valve switches to the first connection mode, and the shut-off valve at port 5 is opened, so that the liquid sample is flushed again and filled with the fixed volume quantitative loop. This process is repeated continuously, while maintaining uninterrupted connection between the liquid phase interface and the liquid sample, and high-frequency detection of the liquid sample is performed.

8. The method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method according to claim 5, characterized in that: When the sample in the pipeline to be tested is a gas, all the shut-off valves downstream of the liquid phase interface are closed. The gas sample enters port 2 of the six-way injection valve through the gas phase interface, enters the flash evaporation module from port 1, and then enters the reaction tube. The flash evaporation module is not working. The combustion gas enters the common inlet of the three-way mixing valve through the combustion gas interface, and then enters the combustion gas inlet of the reaction tube; The gas sample reacts with the combustion-supporting gas in the reaction tube to form a combustion reaction, and the gas after the reaction enters the ultraviolet fluorescence detector for continuous detection of sulfur content.

9. The method for real-time determination of sulfur content in pipeline products using a gas-liquid dual-purpose method according to claim 5, characterized in that: The gas-liquid dual-purpose real-time sulfur content determination device for pipeline products is also equipped with a calibration interface. The calibration interface is a standard liquid sample inlet, and a shut-off valve is provided downstream of it, which is connected to the first inlet of the three-way switching valve. The liquid phase interface is connected to the second inlet of the three-way switching valve. The common outlet of the three-way switching valve is connected to port 4 of the six-way injection valve. When a liquid sample is connected upstream of the liquid phase interface, the three-way switching valve switches periodically or irregularly.

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