Automatic determination system for water separation index of jet fuel

Abstract

The invention discloses an automatic determination system for a jet fuel water separation index. The automatic determination system comprises an automatic sample injector, an emulsifying and filtering device, a sample receiving and detecting device and a system control device, the automatic sample injector is used for supplying a sample to be detected; the emulsifying and filtering device comprises a sample pool, a liquid adding unit, an ultrasonic emulsifying unit and a propelling unit; the sample receiving and detecting device comprises a moisture coalescer, a sample detecting tube and a light detecting unit which are connected through a pipeline; the bottom of the sample pool is communicated with an automatic sample injector and a moisture coalescer through a valve group; the light detection unit comprises a light source and at least two light detectors; and the system control device is used for controlling the operation of each execution component in the automatic sample injector, the emulsifying and filtering device and the sample receiving and detecting device. According to the determination system, an automatic determination process of sample introduction, emulsification, filtration and optical detection can be realized, the detection efficiency of the water separation index of the jet fuel and the accuracy and reliability of a detection result are remarkably improved, and the dependence on the proficiency of operators is reduced.

Description

Technical Field

[0001] This invention belongs to the field of jet fuel water separation index detection technology, specifically relating to an automatic jet fuel water separation index determination system. Background Technology

[0002] The water separation index (MSEP) is an indicator for evaluating the cleanliness of jet fuel. Excessive surfactants in jet fuel can lead to problems such as difficulty in oil-water separation and water settling, thus affecting the product's MSEP. In aviation applications, if the water separation index of jet fuel is too low, it will seriously affect the dehydration effect of the aircraft fuel system. In high-altitude, low-temperature environments, residual water can easily cause fuel icing, which may lead to engine shutdown and pose a flight safety risk. According to the requirements of the national standard for No. 3 jet fuel (GB 6537-2018), the water separation index of aviation kerosene (hereinafter referred to as aviation fuel) should not be less than 85 when no antistatic agent is added; after adding an antistatic agent, it should not be less than 70. Currently, the relevant standard test methods mainly include: national standard GB 11129-89 "Determination of water separation index of jet fuel (handheld separator method)", industry standard SH / T 0616-95 "Determination of water separation index of jet fuel", and international standards ASTM D8073-22, ASTM D3948-22 and ASTM D7224-23.

[0003] The detection of the water separation index currently mainly uses a portable separator method. However, this method has several problems with the instrument used: 1) Cumbersome and time-sensitive operation: The entire operation requires manual sample replacement three times, involving adding distilled water, venting, installing the water coalescer, installing the syringe, and receiving the filtrate. This demands a high level of operator proficiency, especially after the third sample emulsification, where venting, installing the coalescer, placing the syringe, and connecting the grounding wire must be completed within 30 seconds. Inexperienced operators may find this difficult to perform successfully. 2) Poor operational stability: Improper control of the venting force can easily cause the sample to spray out, leading to detection failure. The final 15% of the filtrate also needs to be collected promptly at the end of the filtration process. mL of sample is used for testing; in addition, the entire operation process is highly dependent on manual labor, and the time between steps is short, and any delay in any link may lead to the failure of the entire test; 3) Consumables are not environmentally friendly: this method requires the use of a large number of disposable plastic syringes and water coalescers, which is not conducive to environmental protection; 4) Other problems: the instrument cannot automatically save and record test data after displaying the results; it only supports single detection and cannot achieve continuous detection; operators must frequently come into contact with samples, which may bring health risks; the entire process depends on manual operation by the operator, and the test results are greatly affected by subjective factors. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an automatic determination system for jet fuel water separation index in order to address the shortcomings of the prior art. This system can realize the automatic determination process of sample introduction, emulsification, filtration and optical detection, which significantly improves the detection efficiency, accuracy and reliability of the detection results of jet fuel water separation index, and reduces the dependence on the skill of the operator.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: an automatic jet fuel water separation index determination system, comprising an automatic sampler, an emulsification and filtration device, a sample receiving and detection device, and a system control device; the automatic sampler is used to supply the sample to be tested; the emulsification and filtration device includes a sample cell, a liquid addition unit for quantitatively adding distilled water to the sample cell, an ultrasonic emulsification unit for emulsifying the sample in the sample cell, and a propulsion unit for pushing the sample out of the sample cell; the sample receiving and detection device includes a water coalescer and a sample detection tube connected by a pipeline, and a device for detecting the sample. A photodetector unit for optical detection of samples inside the tube; the bottom of the sample cell is connected to the autosampler and the moisture coalescer via a valve assembly; the photodetector unit includes a light source and at least two photodetectors, the light source and at least one photodetector being disposed opposite each other on both sides of the sample detection tube for transmitted light detection, and at least one photodetector being configured to receive backscattered light from the sample; the system control device is used to control the operation of each actuator in the autosampler, the emulsification and filtration device, and the sample receiving and detection device to perform an automated measurement process including sample introduction, emulsification, filtration, and optical detection.

[0006] Preferably, the sample cell is shaped like an inverted syringe, and the propulsion unit includes a plunger that seals with the sample cell and a propulsion motor that drives the plunger. The plunger is equipped with an injection port and an exhaust valve, and the injection port is connected to the liquid addition unit. The inverted syringe-shaped sample cell, combined with plunger propulsion, facilitates accurate sample measurement and stable, controllable sample discharge. This structural design simplifies the system structure and improves the coordination and sealing reliability of liquid addition, exhaust, and propulsion operations.

[0007] Preferably, the liquid addition unit includes a first metering tube, a water pump, and a distilled water source connected to the water pump. The liquid inlet is connected to the first metering tube via a six-way liquid addition valve. This liquid addition unit enables precise and automatic metering of distilled water. The first metering tube ensures the accuracy of the added volume of distilled water, ensuring the consistency and repeatability of the amount of aqueous phase added during emulsification, so as to ultimately obtain an accurate water separation index.

[0008] Preferably, the ultrasonic emulsification unit includes an ultrasonic device, and the sample cell is placed within the accommodating space of the ultrasonic device. Ultrasonic emulsification has high efficiency and stable energy input, ensuring the consistency of emulsification degree between different samples and different batches of the same sample, thereby effectively avoiding errors introduced by manual operation and improving the reproducibility of measurement results.

[0009] Preferably, the sample detection tube is equipped with a top inlet, an overflow outlet, and a bottom outlet with a valve. The design of the top inlet and overflow outlet ensures that the sample detection tube can be completely and air-free filled with the sample to be tested, thereby ensuring a consistent liquid layer thickness during each optical detection. The bottom valve facilitates precise control of waste liquid discharge after detection or the retention and collection of a specific volume of sample (such as the last 15 mL).

[0010] Preferably, the sample detection tube has a flat, inverted gourd-shaped structure. This flat, inverted gourd-shaped structure reduces energy loss due to refraction and scattering as light passes through the sample, enhancing the intensity or sensitivity of the optical detection signal and improving detection accuracy. Furthermore, the flat, inverted gourd-shaped design facilitates sample flow, allows air bubbles to rise and escape, and ensures stable liquid levels in the optical detection area.

[0011] Preferably, the light source is an ultraviolet (UV) light source. UV light sources are suitable for exciting certain components or impurities in jet fuel to produce specific optical responses, such as fluorescence or specific absorption / scattering characteristics, thereby improving the accuracy of the water separation index determination results.

[0012] Preferably, the moisture coalescer is grounded via a wire to achieve anti-interference effect and to conduct away static electricity that may be generated during the filtration process due to fuel flow, preventing charge accumulation from causing safety hazards and ensuring the safe and stable operation of the system.

[0013] Preferably, the valve assembly includes a three-way valve, a first six-way valve, and a second six-way valve. The sample cell, the three-way valve, the first six-way valve, the second six-way valve, and a sample inlet are connected sequentially. The sample inlet is connected to the sample outlet of the autosampler. The bottom of the sample cell is connected to the water coalescer via the three-way valve. The three-way valve, the first six-way valve, and the second six-way valve are each connected to a waste liquid tank. By controlling the switching states of the above valves, different operations such as sample reception, quantification, transfer, cleaning, filtration and guidance of emulsified samples, and waste liquid discharge can be automatically and sequentially completed in the same pipeline, ensuring an automated measurement process.

[0014] Preferably, the second six-way valve is connected to the second quantitative tube, and the sample inlet is connected to the second quantitative tube via the second six-way valve. The second quantitative tube is used to accurately measure the volume of the sample extracted from the autosampler, ensuring that the amount of sample entering the sample cell is accurate and consistent each time.

[0015] Compared with the prior art, the present invention has the following advantages: The automatic determination system for jet fuel water separation index of the present invention can realize the automatic determination process of sample introduction, emulsification, filtration and optical detection, which significantly improves the detection efficiency, accuracy and reliability of the detection results of jet fuel water separation index, and reduces the dependence on the operator's skill level. It solves the problems of traditional manual methods such as cumbersome operation, high requirements for the connection between steps, large human error, inability to conduct continuous detection and poor repeatability of results. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the automatic jet fuel water separation index determination system in the embodiment; Figure 1 The specific reference numerals in the attached figures are as follows: 1-Automatic sampler, 2-Sample cell, 21-Plunger, 22-Propeller motor, 23-Injection port, 24-Exhaust valve, 25-First quantitative tube, 26-Distilled water source, 27-Six-way valve for liquid addition, 28-Ultrasonic device, 3-Sample detection tube, 31-Moisture coalescer, 32-Top injection port, 33-Overflow port, 34-Outflow port, 41-Three-way valve, 42-First six-way valve, 43-Second six-way valve, 44-Injection interface, 45-Second quantitative tube, 5-Waste liquid tank. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0018] Example: An automatic system for determining the water separation index of jet fuel, such as Figure 1As shown, the system includes an autosampler 1, an emulsification and filtration device, a sample receiving and detection device, and a system control device. The autosampler 1 is used to supply the sample to be tested. The emulsification and filtration device includes a sample cell 2, a liquid addition unit for quantitatively adding distilled water to the sample cell 2, an ultrasonic emulsification unit for emulsifying the sample in the sample cell 2, and a propulsion unit for discharging the sample in the sample cell 2. The sample receiving and detection device includes a water coalescer 31 and a sample detection tube 3 connected by a pipeline, and a photodetector unit (not shown) for optically detecting the sample in the sample detection tube 3. The water coalescer 31 is grounded via a wire. The bottom of pool 2 is connected to autosampler 1 and water coalescer 31 via a valve assembly; the optical detection unit includes a light source and at least two photodetectors, which are arranged opposite each other on both sides of the sample detection tube 3 for transmitted light detection. The light source is an ultraviolet light source with a wavelength of 350nm, and at least one other photodetector is configured to receive the backscattered light of the sample; the system control device (not shown in the figure) is used to control the operation of each execution component in the autosampler 1, the emulsification and filtration device, and the sample receiving and detection device to perform an automatic measurement process including sample injection, emulsification, filtration and optical detection. The system control device is connected to a result output unit.

[0019] In this embodiment, the sample cell 2 is shaped like an inverted syringe, made of polytetrafluoroethylene, with a volume of approximately 80 mL. The propulsion unit includes a plunger 21 that seals with the sample cell 2 and a propulsion motor 22 that drives the plunger 21. The plunger 21 is equipped with an injection port 23 and an exhaust valve 24, and the injection port 23 is connected to the liquid addition unit. The liquid addition unit includes a first metering tube 25, a water pump (not shown in the figure), and a distilled water source 26 connected to the water pump. The injection port 23 is connected to the 50 μL first metering tube 25 via a six-way liquid addition valve 27. The ultrasonic emulsification unit includes an ultrasonic device 28 with a power of 1000 W to 2000 W, and the sample cell 2 is placed within the accommodating space of the ultrasonic device 28. The sample detection tube 3 is a flat, inverted gourd-shaped structure with a volume of approximately 20 mL, and it is equipped with a top inlet 32, an overflow port 33, and a bottom outlet 34 with a valve.

[0020] In this embodiment, the valve group includes a three-way valve 41, a first six-way valve 42, and a second six-way valve 43. The sample cell 2, the three-way valve 41, the first six-way valve 42, the second six-way valve 43, and a sample inlet 44 are connected in sequence. The sample inlet 44 is connected to the sample outlet of the autosampler 1. The autosampler 1 can be an autosampler known in the art. The bottom of the sample cell 2 is connected to the water coalescer 31 through the three-way valve 41. The three-way valve 41, the first six-way valve 42, and the second six-way valve 43 are respectively connected to the waste liquid tank 5. The second six-way valve 43 is connected to the 50mL second quantitative tube 45. The sample inlet 44 is connected to the second quantitative tube 45 through the second six-way valve 43.

[0021] The working principle of the above-mentioned automatic jet fuel water separation index determination system is as follows: After system startup, the autosampler 1 supplies the sample to be tested. The sample is drawn and transported to the sample cell 2 of the emulsification and filtration device via a valve assembly (including a three-way valve 41, a first six-way valve 42, and a second six-way valve 43). The system control unit controls the propulsion unit, causing the propulsion motor 22 to drive the plunger 21 to return to the top and open the vent valve 24. Subsequently, the liquid addition unit is controlled to add precisely measured distilled water (e.g., 50 μL) from the first metering tube 25 into the sample cell 2 through the liquid addition port 23 on the plunger 21 via the liquid addition six-way valve. After the liquid addition is completed, the vent valve 24 is closed.

[0022] The system control device activates the ultrasonic emulsification unit, causing the sample pool 2, placed within the ultrasonic device 28, to undergo ultrasonic treatment for 3-5 minutes, thereby achieving full emulsification of the sample and distilled water.

[0023] After emulsification, the system immediately (e.g., within 30 seconds) performs a filtration operation. The system control unit switches the valve group status, connecting the outlet of sample cell 2 to water coalescer 31 via three-way valve 41. Simultaneously, the propulsion unit is activated, with propulsion motor 22 pushing plunger 21 to filter the emulsified sample through water coalescer 31 at a constant pressure. The filtration process is completed within 45 seconds (or 25 seconds).

[0024] The filtered sample enters the sample receiving and detection device. The sample first flows through the water coalescer 31 (which is grounded via a wire), and then enters the sample detection tube 3. The system control device controls the opening and closing of the valve at the bottom of the sample detection tube 3 to accurately collect the last 15 mL of filtered sample into the detection tube at the end of the filtration process.

[0025] After sample collection, the sample was allowed to stand for 60 seconds. Subsequently, the system control unit activated the photodetector unit, emitting ultraviolet light. At least two photodetectors operated simultaneously to detect the intensity of transmitted and backscattered light from the sample, respectively. Using the detection signal of the sample before filtration as a reference (with the water separation index set at 100), the system automatically calculated the water separation index of the current sample using single-point calibration and interpolation.

[0026] After the measurement is completed, the system control device opens the valve at the bottom of the sample detection tube 3 to discharge waste liquid and controls the valve group to switch to cleaning or waste discharge mode. Simultaneously, it can instruct the autosampler 1 to prepare the next sample to be tested and prompt for replacement of the water coalescer 31 when necessary, thus continuously and automatically executing the measurement process for subsequent samples. All measurement results are output and saved by a result output unit (such as a printer) connected to the system control device.

Claims

1. An automatic system for determining the water separation index of jet fuel, characterized in that, The system includes an autosampler, an emulsification and filtration device, a sample receiving and detection device, and a system control device. The autosampler supplies the sample to be tested. The emulsification and filtration device includes a sample cell, a liquid addition unit for quantitatively adding distilled water to the sample cell, an ultrasonic emulsification unit for emulsifying the sample in the sample cell, and a propulsion unit for discharging the sample from the sample cell. The sample receiving and detection device includes a water coalescer and a sample detection tube connected by a pipeline, and a photodetector unit for optically detecting the sample in the sample detection tube. The bottom of the sample cell is connected to the autosampler and the water coalescer via a valve assembly. The photodetector unit includes a light source and at least two photodetectors. The light source and at least one photodetector are disposed opposite each other on both sides of the sample detection tube for transmitted light detection, and at least one photodetector is configured to receive backscattered light from the sample. The system control device is used to control the operation of each execution component in the autosampler, the emulsification and filtration device, and the sample receiving and detection device to perform an automated measurement process including sample injection, emulsification, filtration, and optical detection.

2. The automatic jet fuel water separation index determination system according to claim 1, characterized in that, The sample cell is shaped like an inverted syringe. The propulsion unit includes a plunger that is sealed to the sample cell and a propulsion motor that drives the plunger. The plunger is provided with an injection port and an exhaust valve. The injection port is connected to the liquid addition unit.

3. The automatic jet fuel water separation index determination system according to claim 2, characterized in that, The liquid addition unit includes a first metering tube, a water pump, and a distilled water source connected to the water pump. The liquid injection port is connected to the first metering tube via a six-way liquid addition valve.

4. The automatic jet fuel water separation index determination system according to claim 1, characterized in that, The ultrasonic emulsification unit includes an ultrasonic device, and the sample cell is placed within the accommodating space of the ultrasonic device.

5. The automatic jet fuel water separation index determination system according to claim 1, characterized in that, The sample detection tube is equipped with a top inlet, an overflow outlet, and a bottom outlet with a valve.

6. An automatic jet fuel water separation index determination system according to claim 1 or 5, characterized in that, The sample detection tube has a flat, inverted gourd-shaped structure.

7. The automatic jet fuel water separation index determination system according to claim 1, characterized in that, The light source is an ultraviolet light source.

8. The automatic jet fuel water separation index determination system according to claim 1, characterized in that, The moisture coalescer is grounded via a wire.

9. The automatic jet fuel water separation index determination system according to claim 1, characterized in that, The valve assembly includes a three-way valve, a first six-way valve, and a second six-way valve. The sample cell, the three-way valve, the first six-way valve, the second six-way valve, and a sample inlet are connected in sequence. The sample inlet is connected to the sample outlet of the autosampler. The bottom of the sample cell is connected to the water coalescer through the three-way valve. The three-way valve, the first six-way valve, and the second six-way valve are respectively connected to waste liquid tanks.

10. The automatic jet fuel water separation index determination system according to claim 9, characterized in that, The second six-way valve is connected to the second quantitative tube, and the injection port is connected to the second quantitative tube via the second six-way valve.

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