An automatic freezing point and cold filter plugging point determination device and method

Abstract

This invention relates to the field of petroleum performance testing technology, and discloses an automatic pour point and cold filter plugging point (CPP) testing device and method. The automatic CPP testing device includes: a testing host, an installation module, and a control module; the installation module is used to install and seal the testing module at the testing station, and includes: a container support, a fixing connector, a clamping drive, and an adjustable seal; the container support is used to connect the testing module and support a storage container containing the test medium. This invention achieves digital closed-loop control of the clamping force during the test tube installation process, ensuring consistent mechanical state and optimal thermal contact for each installation, eliminating differences caused by manual operation; in the sealing process, a dynamically adjustable sealing component is used, and it can compensate for interface changes caused by thermal expansion and contraction in real time based on pressure feedback throughout the testing process, thereby maintaining a stable and reliable long-term seal over a wide temperature range.

Description

Technical Field

[0001] This invention relates to the field of petroleum performance testing technology, and more specifically, to an automatic pour point and cold filter plugging point determination device and method. Background Technology

[0002] The pour point and cold filter plugging point (CPP) of petroleum products are key indicators for evaluating their low-temperature flow performance, and are crucial for fuel storage, transportation, and the normal operation of engines at low temperatures. The corresponding national standards GB / T 510 "Determination of Pour Point of Petroleum Products" and SH / T 0248 "Determination of Cold Filter Pulsating Point of Distillate Fuels" clearly stipulate the testing methods.

[0003] To improve testing efficiency and standardization, various automated testing devices have been developed. While these devices automate testing actions such as heating, cooling, and tilting, effectively reducing manual labor, there is still room for improvement in ensuring a stable, reliable, and consistent physical connection and thermal contact between the test tube and the instrument's constant temperature environment. For example, existing solutions often rely on manual tightening or simple clips to secure the test tube module. While these methods achieve basic connection, the clamping force often depends on the operator's feel and experience, making it difficult to accurately guarantee the consistency of the connection. This uncertainty directly affects the thermal resistance between the test tube wall and the cold bath, becoming a potential variable impacting the final temperature control accuracy and the repeatability of test results.

[0004] Furthermore, the device needs to undergo drastic programmed temperature changes throughout the testing cycle. Within this wide temperature range, components made of different materials (such as metal baths and test tube modules) will experience micron-scale changes at their interface due to differences in their coefficients of thermal expansion and contraction. Traditional static sealing and fastening methods are difficult to dynamically adapt to these changes, which may lead to localized thermal contact deterioration or a decrease in seal integrity, thereby affecting the stability and reliability of long-term testing. Summary of the Invention

[0005] The purpose of this invention is to provide an automatic freezing point and cold filter plugging point determination device and method to solve the above-mentioned technical problems.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0007] This invention provides an automatic freezing point and cold filter plugging point determination device, comprising:

[0008] Measurement host;

[0009] A cooling bath module is installed on the measuring host and has at least one detection station;

[0010] The detection module is used to perform the detection functions of pour point and / or cold filter plugging point;

[0011] An installation module, used to install and seal the detection module at the detection station, includes:

[0012] A container carrier is used to connect the detection module and carry a storage container containing the medium to be tested;

[0013] A fixed connector is fixedly installed at the testing station for docking with the container carrier.

[0014] A clamping drive is provided at the testing station and is used to apply a controllable axial clamping force to the container carrier after the container carrier and the fixed connector have been initially connected.

[0015] An adjustable seal is provided at the mating interface between the container carrier and the fixed connector;

[0016] A pressure monitoring device is used to monitor the sealing pressure of the docking interface and / or the output force of the clamping drive.

[0017] The control module is connected to the clamping drive, the adjustable seal, and the pressure monitoring element respectively; and is configured to:

[0018] The clamping drive is controlled to press the container carrier against the fixed connector, and the clamping force is adjusted to a first target value based on the feedback from the pressure monitoring device.

[0019] Control the adjustable seal to activate it and achieve the set sealing state;

[0020] During the test, based on the feedback from the pressure monitoring device, the output force of the clamping drive and / or the working state of the adjustable seal are dynamically adjusted.

[0021] Preferably, the pressing drive is a linear actuator, and the output end of the linear actuator is provided with a pressing body for pressing the container carrier.

[0022] Preferably, the linear actuator is a servo electric cylinder with its telescopic end facing upward; the pressing body is mounted on the telescopic end of the servo electric cylinder via a sliding pair, and the pressing body is provided with a clamping part for accommodating and positioning the container carrier.

[0023] Preferably, the adjustable seal includes an inflatable sealing ring fixedly installed on the container carrier and an inflation air source connected to the inflatable sealing ring.

[0024] Preferably, the pressure monitoring component includes a pressure sensor integrated into the output end of the clamping drive component and a distributed thin-film pressure sensor laid on the docking interface.

[0025] Preferably, the container carrier includes a detection seat and a locking cap that mates with the detection seat. After the detection seat is connected to the storage container, the locking cap keeps the two in place.

[0026] Preferably, the detection module includes a freezing point detector and a cold filter plugging point detector, which are selectively or simultaneously connected to different container carriers;

[0027] The freezing point detector includes an image acquisition unit, a first temperature sensing unit, and a tilting drive unit, while the cold filter point detector includes a suction filter unit, a second temperature sensing unit, and a photoelectric detection unit.

[0028] An automated method for determining the freezing point and cold filter plugging point includes the following steps:

[0029] S100, Installation preparation: Connect the detection module to the container carrier and install the storage container containing the medium to be tested onto the container carrier;

[0030] S200, Intelligent Installation and Sealing: The container carrier is placed on the fixed connector to achieve initial docking; the clamping drive is controlled to press the container carrier against the fixed connector, and the clamping force is adjusted to the first target value based on the feedback from the pressure monitoring device; the adjustable seal is activated to achieve the set sealing state.

[0031] S300, Dynamic Maintenance and Testing: Initiate the measurement program and control the cooling bath module to perform programmed temperature control on the medium in the storage container; during the test, based on the feedback from the pressure monitoring device, dynamically adjust the output force of the clamping drive and / or the working state of the adjustable seal to maintain stable sealing and thermal contact; synchronously control the detection module to perform the detection operation of the freezing point and / or cold filter point;

[0032] S400, Result Output: Based on the detection data from the detection module, automatically determine and output the measurement results of the pour point and / or cold filter plugging point.

[0033] Preferably, in step S300, dynamic adjustment includes: adjusting the output force of the clamping drive component and / or adjusting the working parameters of the adjustable seal component based on the deviation between the pressure value fed back by the pressure monitoring component and the target value using a closed-loop control algorithm.

[0034] Preferably, in step S300, the control of the detection module to perform the detection operation includes:

[0035] If the detection module is a freezing point detection device, then the freezing point detection sub-process is executed: the tilt drive unit is controlled to tilt the storage container, and the image acquisition unit is controlled to acquire the image sequence of the medium inside the container, and the freezing point is automatically determined based on the analysis of the image sequence.

[0036] If the detection module is a cold filter point detection device, the cold filter point detection sub-process is executed: during the cooling process, the suction filtration unit is controlled to perform intermittent suction filtration, and the flow state of the filtrate is monitored by the photoelectric detection unit to automatically determine the cold filter point.

[0037] The beneficial effects of this invention are as follows:

[0038] This invention achieves digital closed-loop control of the clamping force during test tube installation by coordinating an installation module with a control module featuring an adaptive control strategy. This ensures consistent mechanical state and optimal thermal contact for each installation, eliminating the differences caused by manual operation. In the sealing process, a dynamically adjustable sealing component is used, which compensates for interface changes caused by thermal expansion and contraction in real time based on pressure feedback throughout the testing process, thus maintaining a stable and reliable long-term seal over a wide temperature range. The synergy of these two components improves the test repeatability, result accuracy, and operational reliability of the measuring device. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the external structure of an automatic freezing point and cold filter point measuring device according to the present invention;

[0040] Figure 2 This is a schematic diagram of the internal structure of one of the detection stations in an automatic freezing point and cold filter point determination device of the present invention;

[0041] Figure 3 This is a schematic diagram of the internal structure between the installation module and the freezing point detection element in an automatic freezing point and cold filter point determination device of the present invention.

[0042] Figure 4 This is the present invention. Figure 3 A magnified view of a portion of point A in the middle;

[0043] Figure 5 This is a schematic diagram of the internal structure of the cold filter plugging point (CFPP) detection element in an automatic freezing point and cold filter plugging point (CFPP) measuring device of the present invention.

[0044] Figure 6 This is a block diagram showing the relationship between the modules of the automatic freezing point and cold filter plugging point determination device of the present invention;

[0045] Figure 7 This is a flowchart of an automatic method for determining the freezing point and cold filter plugging point according to the present invention.

[0046] In the diagram: 10. Measuring host; 20. Refrigeration bath module; 201. Detection station; 202. Coil-type evaporator; 203. Thin-film heater; 204. Resistance temperature sensor; 30. Detection module; 301. Image acquisition unit; 302. First temperature sensing unit; 303. Tilt drive unit; 304. Suction filtration unit; 305. Second temperature sensing unit; 306. Photoelectric detection unit; 40. Installation module; 401. Linear actuator; 402. Pressing body; 403. Inflatable sealing ring; 404. Inflatable gas source; 405. Pressure sensor; 406. Distributed thin-film pressure sensor; 407. Detection seat; 408. Locking cap; 409. Fixing connector; 50. Test tube. Detailed Implementation

[0047] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0048] Example 1: Please refer to the following: Figures 1 to 6 This embodiment provides an automatic freezing point and cold filter plugging point determination device, including: a determination host 10, a refrigeration bath module 20, a detection module 30, an installation module 40, and a control module.

[0049] The cooling bath module 20 is the core of the device for achieving a precise temperature environment. It is mounted on the main measuring unit 10 and provides at least one independent detection station 201. In this embodiment, two detection stations 201 are arranged side-by-side. Each detection station 201 is essentially a high-precision metal bath thermostat. Its main body is a rectangular base filled with insulation material, and a coil-type evaporator 202 (connected to the compressor refrigeration system) and a high-power thin-film heater 203 are precisely embedded within the insulation material. A standard-sized test tube 50 insertion hole is provided on the top of the base. The cooling bath module 20 can achieve preset wide-range programmed cooling and heating. Each test tube 50 insertion hole is equipped with an independent resistance temperature sensor 204, providing real-time feedback of the bath temperature, forming a closed-loop control, and providing a highly stable and uniform low-temperature environment for the sample.

[0050] The detection module 30 is the functional execution unit of the device, used to perform the detection functions of pour point and / or cold filter plugging point; it adopts a modular design and mainly includes two configurable types:

[0051] The core of the freezing point detection device is a machine vision inspection system; it includes a high-resolution industrial camera (image acquisition unit 301), a high-precision temperature sensor (first temperature sensing unit 302), and a high-precision stepper motor-driven tilting mechanism (tilt drive unit 303). This tilting mechanism is mainly installed on the outside of the inspection station 201. During operation, the tilting mechanism drives the entire inspection station 201 to tilt according to standards, so that the test tube 50 is precisely tilted at 45 degrees, while the industrial camera simultaneously captures a continuous sequence of images of the liquid surface area inside the test tube 50 for subsequent image processing unit analysis.

[0052] The core of the cold filtration point detection device is an automatic suction filtration and photoelectric sensing system. It includes a suction filtration unit 304 controlled by a miniature vacuum pump and solenoid valve, a high-precision temperature sensor (second temperature sensing unit 305), and a through-beam photoelectric sensor (photoelectric detection unit 306). The suction filtration unit 304 is responsible for timed suction at a specific temperature point according to standard requirements; the optical path of the photoelectric sensor is precisely aligned with the standard droplet path of the filtrate for non-contact detection of droplet passage events and their duration.

[0053] Mounting module 40 is used to mount and seal detection module 30 at detection station 201. It includes: container carrier, fixing connector 409, clamping drive, adjustable seal, and pressure monitoring component.

[0054] The container carrier, serving as an intermediate carrier connecting the detection module 30 and the test tube 50, typically consists of a detection seat 407 and a locking cap 408. The detection seat 407 is used to receive the standard test tube 50, and the locking cap 408 is used to secure the test tube 50 to the detection seat 407, forming a complete detection unit. Meanwhile, in the freezing point detection unit, the image acquisition unit 301 and the first temperature sensing unit 302, as well as the cold filter point detection unit, the suction filtration unit 304, the second temperature sensing unit 305, and the photoelectric detection unit 306, are all fixedly installed with their corresponding detection seats 407 and extend downwards from the top detection seat 407 into the test tube 50.

[0055] The fixed connector 409 is fixedly installed on the testing station 201 of the refrigeration bath module 20, that is, at the top of the test tube 50 insertion hole. It serves as a connecting structure for the receiving container carrier. The fixed connector 409 is provided with a guide groove, and the container carrier is provided with a guide part that cooperates with it to achieve the initial positioning and docking of the two.

[0056] The clamping drive provides a controllable axial clamping force; in this embodiment, a linear actuator 401 is preferred, particularly a servo cylinder with its telescopic end facing upwards. A pressing body 402 is mounted on the output end of the servo cylinder. This pressing body 402 is laterally slidably mounted to the output end of the servo cylinder via a sliding pair. When the test tube 50 is not installed, the pressing body 402 is pulled away from the detection station 201. After the test tube 50 is installed, the pressing body 402 is pushed to move above the detection seat 407. A U-shaped groove (clamping part) is provided on the pressing body 402, allowing it to accommodate the wires of the detection module 30 when it moves above the detection seat 407. This allows the pressing body 402 to cover the top area of ​​the detection seat 407, assisting in positioning during clamping and ensuring vertical and uniform force application.

[0057] An adjustable seal is provided on the annular mating interface between the container carrier and the fixed connector 409. A preferred embodiment is an inflatable sealing ring 403, which is fixedly sleeved on the outside of the detection seat 407. It is connected via a pipeline to a miniature inflation source 404 (such as an air pump and precision pressure regulating valve), which can be installed on the measuring host 10. When not inflated, the contracted sealing ring does not obstruct the detection seat 407, facilitating the insertion of the container carrier. After inflation, the sealing ring expands radially, tightly filling all microscopic gaps at the mating interface.

[0058] The pressure monitoring device is used to provide the feedback signal required for closed-loop control. In this embodiment, it includes a force sensor and a distributed thin-film pressure sensor 406. The force sensor is integrated into the output end of the clamping drive to directly measure the applied clamping force. The distributed thin-film pressure sensor 406 is located at the docking interface and directly measures the pressure distribution on the sealing contact surface.

[0059] The control module, serving as the control center of the entire device, is communicatively connected to the refrigeration bath module 20, the detection module 30, and the installation module 40. It not only incorporates built-in control logic for the automated determination of cold filter plugging point and freezing point, but also includes control logic for the intelligent installation and subsequent adaptive sealing of the test tubes 50, which works in conjunction with the installation module 40. This control logic specifically includes:

[0060] Intelligent installation phase: When the operator places the container carrier into the fixed connector 409, the control module activates the clamping drive (servo electric cylinder) to drive the pressing body 402 to press down; at the same time, it reads the feedback value of the pressure monitoring device (such as a force sensor) and adjusts the output force of the servo electric cylinder in real time through closed-loop control (such as a PID algorithm) until the actual clamping force is accurately stabilized at the preset first target value (P1); this P1 value is determined experimentally to achieve the optimal pressure for the best heat conduction efficiency.

[0061] Dynamic sealing stage: After the clamping force reaches the target, the control module starts the inflation gas source 404 to fill the inflatable sealing ring 403 with gas, so that its internal pressure reaches the second target pressure (P2), the sealing ring expands, and achieves a flexible and reliable radial seal.

[0062] Process maintenance phase: During the subsequent cooling and testing process, which may last for several hours, the control module continuously monitors the pressure feedback. Due to thermal expansion and contraction or mechanical vibration, the pressure may drift. At this time, the control module will dynamically adjust the output force of the servo electric cylinder (to compensate for macroscopic pressure changes) and / or the internal pressure of the sealing ring (to compensate for microscopic gap changes) to keep the system in the optimal sealing and thermal contact state.

[0063] Example 2: On the other hand, please refer to the following: Figure 7 This invention provides an automatic method for determining the freezing point and cold filter plugging point. The method utilizes the aforementioned device, and the specific operating steps are as follows:

[0064] S100, Preparation: The operator inserts test tube 50 into the container carrier that has been connected to the swing arm of the freezing point test piece, and tightens the locking cap 408.

[0065] S200, Intelligent Installation and Sealing:

[0066] The operator places the container carrier into the fixed connector 409 on the test station; the control module controls the servo electric cylinder to press down; the force sensor provides real-time feedback of the pressure value F; the control module runs the PID control routine, compares F with the preset P1, and adjusts the servo electric cylinder accordingly to keep its output F stable;

[0067] After the clamping force reaches the target, the control module starts to control the inflation air source 404 to inflate the inflation sealing ring. The control module judges the pressure value fed back by the diaphragm pressure sensor 405. When the pressure value reaches the preset target value, the control module controls the inflation air source 404 to stop inflating.

[0068] S300, Dynamic Maintenance and Testing:

[0069] If a freezing point test is performed alone, the control module follows the corresponding freezing point test control procedure, controlling the cooling bath module 20 to cool down first; when the expected temperature is reached, the tilt drive unit is controlled to tilt the test tube 50 at 45 degrees, and at the same time, the industrial camera is triggered to capture an image; the image processing algorithm (such as optical flow method) analyzes the image sequence and calculates the average motion vector of the liquid surface; if the vector magnitude is greater than the threshold, it is judged as "flowing", and the system automatically sets the next test temperature to -4℃; if it is judged as "stagnant", it is set to +2℃; this process is iterated until the freezing point is accurately located.

[0070] If a cold filter point test is performed separately, the control module follows the control procedure for the corresponding cold filter point test. The suction filter unit 304 is controlled to work once for every 1°C decrease. The photoelectric detection unit 306 monitors the filtrate droplets. If a droplet signal is detected within a preset time, the temperature is recorded as "filterable"; otherwise, it is recorded as "unfilterable". The system automatically determines the cold filter point.

[0071] If both the freezing point test and the cold filter plugging point test are performed simultaneously, the control module will start the synchronous test control program, so that the control threads of the two test stations run independently and control the corresponding installation modules 40 to continuously maintain the pressure dynamically.

[0072] S400, Results Output: After both tests are completed, the pour point and cold filter plugging point results are displayed on the screen simultaneously, and a report is automatically printed.

[0073] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. An automatic freezing point and cold filter plugging point determination device, characterized in that, include: Measurement host; A cooling bath module is installed on the measuring host and has at least one detection station; The detection module is used to perform the detection functions of pour point and / or cold filter plugging point; An installation module, used to install and seal the detection module at the detection station, includes: A container carrier is used to connect the detection module and carry a storage container containing the medium to be tested; A fixed connector is fixedly installed at the testing station for docking with the container carrier. A clamping drive is provided at the testing station to apply a controllable axial clamping force to the container carrier after the container carrier and the fixed connector have been initially connected. An adjustable seal is provided at the interface between the container support and the fixed connector; Pressure monitoring device, used to monitor the sealing pressure of the docking interface and / or the output force of the clamping drive; The control module is connected to the clamping drive, the adjustable seal, and the pressure monitoring element respectively; and is configured to: Control the action of the clamping drive to clamp the container carrier to the fixed connection, and adjust the clamping force to the first target value based on the feedback from the pressure monitoring device; Control the adjustable seal to activate it and achieve the set sealing state; During the test, the output force of the clamping drive and / or the working state of the adjustable seal are dynamically adjusted based on the feedback from the pressure monitoring device.

2. The automatic freezing point and cold filter plugging point measuring device according to claim 1, characterized in that, The pressing drive is a linear actuator, and the output end of the linear actuator is provided with a pressing body for pressing the container carrier.

3. The automatic freezing point and cold filter plugging point measuring device according to claim 2, characterized in that, The linear actuator is a servo electric cylinder with its telescopic end facing upward; the pressing body is mounted on the telescopic end of the servo electric cylinder via a sliding pair, and the pressing body is provided with a clamping part for accommodating and positioning the container carrier.

4. The automatic freezing point and cold filter plugging point measuring device according to claim 1, characterized in that, The adjustable seal includes an inflatable sealing ring fixedly installed on the container carrier and an inflation source connected to the inflatable sealing ring.

5. The automatic freezing point and cold filter plugging point measuring device according to claim 1, characterized in that, The pressure monitoring device includes a pressure sensor integrated into the output end of the clamping drive and a distributed thin-film pressure sensor laid on the docking interface.

6. The automatic freezing point and cold filter plugging point measuring device according to claim 1, characterized in that, The container carrier includes a detection seat and a locking cap that mates with the detection seat. After the detection seat is connected to the storage container, the locking cap keeps the two in place.

7. The automatic freezing point and cold filter plugging point measuring device according to claim 1, characterized in that, The detection module includes a freezing point detector and a cold filter plugging point detector, which can be connected to different container carriers, either one or both. The freezing point detector includes an image acquisition unit, a first temperature sensing unit, and a tilting drive unit, while the cold filter point detector includes a suction filter unit, a second temperature sensing unit, and a photoelectric detection unit.

8. An automatic method for determining the freezing point and cold filter plugging point, characterized in that, The automatic pour point and cold filter plugging point measuring device applied to any one of claims 1-7 includes the following operating steps: S100, Installation preparation: Connect the detection module to the container carrier and install the storage container containing the medium to be tested onto the container carrier; S200, Intelligent Installation and Sealing: The container carrier is placed on the fixed connector to achieve initial docking; the clamping drive is controlled to press the container carrier against the fixed connector, and the clamping force is adjusted to the first target value based on the feedback from the pressure monitoring device; the adjustable seal is activated to achieve the set sealing state. S300, Dynamic Maintenance and Testing: Start the measurement program and control the cooling bath module to perform programmed temperature control on the medium in the storage container; During the test, based on the feedback from the pressure monitoring device, the output force of the clamping drive and / or the working state of the adjustable seal are dynamically adjusted to maintain stable sealing and thermal contact. The synchronous control detection module performs the detection operations for pour point and / or cold filter plugging point; S400, Result Output: Based on the detection data from the detection module, automatically determine and output the measurement results of the pour point and / or cold filter plugging point.

9. The automatic method for determining the freezing point and cold filter plugging point according to claim 8, characterized in that, In step S300, dynamic adjustment includes: adjusting the output force of the clamping drive component and / or adjusting the working parameters of the adjustable seal component based on the deviation between the pressure value fed back by the pressure monitoring component and the target value using a closed-loop control algorithm.

10. The automatic method for determining the freezing point and cold filter plugging point according to claim 9, characterized in that, In step S300, the control detection module performs the detection operation, including: If the detection module is a freezing point detection device, then the freezing point detection sub-process is executed: the tilt drive unit is controlled to tilt the storage container, and the image acquisition unit is controlled to acquire the image sequence of the medium inside the container, and the freezing point is automatically determined based on the analysis of the image sequence. If the detection module is a cold filter point detection device, the cold filter point detection sub-process is executed: during the cooling process, the suction filtration unit is controlled to perform intermittent suction filtration, and the flow state of the filtrate is monitored by the photoelectric detection unit to automatically determine the cold filter point.

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