Monitoring methods and systems for ultra-high pressure compressors

Abstract

This application belongs to the technical field of ultra-high pressure compressors, specifically relating to a monitoring method and system for ultra-high pressure compressors. The cylinder pressure and working volume of the cylinder mechanism of an ultra-high pressure compressor can reflect the operating state of the compressor. The cylinder mechanism of the ultra-high pressure compressor includes a cylinder body forming a piston chamber, a middle body and a cylinder head respectively disposed at both ends of the cylinder body, a tie rod bolt connecting the middle body and the cylinder head, and a piston component that slides against the wall of the piston chamber. The cylinder pressure refers to the pressure between the piston component and the cylinder head, and the resulting pressure can cause the cylinder head and middle body to separate from the cylinder body. The tie rod bolt is used to balance the pressure; therefore, the axial strain of the tie rod bolt can reflect the cylinder pressure. In this application, the cylinder pressure is indirectly obtained by directly measuring the axial strain of the tie rod bolt, thereby avoiding drilling holes in the cylinder body to install sensors for direct measurement of the cylinder pressure, thus avoiding damage to the cylinder mechanism and reducing the safety risks associated with measuring the cylinder pressure.

Description

Technical Field

[0001] This application belongs to the technical field of ultra-high pressure compressors, and specifically relates to a monitoring method and system for ultra-high pressure compressors. Background Technology

[0002] Ultra-high pressure compressors are widely used in energy technology fields such as petrochemicals and natural gas industries, primarily for gas compression. Theoretically, they can compress gases to the required pressures suitable for different operating conditions. During the operation of an ultra-high pressure compressor, its operating status needs to be monitored in real time to ensure its efficiency and predict potential malfunctions. A common method is to monitor the in-cylinder pressure and working volume of the compressor in real time and plot these parameters as an indicator diagram. Technicians can obtain performance parameters such as suction pressure loss, discharge pressure loss, indicated power, pressure ratio, and volumetric efficiency from the indicator diagram. They can also observe leaks in the discharge valve, piston rings, and packing, as well as airflow pulsation in the pipeline and heat exchange during compressor operation.

[0003] In existing technologies, to measure the cylinder pressure, the cylinder of an ultra-high pressure compressor needs to be machined; specifically, holes need to be drilled in the cylinder to install monitoring sensors. However, drilling these holes can affect the strength and integrity of the cylinder, and may even damage it, thus posing a certain safety risk. Summary of the Invention

[0004] The purpose of this application is to provide a monitoring method and system for ultra-high pressure compressors, thereby reducing the safety risks associated with measuring cylinder pressure.

[0005] To achieve the above objectives, this application provides a monitoring method for an ultra-high pressure compressor, comprising:

[0006] Obtain the axial strain of the tie rod bolt of the cylinder mechanism;

[0007] The cylinder pressure of the cylinder mechanism is calculated based on the axial strain.

[0008] Obtain the working volume of the cylinder mechanism;

[0009] The cylinder pressure and working volume at the same moment are used to form monitoring data points, and the indicator diagram of the ultra-high pressure compressor is obtained based on the monitoring data points within the same working cycle.

[0010] The operating status of the ultra-high pressure compressor is monitored based on the indicator diagram.

[0011] In some implementations, obtaining the axial strain of the tie rod bolt of the cylinder mechanism includes:

[0012] The axial strain is directly measured using a working strain gauge and a strain measurement circuit.

[0013] In some implementations, obtaining the working volume of the cylinder mechanism includes:

[0014] Obtain the crankshaft crank angle;

[0015] The working volume is calculated based on the crank angle.

[0016] In some embodiments, calculating the working volume of the cylinder mechanism based on the crank angle includes:

[0017] Obtain the basic parameters of the ultra-high pressure compressor;

[0018] The working volume is obtained by substituting the basic parameters and the crank angle into the first calculation formula;

[0019] The first calculation formula is:

[0020]

[0021] Among them, V c It is the clearance volume, in meters. 3 D is the diameter of the piston in the cylinder mechanism, in meters (m); r is the crank radius, in meters (m); l is the length of the piston connecting rod, in meters (m); λ is the crank-connecting rod ratio; θ is the crank angle, in degrees (°).

[0022] In some embodiments, calculating the cylinder pressure of the cylinder mechanism based on the axial strain includes:

[0023] Obtain the basic parameters of the ultra-high pressure compressor;

[0024] The cylinder pressure is calculated by substituting the axial strain and the basic parameters into the second calculation formula.

[0025] The second calculation formula is:

[0026]

[0027] Where P is the cylinder pressure, in MPa; ε a E is the axial strain; E is the elastic modulus of the tie rod bolt, in N / m. 2 ; d is the diameter of the tie rod bolt, in meters; D is the diameter of the piston component of the cylinder mechanism, in meters; n is the number of tie rod bolts; F f The unit for reciprocating friction is N.

[0028] To achieve the above objectives, this application also provides a monitoring system for an ultra-high pressure compressor. The ultra-high pressure compressor includes a cylinder mechanism and a crank-connecting rod mechanism. The cylinder mechanism includes a cylinder body forming a piston chamber, a middle body and a cylinder head respectively disposed at both ends of the cylinder body, a tie rod bolt connecting the middle body and the cylinder head, and a piston component that slides in cooperation with the wall of the piston chamber. The crank-connecting rod mechanism includes a piston connecting rod passing through the middle body and connected to the piston component, a crankshaft connected to the piston connecting rod, and a flywheel connected to the crankshaft. The monitoring system includes:

[0029] A strain measurement assembly for measuring the axial strain of the tie rod bolt;

[0030] Angle measuring component for measuring the crank angle of the crankshaft; and

[0031] A data terminal is communicatively connected to the axial strain measurement component and the crank angle measurement component, and the data terminal is configured as follows:

[0032] The cylinder pressure is obtained based on the axial strain.

[0033] The working volume is obtained based on the crank angle.

[0034] In some embodiments, the axial strain measurement assembly includes:

[0035] A working strain gauge is attached to the surface of the tie rod bolt and deforms together with the tie rod bolt.

[0036] A strain measurement circuit is provided, which connects the working strain gauge to the data terminal. The strain measurement circuit is used to convert the deformation of the working strain gauge into an output voltage and transmit it to the data terminal.

[0037] The data terminal is configured as follows:

[0038] The output voltage is converted into the axial strain.

[0039] In some embodiments, the working strain gauge is a T-shaped strain gauge, which includes two measuring parts with mutually perpendicular measuring directions, one of which is arranged along the axial direction of the tie rod bolt, and the other of which is arranged along the circumferential direction of the tie rod bolt.

[0040] In some embodiments, the distance between the working strain gauge and the middle body along the axial direction of the tie rod bolt is 18cm to 22cm.

[0041] In some embodiments, the angle measurement component includes:

[0042] Sending a message is set on the flywheel;

[0043] A key phase sensor is arranged at an interval from the flywheel. The key phase sensor is used to detect the key phase displacement of the transmitting signal and send the corresponding key phase signal to the data terminal.

[0044] The data terminal is configured as follows:

[0045] The key phase signal is converted into the crank angle.

[0046] Through the above technical solution, the monitoring method and system for ultra-high pressure compressors provided in this application have the following beneficial effects:

[0047] The cylinder pressure and working volume of an ultra-high pressure compressor can reflect its operating status. The operating status of the ultra-high pressure compressor is monitored by real-time measurement of these parameters. The cylinder mechanism of an ultra-high pressure compressor includes a cylinder body forming a piston chamber, a middle body and a cylinder head located at both ends of the cylinder body, tie rod bolts connecting the middle body and cylinder head, and piston components that slide against the piston chamber wall. The cylinder pressure refers to the pressure between the piston components and the cylinder head. This cylinder pressure pushes the cylinder head and middle body apart from the cylinder body. The tie rod bolts are used to tighten the cylinder head and middle body; in other words, the cylinder pressure generates an axial tensile force on the tie rod bolts. This axial tensile force causes axial deformation and axial strain in the tie rod bolts. Therefore, the axial strain of the tie rod bolts reflects the magnitude of the cylinder pressure. In this application, the cylinder pressure is indirectly obtained by directly measuring the axial strain of the tie rod bolt, thereby avoiding drilling holes in the cylinder block to install sensors for direct measurement of the cylinder pressure, thus avoiding damage to the cylinder mechanism and reducing the safety risks of measuring the cylinder pressure.

[0048] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0049] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings:

[0050] Figure 1 This is a schematic diagram of the cylinder structure of the ultra-high pressure compressor according to a specific embodiment of this application;

[0051] Figure 2 This is a flowchart illustrating the steps of a monitoring method for an ultra-high pressure compressor according to a specific embodiment of this application;

[0052] Figure 3The circuit diagram is shown in the specific embodiment of the strain measurement circuit according to this application.

[0053] Figure 4 This is an indicator diagram of the ultra-high pressure compressor according to a specific embodiment of this application;

[0054] Figure 5 This is a schematic diagram of the monitoring system for an ultra-high pressure compressor according to a specific embodiment of this application.

[0055] Explanation of reference numerals in the attached figures

[0056] 100. Ultra-high pressure compressor; 1. Cylinder block; 2. Intermediate body; 3. Cylinder head; 4. Piston chamber; 5. Piston components; 6. Tie rod bolt; 7. Working strain gauge; 8. Key phase sensor; 9. Strain measurement circuit; 10. Data acquisition line; 11. Data terminal. Detailed Implementation

[0057] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0058] The monitoring method and system terminology of the ultra-high pressure compressor 100 according to this application are described below with reference to the accompanying drawings.

[0059] like Figure 1 As shown, the ultra-high pressure compressor 100 includes a drive source, a cylinder mechanism, and a crank-connecting rod mechanism. The crank-connecting rod mechanism drives the drive source and the cylinder mechanism to work and compress the gas.

[0060] The cylinder mechanism includes a cylinder body 1, a middle body 2, a cylinder head 3, a tie rod bolt 6, and a piston 5. The cylinder body 1 forms a piston chamber 4 inside. The cylinder head 3 and the middle body 2 are respectively provided at both ends of the cylinder body 1 to close the piston chamber 4. The piston 5 is embedded in the piston chamber 4 and forms a working space with the cylinder head 3. The cylinder head 3 has an intake passage and an exhaust passage that can communicate with the working space. An intake valve is provided in the intake passage, and an exhaust valve is provided in the exhaust passage. The tie rod bolt 6 passes through the middle body 2 and the cylinder head 3 so that both the cylinder head 3 and the middle body 2 are tightly connected to the cylinder body 1.

[0061] The crank-connecting rod mechanism includes a piston connecting rod, a crankshaft, and a flywheel. The piston connecting rod drives the piston 5 to the crankshaft, and the flywheel drives the drive source to the crankshaft. The piston connecting rod and the crankshaft are used to convert the rotational motion of the flywheel into the reciprocating motion of the piston 5, so as to change the size of the working space and the air pressure in the working space.

[0062] The size of the working space is the working volume, and the air pressure inside the working space is the cylinder air pressure.

[0063] The reciprocating motion of piston 5 has a working far point and a working near point. The working far point refers to the farthest position of piston 5 away from cylinder head 3, and the working near point refers to the closest position of piston 5 to cylinder head 3. During the process of piston 5 moving from the closest position to the farthest position, the working volume increases, and the intake valve opens after reaching the intake pressure, allowing gas to enter the working space through the intake passage. During the process of piston 5 moving from the closest position to the farthest position, the working volume decreases, and the exhaust valve opens after reaching the exhaust pressure, allowing gas to be discharged through the exhaust passage.

[0064] The movement of piston 5 from the near working point to the far working point, and then from the far working point to the near working point, constitutes one working cycle of the ultra-high pressure compressor 100. One working cycle corresponds to one rotation of the flywheel. In other words, when the crank angle of the crank connecting rod is 0°, piston 5 is located at the near working point; when the crank angle of the crank connecting rod is 180°, piston 5 is located at the far working point; and when the crank angle of the crank connecting rod is 360°, piston 5 is located at the near working point.

[0065] It should be noted that the structure, working principle and working process of the ultra-high pressure compressor 100 are well known to those skilled in the art. The above is just a simple explanation for ease of understanding. In actual production, the structure and working process of the ultra-high pressure compressor 100 may be adjusted, but it is not related to the core inventive point of this application, and will not be described in detail here.

[0066] like Figure 2 As shown, a specific embodiment of this application provides a monitoring method for an ultra-high pressure compressor 100, including:

[0067] S1: Obtain the axial strain of the tie rod bolt 6 of the cylinder mechanism;

[0068] S2: Calculate the cylinder pressure of the cylinder mechanism based on axial strain;

[0069] S3: Obtain the working volume of the cylinder mechanism;

[0070] S4: The cylinder pressure and working volume at the same moment are used to form monitoring data points, and the indicator diagram of the ultra-high pressure compressor 100 is obtained based on the monitoring data points in the same working cycle.

[0071] S5: Monitor the operating status of the ultra-high pressure compressor 100 based on the indicator diagram.

[0072] The cylinder pressure and working volume of the cylinder mechanism of the ultra-high pressure compressor 100 can reflect the working state of the ultra-high pressure compressor 100. The working state of the ultra-high pressure compressor 100 is monitored by measuring the cylinder pressure and working volume of the cylinder mechanism in real time. During the reciprocating motion of the piston 5, the cylinder pressure changes, and the cylinder pressure exerts pressure on the cylinder head 3. The pressure causes the cylinder head 3 to tend to separate from the middle body 2. Since the cylinder head 3 and the middle body 2 are connected by a tie rod bolt 6, the pressure will cause the tie rod bolt 6 to generate axial tension. Therefore, the tie rod bolt 6 will undergo axial deformation under the action of axial tension, thereby generating axial strain. In other words, there is a certain conversion relationship between the cylinder pressure and the axial strain of the tie rod bolt 6. It can be seen that the cylinder pressure can be obtained by measuring the axial strain of the tie rod bolt 6 during operation. In this application, the conversion relationship between cylinder pressure and axial strain is derived, and the cylinder pressure is indirectly obtained by directly measuring the axial strain of the tie rod bolt 6. This avoids drilling holes in the cylinder body 1 to install sensors for direct measurement of cylinder pressure, thereby ensuring the strength and integrity of the cylinder mechanism and reducing safety risks.

[0073] It should be noted that steps S1 and S2 have a definite order, while steps S3 and S1, and steps S3 and S2 do not have a definite order. In other words, it is sufficient to obtain the cylinder pressure and working volume before step S4.

[0074] Those skilled in the art will understand that the cylinder head 3, cylinder block 1, and intermediate body 2 are all assembled axially, and the tie rod bolt 6 also passes through the cylinder head 3 and intermediate body 2 axially. The reciprocating motion of the piston 5 is also axial. In other words, the pressure generated by the gas pressure inside the cylinder is in the same direction as the axial tension of the tie rod bolt 6. It can be seen that the monitoring method proposed in this application is reliable and effective.

[0075] Furthermore, compared to obtaining cylinder pressure by measuring components inside cylinder 1 and intermediate body 2, since the tie rod bolt 6 is exposed in cylinder 1 and intermediate body 2, this application can directly measure the axial strain of the tie rod bolt 6 without disassembling the ultra-high pressure compressor 100, which is more convenient. At the same time, since the tie rod bolt 6 is always in a relatively stable state during the operation of the ultra-high pressure compressor 100, this application can directly measure the axial strain of the tie rod bolt 6 to adapt to various measurement environments and is suitable for long-term monitoring.

[0076] In some implementations, step S1 includes:

[0077] Axial strain is directly measured using a working strain gauge 7 and a strain measurement circuit 9.

[0078] Specifically, firstly, the working strain gauge 7 is pasted onto the surface of the tie rod bolt 6. Then, the working strain gauge 7 is electrically connected to the strain measurement circuit 9. Next, the strain measurement circuit 9 is connected to the data terminal 11 (the conversion formula is set in advance in the data terminal 11). Finally, the axial strain is read directly from the data terminal 11.

[0079] The working principles of the working strain gauge 7, the strain measurement circuit 9, and the data terminal 11 are well known to those skilled in the art. The working strain gauge 7 is a sensor used to measure strain. Its measurement direction is arranged parallel to the axial direction of the tie rod bolt 6 and deforms together with the tie rod bolt 6. The strain measurement circuit 9 amplifies the small deformation of the working strain gauge 7. Specifically, the deformation of the working strain gauge 7 can cause a change in the resistance value in the strain measurement circuit 9, and the strain measurement circuit 9 can convert the change in resistance value into an output voltage. After receiving the output voltage of the strain measurement circuit 9, the data terminal 11 converts the output voltage into axial strain according to a pre-set conversion formula.

[0080] like Figure 3 As shown, in the exemplary embodiment of this application, the strain measurement circuit 9 is a 1 / 4 bridge circuit, and its principle for converting deformation into output voltage is as follows:

[0081]

[0082] Where R is the resistance value of strain measurement circuit 9; ΔR is the resistance change; E is the elastic modulus of working strain gauge 7; e o The output voltage of strain measurement circuit 9.

[0083] The conversion formula for data terminal 11 is:

[0084]

[0085] Where, ε α λ is the axial strain; k is the sensitivity coefficient; e is the power supply voltage of strain measurement circuit 9, in volts (V).

[0086] Furthermore, a data acquisition line 10 is used to establish a communication connection between the data terminal 11 and the strain measurement circuit 9. The data acquisition line 10 converts the measured output voltage into a digital signal through a protocol and then transmits it to the data terminal 11 for processing.

[0087] In some implementations, step S2 includes:

[0088] S21: Obtain the basic parameters of the ultra-high pressure compressor 100;

[0089] S22: Substitute the axial strain and basic parameters into the second calculation formula to obtain the cylinder pressure.

[0090] Specifically, deriving the second calculation formula requires a force analysis of the cylinder head 3. This analysis reveals the tension in the cylinder head 3 caused by the tie rod bolt 6, the pressure generated by the internal air pressure, and the reciprocating friction between the cylinder head 3 and the tie rod bolt 6. The final second calculation formula is:

[0091]

[0092] Where P is the cylinder pressure, in MPa; ε a E is the axial strain; E is the elastic modulus of tie rod bolt 6, in N / m. 2 ; d is the diameter of the tie rod bolt 6, in meters; D is the diameter of the piston component 5 of the cylinder mechanism, in meters; n is the number of tie rod bolts 6; F f This represents reciprocating friction, measured in N.

[0093] Furthermore, the elastic modulus of the tie rod bolt 6, the diameter of the tie rod bolt 6, the diameter of the piston 5, and the number of tie rod bolts 6 are all basic parameters of the ultra-high pressure compressor 100 that can be directly obtained. However, the value of the reciprocating friction force is very small and differs from the pressure generated by the cylinder gas pressure by several orders of magnitude and is difficult to measure. Therefore, in the actual calculation process, the effect of the reciprocating friction force on the tie rod bolt 6 is ignored.

[0094] In some implementations, step S3 includes:

[0095] Step S31: Obtain the crankshaft crank angle;

[0096] Step S32: Calculate the working volume based on the crank angle.

[0097] In an exemplary embodiment of this application, step S31 includes:

[0098] The crank angle is directly measured using a transmitter and a key phase sensor 8.

[0099] Specifically, since the flywheel rotates coaxially with the crankshaft, the crank angle of the crankshaft can be determined by measuring the rotation angle of the flywheel. The crankshaft and key phase sensor 8 are respectively set on both sides of the flywheel along its own axial direction. The key phase sensor 8 is arranged at intervals with the flywheel. The transmitter is set on the end face of the flywheel facing the key phase sensor 8. The key phase sensor 8 is connected to the data terminal 11 through the data acquisition line 10. The probe of the key phase sensor 8 can detect the key phase position of the transmitter and send out a key phase signal. The data terminal 11 receives the key phase signal and obtains the key phase position of the transmitter and converts it into the crank angle (the conversion formula is set in advance in the data terminal 11). Different key phase positions correspond to different crank angles.

[0100] It should be noted that the working principle of the key phase sensor 8 is well known to those skilled in the art, and the transmitter can be a component that can be detected by the key phase sensor 8, such as a metal sheet protrusion, a magnetic steel sheet, or a reflective strip.

[0101] Further, step S32 includes:

[0102] Obtain the basic parameters of the ultra-high pressure compressor 100;

[0103] The working volume is obtained by substituting the basic parameters and crank angle into the first calculation formula.

[0104] In fact, the first calculation formula for the conversion between crank angle and working volume is a conversion relationship that comes with the production of the ultra-high pressure compressor 100. As long as the crank angle is known, the working volume can be directly calculated. In the exemplary embodiment of this application, the first calculation formula is imported into the data terminal 11, and the working volume is directly read through the data terminal 11.

[0105] The first calculation formula is:

[0106]

[0107] Where V is the working volume, in meters (m). 3 V c It is the clearance volume, in meters. 3 D is the diameter of piston 5 in the cylinder mechanism, in meters; r is the crank radius, in meters; l is the length of the piston connecting rod, in meters; λ is the crank-connecting rod ratio; θ is the crank angle, in degrees.

[0108] Due to the structural, manufacturing, assembly, and operational requirements of the ultra-high pressure compressor 100, certain spaces or gaps are left in some parts of the cylinder mechanism. These spaces or gaps are called clearance volumes.

[0109] In the exemplary embodiment of this application, both the strain measurement circuit 9 and the key phase sensor 8 are connected to the data terminal 11 via the data acquisition line 10. The data acquisition line 10 is also equipped with an acquisition control unit. The sampling frequency of the data acquisition line 10 can be set through the acquisition control unit. Since it is necessary to form monitoring data points corresponding to the cylinder pressure and working volume at the same time, it is only necessary to collect the output voltage and the key phase signal at the same time and set the sampling frequency of the output voltage and the key phase signal to be the same. Then, the cylinder pressure and working volume at the same time can be directly obtained. Thus, step S4 can be directly executed on the data terminal 11, thereby improving the convenience of the monitoring method.

[0110] In some implementations, step S4 includes:

[0111] A PV coordinate system is formed with working volume as the horizontal axis and in-cylinder air pressure as the vertical axis;

[0112] The cylinder pressure and working volume at the same moment are used to form monitoring data points in the PV coordinate system;

[0113] Select all monitoring data points within the same work cycle;

[0114] The indicator diagram of the ultra-high pressure compressor 100 was drawn based on all monitoring data points within the same working cycle.

[0115] One working cycle of the ultra-high pressure compressor 100 is the time it takes for the crank to rotate once. Correspondingly, the piston 5 completes one reciprocating motion, that is, the piston 5 moves from the working near point (working far point) to the working far point (working near point) and then returns from the working far point (working near point) to the working near point (working far point). This is reflected on the data terminal 11 as the time period between the moments when two adjacent crank rotation angles are 0°.

[0116] Those skilled in the art will understand that the time interval between adjacent moments corresponding to a crank angle of 180° or between two adjacent moments corresponding to arbitrary crank angles can also be selected.

[0117] like Figure 4 As shown, the indicator diagram of the ultra-high pressure compressor 100 can be obtained through step S4. The working status of the ultra-high pressure compressor 100 can be monitored by observing the changes in the indicator diagram of each cycle.

[0118] like Figure 5 As shown in the illustration, a specific embodiment of this application also provides a monitoring system for an ultra-high pressure compressor 100, comprising:

[0119] A strain measurement assembly for measuring the axial strain of tie rod bolt 6;

[0120] Angle measuring assembly for measuring the crankshaft crank angle; and

[0121] Data terminal 11 is communicatively connected to the axial strain measurement component and the crank angle measurement component. Data terminal 11 is configured as follows:

[0122] The cylinder pressure is obtained based on the axial strain.

[0123] The working volume is obtained from the crank angle.

[0124] In this application, the axial strain of the tie rod bolt 6 is measured by a strain measurement component and the conversion relationship built into the data terminal 11 to obtain the cylinder pressure of the ultra-high pressure compressor 100. This avoids drilling holes in the cylinder body 1 to install sensors for direct measurement of the cylinder pressure, thereby ensuring the strength and integrity of the cylinder mechanism and reducing safety risks.

[0125] Meanwhile, the working volume of the ultra-high pressure compressor 100 is obtained by measuring the crank angle through the crank angle measuring component and the conversion relationship built into the data terminal 11. Based on the cylinder pressure and working volume, the indicator diagram of the ultra-high pressure compressor 100 is obtained, and the working status of the ultra-high pressure compressor 100 is monitored in real time based on the indicator diagram.

[0126] Furthermore, compared to obtaining cylinder pressure by measuring components inside cylinder 1 and intermediate body 2, since the tie rod bolt 6 is exposed in cylinder 1 and intermediate body 2, the strain measurement component can be directly installed on the tie rod bolt 6 without disassembling the ultra-high pressure compressor 100, which has better installation convenience. At the same time, since the tie rod bolt 6 is always in a relatively stable state during the operation of the ultra-high pressure compressor 100, the strain measurement component connected to the tie rod bolt 6 is subject to less fluctuation, has better measurement stability, and is suitable for long-term monitoring.

[0127] In some embodiments, the axial strain measurement assembly includes a working strain gauge 7 and a strain measurement circuit 9, wherein the working strain gauge 7 is attached to the surface of the tie rod bolt 6 and deforms together with the tie rod bolt 6; the strain measurement circuit 9 connects the working strain gauge 7 to a data terminal 11, and the strain measurement circuit 9 is used to convert the deformation of the working strain gauge 7 into an output voltage and transmit it to the data terminal 11; the data terminal 11 is configured to convert the output voltage into axial strain.

[0128] Specifically, the working strain gauge 7 is a sensor used to measure strain. Its measurement direction is parallel to the axial direction of the tie rod bolt 6 and it deforms together with the tie rod bolt 6. The strain measurement circuit 9 amplifies the small deformation of the working strain gauge 7. Specifically, the deformation of the working strain gauge 7 can cause a change in the resistance value in the strain measurement circuit 9, and the strain measurement circuit 9 can convert the change in resistance value into an output voltage. After receiving the output voltage of the strain measurement circuit 9, the data terminal 11 converts the output voltage into axial strain according to a preset conversion formula.

[0129] Preferably, the working strain gauge 7 is a T-shaped strain gauge, which includes two measuring parts with mutually perpendicular measuring directions. One measuring part is arranged along the axial direction of the tie rod bolt 6, and the other measuring part is arranged along the circumferential direction of the tie rod bolt 6.

[0130] Specifically, the measuring unit arranged along the axial direction of the tie rod bolt 6 is called the axial measuring unit, and the circumferential measuring unit is arranged along the circumference of the tie rod bolt 6. The axial measuring unit is used to measure the axial strain of the tie rod bolt 6, and the circumferential measuring unit is used to measure the circumferential strain of the tie rod bolt 6. The axial measuring unit is connected to the axial strain measuring circuit 9, and the circumferential measuring unit is connected to the circumferential strain measuring circuit 9. Both the axial strain measuring circuit 9 and the circumferential strain measuring circuit 9 are connected to the data terminal 11 through the data acquisition line 10 to obtain the axial strain and circumferential strain of the tie rod bolt 6.

[0131] In fact, when the tie rod bolt 6 is subjected to tension, it will deform both axially and circumferentially, resulting in axial strain and circumferential strain. According to the physical properties of the tie rod bolt 6, the axial strain and circumferential strain should satisfy a proportional relationship. Therefore, measuring the circumferential strain is mainly used to verify whether the measured axial strain has a large error, thereby improving the accuracy of the measurement data and thus improving the reliability of the monitoring system.

[0132] Furthermore, the distance between the working strain gauge 7 and the middle body 2 along the axial direction of the tie rod bolt 6 is 18cm to 22cm, preferably 20cm. By placing the working strain gauge 7 at a position far from the cylinder head 3, the influence of cylinder head 3 disassembly on the working strain gauge 7 is avoided. In addition, the amplitude of axial stress changes more significantly at this location, which is beneficial for accurate measurement.

[0133] It is also important to note that the working strain gauge 7 should be installed before the preload is applied to the tie rod bolt 6, and subsequent work should only proceed after the working strain gauge 7 is fully and firmly attached. Before the formal test begins, i.e., when the ultra-high pressure compressor 100 is shut down and there is no residual pressure in the cylinder mechanism, the data terminal 11 needs to be zeroed to reduce data measurement errors.

[0134] Meanwhile, since there are multiple tie rod bolts 6 between the cylinder head 3 and the middle body 2, and each tie rod bolt 6 has the same specification and is subjected to the same preload during assembly, a working strain gauge 7 can be attached to only one of the tie rod bolts 6. If cross-verification is required to reduce measurement errors, working strain gauges 7 can be installed on multiple tie rod bolts 6 respectively, but it is necessary to ensure that the specifications and installation positions of the working strain gauges 7 are the same to avoid other factors affecting the measurement results.

[0135] In some embodiments, the crank angle measurement assembly includes a transmitter and a key phase sensor 8, wherein the transmitter is disposed on the flywheel; the key phase sensor 8 is arranged at a distance from the flywheel, and the key phase sensor 8 is used to detect the key phase displacement of the transmitter and send the corresponding key phase signal to the data terminal 11; the data terminal 11 is configured to convert the key phase signal into crank angle.

[0136] Specifically, since the flywheel rotates coaxially with the crankshaft, the crank angle of the crankshaft can be determined by measuring the rotation angle of the flywheel. The crankshaft and key phase sensor 8 are respectively set on both sides of the flywheel along its own axial direction. The key phase sensor 8 is arranged at intervals with the flywheel and the distance from the end face of the flywheel is 5mm to 10mm. The transmitter is set on the end face of the flywheel facing the key phase sensor 8. The key phase sensor 8 is connected to the data terminal 11 through the data acquisition line 10. The probe of the key phase sensor 8 can detect the key phase position of the transmitter and send out the key phase signal. The data terminal 11 receives the key phase signal and obtains the key phase position of the transmitter and converts it into the crank angle (the conversion formula is set in advance in the data terminal 11). Different key phase positions correspond to different crank angles.

[0137] It should be noted that the key phase sensor 8 can be an eddy current displacement sensor, and the transmitter can be a component that can be detected by the key phase sensor 8, such as an iron sheet protrusion, a magnetic steel sheet, and a reflective strip. The working principles of the transmitter and the key phase sensor 8 are well known to those skilled in the art and will not be elaborated here.

[0138] In fact, the first calculation formula for the conversion between crank angle and working volume is a conversion relationship that comes with the production of the ultra-high pressure compressor 100. As long as the crank angle is known, the working volume can be directly calculated. In this application, the first calculation formula is imported into the data terminal 11, and the working volume is directly read through the data terminal 11.

[0139] In some embodiments, the monitoring system also includes a data acquisition line 10 and an acquisition control unit. The data acquisition line 10 is used to communicate with the strain measurement circuit 9 and the data terminal 11, as well as the key phase sensor 8 and the data terminal 11. The sampling frequency of the data acquisition line 10 can be set by the acquisition control unit. Since it is necessary to form monitoring data points corresponding to the cylinder pressure and working volume at the same time, it is only necessary to simultaneously acquire the output voltage and the key phase signal and set the sampling frequency of the acquisition output voltage and the key phase signal to be the same to directly obtain the cylinder pressure and working volume at the same time. Thus, the indicator diagram can be directly obtained at the data terminal 11, thereby improving the convenience of the monitoring system.

[0140] Specifically, the data acquisition line 10 converts the output voltage and key phase signal into digital signals and transmits them to the data terminal 11. The acquisition control unit can set the acquisition channels and sampling rates of the working strain gauge 7 and key phase sensor 8. The data terminal 11 calculates and generates dynamometer diagrams using testing software and stores the data. The data terminal 11 can be an electronic device with data processing capabilities, such as a computer.

[0141] This application proposes a monitoring method for an ultra-high pressure compressor 100. The cylinder pressure is calculated by directly measuring the axial strain of the tie rod bolt 6, thereby avoiding drilling holes in the cylinder body 1 to install sensors for direct measurement of the cylinder pressure. This ensures the strength and integrity of the cylinder mechanism and reduces safety risks. Furthermore, a monitoring system for the ultra-high pressure compressor 100 is proposed to execute the monitoring method and obtain the indicator diagram of the ultra-high pressure compressor 100, thereby achieving real-time monitoring of the ultra-high pressure compressor 100.

[0142] Since the monitoring method and monitoring system provided in this application directly measure the axial strain of the multi-strut bolt 6, the monitoring system can be installed on the ultra-high pressure compressor 100 for monitoring at any time without disassembling the ultra-high pressure compressor 100, which greatly improves the convenience of monitoring the working process of the ultra-high pressure compressor 100.

[0143] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0144] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0145] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0146] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A monitoring method for an ultra-high pressure compressor, characterized in that, include: Obtain the axial strain of the tie rod bolt (6) of the cylinder mechanism; The cylinder pressure of the cylinder mechanism is calculated based on the axial strain. Obtain the working volume of the cylinder mechanism; The cylinder pressure and working volume at the same moment are used to form monitoring data points, and the indicator diagram of the ultra-high pressure compressor (100) is obtained based on the monitoring data points in the same working cycle. The operating status of the ultra-high pressure compressor (100) is monitored according to the indicator diagram.

2. The monitoring method for an ultra-high pressure compressor according to claim 1, characterized in that, The axial strain of the tie rod bolt (6) of the cylinder mechanism is obtained by: The axial strain is directly measured using a working strain gauge (7) and a strain measurement circuit (9).

3. The monitoring method for an ultra-high pressure compressor according to claim 1, characterized in that, The working volume of the cylinder mechanism includes: Obtain the crankshaft crank angle; The working volume is calculated based on the crank angle.

4. The monitoring method for an ultra-high pressure compressor according to claim 3, characterized in that, The working volume of the cylinder mechanism is calculated based on the crank angle, including: Obtain the basic parameters of the ultra-high pressure compressor (100); The working volume is obtained by substituting the basic parameters and the crank angle into the first calculation formula; The first calculation formula is: Among them, V c It is the clearance volume, in meters. 3 D is the diameter of the piston (5) of the cylinder mechanism, in meters; r is the crank radius, in meters; l is the length of the piston connecting rod, in meters; λ is the crank-connecting rod ratio; θ is the crank angle, in degrees.

5. The monitoring method for an ultra-high pressure compressor according to claim 1, characterized in that, The calculation of the cylinder pressure of the cylinder mechanism based on the axial strain includes: Obtain the basic parameters of the ultra-high pressure compressor (100); The cylinder pressure is calculated by substituting the axial strain and the basic parameters into the second calculation formula. The second calculation formula is: Where P is the cylinder pressure, in MPa; ε a E is the axial strain; E is the elastic modulus of the tie rod bolt (6), in N / m. 2 ;d is the diameter of the tie rod bolt (6), in meters; D is the diameter of the piston (5) of the cylinder mechanism, in meters; n is the number of tie rod bolts (6); F f The unit for reciprocating friction is N.

6. A monitoring system for an ultra-high pressure compressor, characterized in that, The ultra-high pressure compressor (100) includes a cylinder mechanism and a crank-connecting rod mechanism. The cylinder mechanism includes a cylinder body (1) forming a piston chamber (4), a middle body (2) and a cylinder head (3) respectively disposed at both ends of the cylinder body (1), a tie rod bolt (6) connecting the middle body (2) and the cylinder head (3), and a piston component (5) that slides in cooperation with the cavity wall of the piston chamber (4). The crank-connecting rod mechanism includes a piston connecting rod that passes through the middle body (2) and connects to the piston component (5), a crankshaft connected to the piston connecting rod, and a flywheel connected to the crankshaft. The monitoring system includes: A strain measurement assembly for measuring the axial strain of the tie rod bolt (6); Angle measuring component for measuring the crank angle of the crankshaft; and A data terminal (11) is communicatively connected to the axial strain measurement assembly and the crank angle measurement assembly, and the data terminal (11) is configured to: The cylinder pressure is obtained based on the axial strain. The working volume is obtained based on the crank angle.

7. The monitoring system for the ultra-high pressure compressor according to claim 6, characterized in that, The axial strain measurement component includes: The working strain gauge (7) is attached to the surface of the tie rod bolt (6) and deforms together with the tie rod bolt (6); The strain measurement circuit (9) connects the working strain gauge (7) and the data terminal (11). The strain measurement circuit (9) is used to convert the deformation of the working strain gauge (7) into an output voltage and transmit it to the data terminal (11). The data terminal (11) is configured as follows: The output voltage is converted into the axial strain.

8. The monitoring system for the ultra-high pressure compressor according to claim 7, characterized in that, The working strain gauge (7) is a T-shaped strain gauge, which includes two measuring parts with mutually perpendicular measuring directions. One of the measuring parts is arranged along the axial direction of the tie rod bolt (6), and the other measuring part is arranged along the circumferential direction of the tie rod bolt (6).

9. The monitoring system for the ultra-high pressure compressor according to claim 7, characterized in that, The distance between the working strain gauge (7) and the middle body (2) along the axial direction of the tie rod bolt (6) is 18cm to 22cm.

10. The monitoring system for the ultra-high pressure compressor according to claim 6, characterized in that, The angle measurement component includes: Sending a message is set on the flywheel; A key phase sensor (8) is arranged at an interval from the flywheel. The key phase sensor (8) is used to detect the key phase displacement of the sending letter and send the corresponding key phase signal to the data terminal (11). The data terminal (11) is configured as follows: The key phase signal is converted into the crank angle.

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